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Aim To discuss the effects and mechanism of Ganoderma lucidum polysaccharides and metformin on myocardial structure and hemodynamics in type 2 diabetic rats.Methods High fat diet combined with intraperitoneal injection of low dose streptozotocin 30 mg· kg -1 was applied to establish rat model of type 2 diabetes mellitus .The diabetic rats were randomly into normal control group ,diabetes group , ganoderma lucid-um polysaccharides group (600 mg· kg -1 ) , metformin group ( 600 mg · kg -1 ) , combination group ( ganoder-ma lucidum polysaccharides 300 mg · kg -1 +metform-in 300 mg· kg -1 ) .After 12 weeks′treatment,the lev-els of fasting serum glucose were determined and the hemodynamic parameters (LVSP,LVEDP,dp/dtmax,-dp/dtmax ) were determined.Collagen volume fraction ( CVF ) was detected by Van Gieson . Immunohisto-chemical method and Western blot were used to detect myocardial tissue MMP-2 protein expression .Results The fasting blood glucose was significantly decreased in the combined treatment group .Combined medication could significantly improve hemodynamic parameters in diabetic rats: reduced LVEP and raised LVEDP , dp/dtmax and -dp/dtmax .CVF was significantly decreased in combination group .The expression of MMP-2 in my-ocardial tissue was significantly inhibited .Conclusions The combination of Ganoderma lucidum polysaccha-ride and metformin can significantly improve the hemo-dynamic parameters in type 2 diabetic rats, and have a preventive effect on diabetic cardiomyopathy . The mechanism may be related to the down regulation of the expression of MMP-2.
ABSTRACT
Objective To study the effect of ganoderma lucidum polysaccharides combined with metformin on oxidative stress of type 2 diabetic rats. Methods SD rats were fed with high fat diet for 4 weeks and injected with streptozotocin (30 mg·kg-1 ) to produce type 2 diabetic model. The diabetic rats were randomly divided into diabetes model group, ganoderma lucidum polysaccharides group (600 mg·kg-1 ), metformin group (600 mg·kg-1 ), combination group (ganoderma lucidum polysaccharides 300 mg·kg-1+ metformin 300 mg·kg-1 ), After 12 weeks of treatment, the level of fasting blood glucose was determined, and the activity of superoxide dismutase ( SOD), malondialdehyde ( MDA), catalase ( CAT), glutathione peroxidase (GSH-Px), total cholesterol (TC) and triglyceride (TG) were detected. Results The levels of fasting blood glucose in the treatment groups were significantly lower than that in the diabetes model group (P<0. 01). Furthermore, fasting blood glucose in the combination group was significantly lower than that in ganoderma lucidum polysaccharides group and metformin group (P<0. 01). Compared with diabetes model group, serum TC and TG in the treatment groups were significantly lower (P<0. 05, P<0. 01). Serum TC and TG were significantly lower in the combination group than in ganoderma lucidum polysaccharides group and metformin group (P<0. 05, P<0. 01). Compared with diabetes model group, serum SOD levels in the treatment groups were significantly higher (P<0. 01). Compared with ganoderma lucidum polysaccharides group and metformin group, serum SOD levels in the combination group was significantly higher (P<0. 05). Compared with diabetes group, serum MDA levels in the treatment groups were significantly lower (P<0. 01). Serum MDA in the combination group was significantly lower than that in ganoderma lucidum polysaccharides group and metformin group ( P<0. 05). Compared with diabetes model group, serum CAT and GSH-Px in the treatment groups were significantly higher (P<0. 05, P<0. 01). Serum CAT and GSH-Px in the combination group were significantly higher than those in ganoderma lucidum polysaccharides group and metformin group (P<0. 05). Conclusion Ganoderma lucidum polysaccharides combined with metformin could effectively inhibit oxidantion stress in type 2 diabetic rats. The effect was better than ganoderma lucidum polysaccharides or metformin used alone. The possible mechanism may be related to increased activity of SOD, CAT, GSH-Px in vivo and regulation of dyslipidemia.
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Aim To study the effects of ganoderma lu-cidum polysaccharides and metformin on myocardial fi-brosis of type 2 diabetic rats and its mechanism. Methods SD rats were fed with high fat diet for 4 weeks, and then were injected with streptozotocin (30mg·kg-1 ) to replicate type 2 diabetic model. The diabetic rats were randomized into normal control group,diabetes group, ganoderma lucidum polysaccha-rides group ( 600 mg · kg-1 ) , metformin group ( 600 mg·kg-1 ) , and combination group( ganoderma lucid-um polysaccharides 300 mg·kg-1 +metformin 300 mg ·kg-1 ) . After 12 weeks’ treatment,the levels of fast-ing serum glucose were determined and the extent of myocardial fibrosis was observed by Picro-sirius red staining. The contents of AGEs in serum were deter-mined by fluorescence spectrophotometer. The activities of CAT and GSH-Px in myocardium were detected. Im-munohistochemical method and Western blot were used to detect myocardial tissue AGEs and CTGF protein ex-pression. Results Combination group could repress patho-proceeding of myocardial fibrosis efficiently, im-prove the activity of CAT and GSH-Px in myocardium and lower the concentration of AGEs in serum, as well as reduce the expression of AGEs and CTGF in myo-cardium. Conclusions Ganoderma lucidum polysac-charides and metformin could prevent myocardial fibro-sis. The possible mechanism may be related to repress-ing oxidative stress of myocardium, lowering serum AGEs and down regulating AGEs and CTGF of myocar-dium.
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Aim To investigate the effects and mecha of ganoderma lucidum polysaccharides and metformin on pathological changes of thoracic aorta in diabetic ratsandthemechanisms.Methods SDratswerefed with high fat diet for 4 weeks and injected with strepto-zotocin ( 30 mg · kg-1 ) to replicate type 2 diabetic model. The diabetic rats were randomly into diabetes group, ganoderma lucidum polysaccharides group ( 600 mg·kg-1 ) ,metformin group(600 mg·kg-1 ) ,combi-nation group ( ganoderma lucidum polysaccharides 300 mg· kg-1 + metformin 300 mg · kg-1 ) and normal control group. After 12 weeksˊ treatment, the levels of fasting serum glucose, the activity of catalase(CAT), glutathione peroxidase ( GSH-Px ) , total cholesterol (TC)and triglyceride(TG) in serum were detected. Pathological changes of thoracic aorta were observed by HE staining. Immunohistochemy and Western blot were used to detect thoracic aorta VEGF protein expression. Results Combination group could lower fasting serum glucose and blood fat significantly, meanwhile the ac-tivity of CAT and GSH-Px in serum was improved. The expression of VEGF in thoracic aorta was repressed. The result of HE staining suggested that the lipid de-posits in aortic endothelium in combination group were lessthanthoseinthemodelgroup.Conclusions Ga-noderma lucidum polysaccharides combined with met-formin has an obvious prevention on pathological chan-ges of thoracic aorta in diabetic rats. The possible mechanism may be related to repressing oxidative stress of thoracic aorta, regulating the dyslipidemia, and the down regulation of the expression of VEGF in thoracic aorta.