TDK conference 2018

Flavonoids are secondary plant metabolites, that are well known for their beneficial effects, such as anti-inflammatory, antioxidant, antiviral, antibacterial and antiparasitic effects, besides that, they have also cancer preventive activity. Many studies have shown, that in farm animals these compounds can reduce the damage caused by oxidative stress, have positive impact on some reproductive parameters and can improve meat quality. Unfortunately, their effects are limited because of the poor bioavailability. However, based on some recent studies it is assumed, that methoxy-flavonoids are better absorbed from the small intestine, than the more studied hydroxy-forms, therefore they may have more potent effect.

The goal of our study was to examine the absorption properties of quercetin, one of the most prevalent flavonoid, and its methylated derivatives, 3-o-methylquercetin and 3’7-dimethylquercetin. In addition, we wanted to study the metabolites, resulted by the metabolic activity of the intestinal epithelial cells.

In our study we used IPEC-J2 porcine intestinal epithelial cells cultured on membrane inserts. These cells were treated with quercetin and its methylated derivatives, and after 30, 90 and 120 minutes of incubation we took samples from both of the apical and the basolateral supernatant, which samples were analysed by HPLC-MS method.

Our results show, that carboxy-, sulphonate-, methyl- and glucuronide-derivatives were formed from the studied flavonoids. In case of 3-o-methylquercetin and 3’7-dimethylquercetin demethylated compounds also were formed, but we could no observe carboxy-derivatives during the metabolism of 3’7-dimethylquercetin. In case of quercetin and 3-o-methylquercetin the methyl-derivatives were dominant on the apical side of the inserts, while on the basolateral side we detected mostly sulphonate-derivatives. During the metabolism of 3’7-dimethylquercetin demethylated compounds were formed in a great amount. 3-o-methylquercetin showed the highest extent of transport from the apical to the basolateral side.

Based on our result we assume, that 3-o-methylquercetin is absorbed better from the small intestine than quercetin, therefore it could be a starting point for further studies. In case of our assumption will be confirmed during further studies, 3-o-methylquercetin could be a better alternative for therapeutic use and growth promotion compared to the widespread quercetin.