Red Maca (Lepidium meyenii ) did not affect cell viability despite increased androgen receptor and prostate-specific antigen gene expression in the human prostate cancer cell line LNCaP

Not All Maca Is Created Equal: A Review of Colors, Nutrition, Phytochemicals, and Clinical Uses

Maca (Lepidium meyenii, Lepidium peruvianum) is part of the Brassicaceae family and grows at high altitudes in the Peruvian Andes mountain range (3500-5000 m). Historically, it has been used as a nutrient-dense food and for its medicinal properties, primarily in enhancing energy and fertility. Scientific research has validated these traditional uses and other clinical applications by elucidating maca's mechanisms of action, nutrition, and phytochemical content. However, research over the last twenty years has identified up to seventeen different colors (phenotypes) of maca. The color, hypocotyl size, growing location, cultivation, and post-harvest processing methods can have a significant effect on the nutrition content, phytochemical profile, and clinical application. Yet, research differentiating the colors of maca and clinical applications remains limited. In this review, research on the nutrition, phytochemicals, and various colors of maca, including black, red, yellow (predominant colors), purple, gray (lesser-known colors), and any combination of colors, including proprietary formulations, will be discussed based on available preclinical and clinical trials. The gaps, deficiencies, and conflicts in the studies will be detailed, along with quality, safety, and efficacy criteria, highlighting the need for future research to specify all these factors of the maca used in publications.

Glucosinolate-Enriched Fractions from Maca (Lepidium meyenii) Exert Myrosinase-Dependent Cytotoxic Effects against HepG2/C3A and HT29 Tumor Cell Lines

The consumption of glucosinolate (GL)-rich foods, including Brassica vegetables, such as mustard, broccoli, and maca, is associated with decreased risk of developing cancer. The GL content in maca, which is recognized as a "superfood", is approximately 100-times higher than that in other brassicas. Although maca is a potential dietary source of GLs, limited studies have examined the bioactivity of maca GLs using the combination of chemical characterization and bioassays. In this study, the fractions (Lm-II and Lm-III) rich in intact GLs (glucotropaeolin and glucolimnanthin) were isolated and characterized from maca ethanolic extracts using chromatography and mass spectrometry. Additionally, the growth-inhibitory effects of Lm-II and Lm-II fractions against hepatocellular carcinoma (HepG2/C3A) and colon adenocarcinoma (HT29) cell lines were examined in the absence or presence of myrosinase (MYR). Fractions lacking low molecular weight sugars dose-dependently exerted cytotoxic effects in the presence of MYR. The half-maximal inhibitory concentration values of Lm-II and Lm-III against HepG2/C3A were 118.8 and 69.9 µg/mL, respectively, while those against HT29 were 102.6 and 71.5 µg/mL, respectively. These results suggest that the anticancer properties of maca can be attributed to GLs and corroborate the categorization of maca as a "superfood."Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.1952444.

Maca Root (Lepidium meyenii) Extract Increases the Expression of MMP-1 and Stimulates Migration of Triple-Negative Breast Cancer Cells

Maca root (Lepidium meyenii) extract is a worldwide consumed food supplement for sexual dysfunctions, increasing sperm production and its motility, and alleviating menopausal symptoms. Once maca root has a role in cell proliferation and motility, and its consumption may increase along with age, mainly in menopausal women, we aimed to investigate the plant effects on triple-negative breast cancer (TNBC) cell lines. Standardized maca root powdered extract showed significant cytotoxic activity in both MDA-MB-231 and Hs578T cells, and the IC₅₀s were 2000 μg/ml and 3000 μg/ml, respectively. Both cell lines showed an increase in migratory capacity. Using bioinformatics tools, we established genes involved in the metastatic process, CAV1, LAMA4, and MMP-1, and the mRNAs expression was assessed by qPCR. Comparing the treated cells to the negative control, CAV1 presented a decreased expression by 2-fold in MDA-MB-231. LAMA4 presented a decrease by 4-fold in Hs578T cells. MMP-1 showed substantially increase mRNA expression in MDA-MB-231 by 86-fold and in Hs578T by 5-fold. To the best of our knowledge, this is the first study indicating that the human consumption of maca may be dangerous due to the upregulation in MMP-1 expression and the increase in TNBC migrated cells.

