Previous studies of Dendrobium officinale on anti-hypertension effect always focused only on the blood pressure,while polysaccharides of D. officinale( DOP) have been traditionally considered as one of the main effective substances. This study aimed to evaluate the effect of ethanol extract from D. officinale( DOE) on blood pressure,Glu and lipid profile in metabolic hypertensive rats induced by comprehensive dietary factors,and elucidate the composition of effective fractions from DOE. A metabolic hypertension model of rat induced by high-sugar,high-fat diet and alcohol drinking was adopted to evaluate the effect of DOE on hypertension and other metabolic disorders. Blood pressure,Glu and lipid profile were detected to find the features and differences of DOE and DOP on metabolic hypertension. Furthermore,DOE was separated with three different common solvents according to the polarity. Along with blood pressure,Glu,UA and lipid profile,hemorheology,oxidative index and aortas structure changes were adopted to evaluate the comprehensive effects of the most effective fractions on metabolic hypertension. Finally,HPLC-DAD-MS was adopted to identify the components of the most effective fraction. The SBP and Glu of models were decreased significantly after administration of DOE and DOP for 6 weeks,while TG in DOE groups also reduced dramatically. The DOE was separated with ether,n-butanol respectively and named NAF,NBF and NCF. SBP,TG,Glu,UA of model rats were decreased significantly after 4 weeks administration with NBF. The level of MDA in serum was down-regulated,while GSH-Px and T-AOC were up-regulated obviously after 12 weeks.And the blood viscosity also obviously decreased,with less collagen deposition of aortas by Masson's trichrome staining. NBF was mainly composed of phenols and flavone C-glycosides,whose aglycone was apigenin,and monosaccharide was connected to C-6 and C-8. Ethanol extract from D.officinale has an positive effect in alleviating hypertension and metabolic disorders in metabolic hypertension. Medium polarity fraction was the effective fraction of alcohol extraction from D. officinale,and mainly composed of phenols and flavone C-glycosides.
Keywords: Dendrobium officinale; effective fraction; ethanol extract; flavone C-glycosides; metabolic disorders; metabolic hypertension.