Maca Vibe scientific update |
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2010 Jul;20(4):705-19.
Lu Q, Tse SK, Chow SC.
Department of Statistics & Finance, University of Science and Technology of China, Anhui, People's Republic of China.
Analysis of time-to-event data under a two-stage survival adaptive design in clinical trials.
In recent years, the use of a two-stage seamless design in clinical trials has attracted much attention. A two-stage seamless trial design is referred to as a study design that combines two separate clinical studies that are normally conducted to achieve separate objectives, such as a phase II study for treatment selection and a phase III study for efficacy confirmation. Furthermore, it is not uncommon to consider study endpoints with different treatment durations at different stages (see, e.g., Chow and Chang, 2006; Maca et al., 2006). Chow et al. (2007) and Lu et al. (2009) considered the cases where the study endpoints are continuous variables and binary responses, respectively. In this article, our attention is placed on the case where the study endpoints are time-to-event data with different treatment durations. For testing equality, superiority, and noninferiority/equivalence of two treatments, test statistics for the analysis of the combined data collected from the two stages are developed for Weibull distributed data. In addition, formulas for sample size calculation and sample size allocation between the two stages for each of the hypotheses are derived. Corresponding results are also derived under Cox's proportional hazards model.
2010 May 7. [Epub ahead of print]
Clément C, Kneubühler J, Urwyler A, Witschi U, Kreuzer M.
ETH Zurich, Institute of Plant, Animal and Agroecosystem Sciences, Universitaetstrasse 2, 8092 Zurich, Switzerland.
Effect of maca supplementation on bovine sperm quantity and quality followed over two spermatogenic cycles.
Maca (Lepidium meyenii Walpers), is an Andean crop that grows between 3,800 and 4,500 m a.s.l. The persistent interest in this plant is based on its assumed effects on fertility of male mammals due to the prevalence of certain, partially specific, secondary compounds. The present study aimed at evaluating the effect of maca supplementation on quality and quantity of semen, mating behavior, and clinical status of peripubertal breeding bulls. The experiment followed a cross-over design lasting for 23 wk with 3 wk of adaptation and baseline measurements, and 2 x 10 wk of treatment feeding thus covering two times the complete 8-wk spermatogenic cycle. Seventy-eight 55 wk to 84 wk old breeding bulls received either no maca (control) or maca (233 mg dried hypocotyls/kg body weight/day) for 10 wk followed by 10 wk without maca (maca early) or maca only in the last 10 wk (maca late). Measurements were always made in the last 2 wk of each period. Apart from standard analyses, ejaculates were analyzed by flow cytometry. Data was evaluated by analysis of variance considering the repeated measurement structure of the data. Significant treatment by measurement period indicated direct or carry-over effects of maca. Maca supplementation had no direct effect on body weight, testes circumference, rectal temperature, mating behavior, and ejaculate volume. However, supplementing maca in the first 10 wk period increased the number of sperms in the second 10 wk period, i.e., when the animals no longer received maca. The DNA fragmentation index and the visually assessed motility of the sperms of bulls, that initially showed a borderline sperm quality, were significantly improved with early maca supplementation, while no such effect was observed in the two other groups. No effects occurred in the proportion of intact sperm plasma membranes or acrosomes or both. In conclusion, maca supplementation seems to improve sperm quantity and quality of bulls to a certain degree, while mating behavior appears unaffected. Copyright © 2010 Elsevier Inc. All rights reserved.
2010 Apr 15;90(5):861-9.
Clément C, Diaz Grados DA, Avula B, Khan IA, Mayer AC, Ponce Aguirre DD, Manrique I, Kreuzer M.
ETH Zurich, Institute of Plant, Animal and Agroecosystem Sciences, 8092 Zurich, Switzerland.
Influence of colour type and previous cultivation on secondary metabolites in hypocotyls and leaves of maca (Lepidium meyenii Walpers).
BACKGROUND: Maca is an Andean crop of the Brassicaceae family which is mainly known for its fertility-enhancing properties following consumption. The hypocotyls display various colours ranging from white to black. Each colour has different biological effects. The aim of this study was to analyse the concentrations of major secondary metabolites in hypocotyls and leaves of maca in a controlled planting experiment in the Peruvian Andes at 4130 m above sea level. The effects of colour type and of previous cultivation of the field were examined. RESULTS: In the hypocotyls, the colour type effect was significant for most secondary metabolites; exceptions were beta-sitosterol and campesterol. The lead-coloured, yellow and violet maca hypocotyls were rich in glucosinolates, macaene and macamides, respectively. Previous cultivation affected macaene, campesterol and indole glucosinolate concentrations. Effects on metabolite concentrations in the leaves were minor. Hypocotyls were richer in macaene, macamides and glucosinolates than were leaves, and were poorer in beta-sitosterol and total phenols. CONCLUSION: Colour type has to be considered in maca production, as colour associates with variations in concentrations of distinct bioactive metabolites. Leaves may be interesting for animal nutrition purposes as they contain essentially the same secondary metabolites as the hypocotyls but in clearly lower concentrations. (c) 2010 Society of Chemical Industry.
2010 Apr 16;394(4):962-5. Epub 2010 Mar 20.
Xu Y, Sim SH, Song S, Piao S, Kim HM, Jin XL, Lee K, Ha NC.
Department of Manufacturing Pharmacy, College of Pharmacy and Research Institute for Drug Development, Pusan National University, Busan 609-735, Republic of Korea.
The tip region of the MacA alpha-hairpin is important for the binding to TolC to the Escherichia coli MacAB-TolC pump.
The tripartite efflux pump MacAB-TolC found in gram-negative bacteria is involved in resistance to antibiotics. We previously reported the funnel-like hexameric structure of the adaptor protein MacA to be physiologically relevant. In this study, we investigated the role of the tip region of its alpha-hairpin, which forms a cogwheel structure in the funnel-like shape of the MacA hexamer. Mutational and biochemical analyses revealed that the conserved residues located at the tip region of the alpha-hairpin of MacA play an essential role in the binding of TolC. Our findings offer a molecular basis for understanding the drug resistance of pathogenic bacteria. 2010 Elsevier Inc. All rights reserved.
