The purpose of the present work was to characterize the possible inhibition of pancreatic lipase by a tannin-rich extract obtained from the pinh?o (Araucaria angustifolia seed) coat, based on the previous observation that this preparation inhibits á-amylases. Kinetic measurements of pancreatic lipase revealed that the pinh?o coat tannin is an effective inhibitor. Inhibition was of the parabolic non-competitive type. The inhibition constants, Ki1 and Ki2, were equal to 332.7 ± 146.1 ìg/mL and 321.2 ± 93.0 ìg/mL, respectively, corresponding roughly to the inhibitor concentration producing 50% inhibition ([I]50). Consistently, the pinh?o coat extract was also effective at diminishing the plasma triglyceride levels in mice after an olive oil load; 50% diminution of the area under the plasma concentration versus the time curve occurred at a dose of 250 mg/kg. This observation is most probably the consequence of an indirect inhibition of triglyceride absorption via inhibition of pancreatic lipase. For the pinh?o coat tannin, this is the second report of a biological activity, the first one being a similar inhibition of the absorption of glucose derived from starch as a consequence of an inhibitory action on á-amylases. Taken together, these effects represent a potential anti-obesity action, as suggested for other polyphenol or tannin-rich preparations.
Animals Lactones