Protective Effect Of Berberine On Cardiac Hypertrophy Induced By L-thyroxine In Rats

Cardiac hypertrophy is a common complication of clinical cardiovascular diseases, and one of fatal factors of cardiovascular diseases' incidences and mortalities. So it is very beneficial to prevent cardiac hypertrophy for the people. Cardiac hypertrophy induced by L-thyroxine in rats is an adequate model to study the hypertrophic cadiomyopathy. To explore the medicine of preventing the occurring of cardiac hypertrophy, we established a cardiac hypertrophy model induced by ip L-thyroxine 0.5mg·kg^-1 · d^-1 × 10d. The SD rats were divided into three groups: 1) control( sodium chloride); 2) L-Thy; 3)L-Thy + Berberine, po 30 mg · kg ^-1 · d^-1 × 10d. We measured cardiac hypertrophy index (HW/BW, LVW/BW, RVW/BW), cardiomyocyte diameter, collagen volume fraction, myocardial pathological changes, Na⁺-K⁺-ATPase activity, Ca²⁺-ATPase activity, the cardiac nitric oxide (NO) content, the CaN activity and the expression of ICAM-1, bax, bcl-2 in cardiomycyte. To study the effect of berberine on cardiac hypertrophy induced by L-Thy in rats.RESULTS: In the L-Thy group, HW/BW, LVW/BW, RVW/BW were respectively increased into 4.5089mg/g, 3.0726mg/g, 1.0313mg/g, Compared with the Control group in which HW/BW, LVW/BW, RVW/BW wererespectively 3.5452mg/g, 2.4392mg/g, 0.7352mg/g, the differences are very significant (p<0.01) ; Cardiomyocyte diameter and collagen volume fraction were increased remarkably (pO.001) , and under electron microscope, expanding of sarcoplasmic reticulum, oedema in mitochondrion and nucleus necrosis were found in the L-Thy group; However, Na+-K+-ATPase activity, Ca + -ATPase activity and NO content were respectively decreased remarkably into 0.3661 y molPi/mg.h, 0.4771 u molPi/mg.h, 0.2401 u mol/g, compared with those of the control group which were 0.8139 V- molPi/mg.h, 0.9107 umolPi/mg.h, 0.4201 u mol/g, the differences are very notable ( p<0.01) ; But the CaN activity was increased into 1.8372 umolPi/mg.h, compared with that of the control group which was 0.6425 u molPi/mg.h, the difference is very notable ( p<0.01 ) . After treating with berberine, compared with those of the L-Thy group, HW/BW, LVW/BW both were decreased notably (p<0.01) ^specially, RVW/BW was decreased into the normal level; Cardiomyocyte diameter and collagen volume fraction were decreased remarkably (pO.001) ; And there were not obviously pathological changes in myocardial cells; Na+-K+-ATPase activity, Ca2+-ATPase activity and NO content were however increased notably (p<0.01) ; But CaN activity was decreased remarkably (p<0.01) ; In hypertrophic group, the expressions of ICAM-1 and Bax in cardiomycytes were increased remarkably (pO.001) , but after treating with berberine, the expressions were decreased, and compared with the expressions in hypertrophic group, the differences were notable (pO.001); But the expression of bcl-2 in hypertrophic cardiomycyte were decreased (pO.001) , after treating with berberine, the expression were increased remarkably( p<0.001).CONCLUSION: Berberine can weaken the hypertrophic levels of the left and right ventricles, decrease the collagen content, increase the activity of myocardial Sarco/Endoplasmic Ca2+-ATPase (SERCA), myocardial Na+-K+ -ATPase activity, NO content and the expression of bcl-2 protein, and decrease the CaN activity and the expression of ICAM-1 and bax protein. So berberine can exerts an anti-hypertrophy effect through CaN pathway, NO pathway, and effects on the expression of ICAM-1, the activity of myocardial SERCA and myocardial Na+-K+-ATPase activity.