2010 Jun;101(12):4676-89. Epub 2010 Feb 25.
Ranilla LG, Kwon YI, Apostolidis E, Shetty K.
Escuela de Alimentos, Facultad de Recursos Naturales, Pontificia Universidad Católica de Valparaíso, Avenida Waddington 716, Playa Ancha, Valparaíso, Chile.
Phenolic compounds, antioxidant activity and in vitro inhibitory potential against key enzymes relevant for hyperglycemia and hypertension of commonly used medicinal plants, herbs and spices in Latin America.
Traditionally used medicinal plants, herbs and spices in Latin America were investigated to determine their phenolic profiles, antioxidant activity and in vitro inhibitory potential against key enzymes relevant for hyperglycemia and hypertension. High phenolic and antioxidant activity-containing medicinal plants and spices such as Chancapiedra (Phyllantus niruri L.), Zarzaparrilla (Smilax officinalis), Yerba Mate (Ilex paraguayensis St-Hil), and Huacatay (Tagetes minuta) had the highest anti-hyperglycemia relevant in vitro alpha-glucosidase inhibitory activities with no effect on alpha-amylase. Molle (Schinus molle), Maca (Lepidium meyenii Walp), Caigua (Cyclanthera pedata) and ginger (Zingiber officinale) inhibited significantly the hypertension relevant angiotensin I-converting enzyme (ACE). All evaluated pepper (Capsicum) genus exhibited both anti-hyperglycemia and anti-hypertension potential. Major phenolic compounds in Matico (Piper angustifolium R.), Guascas (Galinsoga parviflora) and Huacatay were chlorogenic acid and hydroxycinnamic acid derivatives. Therefore, specific medicinal plants, herbs and spices from Latin America have potential for hyperglycemia and hypertension prevention associated with Type 2 diabetes. (c) 2010 Elsevier Ltd. All rights reserved.
2010 Mar;7(1):57-67.
Pucheu-Haston CM, Copeland LB, Haykal-Coates N, Ward MD.
Curriculum in Toxicology, University of North Carolina-Chapel Hill, Chapel Hill, NC 27711, USA.
Maternal respiratory sensitization and gestational allergen exposure does not affect subsequent pup responses to homologous or heterologous allergen.
Evidence suggests that the predisposition towards atopy begins early in life. Maternal allergy has been associated with an increased risk of the development of allergic disease in offspring. Some studies suggest that the development of childhood atopy may also be influenced by prenatal allergen exposure. In this study, a respiratory allergen exposure model was used to determine the impact of maternal sensitization (with or without additional exposures during pregnancy) on subsequent pup responses to homologous or heterologous allergen. Female BALB/c mice received two intratracheal aspiration (IA) exposures to Metarhizium anisopliae crude antigen (MACA) or Hank's buffered salt solution (HBSS) prior to breeding. Some mice also received three additional exposures during pregnancy. Control mothers did not receive treatment. Young adult offspring received three IA exposures to MACA, house dust mite extract (HDM) or HBSS. Offspring sensitized as young adults to either HDM or MACA developed an airway inflammatory response, including increased bronchoalveolar lavage fluid lactate dehydrogenase activity, total protein and total and differential cell counts compared to offspring exposed to HBSS. Increased airway responsiveness to methacholine was observed in pups treated with HDM but not with MACA. Maternal sensitization status (with or without gestational allergen exposure) had no effect on offspring response to either MACA or HDM. In conclusion, this study demonstrates that IA administration of MACA or HDM extract to young adult BALB/c mice induces the development of an inflammatory airway response. In contrast to previous reports, neither maternal sensitization nor gestational allergen exposure could be demonstrated to have a clear effect on offspring sensitization. This discrepancy may be a function of the respiratory sensitization and exposure protocol used in this study, which mimics natural sensitization more closely than do parenteral routes of exposure.
2009 Dec;16(6):373-80. Epub 2009 Dec 16.
Gonzales GF, Gonzales C, Gonzales-Castañeda C.
Instituto de Investigaciones de la Altura, and Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru.
Lepidium meyenii (Maca): a plant from the highlands of Peru--from tradition to science.
This review summarizes the current state of knowledge on Lepidium meyenii (maca), a cruciferous plant (Brassicaceae family) which is cultivated exclusively at an altitude of 4,000-4,500 m in the Peruvian Central Andes. Maca is traditionally used for its nutritional and presumed medicinal properties. Over the past 20 years, interest in maca has increased in many parts of the world, and since 2005 maca is considered one of the seven Peruvian flag products. Maca is exported as powder, capsules, pills, flour, liquor, and extracts. There are different types of maca with differ-ent colors ranging from white to black. We have studied the pharmacological effects of 3 types; yellow, black, and red maca. Evidence from experimental studies indicates effects of maca on nutrition, fertility, memory, and mood. Black maca has better effects on sperm production than yellow maca which has only moderate effects. Red maca, however, has no effect on sperm production. However, red maca has been shown to reduce prostate size in rats in which prostate hyperplasia had been induced with testosterone enanthate; yellow maca has shown moderate effects here, whereas black maca has not shown any effects. Randomized clinical trials have shown that maca has favorable effects on energy and mood, may decrease anxiety and improve sexual desire. Maca has also been shown to improve sperm production, sperm motility, and semen volume. Serum levels of testosterone, estradiol, LH, FSH, and prolactin were not affected. The exact mechanisms of action are still unclear, but so far research clearly indicates that various bioactive constituents contribute to the clinical effects reported.
2009 Dec 10;126(3):574-6. Epub 2009 Sep 23.
Stone M, Ibarra A, Roller M, Zangara A, Stevenson E.
School of Psychology and Sports Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK.
A pilot investigation into the effect of maca supplementation on physical activity and sexual desire in sportsmen.
