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.

Genistein Affects Expression of Cytochrome P450 (CYP450) Genes in Hepatocellular Carcinoma (HEPG2/C3A) Cell Line.

BACKGROUND: Genistein (5,7-Dihydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) is the most abundant isoflavone in soybean, which has been associated with a lower risk of development of cancer and cardiovascular diseases. Of particular interest regarding cancer preventive properties of flavonoids is their interaction with cytochrome P450 enzymes (CYPs). However, contradictory data report the effect of genistein on expression of СYPs enzymes. OBJECTIVE: The aim of this study was to investigate the effects of genistein on cytochrome P450 (CYP) gene expression levels in human hepatocellular carcinoma (HepG2/C3A) and colon adenocarcinoma (HT29) cells. METHODS: Real-time RT-PCR was used to examine the expression of genes families involved in xenobiotic metabolism, such as CYP1 (CYP1A1, CYP1B1), CYP2 (CYP2E1, CYP2D6), CYP3 (CYP3A4); and of a family involved in the catabolism of the all-trans-retinoic acid (ATRA), CYP26 (CYP26A1, CYP26B1). RESULTS: RT-qPCR data analysis showed that after 12 h of exposure of HepG2/C3A cells to genistein (5 and 50 µM) there was an upregulation of CYP1A1 and CYP1B1 and downregulation of CYP2D6, CYP26A1 and CYP26B1 mRNA levels. There was no change in the mRNA levels of CYP P450 genes in HT29 cells. CONCLUSION: Our results suggest that treatment with genistein in non-toxic concentrations may impact the expression level of CYPs involved in the biotransformation of xenobiotics and drug metabolizing enzymes. Moreover, the downregulation of ATRA metabolism-related genes opens a new research path for the study of genistein as retinoic acid metabolism blocking agent for treating cancer and other pathologies.