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.

Rapid analysis technologies with chemometrics for food authenticity field: A review

In recent years, the problem of food adulteration has become increasingly rampant, seriously hindering the development of food production, consumption, and management. The common analytical methods used to determine food authenticity present challenges, such as complicated analysis processes and time-consuming procedures, necessitating the development of rapid, efficient analysis technology for food authentication. Spectroscopic techniques, ambient ionization mass spectrometry (AIMS), electronic sensors, and DNA-based technology have gradually been applied for food authentication due to advantages such as rapid analysis and simple operation. This paper summarizes the current research on rapid food authenticity analysis technology from three perspectives, including breeds or species determination, quality fraud detection, and geographical origin identification, and introduces chemometrics method adapted to rapid analysis techniques. It aims to promote the development of rapid analysis technology in the food authenticity field.

Evaluation of the Therapeutic Effect of the Traditional Herbal Medicine Atrifil and Oshagh Gum on Testosterone-Induced Benign Prostatic Hyperplasia in Wistar Rats

Benign prostatic hyperplasia (BPH) is a common disease that affects elderly men with various complications. This study evaluates the effects of an Iranian traditional herbal medicine “Atrifil and Oshagh gum” on BPH in male Wistar rats. Atrifil is a combination of three medicinal plants: Emblica officinalis Gaertn, Terminalia chebula Retz, and Terminalia bellerica Retz” extracts, and Oshagh gum is Dorema ammoniacum D. Dono gum. In this study, 30 male Wistar rats were divided into five groups: normal control, disease, finasteride, and extract with 300 and 600 mg/kg groups. The extract is a combination of hydroalcoholic Atrifil extract and Oshagh gum. All groups received intramuscular testosterone enanthate to induce BPH except the normal control group. On the twenty-eighth day, prostate glands were separated. Histopathological changes were observed. Furthermore, the prostate-specific antigen (PSA) and prostate weights were measured. The binding propensities of finasteride, equol, and flavonoids present in this extract such as quercetin, rutin, and kaempferol for 5α-reductase, estrogen receptor alpha and beta, and estrogen-related receptor gamma were assessed using in silico docking approach. Histopathological evaluation, biochemical parameter, and PSA level results indicated significant inhibition of accruing and progression of BPH in groups treated with 600 mg/kg extract (p < 0.01). Furthermore, molecular docking showed that rutin had a high affinity to bind the receptors 5α-reductase, estrogen receptor beta, and estrogen-related receptor gamma even more than finasteride, and on average, quercetin had a higher affinity to all these receptors. In the end, it can be concluded that Atrifil and Oshagh gum is effective in preventing BPH.

Evaluation of the effect of Lepidium meyenii Walpers in infertile patients: A randomized, double-blind, placebo-controlled trial

Male infertility refers to the inability to conceive a natural pregnancy in a fertile female, and approximately 15% of reproductive‐aged couples worldwide face this problem. Several plants were used to treat fertility disorders and, among them, Lepidium meyenii, a folk medicament of Andean regions, is still used to enhance vitality and treat sterility in humans and domestic animals. The aim of the study was to evaluate the effects of L. meyenii Walpers on infertile patients by a randomized, double‐blind, placebo‐controlled trial. Fifty patients suffering from various reproductive‐related problems were enrolled for 16 weeks to evaluate the effect of yellow maca on semen quality and serum hormone levels. Treatment with maca improved the percentage of sperm concentration by 40%, whereas the placebo improved by 76% after 8 and 16 weeks of treatment, but the results were statistically non‐significant. No statistically significant change in hormone levels was reported by using maca, except a decrease in the level of free testosterone. Results are not sufficient to assess the efficacy of maca on male fertility. Further investigation and trials are required to obtain conclusive results.

Yohimbine hydrochloride inhibits benign prostatic hyperplasia by downregulating steroid 5α-reductase type 2

