Inhibitory Effects of Edible and Medicinal Plant Extracts on the Enzymatic Activity of Pancreatic Lipase

Plants with a strong activity to reduce the digestion of lipids from the diet are a possible way to prevent and combat obesity. This study evaluated 37 ethanol extracts of plants, some edible, medicinal, or belonging to a family that has the inhibitory activity of pancreatic lipase, aimed at looking for a new anti-obesity agent. Inhibition of pancreatic lipase (PL) was measured in vitro and in vivo assay. The plasma triacylglycerol levels after 1, 2, and 3 h in fasted male Wistar rats fed, by oral administration, with a lipid emulsion were measured. The antioxidant activities were evaluated using DPPH (1,1-diphenyl-2-picrylhydrazyl radical scavenging activity), FRAP (ferric reducing antioxidant power) and ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid), and the total phenol and flavonoid content were determined. Nine plants exhibited low inhibition (<41 %), nine showed medium inhibition (41-50 %), eight demonstrated high inhibition (51-60%) and 11 plants had the highest inhibition (& GE; 61 %). Hibiscus rosa-sinensis, dried leaves extract displayed the highest inhibitory activity of pancreatic lipase 71.90 % at 400 & mu;g/mL, with a dose-dependent inhibition against PL similar to orlistat. The kinetic study showed uncompetitive inhibition. Moreover, H. rosa sinensis extract also reduced the elevation of plasma triacylglycerol levels after lipid emulsion administration similar as orlistat did. H. rosa-sinensis dried leaves had higher antioxidant activity and total phenolic compounds than fresh leaves. H. rosa-sinensis presented the strongest antilipase activity and could be used as an anti-obesogenic agent or as a food additive to reduce the absorption of fats from the diet.