Chemical composition and health effects of maca (Lepidium meyenii)

Maca (Lepidium meyenii Walpers) has emerged as a popular functional plant food due to various claimed health effects. This review details the major (i.e., starch, dietary fiber, and protein) and minor constituents (i.e., minerals, non-starch polysaccharides, polyphenols (flavonolignans), macaenes, macamides, glucosinolates, and alkaloids) of maca (root and aerial parts). Diverse health effects of maca are also summarized. Various bioactivities of maca include enhanced reproductive health, antifatigue, antioxidation, neuroprotection, antimicrobial activity, anticancer, hepatoprotection, immunomodulation, and improving skin health and digestive system's function. Plant genetics, botanical parts, processing, extraction, and experimental protocols represent the major factors affecting the chemical composition, physicochemical attributes, and health effects of maca-based products. However, clinical studies to support the claimed health effects of maca and related mechanisms appear to be lacking. Product innovation and diversification in food and non-food utilization of different parts of maca to maximize the value perceptions are suggested.

Is the hype around the reproductive health claims of maca (Lepidium meyenii Walp.) justified?

ETHNOPHARMACOLOGICAL RELEVANCE

Maca - Lepidium meyenii Walp. has been cultivated and used by Andean people for over 1300-2000 years in Peru as food and medicine. Starting in the late 1990's it has developed into an important herbal medicine in China and is now cultivated there widely, too AIM OF STUDY: This study aims to provide an insight into the emergence of maca on the global market as an alternative remedy to treat reproductive health related problems in both men and women and to critically assess these health claims.

METHODOLOGY

A search of electronic databases such as EMBASE and a hand-search was done to acquire peer-reviewed articles and reports about maca.

RESULTS AND DISCUSSION

Lepidium meyenii is used traditionally as a tonic, fertility enhancer for both humans and cattle, and to treat a variety of ailments such as rheumatism, respiratory disorders and anaemia among others. Maca root is cooked, baked, fermented as a drink and made into porridge. In the last twenty years, maca was introduced onto the global market and demand has dramatically grown over this time with its promotion on the internet, as the 'Peruvian Ginseng' for libido and fertility enhancement. It has also been said to treat menopausal symptoms, erectile dysfunction and benign prostatic hyperplasia. The sky-rocketing demand for the plant has seen a shift from traditional cultivation methods to mass production practices with the use of fertilisers and also pesticides; as maca is now grown in areas other than the Andes such as in the Yunnan province in China. This can potentially affect the phytochemistry and composition of the plant and thus, the quality, safety and efficacy of maca products. Meanwhile, research into maca's medicinal properties has followed the spike in popularity of maca and has been focused mainly on maca's aphrodisiac and fertility enhancing properties. So far, the in vivo studies and clinical trials conducted have yielded inconclusive results. Some of the key limitations reside in methodology and sample size. Chemical profiling, led to the discovery of new compounds unique to maca, such as, 'macamides' and also other active metabolites like the glucosinolates; to which the medicinal effects of maca have been ascribed but cannot be confirmed due to lack of data.

CONCLUSIONS

To date, the health claims of maca cannot be fully supported from a scientific standpoint and more research is needed. It appears that the indigenous local knowledge about the health benefits of maca has been dragged out of context to fit the demands of a growing market for herbal remedies. This globalisation (or hype esp. in China) also has had serious consequences for the local producers in Peru. The lack of protocols to regulate the production and marketing of maca during this rapid expansion, poses a threat to both the safety of consumers and the sustainability of supply.