AIMS OF THE STUDY: Maca (Lepidium meyenii Walp) is consumed both as a sports supplement by strength and endurance athletes, and as a natural stimulant to enhance sexual drive. However, whether or not the postulated benefits of maca consumption are of scientific merit is not yet known. The aim of the study was therefore to investigate the effect of 14 days maca supplementation on endurance performance and sexual desire in trained male cyclists. MATERIALS AND METHODS: Eight participants each completed a 40 km cycling time trial before and after 14 days supplementation with both maca extract (ME) and placebo, in a randomised cross-over design. Subjects also completed a sexual desire inventory during each visit. RESULTS: ME administration significantly improved 40 km cycling time performance compared to the baseline test (P=0.01), but not compared to the placebo trial after supplementation (P>0.05). ME administration significantly improved the self-rated sexual desire score compared to the baseline test (P=0.01), and compared to the placebo trial after supplementation (P=0.03). CONCLUSIONS: 14 days ME supplementation improved 40 km cycling time trial performance and sexual desire in trained male cyclists. These promising results encourage long-term clinical studies involving more volunteers, to further evaluate the efficacy of ME in athletes and normal individuals and also to explore its possible mechanisms of action.
2009 Apr;41(2):95-9.
Zenico T, Cicero AF, Valmorri L, Mercuriali M, Bercovich E.
Department of Urology, Morgagni-Pierantoni Hospital, Forlì, Italy. t.zenico@ausl.fo.it
Subjective effects of Lepidium meyenii (Maca) extract on well-being and sexual performances in patients with mild erectile dysfunction: a randomised, double-blind clinical trial.
Lepidium meyenii (Maca) is a cultivated root belonging to the brassica family used in the Andean region for its supposed aphrodisiac properties. We carried out a double-blind clinical trial on 50 Caucasian men affected by mild erectile dysfunction (ED), randomised to treatment with Maca dry extract, 2400 mg, or placebo. The treatment effect on ED and subjective well-being was tested administrating before and after 12 weeks the International Index of Erectile Function (IIEF-5) and the Satisfaction Profile (SAT-P). After 12 weeks of treatment, both Maca- and placebo-treated patients experienced a significant increase in IIEF-5 score (P < 0.05 for both). However, patients taking Maca experienced a more significant increase than those taking placebo (1.6 +/- 1.1 versus 0.5 +/- 0.6, P < 0.001). Both Maca- and placebo-treated subjects experienced a significant improvement in psychological performance-related SAT-P score, but the Maca group higher than that of placebo group (+9 +/- 6 versus +6 +/- 5, P < 0.05). However, only Maca-treated patients experienced a significant improvement in physical and social performance-related SAT-P score compared with the baseline (+7 +/- 6 and +7 +/- 6, both P < 0.05). In conclusion, our data support a small but significant effect of Maca supplementation on subjective perception of general and sexual well-being in adult patients with mild ED.
2009 Jan 9;284(2):1145-54. Epub 2008 Oct 27.
Lin HT, Bavro VN, Barrera NP, Frankish HM, Velamakanni S, van Veen HW, Robinson CV, Borges-Walmsley MI, Walmsley AR.
School of Biological and Biomedical Sciences, Durham University, South Road, Durham DH1 3LE, UK.
MacB ABC transporter is a dimer whose ATPase activity and macrolide-binding capacity are regulated by the membrane fusion protein MacA.
Gram-negative bacteria utilize specialized machinery to translocate drugs and protein toxins across the inner and outer membranes, consisting of a tripartite complex composed of an inner membrane secondary or primary active transporter (IMP), a periplasmic membrane fusion protein, and an outer membrane channel. We have investigated the assembly and function of the MacAB/TolC system that confers resistance to macrolides in Escherichia coli. The membrane fusion protein MacA not only stabilizes the tripartite assembly by interacting with both the inner membrane protein MacB and the outer membrane protein TolC, but also has a role in regulating the function of MacB, apparently increasing its affinity for both erythromycin and ATP. Analysis of the kinetic behavior of ATP hydrolysis indicated that MacA promotes and stabilizes the ATP-binding form of the MacB transporter. For the first time, we have established unambiguously the dimeric nature of a noncanonic ABC transporter, MacB that has an N-terminal nucleotide binding domain, by means of nondissociating mass spectrometry, analytical ultracentrifugation, and atomic force microscopy. Structural studies of ABC transporters indicate that ATP is bound between a pair of nucleotide binding domains to stabilize a conformation in which the substrate-binding site is outward-facing. Consequently, our data suggest that in the presence of ATP the same conformation of MacB is promoted and stabilized by MacA. Thus, MacA would facilitate the delivery of drugs by MacB to TolC by enhancing the binding of drugs to it and inducing a conformation of MacB that is primed and competent for binding TolC. Our structural studies are an important first step in understanding how the tripartite complex is assembled.
2008 Fall;14(3):182-91.
Dording CM, Fisher L, Papakostas G, Farabaugh A, Sonawalla S, Fava M, Mischoulon D.
Depression Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA.
A double-blind, randomized, pilot dose-finding study of maca root (L. meyenii) for the management of SSRI-induced sexual dysfunction.
We sought to determine whether maca, a Peruvian plant, is effective for selective-serotonin reuptake inhibitor (SSRI)-induced sexual dysfunction. We conducted a double-blind, randomized, parallel group dose-finding pilot study comparing a low-dose (1.5 g/day) to a high-dose (3.0 g/day) maca regimen in 20 remitted depressed outpatients (mean age 36+/-13 years; 17 women) with SSRI-induced sexual dysfunction. The Arizona Sexual Experience Scale (ASEX) and the Massachusetts General Hospital Sexual Function Questionnaire (MGH-SFQ) were used to measure sexual dysfunction. Ten subjects completed the study, and 16 subjects (9 on 3.0 g/day; 7 on 1.5 g/day) were eligible for intent-to-treat (ITT) analyses on the basis of having had at least one postbaseline visit. ITT subjects on 3.0 g/day maca had a significant improvement in ASEX (from 22.8+/-3.8 to 16.9+/-6.2; z=-2.20, P=0.028) and in MGH-SFQ scores (from 24.1+/-1.9 to 17.0+/-5.7; z=-2.39, P=0.017), but subjects on 1.5 g/day maca did not. Libido improved significantly (P<0.05) for the ITT and completer groups based on ASEX item #1, but not by dosing groups. Maca was well tolerated. Maca root may alleviate SSRI-induced sexual dysfunction, and there may be a dose-related effect. Maca may also have a beneficial effect on libido.
