| Objectives:To investigate the inhibiting effect and mechanism of berberine on the Insulin-resistant- left ventricular hypertrophy (LVH) rats fed by enriched high fat-salt-fructose diet and its mechanism.Methods:(1) SD rats were randomly divided into control group and model group.Model rats were fed by enriched high fat-salt-fructose diet for 8 weeks.On the basis of animal blood pressure (BP>130mmHg),hypertensive rats were randomly divided into model control group, captopril group (25mg·kg-1), berberine high dose group(300 mg·kg-1) and low dose group (100 mg·kg-1).These rats were fed by enriched high fat-salt-fructose diet and treated by intragastric administration with drugs for 4 weeks.Blood pressure was determined at each 2 weekend. (2) At the end of drugs treatment,the VisualSonics Vevo770(?) ultrasonic imaging was used to detect the rats'heart condition. (3) Glucose tolerance and blood pressure of rats were measured at the 8th week,following by intragastric administration of drugs once a day for 4 weeks.Rats in model group and control group were administered with identical volume of 50% distilled water. (4) Weight and BP were measured at the end of 0,4th,8th,10th 12th weeks.Glucose tolerance test and the levels of serum lipid,serum glucose,fasting serum insulin,NO,NOS,MDA, TNF-α,TGF-β1, AngⅡ, ATPase, the activity of SOD and the body length were measured. The insulin-sensitivity index and obesity index were calculated at the end of the experiment.Whole heart and left ventricle was weighted respectively,and index of cardiac weight and myocardium proliferation was calculated.Hearts were collected to observe the histological changes.Results:(1) High and low dosage of berberine can significantly decrease blood pressure (P<0.01),whose effect was inferior to that of captopril. (2) High and low dosage of berberine can significantly improve glucose tolerance (P<0.01 or P<0.05).The levels of serum glucose and insulin were reduced (P<0.05) and insulin-sensitivity index was increased significantly by high dose of berberine notably. (3) Berberine (H and L) lowered the value of total cholesterol (TC) (P<0.01),triglyceride (TC) (P<0.01),LDL-C (P<0.01) and HDL-C (P<0.01) evidently. (4) The level of TNF-a was significantly decreased by high and low dose of berberine (P<0.01). (5) The level of MDA (P<0.05) was significantly decreased by high and low dose of berberine; and the activity of SOD (P<0.01) was increased obviously. (6) The level of angiotensinllwas markedly decreased by high and dose of berberine,and the level of TGF-β1 was also affected evidently. (7) Berberine did not exert an effect on weight and index of cardiac weight significantly. (8) The high lipid injured cells of heart were markedly protected by berberine and captopril.Conclusions:Berberine possesses the effects of decreasing the baseline levels of serum glucose,blood pressure and serum lipid,and improves glucose tolerance and insulin sensitivity in model rats of insulin resistance.Berberine can decrease the damaged degree of cardiovascular system and hepatocyte in IRS.The acting mechanism of Berberine may be concerned with the decreased levels of oxygen-derived free radicals and TNF-a and the changes of renin-angiotensin system.
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