Exploring the metabolic fate of malvidin and pelargonidin rich-extracts in the gut through in-vitro fermentation. Potential of native anthocyanins and their microbial metabolites as anti-apoptotic agents in colon cancer cells

MOSSE JUANA INÉS; LÓPEZ DE LAS HAZAS MARÍA DEL CARMEN; ALBA MACIÁ; MOTILVA MARÍA JOSÉ

Viena

Congreso; The XXVIIIth International Conference on Polyphenols; 2016

Beneficial properties attributed to the intake of berries and red wine have been associated to the presence of high amounts of anthocyanins. However, their low absorption and consequent accumulation in the gut have generated the suspicion that microbial metabolites of anthocyanins are probably involved in their protective effects. Two anthocyanins-rich extracts from grapes pomace and strawberries were in-vitro fermented using human faeces as microbial inoculum. After 8 h of in-vitro fermentation, anthocyanins were almost completely degraded and their microbial metabolites started to increase gradually until reach maximum concentration at 24 h of incubation. We detected syringic acid as main catabolic product of grape pomace fermentation and, for the first time, tyrosol as main microbial product of strawberry anthocyanin rich extract fermentation. Based on the results observed at different times during the in-vitro incubation, we proposed the metabolic pathways of malvidin and pelargonidin, the most abundant anthocyanins in the grape pomace and strawberry extract, respectively. Since anti-proliferative properties have been described for anthocyanins, their apoptotic activity was evaluated in colon cancer cell line HT-29. To better imitate the physiological conditions we exposed to HT-29 cells different mixtures of anthocyanin microbial metabolites obtained at early and latter times of the in-vitro fermentation experiment. The final objective was to study the most effective combination of anthocyanins and their microbial metabolites as anti-proliferative agents in colon cancer cell line.