2008 Oct 9. [Epub ahead of print]
Rubio J, Qiong W, Liu X, Jiang Z, Dang H, Chen SL, Gonzales GF.
Research Center for Pharmacology & Toxicology, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, P.R. China.
Aqueous Extract of Black Maca (Lepidium meyenii) on Memory Impairment Induced by Ovariectomy in Mice.
The present study aims to test two different doses of aqueous extract of black maca on learning and memory in ovariectomized (OVX) mice and their relation with malonalehyde (MDA), acetylcholinesterase (Ache) and monoamine oxidase (MAO) brain levels. Female mice were divided into five groups: (i) naive (control), (ii) sham, (iii) OVX mice and OVX mice treated with (iv) 0.50 g kg(-1) and (v) 2.00 g kg(-1) black maca. Mice were orally treated with distilled water or black maca during 35 days starting 7 days after surgery. Memory and learning were assessed using the water Morris maze (from day 23-27) and the step-down avoidance test (days 34 and 35). At the end of each treatment, mice were sacrificed by decapitation and brains were dissected out for MDA, Ache and MAO determinations. Black maca (0.5 and 2.0 g/kg) increased step-down latency when compared to OVX control mice. Black maca decreased MDA and Ache levels in OVX mice; whereas, no differences were observed in MAO levels. Finally, black maca improved experimental memory impairment induced by ovariectomy, due in part, by its antioxidant and Ache inhibitory activities.
2008 Dec;190(23):7693-8. Epub 2008 Sep 19.
Yamanaka H, Kobayashi H, Takahashi E, Okamoto K.
Laboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Hiro-Koshingai, Kure, Hiroshima 737-0112, Japan. h-yamana@ps.hirokoku-u.ac.jp
MacAB is involved in the secretion of Escherichia coli heat-stable enterotoxin II.
The heat-stable enterotoxin (ST) produced by enterotoxigenic Escherichia coli is an extracellular peptide toxin that evokes watery diarrhea in the host. Two types of STs, STI and STII, have been found. Both STs are synthesized as precursor proteins and are then converted to the active forms with intramolecular disulfide bonds after being released into the periplasm. The active STs are finally translocated across the outer membrane through a tunnel made by TolC. However, it is unclear how the active STs formed in the periplasm are led to the TolC channel. Several transporters in the inner membrane and their periplasmic accessory proteins are known to combine with TolC and form a tripartite transport system. We therefore expect such transporters to also act as a partner with TolC to export STs from the periplasm to the exterior. In this study, we carried out pulse-chase experiments using E. coli BL21(DE3) mutants in which various transporter genes (acrAB, acrEF, emrAB, emrKY, mdtEF, macAB, and yojHI) had been knocked out and analyzed the secretion of STs in those strains. The results revealed that the extracellular secretion of STII was largely decreased in the macAB mutant and the toxin molecules were accumulated in the periplasm, although the secretion of STI was not affected in any mutant used in this study. The periplasmic stagnation of STII in the macAB mutant was restored by the introduction of pACYC184, containing the macAB gene, into the cell. These results indicate that MacAB, an ATP-binding cassette transporter of MacB and its accessory protein, MacA, participates in the translocation of STII from the periplasm to the exterior. Since it has been reported that MacAB cooperates with TolC, we propose that the MacAB-TolC system captures the periplasmic STII molecules and exports the toxin molecules to the exterior.
2008 Dec;62(6):1207-14. Epub 2008 Sep 10.
Delgado A, Zaman S, Muthaiyan A, Nagarajan V, Elasri MO, Wilkinson BJ, Gustafson JE.
Microbiology Group, Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA.
The fusidic acid stimulon of Staphylococcus aureus.
OBJECTIVES: Fusidic acid interferes with the release of elongation factor G (EF-G) after the translocation step of protein synthesis. The objective of this study was to characterize the fusidic acid stimulon of a fusidic acid-susceptible strain of Staphylococcus aureus (SH1000). METHODS: S. aureus microarrays and real-time PCR determined transcriptome alterations occurring in SH1000 grown with fusidic acid. The Staphylococcus aureus microarray meta-database (SAMMD) compared and contrasted the SH1000 fusidic stimulon with 89 other S. aureus transcriptional datasets. Fusidic acid gradient analyses with mutant-parent strain pairs were used to identify genes required for intrinsic fusidic acid susceptibility identified during transcriptional analysis. RESULTS: Many genes altered by fusidic acid challenge are associated with protein synthesis. SAMMD analysis determined that the fusidic acid stimulon has the greatest overlap with the S. aureus cold shock and stringent responses. Six out of nine peptidoglycan hydrolase genes making up the two component YycFG regulon were also up-regulated by fusidic acid, as were a carboxylesterase gene (est) and two putative drug efflux pump genes (emr-qac1 and macA). Genes down-regulated by fusidic acid induction encoded a putative secreted acid phosphatase and a number of protease genes. Roles for the agr operon, the peptidoglycan hydrolase gene isaA and two proteases (htrA1 and htrA2) in the expression of fusidic acid susceptibility were revealed. CONCLUSIONS: The SH1000 fusidic acid stimulon includes genes involved with two stress responses, YycFG-regulated cell wall metabolism, drug efflux, and protein synthesis and turnover.
2008 Nov-Dec;15(6):1157-62.
Brooks NA, Wilcox G, Walker KZ, Ashton JF, Cox MB, Stojanovska L.
School of Biomedical and Health Sciences, Victoria University, St. Albans, Victoria, Australia.
