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

Abstract

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

We would like to thank Eduardo Purgatto (College of Pharmaceutical Sciences, FCF, USP) for his generous donation of SIN monohydrate and Fernanda Bovo (Pharmacy Skills Laboratory, UFPR) for the Glucose Liquiform kit. We also thank Flávia Lada Degaut Pontes (Biochemistry and Molecular Biology, UFPR) and Arquimedes P. de Santana Filho (Biochemistry and Molecular Biology, UFPR) for their technical assistance with the LC-MS/MS analyses and NMR analyses, respectively. We acknowledge PROEX-CAPES for their partial financial support and CAPES for the fellowship granted to R.M.L.

Disclosure Statement

No potential conflict of interest was reported by the authors.