Benign prostatic hyperplasia (BPH) is a frequently encountered disease in older men that affects sexual function and is capable of causing lower urinary tract dysfunction. Unfortunately, current treatment options for BPH primarily seek to address the lower urinary tract dysfunction aspect of the disease and do not improve sexual function. Yohimbine has been effectively used for decades to treat erectile dysfunction. Therefore, the objective of this study was to evaluate the inhibitory effect of yohimbine on BPH and explore the associated underlying mechanisms. Thirty-six rats were randomly divided into the control, BPH, finasteride (1 mg/kg), and yohimbine (2, 4, and 8 mg/kg) groups. Except for the rats in the control group, those in the other groups were subcutaneously injected testosterone propionate (5 mg/kg/day) daily for a period of 4 weeks to establish BPH models. They were also administration the corresponding drug daily for a period of 6 weeks. After the treatments, in addition to determining prostate wet weight and index, the histopathological status of the prostate was observed, and the levels of testosterone, dihydrotestosterone, prostatic acid phosphatase, the prostate-specific antigen, proliferating cell nuclear antigen, and steroid 5α-reductase were determined. Specifically, the administration of 2, 4, and 8 mg/kg yohimbine inhibited prostatic index increase by 46.7, 55.1, and 69.3%, respectively, in BHP rats. Further, yohimbine significantly reduced the levels of dihydrotestosterone, prostatic acid phosphatase, prostate-specific antigen, proliferating cell nuclear antigen, and steroid 5α-reductase, suggesting that it exerts beneficial effects against BPH by modulating the steroid 5α-reductase pathway.

Evaluation of Juniperus communis L. seed extract on benign prostatic hyperplasia induced in male Wistar rats

Background

Benign prostatic hyperplasia (BPH) is a common disease which causes various health problems for elderly men such as urinary retention, recurring urinary tract infection and bladder stones. The aim of this study is to evaluate the therapeutic effects of Juniperus communis L. seed extract (JCS) on BPH in male Wistar rats.

Methods

To this end, 30 rats were divided into 5 groups (N = 6): group 1 (vehicle), group 2 (disease control), group 3 (standard medicine; 10 mg/kg finasteride), and groups 4 and 5 were treated with 300 mg/kg and 600 mg/kg of the hydroalcoholic JCS seed extract, respectively. Groups 2, 3, 4 and 5 received testosterone enanthate to induce prostatic hyperplasia. At the end of experimental period (28 days), prostate glands were cut off under anesthesia. Histopathological examination was done and biochemical parameters such as Malondialdehyde, Glutathione and protein carbonyl were also measured. Their body weights were also observed during the study. At the end of the experiment, prostate weights and prostate specific antigen (PSA) levels were measured. Prostate index, inhibition prostate weight and inhibition prostate index were also calculated.

Results

Both histopathological examination and biochemical parameter results showed significant improvements in rats treated with finasteride and 600 mg/kg JCS extract (p < 0.01). In addition, PSA levels showed significant decrease in comparison with the disease group. But acute toxicity test indicated that using JCS extract resulted in an increase in liver enzymes (ALP, LDH, SGOT, SGPT). As a result, the extract should be used with caution.

Conclusions

Oral administration of JCS extract is effective on preventing testosterone-induced benign prostatic hyperplasia.

Histoprotective Effect of Essential Oil from Citrus aurantifolia in Testosterone-Induced Benign Prostatic Hyperplasia Rat

Background

Benign prostatic hyperplasia (BPH) is a common urological disorder reported among ageing men.

Objective

The study assessed histoprotective effect of lime essential oil (LEO) in a rat model of testosterone-induced benign prostatic hyperplasia (BPH) and evaluated its ability to reverse testosterone-mediated changes in the testis, kidney, and liver.

Materials and Methods

Adult Sprague Dawley (aged 12 weeks, 240–390 g) male rats were intramuscularly injected with testosterone enanthate (TE) (10 mg/kg) reconstituted in olive oil for ten days to establish benign prostatic hyperplasia (serum PSA level ≥ 1.24 ng/ml) in. After confirmation of BPH (sustained serum PSA level ≥ 1.24 ng/ml), rats in all groups (LEO: 30, 100, and 300 mg/kg, po, n = 6; finasteride: 15 mg/kg, po, n = 6) except model (BPH without treatment) and sham (no BPH and no treatment) groups were treated for 21 days. At the end of treatment, rats were anesthetised and blood was collected via cardiac puncture to determine serum PSA and total antioxidant capacity (TAC) levels. The prostate gland, testis, kidney, and liver were harvested, weighed, histologically processed and stained with H&E.

Results

LEO- and finasteride-treated groups recorded lesser mean prostatic weights relative to their model group. Baseline mean serum PSA level of LEO- and finasteride-treated groups reduced significantly (p < 0.05) relative to model group. Serum TAC levels were also higher in LEO- and finasteride-treated groups relative to model group. LEO-treated groups had less thickened glandular epithelium, smaller acini, fewer prostatic secretions and more fibromuscular stroma relative to model group. LEO and finasteride treatment produced improved histomorphological characteristics of testis, kidney, and liver compared to model group.

Conclusion

By the current results, Citrus aurantifolia LEO may possess active agents that can be explored for translational medicine against BPH.

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.