Beneficial effects of Lepidium meyenii (Maca) on psychological symptoms and measures of sexual dysfunction in postmenopausal women are not related to estrogen or androgen content.
OBJECTIVE: To examine the estrogenic and androgenic activity of Lepidium meyenii (Maca) and its effect on the hormonal profile and symptoms in postmenopausal women. DESIGN: Fourteen postmenopausal women completed a randomized, double-blind, placebo-controlled, crossover trial. They received 3.5 g/day of powered Maca for 6 weeks and matching placebo for 6 weeks, in either order, over a total of 12 weeks. At baseline and weeks 6 and 12 blood samples were collected for the measurement of estradiol, follicle-stimulating hormone, luteinizing hormone, and sex hormone-binding globulin, and the women completed the Greene Climacteric Scale to assess the severity of menopausal symptoms. In addition, aqueous and methanolic Maca extracts were tested for androgenic and estrogenic activity using a yeast-based hormone-dependent reporter assay. RESULTS: No differences were seen in serum concentrations of estradiol, follicle-stimulating hormone, luteinizing hormone, and sex hormone-binding globulin between baseline, Maca treatment, and placebo (P > 0.05). The Greene Climacteric Scale revealed a significant reduction in scores in the areas of psychological symptoms, including the subscales for anxiety and depression and sexual dysfunction after Maca consumption compared with both baseline and placebo (P < 0.05). These findings did not correlate with androgenic or alpha-estrogenic activity present in the Maca as no physiologically significant activity was observed in yeast-based assays employing up to 4 mg/mL Maca extract (equivalent to 200 mg/mL Maca). CONCLUSIONS: Preliminary findings show that Lepidium meyenii (Maca) (3.5 g/d) reduces psychological symptoms, including anxiety and depression, and lowers measures of sexual dysfunction in postmenopausal women independent of estrogenic and androgenic activity.
2008 Sep;286(1):39-44.
Kim BC, Lovley DR.
Department of Microbiology, 203 Morrill Science IVN, University of Massachusetts, Amherst, MA 01003, USA.
Investigation of direct vs. indirect involvement of the c-type cytochrome MacA in Fe(III) reduction by Geobacter sulfurreducens.
The electron transfer pathway to Fe(III) reduction in Geobacter sulfurreducens has been hypothesized to consist of a series of c-type cytochromes. Previous genetic studies suggested that the inner membrane-associated, c-type cytochrome, MacA, was a component of the electron transfer chain leading to Fe(III) reduction in the dissimilatory Fe(III)-reducer, G. sulfurreducens. However, investigation of the expression of OmcB, an outer-membrane c-type cytochrome demonstrated previously to be critical for optimal Fe(III) reduction, revealed that both omcB transcript and protein levels were dramatically reduced in the MacA-deficient mutant. Expression of the omcB gene in trans enabled the MacA-deficient mutant to reduce Fe(III) at a rate that was proportional to the level of omcB expression. These results suggest that MacA is not directly involved in electron transfer to Fe(III) and further confirm the importance of OmcB in Fe(III) reduction by G. sulfurreducens.
2007 Oct;45(10):1882-90. Epub 2007 Apr 20.
Rubio J, Dang H, Gong M, Liu X, Chen SL, Gonzales GF.
Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy and Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, P.O. Box 1843, Lima, Peru.
Aqueous and hydroalcoholic extracts of Black Maca (Lepidium meyenii) improve scopolamine-induced memory impairment in mice.
Lepidium meyenii Walp. (Brassicaceae), known as Maca, is a Peruvian hypocotyl growing exclusively between 4,000 and 4,500 m altitude in the central Peruvian Andes, particularly in Junin plateau. Previously, Black variety of Maca showed to be more beneficial than other varieties of Maca on learning and memory in ovariectomized mice on the water finding test. The present study aimed to test two different doses of aqueous (0.50 and 2.00 g/kg) and hydroalcoholic (0.25 and 1.00 g/kg) extracts of Black Maca administered for 35 days on memory impairment induced by scopolamine (1mg/kg body weight i.p.) in male mice. Memory and learning were evaluated using the water Morris maze and the step-down avoidance test. Brain acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities in brain were also determined. Both extracts of Black Maca significantly ameliorated the scopolamine-induced memory impairment as measured in both the water Morris maze and the step-down avoidance tests. Black Maca extracts inhibited AChE activity, whereas MAO activity was not affected. These results indicate that Black Maca improves scopolamine-induced memory deficits.
2007 Mar;4(2):332-9; discussion 339-40.
Lentz A, Gravitt K, Carson CC, Marson L.
Division of Urology, Department of Surgery, University of North Carolina, Chapel Hill, NC, USA.
Acute and chronic dosing of Lepidium meyenii (Maca) on male rat sexual behavior.
INTRODUCTION: The use of natural remedies for the treatment of sexual disorders is under current investigation. For generations people of the rural community in Peru have used Lepidium meyenii Walpers (Maca), because of their belief that it improves fertility and sexual desire. AIM: To determine the acute and chronic effects of Maca on male sexual behavior and to examine chronic administration of Maca on anxiety. MAIN OUTCOME MEASURES: Ejaculatory and mounting behavior and postejaculatory interval. Anxiety tests using an elevated plus maze, locomotion, and social interaction with another male. METHODS: Maca (25 and 100 mg/kg) was orally administered to male rats for 30 days. Male sexual behavior was monitored after acute, 7 and 21 days of treatment. Anxiety behavior and locomotion were measured at 28-29 days using the elevated plus maze and social interaction tests. RESULTS: Maca treatment did not produce large changes in male sexual behavior. However, an increase in ejaculation latency and postejaculatory interval was observed after both acute and 7 days of treatment. After 21 days of treatment Maca had no effect on sexual behavior. Chronic administration of Maca did not increase locomotion or anxiety. CONCLUSION: Acute and short-term administration of Maca produced a small effect of rat male sexual behavior and long-term administration did not increase anxiety.
