Research Of Anti-gout Flavonoids And Intestinal Absorption Of Luteolin

Gout is a group of heterogeneous diseases in which long-term metabolic disorders in the body lead to the increase of blood uric acid levels or reduced uric acid excretion.In recent years,with the changes in human diet and lifestyle,the incidence of gout has increased year by yeart.The drugs for treating gout have many side effects,so finding a safe and effective drug for treating gout has become a research hotspot.Flavonoids are natural product with less toxic side effects.Some studies have shown that plant total flavonoids have certain improvement and therapeutic effects on gout,but the mechanism of action of gout is still unclear.In this paper,the flavonoids with therapeutic effect of gout will be screened from the in vitro and in vivo experiments,and the mechanism of action will be studied.The absorption rate and mode of the flavonoids will be used as an anti-gout drug.The main contents and results were:The inhibitory effect of 30 flavonoids on xanthine oxidase activity（XOD）in vitro was determined by modified high performance liquid chromatography.The results showed that 12flavonoids inhibited XOD at 120μmol/L,and 9 flavonoids inhibited XOD at 60μmol/L.The four flavonoids with the best inhibition were luteolin,quercetin,apigenin and kaempferol.The IC50 values were 42.02,120.22,135.98 and 184.36μmol/L,respectively.Experiments showed that some flavonoids had an inhibitory effect on XOD in vitro.The uricase inhibitor potassium oxonate induced hyperuricemic mice model by UV spectrophotometric method in detection of serum XOD,UA,BUN,SCr level,it was used as indexes,the effects of in vitro screened from luteolin of 4 flavonoid compounds on mice with hyperuricemia.The results showed that compared with model group,the activities of UA,XOD,BUN and SCR in serum were significantly decreased in positive drug control group,luteolin（20,40,80 mg/kg）,apigenin（200 mg/kg）,kaempferol（150,300 mg/kg）（P<0.01,P<0.05）.The results showed that luteolin,apigenin and kaempferol had good therapeutic effects on hyperuricemia in mice,and luteolin had the best inhibitory effect on XOD in vivo and in vitro.The thesis investigated anti-inflammatory and analgesic effects of luteolin on gouty arthritis animals by adopting the test of xylene-induced ear swelling in mice,the test of acetic acid-induced mice writhing,and the model of acute gouty arthritis rats and taking the ear swelling degree,writhing latent period,writhing times of mice and ankle joint swelling degree of rats as indicators.Results showed that in the anti-inflammatory and analgesic model,comparing with the model group,the positive medicine comparing group and each group of luteolin made the ear swelling degree of mice reduced obviously,writhing times of mice decreased obviously and writhing latent period extended obviously（P<0.01,P<0.05）;in the the model of acute gouty arthritis rats,comparing with the model group,the ankle joint swelling degree of rats decreased obviously in the positive medicine comparing group and luteolin（28,56 mg/kg）at 2-12h（P<0.01,P<0.05）,and the most effective was at 8h（P<0.01）.The test indicated that the luteolin had a good anti-inflammatory and analgesic effect on acute gouty arthritis.The thesis established the model of acute gouty arthritis rats by adopting puncturing sodium urate injection,and detected rats serum interleukin-1β（IL-1β）,tumour necrosises factor-α（TNF-α）,nitric oxide（NO）,malonaldehyde（MDA）,catalase（CAT）,and superoxide dismutase（SOD）activity by using enzyme linked immunosorbent assay and colorimetric method,and preliminary discussed its function mechanism on the treatment of acute gouty arthritis.Results showed that comparing with the model group,the positive medicine comparing group and luteolin（28,56 mg/kg）could reduce the serumTNF-α,IL-1βand MDA obviously（P<0.01或P<0.05）;the positive medicine comparing group and luteolin（28,56 mg/kg）could raise NO,CAT and SOD obviously（P<0.01或P<0.05）.The test indicated that the mechanism of acute gouty arthritis treatment by luteolin could be through inhibiting inflammatory factors and be related with antioxidation.The thesis adopted the rat single-pass intestinal perfusion model,measured the luteolin content in the perfusate with phenol red as the marker by HPLC method,and investigated intestinal absorption dynamics features of luteolin and effects of P-glycoprotein（P-gp）on intestinal absorption.Results showed that the absorption of luteolin with the same concentration in duodenum,jejunum and ileum is better than that in colon;the absorption rate constant（K_a）and apparent permeability coefficient(P_eff)of luteolin with the different concentration and in the same intestinal segment of rats had no significant differences;after adding P-pg inhibitor and accelerant,the Peff and Ka had no obvious changes.The test indicated that the luteolin was a hypertonicity component,which had no saturable absorption phenomenon in certain mass concentration.