Inhibition by seeds of Phalaris canariensis extracts of key enzymes linked to obesity

Context • Obesity and its associated diseases are an increasing problem around the world. One hyperglycemic remedy is reduction of glucose absorption performed by suppressing digestion of carbohydrates and lipids through the use of inhibitors. Phalaris canariensis (P canariensis) is a species belonging to the Graminaceae family and is used in traditional medicine in Mexico for treatment of diabetes and obesity. Objective • The aim of the study was to evaluate the effects of different extracts of the seeds of P canariensis on enzymes metabolizing fat and carbohydrates, obtained using 3 solvents. Design • The seeds of P canariensis were extracted using hexane (ALH), chloroform (ALC), and methanol (ALM) and were investigated for their antiobesity potential. Setting • This research was conducted in the Laboratory of Research of Natural Products in the School of Chemical Engineering at the National Polytechnic Institute and in the Research Laboratory of Enzymology in the National School of Biological Sciences. Outcome Measures • Different concentrations of the extracts were used to study the inhibition of enzymatic activity by porcine pancreatic α-amylase, with carbose as a positive control. The inhibitory activity of α-glucosidase was determined using the standard method with bovine serum albumin (BSA). Pancreatic lipase (PL) activity was measured by absorbance at 412 nm, and the data obtained were compared with orlistat. The PL activity was assessed using a second method measuring the rate of release of oleic acid from triolein. Lipoprotein lipase (LPL) activity was measured by released (3H)-oleic acid. Lipolytic activity in cultured, mouse, 3T3-Ll adipocytes was used as a measure of hormone-sensitive lipase activity. The inhibitory activity of rat intestinal sucrase was determined by measuring the glucose released. A Caco-2 cell assay determined the content of free glucose. Results • The ALH extract of P canariensis showed potent inhibitory activity with IC₅₀ values of 2.13 and 1.25 mg/mL as compared with α-amylase and α-glucosidase, respectively, and produced inhibition in rat intestinal sucrose. Further, the ALM extract showed significantly inhibitory effects against PL, LPL, and lipolysis of 3T3-LI adipocytes. Conclusions • The results provide evidence for the effects of the seeds of P canariensis for a retarded absorption of carbohydrates and lipids through the inhibition of enzymes that are related to obesity and diabetes mellitus type 2.