Biotransformation of Cranberry Proanthocyanidins to Probiotic Metabolites byEnhances Their Anticancer Activity in HepG2 Cells.
Oxid Med Cell Longev. 2019 ;2019:4750795. Epub 2019 Jun 17. PMID: 31316718
H P Vasantha Rupasinghe
This study was designed to unravel the role ofin the bioconversion of cranberry proanthocyanidins and cytotoxicity of resulting metabolites to hepatocellular carcinoma HepG2 cells. Crude (CR) and flavonol+dihydrochalcone- (FL+DHC-), anthocyanin- (AN-), proanthocyanidin- (PR-), and phenolic acid+catechin- (PA+C-) rich fractions were subjected to fermentation withat 37°C for 12, 24, and 48 h under anaerobic conditions. The major metabolites produced by bioconversion of polyphenols were 4-hydroxyphenylacetic acid, 3-(4-hydroxyphenyl)propionic acid, hydrocinnamic acid, catechol, and pyrogallol. Furthermore, cytotoxicity of the biotransformed extracts was comparedto their parent extracts using human hepatocellular carcinoma HepG2 cells. The results showed that PR-biotransformed extract completely inhibited HepG2 cell proliferation in a dose- and time-dependent manner with ICvalues of 47.8 and 20.1g/mL at 24 and 48 h, respectively. An insight into the molecular mechanisms involved revealed that the cytotoxic effects of PR at 24 h incubation were mitochondria-controlled and not by proapoptotic caspase-3/7 dependent. The present findings suggest that the application of a bioconversion process using probiotic bacteria can enhance the pharmacological activities of cranberry proanthocyanidins by generating additional biologically active metabolites.