Jiong Yang¹, Chaoyin Chen^1,, Shenglan Zhao^2,, Feng Ge¹, Diqiu Liu¹

In this article, the effect of the solvents (water, methanol, ethanol, chloroform, N-butanol and ethyl acetate) on the extraction yields (EY), total flavonoids content (TFC), total phenols content (TPC) form walnut shell and the inhibitory effect of extracts on pancreatic lipase were analysed. The kinetics of enzyme inhibition and was investigated. The inhibitory effect of extracts on adipogenesis of 3T3-L1 preadipocytes was also investigated. The highest EY, TFC and TPC were achieved with N-butanol (4.54%), Ethyl acetate (80.40 mg QEs/g extract) and ethyl acetate (200.40 mg GAE/g extract). The order of inhibitory activity was methanol extract (ME) > ethyl acetate extract (EAE) > ethanol extract (EE) > water extract (WE) > N-butanol extract (NBE) > chloroform extract (CE), the inhibition ratios were 82.51%, 73.13%, 70.49%, 69.42%, 65.57% and 60.66%, respectively under the concentration of 500 μg/mL. The IC₅₀ values of WE, ME, EE, CE, NBE and EAE were 371.35, 308.91, 407.57, 196.50, 247.79 and 254.27 μg/mL respectively. The inhibitory types of walnut shell extracts were noncompetitive. All the extracts were non-toxic to 3T3-L1 preadipocytes. The ME, EE, CE, NBE and EAE have inhibitory effect on triglyceride accumulation of 3T3-L1 cells.

walnut shell, solvents extraction, pancreatic lipase, obesity