ABSTRACT
Objective To observe the effect of extract from Branchlets roses on blood glucose and glucose tolerance in diabetes mice induced by alloxan.Methods Diabetes animal model was established by alloxan.Dividing the model mice into eight groups:model group,water extract high,middle,and low dose (3.70,1.85,and 0.93 g/kg) group,and ethanol extract high,middle,and low dose (2.75,1.37,and 0.70 g/kg) group,and metformin (positive drug,200 mg/kg) group,and normal mice were taken as control group.Drug was ig administered to mice 3 d after molding once daily.Blood glucose test paper was used to determine fasting blood glucose 0,10,20,and 28 d after modeling,and the glucose tolerance test was performed 30 d after modeling.Results The extract of Branchlets roses from all the groups could decrease the blood glucose and improve the glucose tolerance,and showed a certain dose-effect relationship.In all the extracts,the alcohol extract had the best effect,but the effect was not as good as the positive control drug metformin hydrochloride group.Conclusion The extract of Branchlets roses can reduce the blood sugar content of diabetic mice,and improve the glucose tolerance.
ABSTRACT
OBJECTIVE:To study the vasodilatation effects of the alcohol extract from Uighur medicine Ziziphora clinopodioi-des(EEZ)on isolated rat thoracic aorta vessel rings. METHODS:Isolated rat thoracic aorta vessel rings were prepared. There was a group with intact vessel ring endothelium and a group with vessel ring endothelium removed in the test. After preshrinking the ves-sel rings with phenylephrine(PE),EEZ of 100,300,500,700,900 and 1 100 mg/L was added gradually,concentration-vasodila-tation curve was drawn and maximal vasodilatation rate (Emax) and median effective concentration (EC50) were calculated. For the group with vessel ring endothelium removed,after the vessel ring was pretreated with EEZ at EC50 in calcium-free solution or calci-um-free high-potassium solution,CaCl2 of 0.4,0.8,1.2,1.6,2.0 and 2.4 mmol/L was added gradually,and calcium concentra-tion-tension curve was drawn;following the pretreatment of the vessel ring with EEZ at EC50,1 μmol/L PE was added and shrink tension was recorded and vasoconstriction percentages was calculated. RESULTS:EEZ had vasodilatation effect on the vessel ring preshrunk with PE in a concentration and smooth muscle-dependent manner. The group with intact vessel ring endothelium and the group with vessel ring endothelium removed respectively had Emax of (58.18 ± 16.23)% and (73.54 ± 17.21)%,and EEZ EC50 of 773.27 mg/L. For calcium-free high-potassium solution,EEZ could cause the calcium ion-vasoconstriction curve to move to the right obviously;for calcium-free solution,EEZ could inhibit the vasoconstriction caused by PE. CONCLUSIONS:EEZ has vasodi-latation effects by a mechanism which may be related to inhibiting calcium influx and intracytoplasmic calcium release through the inhibition of voltage-dependent calcium channels(VDCCs),and thus interfering intracytoplasmic calcium ion balance.
ABSTRACT
Objective To investigate the relaxant effects of ethanol extract fromRhodiola crenulata (Hook.f.et Thoms.) H.Ohba in isolated rat thoracic aorta and its possible mechanisms.MethodsThe thoracic aortas from male Sprague-Dawley rats were isolated and cut into 3- to 4-mm-wide transverse rings, and the tension in endothelium-intact or endothelium-denuded aortic rings was recorded. The relaxant effects of ethanol extract fromRhodiola crenulata in various concentrations (100, 300, 500, 700, 900, and 1 100 mg/L) in aortic rings precontracted with phenylephrine (1 μmol/L) were observed. The effects of pretreatment with soluble guanylyl cyclase inhibitor ODQ (10 μmol/L) on the relaxant effects of ethanol extract fromRhodiola crenulata were observed. The effects of ethanol extract fromRhodiola crenulataon calcium-induced contractions in calcium-free high-potassium medium and phenylephrine-induced contractions in calcium-free medium were also observed.ResultsEthanol extract fromRhodiola crenulatashowed a concentration-dependent relaxation in aortic rings precontracted with phenylephrine. The maximal relaxations of ethanol extract fromRhodiola crenulataln endothelium-intact or endothelium-denuded aortic rings were 57.4% ± 21.81% and 60.51% ± 0.34%, respectively, with a half-maximal effective concentration of 1 062.88 mg/L. The relaxant effects of ethanol extract fromRhodiola crenulatawere not statistically inhibited by pretreatment with ODQ (P>0.05). Contractions of aortic rings resulted from phenylephrine-induced Ca2+ release from intracellular stores in calcium-free medium or high potassium-induced influx of Ca2+ in calcium-free high-potassium medium were significantly inhibited by ethanol extract fromRhodiola crenulata(allP<0.05).ConclusionEthanol extract fromRhodiola crenulatahas a concentration-dependent vasorelaxation, its mechanisms may be involved in blocking extracellular Ca2+ influx and intracellular Ca2+ release.