Effects And Relevant Mechanism Of Averrhoacarambola L. Root Extract On Diabetic Cardiomyopathy In Rats

Obejective:To investigate the potential effects and relevant mechanism of Averrhoa Carambola L. Root (Yangtaogen, YTG) extract on diabetic cardiomyopathy in rats.Methods:Male wistar rats were fed a high glucose and hyperlipid diet for 4 weeks. Then diabetes mellitus model was induced by a single injection of STZ. Diabetes mellitus rats were divided into the metformin group, the model group, the high-, medium-, low-dose YTG extract groups (0.6,0.3,0.15 g.kg-1.d-1). Another 8 rats were assigned to the normal group. The following indexes were determined at the end of the experiment:1. Examining the levels of fasting blood-glucose (FBG) and body weight (BW); the levels of serum of TG, LDLC, CHOL, CK, AST, CK-MB, LDH, HBDH were assessed by Hitachi 7600 automatic biochemical analyzer; the levels of MDA, NEFA, NO, T-SOD, NOS, Na+-k+-AT and Ca2+-ATP were measured using commercial kits.2. Taking myocardial tissue for HE staining and Masson staining; collagen Ⅰ and collagen Ⅲ, NF-κB, p-NF-κB and c-fos were evaluated by immunohistochemical staining.3. PKC-α, p-PKC-α, PKC-β2 and p-PKC-β2 were examined by Western blot.Results:1. The levels of FBG, TG, LDLC, CHOL, MDA, NEFA, CK, CK-MB, AST, LDH, HBDH were higher in the normal control group than those of the diabetic group (p<0.05); The levels of NO, BW, NOS, T-SOD, Na+-K+-ATP and Ca2+-ATP were lower in the normal control group than in the diabetic group (p<0.05). Compared with the diabetic group, the expressions of FBG, TG, LDLC, CHOL, MDA, NEFA, CK, CK-MB, AST, LDH, HBDH were decreased significantly in the H-ACLR group (p< 0.05), in contrast the expressions of NO, BW, NOS, T-SOD, Na+-K+-ATP and Ca2+-ATP were increased significantly (p<0.05).2. Compared with normal control group, the diabetic group’s cells which arranged disorderly and irregularly, are deformation and hypertrophy, at the same time, the myocardial tissue fibrosis seriously, and the expressions of NF-κB, p-NF-κB and c-fos increased significantly (p<0.05). Compared with diabetic group, relatively the H-ACLR group’s cells with no obvious netting, arranged orderly and around the low degree of fibrosis, at the same time, the expressions of NF-κB, p-NF-κB and c-fos decreased significantly (p<0.05).3. Compared with normal control group, the expressions of PKC-a, p-PKC-α, PKC-β2 and p-PKC-β2 increased significantly (p<0.05) in the diabetic group; compared with diabetic group, the expressions of PKC-a, p-PKC-α, PKC-β2 and p-PKC-β2 decreased significantly (p<0.05) in the H-ACLR group.Conclusion:YTG extract can decrease the level of FBG, TG, LDLC, CHOL, MDA, NEFA, CK, CK-MB, AST, LDH, HBDH, and increase the level of NO, BW, T-SOD, NOS, Na+-K+-ATP, Ca2+-ATP in diabetic cardiomyopathy rats meanwhile, reduce the expression of PKC-a, p-PKC-a, PKC-02, p-PKC-β2, NF-κB, p-NF-κB, c-fos. Therefore, YTG extract have protective effect on diabetic cardiomyopathy in rats, and the mechanism may be relative to inhibiting the expressions of PKC and related proteins.