| Bamboo,which belongs to gramineae herbaceous plant,has a long medicinal and edible value in China.Bamboo leaf extract contains flavonoids,polysaccharides,minerals and other components.Thus,it has been used various diseases treatments.Bamboo leaf has abundant flavonoids and the main constituents are C-glycosides,including orientin,isoorientin,vitexin and isovitexin.Compared with O-glycoside,C-glycoside flavonoids are less distributed in nature and less concerned.However,studies have shown that the C-glycoside flavonoids seem to have higher antioxidant and anti-diabetic potential than O-glycoside.Bamboo leaf flavonoids were approved for the new food ingredients in 2014.In our previous study,the content of C-glycoside flavonoids in Bambusa multiplex cv.Fernleaf leaf（B.multiplex）was much higher than Phyllostachys heterocycla cv.Pubescens we usually used.In our present study,the B.multiplex C-glycoside flavonoid was purified in our laboratory,the contents of isoorientin and vitexin were 10.84 and 6.87%.Then,the absorption,excretion,metabolism and tissue distribution of B.multiplex C-glycoside flavonoid in rats were studied through zein nanoparticles.Subsequently,the inhibitory effect of C-glycoside flavonoids on pancreatic lipase in vivo and in vitro was also involved.Finally,the anti-obesity effect of C-glycoside flavonoids was explored through male C57BL/6J male mice induced by high-fat diet.The results were as follows:The metabolism,pharmacokinetics,tissue distribution and excretion of C-glycoside flavone of B.multiplex were studied by using zein nanoparticles（BZP）loaded with C-glycoside flavone in rats.The main components of C-glycoside flavonoid in B.multiplex were isoorientin and vitexin.Isoorientin,vitex and their main metabolites were identified in rat feces,plasma,tissues a nnd urine by UPLC-QTOF-MS.The metabolic pathways of isoorientin and vitexin in rat plasma were different,which attributed to its structure and sensitivity to LPH.Isoorientin was mainly metabolized in its intact form,while vitexin is mainly metabolized in the form of its metabolite（Apigenin-Glu）.The dynamic variations of isoorientin and vitexin and its metabolites in plasma,organs and urine were then quantified by UPLC-Qq Q-MS/MS.isoorientin,vitexin and their metabolites could be absorbed rapidly in tissues,and vitexin and its metabolite still have relatively high concentration after 12h.The total feces excretion of isoorientin and vitexin were 18.13 and 19.00%,respectively.Isoorientin was excreted in the forms of luteolin and methylation in urine,however,as for vitexin,was eliminated mainly in the form of apigenin and glucuronidation.The inhibitory activities of C-glycoside flavone on pancreatic lipase were studies in vitro and in vivo.The inhibitory effect of C-glycoside flavonoids on pancreatic lipase was found with IC50 value of 0.91 mg/m L.B.multiplex extract could be combined with pancreatic lipase and showed mixed inhibition.Animal experiment have shown that the C-glycoside flavones of B.multiplex could significantly reduce the absorption of triglycerides and increase the excretion of triglycerides through feces.The variation of C-glycoside flavonoid content in feces was consistent with that of triglyceride.In vitro and in vivo experiments confirmed that C-glycoside flavonoids possess inhibitory activity on pancreatic lipase.The anti-obesity effect of B.multiplex C-glycoside flavonoids was studied through C57BL/6J mice fed with high fat diet.As a result,first of all,the supplementation of B.multiplex C-glycoside flavone could reduce weight gain,decrease TG and TC contents in serum and liver,increase the excretion of TG via feces caused by high fat diet.Secondly,the insulin sensitivity of mice was significantly improved by B.multiplex C-glycoside flavonoids supplementation.B.multiplex C-glucoside flavnoids could significantly reduce the level of MDA and increase the activities of antioxidant enzymes in liver tissue,which could improve the lipid peroxidation and liver cell injury to some extent caused by high fat diet.Therefore,the intake B.multiplex C-glycoside flavonoids daily has a favourable improvement effect on obesity caused by high fat diet. |
