In Vitro Inhibitory Effects From Flower Buds Of Cleistocalyx Operculatus(Roxb.) Merr.Et Perry On Pancreatic Lipase And α-amlyase

Obesity constitutes a key risk factor for a variety of adulthood chronic disorders such as dyslipidemia, high blood pressure, type Ⅱ diabetes, cardiovascular disease, osteoarthritis and some forms of cancer (such as thymic carcinoma, ovarian cancer). Extracts from flower buds of Cleistocalyx operculatus, has many bioactivity, such as anticancer, reversing multi-drug resistance. Hence the interest in the search for new natural substances that show potent inhibitory activity against digestive enzyme and have fewer side effects than the current ones.Firstly, extracts of flower buds of Cleistocalyx operculatus were prepared by ultrasonic method, the yield of aqueous extract,30%,60%and95%ethanol extract, petroleum ether extract and ethyl acetate extract was18.18%,18.48%,19.48%,20.35%,1.64%and10.20%. The yield of2’,4’-dihydroxy-6’-methoxy-3’,5’-dimethyl-chalcone (DMC) were0.62%o, the purity was98.57%.Secondly, the inhibitroy model of pancreatic lipase and a-amylase were used to screen the effective parts of Cleistocalyx operculatus. DMC, petroleum ether extract, ethyl acetate extract and95%ethanol extract which IC50values were101.5μM,38.65μg/mL,76.62μg/mL and109.76μg/mL, showed strong inhibitroy activity to pancreatic lipase. The inhibition mode of extracts was noncompetitive. DMC, aqueous extract,30%ethanol extract and60%ethanol extract which IC50values were69.35μM,73.10μg/mL,165.93μg/mL and231.23μg/mL, showed better inhibitroy activity to pancreatic a-amylase than other extracts. The inhibition mode of extracts was competitive.Finally, in order to identify the material basis of inhibitory activity, chemical composition and content of different extracts of Cleistocalyx operculatus were characterized by HPLC and UV methods. The results showed that:the DMC content of petroleum ether extract, ethyl acetate extracte and ethanol extract is in a reduced; The total polyphenol content of aqueous extract, ethanol extract, petroleum ether extract and ethyl acetate extract is in a reduced. It is found that inhibitroy activity of extracts of the plant could be associated with the presence of DMC and phenolic compounds.