The anti-diabetic effects of betanin in streptozotocin-induced diabetic rats through modulating AMPK/SIRT1/NF-kappa B signaling pathway

Background: In the last few years, the effects of bioactive food components have received much attention because of their beneficial effects including decreasing inflammation, scavenging free radicals, and regulating cell signaling pathways. Betanin as a potent antioxidant has been previously reported to exhibit anti diabetic effects. The present study aimed to evaluate the effects of betanin on glycemic control, lipid profile, hepatic function tests, as well as the gene expression levels of 5 ' adenosine monophosphate-activated protein kinase (AMPK), sirtuin-1 (SIRT1), and nuclear factor kappa B (NF-kappa B) in streptozocin (STZ) induced diabetic rats. Methods: Diabetes was induced in male Sprague-Dawley rats by intraperitoneal administration of STZ. Different doses of betanin (10, 20 and 40 mg/kg.b.w) was administered to diabetic rats for 28 days. Fasting blood glucose and serum insulin were measured. The histopathology of liver and pancreas tissue evaluated. Real-time PCR was performed to assess gene expression levels. Results: Treatment of diabetic rats with betanin (10 and 20 mg/kg.b.w) reduced FBG levels compared to the control diabetic rats (P < 0.001). Betanin at the dose of 20 mg/kg.b.w was most effective in increasing serum insulin levels (P < 0.001) improving glucose tolerance test (GTT) as well as improvement in lipid profile and liver enzymes levels. According to histopathologic assay, different damages induced by STZ to liver and pancreas tissues was largely eliminated by treatment with 10 and 20 mg/kg.b.w of betanin. Betanin also significantly upregulated the AMPK and SIRT1 and downregulated the NF-kappa B mRNA expression compared to the diabetic control rats (P < 0.05). Conclusion: Betanin could modulate AMPK/SIRT1/NF-kappa B signaling pathway and this may be one of its anti-diabetic molecular mechanisms.