METABOLITE PROFILING, ANTIOXIDANT, CYTOXOTIC AND ANTIMICROBIAL ACTIVITIES OF Lepidium meyenii EXTRACTS
Peruvian Maca. Metabolomics. Natural Products.
INTRODUCTION: Lepidium meyenii is a plant that has several medicinal properties, however, the correlation between the metabolites and the biological activities tested in the plant is limited. OBJECTIVE: To characterize the metabolomic profile as well as to evaluate the antioxidant, antimicrobial and cytotoxic activities of extracts obtained from the dehydrated plant and its commercial products and to correlate the metabolomic profile with biological activities. MATERIALS AND METHODS: The extracts were obtained from the root of the plant and its commercial products by maceration in different organic solvents. The metabolomic profile was evaluated by mass performance coupled high chromatography (HPLC-MS) and gas chromatography coupled to mass spectrometry (GC-MS). The antioxidant activity was determined by the free radical sequestration method 2,2-diphenyl-1-picrylhydrazyl (DPPH) and total phenols will be quantified by the Folin-Ciocalteu method. Antimicrobial activity was evaluated against bacteria and yeast by broth microdilution method, cytotoxicity was evaluated against C6 cell line and astrocytes. RESULTS AND DISCUSSION: The antioxidant activity (IC50) ranged from 64.97 μg∙mL-1 for the ethyl acetate extract from the root of the dehydrated plant to 935.61 μg∙mL-1 for the hexane extract of the plant commercial product. The total phenol values ranged from 6.83 mg∙GAE∙g-1 for the ethanol extract at 49.83 mg∙GAE∙g-1 for the ethyl acetate extract, both extracts are form the commercial products. The ethanol extracts and ethyl acetate were the most active and had the highest antioxidant potential, in addition they also showed antimicrobial activity against M. luteus and B. cereus and antitumor activity against C6 cells, with no cytotoxicity to astrocytes. Seventy-six metabolites were identified in the extracts and among these, terpenes were the main metabolites responsible for antioxidant and cytotoxic activities and fatty acids for antibacterial activity. CONCLUSION: The metabolomic approach through the several analytical techniques allowed to correlate the obtained results being possible to identify the main bioactive compounds of L. meyenii related to the antioxidant, antimicrobial and antitumor activities of the plant.