Tag Archives: PPARγ

L-carnitine administration effects on AMPK, APPL1 and PPARγ genes expression in the liver and serum adiponectin levels and HOMA-IR in type 2 diabetes rat model induced by STZ and nicotinamide

B. Shahouzehi1,2, H. Fallah3, Y. Masoumi-Ardakani4*

1Student Research Committee, Kerman University of Medical Sciences, Kerman, Iran;
2Cardiovascular Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran;
3Department of Biochemistry, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran;
4Physiology Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran;
*e-mail: ymab125@gmail.com

Received: 18 January 2020; Accepted: 25 June 2020

Diabetes is a chronic disease and a public health problem globally. L-Carnitine is synthesized in the liver, promotes fatty acids oxidation and currently is used as a supplement against weight gain. Carnitine level is found to be reduced in diabetic patients and to be beneficial as a supplement at diabetes, but the mechanisms­ of this effect is not fully understood. Therefore, we evaluated the oral L-carnitine supplementation on expression of AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor gamma (PPARγ), adaptor protein APPL1 genes in the liver and insulin and adiponectin levels  in the serum of diabetic rats. Rats were randomly divided into three groups (n = 8) as follow: group 1 – control without any treatment, group 2 – diabetic control rats which received STZ (45 mg/kg) and nicotinamide (200 mg/kg) by i.p. injection, group 3 – diabetic rats which received 600 mg/kg/day carnitine orally for 35 days. It was found that L-carnitine supplementation reduced the level of fasting glucose compared to that in control and diabetic groups (P = 0.001,  P = 0.0001 respectively) and increased adiponectin level compared to diabetic nontreated rats (P = 0.0001). Homeostasis model assessment of insulin resistance (HOMA-IR) was significantly increased in the diabetic group and reduced in the group that received L-carnitine. These promising beneficial effect of L-carnitine on the type 2 diabetes in rats’ model was shown to be conducted through the up-regulation of AMPK, PPARγ and APPL1 genes expression in the liver and elevation of serum adiponectin level.

Effect of L-carnitine administration on serum insulin and adiponectin levels, and AMPK, APPL1 and PPARγ gene expression in STZ-induced diabetic rat liver

B. Shahouzehi1, K. Barkhordari2, S. Aminizadeh3, Y. Masoumi-Ardakani4*

1Cardiovascular Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Iran;
e-mail: bshahouzehi@yahoo.com;
2Department of Virology, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran;
e-mail: khabatzanbil@gmail.com;
3Physiology Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Iran;
e-mail: soheilaminizadeh@gmail.com;
4Physiology Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Iran;
*e-mail: ymab125@yahoo.com

Diabetes is considered as a metabolic disease in which insulin secretion and functions are disturbed and characterized by hyperglycemia. L-carnitine is synthesized in most mammals and plays critical role in fatty acid oxidation and energy production. Data about the L-carnitine hypoglycemic effects are controversial. We evaluated long-term oral L-carnitine administration effects on blood glucose, insulin and adiponectin levels, as well as expression of AMPK, APPL1 and PPARγ genes in liver of STZ-induced diabetic rats. Group 1 (control), did not receive any treatment, group 2 received 50 mg/kg STZ by i.p injection, group 3 received single dose of 50 mg/kg STZ by i.p injection and also 600 mg/kg/day L-carnitine orally for 5 weeks. Our results showed that L-carnitine long-term oral supplementation significantly reduced blood glucose and normalized insulin levels in diabetic rats. Also, we found that L-carnitine significantly increased AMPK and APPL1 expression, and showed a mild elevation of PPARγ expression. In sum, we suggest that long-term L-carnitine supplementation has beneficial effects on diabetic rats which showed hypoglycemic effects. Probably the beneficial effects of L-carnitine are contributed to the upregulation of insulin sensitizers such as AMPK and adiponectin.