Potato extract inhibits lipase activity and ameliorates gut microbiome dysbiosis and weight gain in mice fed a high-fat diet

Curtailing the absorption of triglycerides (TGs) is a preferred pathway for treating obesity. Our previous study demonstrated that the water-soluble fraction from potato could inhibit the lipase activity of patatin, one of the major proteins in potato. This aqueous fraction was purified and concentrated by deproteination and reversed-phase chromatography to investigate the effectiveness against obesity. Biochemical analyses indicated that the fraction non-competitively inhibited pancreatic lipase (PLase) with a half-maximal inhibitory concentration of 10.17 µg/mL, and was named as potato-derived lipase inhibitory fraction (PI). Animal studies on C57BL/6 mice showed that in mice fed a high-fat diet (HFD), PI treatment resulted in reductions in body weight gain, adipose fat deposition, and liver TGs, and ameliorated the gut microbiome dysbiosis caused by HFD feeding; meanwhile, orlistat, a well-known lipase inhibitor, diverged the gut microbiome profile in mice fed a HFD. High resolution electronspray ionization-Orbitrap tandem mass spectrometry identified gallic acid, 4-hydroxybenzoic acid, and protocatechuic acid, which are known to have lipase inhibitory activities, in PI. However, these compounds could not reconstitute comparable specific inhibitory activity of PI inferring the existence of another inhibitory compound(s) to be identified in PI.