The Procyanidin Structure, Antioxidant Activity And Lipid-lowering Effect Of Lotus By-product

This research aimed to solve the utilization problem of lotus by-products?including lotus seedpot and lotus seed epicarp?.This ariticle mainly researched the structure,function and main application of OPC extracted from lotus epicarp and seedpot.The stuctures,in vitro and cell based antioxidant activities,in vivo metabolism and antiobesity effect were all investigated.The main resulted were as follows:1.The response surface optimization of ultrasonic assisted extraction of procyanidins from lotus seed pericarp and ultrasonic assisted extraction of the best condition of procyanidins as follows: the best conditions of lotus seed epicarp were ultrasonic time 21 min,ultrasonic power 720 w,70% acetone concentration,liquid/material 33:1 mL/g.At this condition,lotus seed epicarp procyanidins content is 43.96 mg/g.2.UV,IR and HPLC-QTOF-MS were used to analysis the structures of procyanidins from lotus seedpot and lotus seed epicarp.A total of 21 kinds of procyanidins were identified in lotus seedpot and 15 kinds of procyanidins were identified in lotus seed epicarp.Catechin,gallocatechine,epicatechin a nd epigallocatechin were their compo nent units.Procyanidins from lotus mainly consisted of dimmers and trimmers.3.Lotus seed by-products showed well ABTS and DPPH radicals scavenging activity than ascorbic acid.Lotus seed epicarp and lotus seedpot sho wed high DPPH scavenging ability.Lotus seed epicarp procyanidins' s DPPH free radical ability was slightly higher than that of VC,and lotus seedpot procyanidins was 2.26-fold VC.Lotus seed epicarp procyanidins and lotus seedpot procyanidins' s ABTS radical scavenging ability were 2.15-fold VC and 7.61-fold VC respectively.HUVECs?Human umbilical vein endothelial cells?pretreated with low,medium and high concentration of crude lotus procyanidins?including lotus seed epicarp procyanidins and lotus seedpot procyanidins?and then treated with 500 mM of H₂O₂ to stimulate cel.The procyanidins pretreated group showed good damage protective effects.4.PAs were extracted from lotus by-product by chloroform,diethyl ether and ethyl acetate in sequence and then was loaded on a AB-8 column to get the purified PAs.The purity PAs of lotus seed epicarp and lotus seedpot were reached 71.34 and 76.51%,respectively.1500 mg purified procyanidins /kg body weight to feed rats and then analysis of the procyanidins metabolites by rats,27 kind of relation products were found.The main metabolites were?vanillic acid,p-coumaric acid,etc.?coumaric acid sulfate,3-O-Methyl?epi?catechin 5-or 7-O-sulfate,trimethyl gallic acid,etc.5.The obese mice feed with lotus procyanidins?25 mg/kg and 100 mg/kg?induced by feeding high-fat for eight weeks,lotus seedpot and the lotus seed epicarp procyanidins extract showed evident lipid-lowering effect.High concentrations of lotus seed pot group showed obvious lipid-lowering effect.The blood lipid level of TG,TC and LDL-C decreased by 45.45,45.45 and 43.53% respectively,compared with high-fat group.The hepatic lipid level of TG,TC and LDL-C decreased by 46.83,46.83 and 42.71% respectively,compared with high-fat diet group.In the high concentrations of lotus seed pot group,leptin,alanine transaminase,aspartate transferase and alkaline phosphatase levels decreased by 55.87,46.74,22.33 and 5% respectively,compared with high-fat diet group.The hepatic antioxidant enzymes,GSH-S-transferase,GSH activity 1.62-fold,3.36-fold and 1.28-fold compare with high-fat diet group,and MDA activity was 0.59-fold compare with high-fat diet group.