Effects Of Artificial Cordyceps Sinensis On The Expressions Of NF-κB And TGF-β1in The Cardiac Muscle Of STZ Induced Diabetic Rats

Background:The chronic complications of diabetes mellitus can involved in a variety of tissues and organs. Diabetic cardiomyopathy is a special type of myocardiopathy which is closely related to diabetes mellitus. The main pathological feature of diabetic cardiomyopathy is myocardial hypertrophy, severe myolysis and damage, hyaline degeneration, interstitial fibrosis and infiltration of several kinds of inflammatory cells, and the pathogenesis is still uncertain. Recent studies have revealed that immune response and low-level inflammation might play an important role in the diabetes mellitus and diabetic cardiomyopathy, and the changes on the expressions of inflammatory factor NF-κB and TGF-β1in the myscardial tissue may be involved in the occurrence of diabetic cardiomyopathy. Previous study showed that there may be multiorgans immune injury in streptozotocin induced diabetic rats, and immune damage can be relieved after treatment of immunosuppressant cyclosporine. Cyclsporine has a variety of toxic side effects, such as hepatic and renal toxicity, hypertension and so on, so we should positively find a therapeutic schedule which is effective and have lesser toxicity. Cordyceps sinensis cultivated by artficial fermentation is the succedaneum of the wild cordyceps sinensis, and they have the same effective constituent. Recent studies have shown that cordyceps sinensis and its mycelial cultures have a strong inhibitory effect on immune function.Object:In this study, type1diabetic rat model was established by intravenous injection of streptozocin. Cordyceps sinensis cultivated by artificial fermentation was applied to the diabetic rats. We observate the artificial fermented Cordyceps sinensis (CS) on the expressions of NF-κB and TGF-B1in the cardiac muscle of diabetetic rats.Methods:A total of ninety eight-week male SD rats were divided into two groups, ten were randomly selected as normal control group (group CON) and eighty as experimental group. The DM rat models were made by intravenous injection of STZ(45mg/kg). Then, they were randomly assigned into six groups, including control group (group CON), diabetes group (group DM), small-dose CS group (group L,0.6g/kg/d), medium-dose CS group (group M,2.5g/kg/d), large-dose CS group (group H,5g/kg/d), PIO treatment group (group PIO,4mg/kg/d). After drug intervention for8weeks, rats were killed and blood and urine samples were used to detect liver and kidney function, blood sugar, blood lipids and urinary albumin. The pathological and histological changes were observed by light microscope and the expressions of NF-κB and TGF-β1proteins and mRNA in the cardiac muscle were determined by using immunohistochemistry staining and reverse transcription-polymerase chain reaction method. The data were analyzed using one-factor analysis of variance.Results:1.The STZ-induced DM rat model were successfully established.2. The level of random blood glucose in every experimental group were significantly higher than group CON (P<0.05).One week after diabetic rat model was established, the weight of rats in every experimental group were observably lower than group CON (P<0.05). At the end of the test, the level of UAL、ALT、TC、TG in group DM were significantly higher than group CON (P<0.05); and the above mentioned indexs in every CS group were all significantly lower than those in group DM(P<0.05). The level of BUN in every experimental group was significantly higher than group CON (P<0.05), which could be decreased by CS (P<0.05). The level of creatinine was no significant difference between the groups (P<0.05).3.Myocardial hypertrophy, severe myolysis and damage, hyaline degeneration, interstitial fibrosis and infiltration of several kinds of inflammatory cells were observed by light microscope, and cardiac injury can be relieved by CS.4.The expressions of NF-κB and TGF-β1proteins and mRNA in the cardiac muscle of diabetic rats were significantly raised (P <0.05), which could be decreased by CS(P<0.05).Conclusions:STZ-induced DM rats had significantly cardiacal damage.The changes on the expressions of NF-κB and TGF-β1in the myscardial tissue may be involved in the occurrence of diabetic cardiomyopathy. CS by regulating the expressions of NF-κB and TGF-β1in the myocardium play its role on myocardial protection.