ABSTRACT
OBJECTIVE:To optimize the purification technology of total alkaloids from the leaves of Nitraria sibirica with macroporous resin,and to evaluate its antioxidant activity. METHODS:Using the content of total alkaloids(by atropine sulfate)as index,static adsorption and analytical method were used to investigate the type of macroporous resin. Dynamic adsorption and analytical method were used to investigate the concentration of the sample solution,the pH of the sample solution,the flow rate of the sample solution,diameter-height ratio of column,sample capacity,the volume of elution water and volume fraction of elution solvent so as to optimize macroporous resin purification technology. Using vitamin C as positive control,scavenging capacity of total alkaloids to 1,1- diphenyl-2-diphenyl picryl hydrazinyl(DPPH)radicals was investigated to evaluate its antioxidant activity. RESULTS:The adsorption and desorption effects of HPD-450 macroporous resin on total alkaloids were the best. The optimal purification technology included the sample solution concentration 0.88 mg/mL,sample solution pH 6,sample solution flow rate 2 BV/h,diameter-height ratio of column 1∶8,sample capacity 5 BV,the volume of elution water 5 BV,elution solvent 30%ethanol. The content of total alkaloid was 16.94 mg/g,and IC50was (58.78 ± 3.00)μ g/mL by optimal purification technology. CONCLUSIONS:Optimized purification technology is stable and feasible,and can separate and purify total alkaloids from the leaves of N. sibirica. Purified total alkaloids display good antioxidant activities. The total alkaloids eluted with 30% ethanol show the strongest scavenging activity to DPPH radicals.
ABSTRACT
In traditional Chinese medicine, Nitraria sibirica Pall. (Nitrariaceae) is used to treat hypertension. This study determined the effects of the total alkaloids of the leaves of Nitraria sibirica (NSTA) on blood pressure and albuminuria in mice treated with angiotensin II and a high-salt diet (ANG/HS). Adult mice were divided into three groups: control; infused with angiotensin II and fed a diet containing 4% NaCl (ANG/HS; and ANG/HS plus injection of NSTA (1 mg·kg(-1)·d(-1), i.p.). After treatment of these regimens, daily water and food intake, kidney weight, blood pressure, urinary albumin excretion, renal concentrations of inflammatory markers, including soluble intercellular adhesion molecule-1 (sICAM-1) and monocyte chemoattractant protein-1 (MCP-1), and the expression of renal fibrosis markers were determined. Compared to the control group, the ANG/HS group had higher blood pressure and urinary albumin excretion. Treatment with NSTA in ANG/HS mice for three weeks significantly reduced blood pressure and urinary albumin excretion. ANG/HS treatment caused elevated levels of sICAM-1 and MCP-1, as well as increased fibrosis markers. Concurrent treatment with ANG/HS and NSTA attenuated the levels and expression of renal inflammatory and fibrosis markers. Treatment with NSTA effectively reduces hypertension-induced albuminuria through the reduction of renal inflammatory and fibrosis markers.