Phenolic Fractions from Muscadine Grape “Noble” Pomace can Inhibit Breast Cancer Cell MDA‐MB‐231 Better than those from European Grape “Cabernet Sauvignon” and Induce S‐Phase Arrest and Apoptosis

Tons of grape pomace which still contained a rich amount of plant polyphenols, is discarded after winemaking. Plant polyphenols have multi‐functional activities for human body. In this study, polyphenols of pomaces from Muscadinia rotundifolia “Noble” and Vitis vinifera “Cabernet Sauvignon” were extracted and fractionated, and then they were analyzed with LC‐MS and the inhibitory effects on breast cancer cells were compared. The inhibition on MDA‐MB‐231 cells of fractions from “Noble” was further evaluated. The results showed that polyphenols from 2 grape pomaces could be separated into 3 fractions, and ellagic acid and/or ellagitannins were only detected in fractions from “Noble” pomace. All 3 fractions from “Noble” pomace inhibited MDA‐MB‐231 better than MCF‐7. But fraction 2 from “Cabernet Sauvignon” inhibited MCF‐7 better while fraction 1 and fraction 3 inhibited both 2 cells similarly. Moreover, the fractions from “Noble” pomace rather than “Cabernet Sauvignon” can inhibit MDA‐MB‐231 better. Finally, fractions from “Noble” pomace can induce S‐phase arrest and apoptosis on MDA‐MB‐231. These findings suggested the extracts from grape pomace especially those from “Noble,” are potential to be utilized as health beneficial products or even anti‐breast cancer agents.