Combining Targeted Metabolites Analysis and Transcriptomics to Reveal Chemical Composition Difference and Underlying Transcriptional Regulation in Maca (Lepidium Meyenii Walp.) Ecotypes

Maca (Lepidium meyenii Walp.) is a traditional Andean crop with great potential for various sanitarian and medical functions, which is attracting increased research attention. The majority of previous Maca studies were focused on biochemistry and pharmacodynamics, while the genetic basis of its unique characteristics lagged due to a lack of genome information. The authors perform gas chromatography-mass spectrometry (GC/MS) analysis in the hypocotyls of three Maca ecotypes and identify 79 compounds. Among them, 62 compounds have distinct profiles among Maca ecotypes. To reveal the underlying regulatory mechanism of the chemical composition differences, de novo transcriptome sequencing is performed and the transcription profiles of three Maca ecotypes are comparatively analyzed. Functional analysis indicates several key pathways, including “starch and sucrose metabolism,” “phenylpropanoid biosynthesis,” “phenylalanine metabolism” and “plant-pathogen interaction,” are involved in regulating the chemical compositions of Maca. Combining metabolomics and transcriptomics analysis indicates transcription factors such as MYB and WRKY and mediators such as protein kinase and bifunctional inhibitors might be critical regulators of chemical composition in Maca. The transcriptome reference genome and differentially expressed genes (DEGs) obtained in this study might serve as an initial step to illustrate the genetic differences in nutrient component, secondary metabolites content, medicinal function and stress resistance in Maca.

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.

N-Butanol and Aqueous Fractions of Red Maca Methanolic Extract Exerts Opposite Effects on Androgen and Oestrogens Receptors (Alpha and Beta) in Rats with Testosterone-Induced Benign Prostatic Hyperplasia

Benign Prostatic Hyperplasia (BPH) affects, worldwide, 50% of 60-year-old men. The Peruvian plant red maca (Lepidium meyenii) inhibits BPH in rodents. This study aimed to determine the effects of methanolic red maca extract and its n-butanol and aqueous fractions on expression of androgen and oestrogen receptors in rats with testosterone enanthate-induced BPH. Thirty-six rats in six groups were studied. Control group received 2 mL of vehicle orally and 0.1 mL of propylene glycol intramuscularly. The second group received vehicle orally and testosterone enanthate (TE) (25 mg/0.1 mL) intramuscularly in days 1 and 7. The other four groups were BPH-induced with TE and received, during 21 days, 3.78 mg/mL of finasteride, 18.3 mg/mL methanol extract of red maca, 2 mg/mL of n-butanol fraction, or 16.3 mg/mL of aqueous fraction from red maca. Treatments with red maca extract and its n-butanol but not aqueous fraction reduced prostate weight similar to finasteride. All maca treated groups restored the expression of ERβ, but only the aqueous fraction increased androgen receptors and ERα. In conclusion, butanol fraction of red maca reduced prostate size in BPH by restoring expression of ERβ without affecting androgen receptors and ERα. This effect was not observed with aqueous fraction of methanolic extract of red maca.

Effect of sildenafil citrate in testosterone induced benign prostate hyperplasia rat model

Objective

Efficacy of treatments for benign prostate hyperplasia (BPH) is limited because the disease has complex etiopathogenesis. Recent studies have demonstrated the presence of phosphodiesterase-5 (PDE-5) receptors in prostate tissue. We investigated efficacy of sildenafil citrate in testosteron - induced BPH in rats.

Material and methods

The rats were divided into three groups. Each groups had 7 rats. Group 1 was control group. Testosteron propionate 3 mg/kg/day was injected subcutaneously for two weeks in Group 2. The same procedure was done for Group 3 and sildenafil citrate was added to water at daily doses of 2 mg/kg for two weeks. The rats were euthanized with intraperitoneal pentobarbital. The body weights were measured and the prostates were removed.

Results

The mean weights of rats were 288±31.93, 345±23.23 and 294±32.86 g in Groups 1, 2 and 3, respectively. The mean prostate weights of rats were 0.74±0.18, 1.3±0.13 and 0.72±0.24 g in Groups 1, 2, and 3, respectively. Group 2 had statistically significantly higher prostate weights than the other groups (p<0.01). Relative prostate weight is calculated with ratio of prostate weight to body weight. BPH group showed an increase in relative prostate weight compared with other groups with significant difference (p=0.036 and p=0.040). There was statistical difference for acinar area between Group 2 and the others, no significant difference of number of acini, interstitial space and epithelial thickness. Group 2 has more papillary projections per acini than the other groups.

Conclusion

Favourable effect of sildenafil citrate on dimensions of prostate but not all on histological parameters was observed. We expect that PDE-5 inhibitors might be a treatment option for BPH patients if the studies support our findings in the future.