| ObjectiveResearch showed that Kuding tea have the effects of lipid lowering and anti-oxidization.Nevertheless,it was not accepted by most of people because of its bitter taste,and it always need high-dose for lipid-lowering.The high-dose may be harm to the kidney.So how to improve the compliance and bioavailability of taking Kuding tea was the goal to pursue.This experiment was to extract the flavonoids from Kuding tea,and prepared the chitosan-Kuding tea total flavonoids nanoparticles with chitosan.Pharmacology and preliminary safety were studied on chitosan-Kuding tea total flavonoids nanoparticles.Method1.Kuding tea total flavonoids were extracted,purified and the content determination was performedKuding tea total flavonoids were extracted by gradient ethanol and purified by chitosan.And the content determination was performed with UV-spectrophotometer.2.Chitosan-kuding tea total flavonoids nanoparticles were prepared,and its physicochemical properties were investigatedChitosan-kuding tea total flavonoids nanoparticles were prepared by ionic crosslinking.To optimize the preparation of chitosan-kuding tea total flavonoids nanoparticles,the factors of preparation including the concentration of kuding tea total flavonoids,chitosan,TPP,temperature,time and stirring speed were investigated.In terms of encapsulation efficiency,the best prescription of chitosan-kuding tea total flavonoids nanoparticles were established by orthogonal design.Then,spray-drying conditions were observed and the optimal amplification process were established.The morphology and distribution of particles were examined.Furthermore,characteristics of the release in vitro studies were observed.3.Hypolipidemic effect of chitosan-kuding tea total flavonoids nanoparticles was studiedRats were divided randomly into eight groups:blank group,model group,normal group,chitosan-kuding tea total flavonoids nanoparticles high dose group,chitosan-kuding tea total flavonoids nanoparticles middle dose group,chitosan-kuding tea total flavonoids nanoparticles low dose group,chitosan nanoparticles group and kuding tea total flavonoids group.Different interventions for four weeks,the rats were weighed of body,liver,peripheral and epididymis fat weight.Then,the ratio of liver and body and internal organs fat content were calculated.Blood serum triglyceride(TG),serum total cholesterol(TC),serum low density lipoperotein cholesterol(LDL-C),serum high density lipoperotein cholesterol(HDL-C),aspartate transaminase(AST),alanine amino transferase(ALT),MDA content and the activity of SOD of blood serum and liver were determined.The HE stain section of liver was observed under microscope.4.Acute toxicity tests on Chitosan-kuding tea total flavonoids nanoparticlesGiven drugs to mice and determined median lethal dose(LD50)by Horn method.Results1.The content of total flavonoids from kuding tea was 31.84%.2.The chitosan-kuding tea total flavonoids nanoparticles were spherical in shape and the size ranged between 200 and 400 nm.The polydispersity was 0.137.For one thing,the optimal preparation process of nanoparticles was as follow:chitosan concentration 1mg/ml,TPP concentration 1 mg/ml,and concentration of kuding total flavonoids 1 mg/ml.For another,the optimal amplification process of nanoparticle was as follow:inlet temperature 170 ℃,outlet temperature 100 ℃,sampling flow rate 600mL/h.The in vitro release profile showed that the nanoparticles have sudden release effect in the first two hours,with 45.6%to 48.9%.Total release rate was 91.9%in 24 hours.3.Animal experiments showed that chitosan-kuding tea total flavonoids nanoparticles could decreased TG levels and body fat in hyperlipemia rats,simultaneously,SOD levels increased and MDA levels decreased.4.The LD50 of chitosan-kuding tea total flavonoids nanoparticles was 2000mg/kg which was determined by Horn method.Conclusions1.Kuding total flavonoids are more pure,less mustiness extracted by gradient ethanol than water.2.The chitosan-kuding tea total flavonoids nanoparticles are spherical in shape and the size ranges between 200 and 400 nm which are prepared by ionic crosslinking.In vitro studies show the chitosan-kuding tea total flavonoids nanoparticles had a sustained release.3.Chitosan-kuding tea total flavonoids nanoparticle has lipid regulation,antioxidant ability and superior liver protective effects.4.The test of acute toxicity showed that:chitosan-kuding tea total flavonoids nanoparticle was the low toxicity material. |