2007 Mar 8;7:16.
Shelobolina ES, Coppi MV, Korenevsky AA, DiDonato LN, Sullivan SA, Konishi H, Xu H, Leang C, Butler JE, Kim BC, Lovley DR.
Department of Microbiology, University of Massachusetts, Amherst, MA, USA. shelobolina@wisc.edu
Importance of c-Type cytochromes for U(VI) reduction by Geobacter sulfurreducens.
BACKGROUND: In order to study the mechanism of U(VI) reduction, the effect of deleting c-type cytochrome genes on the capacity of Geobacter sulfurreducens to reduce U(VI) with acetate serving as the electron donor was investigated. RESULTS: The ability of several c-type cytochrome deficient mutants to reduce U(VI) was lower than that of the wild type strain. Elimination of two confirmed outer membrane cytochromes and two putative outer membrane cytochromes significantly decreased (ca. 50-60%) the ability of G. sulfurreducens to reduce U(VI). Involvement in U(VI) reduction did not appear to be a general property of outer membrane cytochromes, as elimination of two other confirmed outer membrane cytochromes, OmcB and OmcC, had very little impact on U(VI) reduction. Among the periplasmic cytochromes, only MacA, proposed to transfer electrons from the inner membrane to the periplasm, appeared to play a significant role in U(VI) reduction. A subpopulation of both wild type and U(VI) reduction-impaired cells, 24-30%, accumulated amorphous uranium in the periplasm. Comparison of uranium-accumulating cells demonstrated a similar amount of periplasmic uranium accumulation in U(VI) reduction-impaired and wild type G. sulfurreducens. Assessment of the ability of the various suspensions to reduce Fe(III) revealed no correlation between the impact of cytochrome deletion on U(VI) reduction and reduction of Fe(III) hydroxide and chelated Fe(III). CONCLUSION: This study indicates that c-type cytochromes are involved in U(VI) reduction by Geobacter sulfurreducens. The data provide new evidence for extracellular uranium reduction by G. sulfurreducens but do not rule out the possibility of periplasmic uranium reduction. Occurrence of U(VI) reduction at the cell surface is supported by the significant impact of elimination of outer membrane cytochromes on U(VI) reduction and the lack of correlation between periplasmic uranium accumulation and the capacity for uranium reduction. Periplasmic uranium accumulation may reflect the ability of uranium to penetrate the outer membrane rather than the occurrence of enzymatic U(VI) reduction. Elimination of cytochromes rarely had a similar impact on both Fe(III) and U(VI) reduction, suggesting that there are differences in the routes of electron transfer to U(VI) and Fe(III). Further studies are required to clarify the pathways leading to U(VI) reduction in G. sulfurreducens.
2007 Mar;9(2):245-51.
Gonzales GF, Vasquez V, Rodriguez D, Maldonado C, Mormontoy J, Portella J, Pajuelo M, Villegas L, Gasco M.
Biological and Physiological Sciences, Cayetano Heredia University, Lima, Peru. iiad@upch.edu.pe
Effect of two different extracts of red maca in male rats with testosterone-induced prostatic hyperplasia.
AIM: To determine the effect of two different extracts of red maca in male rats. METHODS: Prostatic hyperplasia was induced in male rats with testosterone enanthate (TE). The study comprised six groups: one control group (group 1), one group treated with TE (group 2), two groups treated with TE and aqueous extract of red maca (groups 3 and 4), one group treated with hydroalcoholic extract of red maca (group 5) and one group treated with finasteride (0.1 mg, group 6). Differences in the aqueous extract dependent on the length of time of boiling, whether for 2 or 3 hours, for groups 3 and 4 was assessed. Extracts of red maca contained 0.1 mg of benzylglucosinolate. Thereafter, a dose-response effect of different doses of benzylglucosinolates (0.02-0.08 mg) in red maca extracts was assessed. RESULTS: Prostate weight was similar in rats treated with freeze-dried aqueous extract of red maca prepared after 2 and 3 hours of boiling. Freeze-dried aqueous extract of red maca, hydroalcoholic extract of red maca and finasteride reduced prostate weight in rats with prostatic hyperplasia. No difference was observed between the data obtained from aqueous extract or hydroalcoholic extract of red maca. A dose dependent reduction of prostate weight was observed with the increase of the dose of benzylglucosinolates in red maca extracts. CONCLUSION: The present study showed that hydroalcoholic or aqueous extract of red maca containing 0.1 mg of benzylglucosinolate can reduce prostate size in male rats in which prostatic hyperplasia had been induced by TE.
2007 Jun;62(2):59-63.
Vecera R, Orolin J, Skottová N, Kazdová L, Oliyarnik O, Ulrichová J, Simánek V.
Institute of Pharmacology, Medical Faculty, Palacký University, Hnevotínská 3, 775 15, Olomouc, Czech Republic.
The influence of maca (Lepidium meyenii) on antioxidant status, lipid and glucose metabolism in rat.
This work focused on the effect of Maca on lipid, anti-oxidative, and glucose parameters in hereditary hypertriglyceridemic (HHTg) rat. Maca (1%) was administred to rats as a part of a high-sucrose diet (HSD) for 2 weeks. Rosiglitazone (0.02%) was used as a positive control. Maca significantly decreased the levels of VLDL (very low density lipoproteins), LDL (low density lipoproteins), and total cholesterol, and also the level of TAG (triacylglycerols) in the plasma, VLDL, and liver. Maca, as well as rosiglitazone, significantly improved glucose tolerance, as the decrease of AUC (area under the curve) of glucose showed, and lowered levels of glucose in blood. The activity of SOD (superoxide dismutase) in the liver, the GPX (glutathione peroxidase) in the blood, and the level of GSH (glutathione) in liver increased in all cases significantly. Results demonstrate that maca seems to be promising for a positive influence on chronic human diseases (characterized by atherogenous lipoprotein profile, aggravated antioxidative status, and impaired glucose tolerance), and their prevention.
