Quality Evaluation and Analysis of the Neuroprotective Effects of Different Maca Varieties

Lepidium meyenii (Maca) is an annual herb belonging to the genus Lepidium in the Brassicaceae family. It is cultivated in different color varieties, including purple, black, and yellow types, but systematic comparisons of their chemical composition and neuroprotective effects remain limited, hindering the development of reliable approaches for quality evaluation and variety selection. In this study, an integrated chemical composition–biological effect strategy was established to characterize the quality differences among purple, black, and yellow Maca. Untargeted metabolomic profiling based on UHPLC–LTQ–Orbitrap MS identified 4113 and 1021 metabolic features in positive and negative ion modes, respectively, and revealed distinct metabolic profiles among the three color varieties. A total of 35–48 differential metabolites were identified in pairwise comparisons, mainly involving macamides, glucosinolates, phenylpropanoid derivatives, and phosphatidic acids. Complementary targeted HPLC-DAD analysis was performed to quantify three representative macamides and one macaene, selected based on their characteristic occurrence in Maca and relevance to compositional quality evaluation. Their contents were significantly higher in purple and black Maca than in yellow Maca. In an MPTP-induced zebrafish Parkinson’s disease model, all three Maca varieties showed neuroprotective effects, with purple Maca exhibiting the greatest improvement in locomotor activity and preservation of dopaminergic neurons. Correlation analysis suggested a positive association between characteristic constituent contents and dopaminergic neuronal area. These findings demonstrate distinct chemical and pharmacological differences among Maca color varieties and support characteristic macamides as quality-related markers for the quality evaluation and rational utilization of Maca.