2007 Aug;14(7-8):460-4. Epub 2007 Feb 7.
Gasco M, Villegas L, Yucra S, Rubio J, Gonzales GF.
Department of Biological and Physiological Sciences, Universidad Peruana Cayetano Heredia, Lima, Peru.
Dose-response effect of Red Maca (Lepidium meyenii) on benign prostatic hyperplasia induced by testosterone enanthate.
The main goal of this study was to determine the effect of a freeze-dried aqueous extract of the red variety of Lepidium meyenii (Red Maca) on testosterone-induced benign prostatic hyperplasia (BPH) in adult rats of the Holtzman strain. Rats were treated with freeze-dried aqueous extract of Red Maca at doses of 0, 0.01, 0.05, 0.1, and 0.5 g/kg body wt. A positive control group received Finasteride (0.6 mg/kg body wt.). After treatment, the animals were sacrificed, and the ventral prostate was extracted, and weighed. HPLC was used to determine the presence of glucosinolates in Red Maca. The prostate weight diminished in a dose-dependent fashion in rats treated with Red Maca. The effect of Red Maca was better than that observed with Finasteride. Finasteride, but not Red Maca, reduced seminal vesicles weight. Analysis of the HPLC indicated the presence of benzyl glucosinolate (Glucotropaeolin) with a content of 0.639%. Serum testosterone levels were not affected by Red Maca. Moreover, serum testosterone levels were not related to prostate or seminal vesicles weight in rats treated with vehicle and Red Maca. In conclusion, Red Maca administered orally in rats seems to exert an inhibitory effect at a level post DHT conversion, on the BPH-induced experimentally, although a direct measure of reductase action would still be required.
Cell Biol Toxicol. 2006 Mar;22(2):91-9.
Valentová K, Buckiová D, Kren V, Peknicová J, Ulrichová J, Simánek V.
Institute of Medical Chemistry and Biochemistry, Faculty of Medicine, Palacký University, Olomouc.
The in vitro biological activity of Lepidium meyenii extracts.
In his study the biological activity of methanolic and aqueous extracts from dehydrated hypocotyls of Lepidium meyenii was studied on rat hepatocytes and human breast cancer MCF-7 cells. The findings in the present study show that maca does not display in vitro hepatotoxicity. In contrast, a slight cytoprotective effect, probably not mediated by antioxidant capacity, was noted. Maca extracts exhibited estrogenic activity comparably to the effect of silymarin in MCF-7 cells.
The biological activity of methanolic and aqueous extracts from dehydrated hypocotyls of Lepidium meyenii (Brassicaceae, vernacular name "maca"), was studied on rat hepatocytes and human breast cancer MCF-7 cells. The extracts did not exhibit cytotoxicity in hepatocyte primary cultures up to 10 mg/ml as measured by the MTT viability test, and lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) leakage. Moreover, after 72 h, extracts inhibited LDH and AST leakage from the hepatocytes. When hepatocytes were intoxicated by t-butyl hydroperoxide, neither extract prevented oxidative damage. Both extracts showed weak antioxidant activity in the DPPH radical scavenging test with IC(50) values of 3.46 +/- 0.16 and 0.71 +/- 0.10 mg/ml, for aqueous and methanolic extracts, respectively. Thus, the observed effect on spontaneous enzyme leakage is probably mediated through mechanisms other than antioxidant activity. Both methanolic and aqueous extracts have shown estrogenic activity comparable with that of silymarin in MCF-7 cell line. Maca estrogenicity was exhibited in the range from 100 to 200 mug of extract per ml. The findings in the present study show that maca does not display in vitro hepatotoxicity. In contrast, a slight cytoprotective effect, probably not mediated by antioxidant capacity, was noted. Maca extracts exhibited estrogenic activity comparably to the effect of silymarin in MCF-7 cells.
Anticancer Agents Med Chem. 2006 Sep;6(5):429-44.
Gonzales GF, Valerio LG Jr.
Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy and Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, Lima, Peru.
Medicinal plants from Peru: a review of plants as potential agents against cancer.
In the following review scientists present an evidence-based analysis of the chemistry, biological properties, and anti-tumor activities of three plant materials, Cat's claw (Uncaria tomentosa), Maca (Lepidium meyenii), and Dragon's blood (Croton lechleri) . In addition, this review will discuss areas requiring future study and the inherent limitations in their experimental use as anti-cancer agents.
Natural products have played a significant role in drug discovery and development especially for agents against cancer and infectious disease. An analysis of new and approved drugs for cancer by the United States Food and Drug Administration over the period of 1981-2002 showed that 62% of these cancer drugs were of natural origin. Natural compounds possess highly diverse and complex molecular structures compared to small molecule synthetic drugs and often provide highly specific biological activities likely derived from the rigidity and high number of chiral centers. Ethnotraditional use of plant-derived natural products has been a major source for discovery of potential medicinal agents. A number of native Andean and Amazonian medicines of plant origin are used as traditional medicine in Peru to treat different diseases. Of particular interest in this mini-review are three plant materials endemic to Peru with the common names of Cat's claw (Uncaria tomentosa), Maca (Lepidium meyenii), and Dragon's blood (Croton lechleri) each having been scientifically investigated for a wide range of therapeutic uses including as specific anti-cancer agents as originally discovered from the long history of traditional usage and anecdotal information by local population groups in South America. Against this background, we present an evidence-based analysis of the chemistry, biological properties, and anti-tumor activities for these three plant materials. In addition, this review will discuss areas requiring future study and the inherent limitations in their experimental use as anti-cancer agents.
Photodermatol Photoimmunol Photomed. 2008 Feb;24(1):24-31.
Gonzales-Castańeda C, Gonzales GF.
Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru.
Hypocotyls of Lepidium meyenii (maca), a plant of the Peruvian highlands, prevent ultraviolet A-, B-, and C-induced skin damage in rats.
The given study is to determine if two extracts of maca can provide dermal protection against ultraviolet radiation (UVR). The study resulted that maca extracts protect the skin of rats against UV irradiations and can be suggested as an alternative means of solar protection.
BACKGROUND: Lepidium meyenii (maca) is a plant that grows exclusively in the Peruvian Central Andes, where ultraviolet radiation (UVR) is predominant. Objective: Determine if two extracts of maca can provide dermal protection against UVR. METHODS: We have administered two maca extracts (0.13 mg/ml), one obtained after boiling and the other without boiling, on the dorsal surface of male Holtzman rats exposed to UVC radiation once a week during 3 consecutive weeks. A dose-response effect of an aqueous extract of maca after a boiling process under exposure of rats to UVA, UVB, or UVC was also studied. A commercial sunscreen was used as a positive control. RESULTS: UVR caused significant increase in skin epidermal thickness. The epidermal height in animals treated with maca was similar to those who did not receive UVR. The aqueous extract of maca after a boiling process had better effect than maca extract without a boiling process. A dose-response effect was observed with increasing doses of aqueous extract of maca after a boiling process. Maca extract had benzyl glucosinolates and polyphenols. CONCLUSIONS: Maca extracts protect the skin of rats against UV irradiations and can be suggested as an alternative means of solar protection.
Food Chem Toxicol. 2008 Mar;46(3):1006-13.
Valentová K, Stejskal D, Bartek J, Dvorácková S, Kren V, Ulrichová J, Simánek V.
Department of Medical Chemistry and Biochemistry, Palacký University, Olomouc, Czech Republic.
Maca (Lepidium meyenii) and yacon (Smallanthus sonchifolius) in combination with silymarin as food supplements: in vivo safety assessment.
The present study was to evaluate the effects of yacon and maca in combination with silymarin on plasma and lipoprotein lipids, serum glucose and safety parameters in patients suffering from the metabolic syndrome. According to the present study, the effect of maca on AST level and blood pressure must be considered when using high doses of maca powder. This effect could be reversed by supplementation with silymarin.
Yacon and maca are native Andean crops with growing popularity as food supplements often in combination with other components, e.g. silymarin. There are however no published data on their toxicity and safety in humans. The aim of our randomized placebo-controlled 90-day study was to evaluate the effects of yacon and maca in combination with silymarin on plasma and lipoprotein lipids, serum glucose and safety parameters in patients suffering from the metabolic syndrome. No adverse effects were found in volunteers using silymarin (0.8 g/day), silymarin+yacon (0.8+2.4 g/day) and silymarin+maca (0.6+0.2 g/day). A moderate AST level and diastolic blood pressure increase was found in volunteers using maca (0.6 g/day). In conclusion, the combination silymarin+yacon appears to be promising as a nutraceutical in the prevention of diseases with a proatherogenic lipoprotein profile and liver steatosis. The effect of maca on AST level and blood pressure must be considered when using high doses of maca powder. This effect could be reversed by supplementation with silymarin.
Andrologia. 2007 Aug;39(4):151-8.
Gasco M, Aguilar J, Gonzales GF.
Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru.
Effect of chronic treatment with three varieties of Lepidium meyenii (Maca) on reproductive parameters and DNA quantification in adult male rats.
The following study was to evaluate the chronic effect of different varieties of Lepidium meyenii. The study resulted that Yellow and Black Maca increased epididymal sperm count after 84 days of treatment without affecting daily sperm production (DSP). Maca seems to act as a modulator of sperm count at the reproductive tract level.
The aim of this study was to evaluate the chronic effect of different varieties of Lepidium meyenii (Red Maca, Yellow Maca and Black Maca). Male rats were treated by gavage with aqueous extract of each variety of maca equivalent to 1 g hypocotyl kg(-1) body weight (BW) for 84 days. At the end of the treatment, daily sperm production (DSP), epididymal sperm count (ESC) and sperm count in vas deferens (SCVD) were assessed. In addition, testis DNA quantification was also determined. Any toxic effect was assessed in liver and spleen by histological studies. The results indicate that Yellow Maca and Black Maca improved ESC and that three varieties of maca increased the SCVD without affecting DSP. Moreover, testis DNA levels were not affected by treatment with any of the three varieties of maca. Histological picture of the liver in animals treated with the three varieties of maca was similar to that observed in controls. In conclusion, Yellow and Black Maca increased epididymal sperm count after 84 days of treatment without affecting DSP. Maca seems to act as a modulator of sperm count at the reproductive tract level.
Food Chem Toxicol. 2007 Oct;45(10):1882-90.
Rubio J, Dang H, Gong M, Liu X, Chen SL, Gonzales GF.
Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy and Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, P.O. Box 1843, Lima, Peru.
Aqueous and hydroalcoholic extracts of Black Maca (Lepidium meyenii) improve scopolamine-induced memory impairment in mice.
The given study resulted that Black Maca extracts inhibited Brain acetylcholinesterase (AChE) activity, whereas monoamine oxidase (MAO) activity was not affected. These results indicate that Black Maca improves scopolamine-induced memory deficits.
Lepidium meyenii Walp. (Brassicaceae), known as Maca, is a Peruvian hypocotyl growing exclusively between 4,000 and 4,500 m altitude in the central Peruvian Andes, particularly in Junin plateau. Previously, Black variety of Maca showed to be more beneficial than other varieties of Maca on learning and memory in ovariectomized mice on the water finding test. The present study aimed to test two different doses of aqueous (0.50 and 2.00 g/kg) and hydroalcoholic (0.25 and 1.00 g/kg) extracts of Black Maca administered for 35 days on memory impairment induced by scopolamine (1mg/kg body weight i.p.) in male mice. Memory and learning were evaluated using the water Morris maze and the step-down avoidance test. Brain acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities in brain were also determined. Both extracts of Black Maca significantly ameliorated the scopolamine-induced memory impairment as measured in both the water Morris maze and the step-down avoidance tests. Black Maca extracts inhibited AChE activity, whereas MAO activity was not affected. These results indicate that Black Maca improves scopolamine-induced memory deficits.
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Drug category:Antioxidants and Vitamines
 Maca Vibe scientific update
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