Beta-carotene ameliorates diabetic nephropathy in rats: involvement of AMPK/SIRT1/autophagy pathway.

Objective: This study aimed to demonstrate the protective effect of beta-carotene against STZ-induced DN in rats and explore the possible underlying mechanisms that may have mediated such condition.

Material and methods: Wistar rats were allocated into four groups. Normal group received distilled water for 3 weeks. The other three groups were rendered diabetic by an intraperitoneal dose of STZ (50 mg/kg), 48 h later, group 2: received the vehicle and served as control, groups (3 &4) received orally beta-carotene in doses of 10 and 20 mg/kg, respectively for 3 weeks. Then serum and renal tissue were collected for biochemical, molecular, immunohistopathological, and histopathological examination.

Results: Beta-carotene ameliorated the reduction in body weight, reduced blood glucose, elevated serum insulin, reduced blood urea nitrogen, and serum creatinine levels. Beta-carotene elevated phosphorylated 5' adenosine monophosphate-activated protein kinase (p-AMPK)/AMPK, alleviated phosphorylated mammalian target of rapamycin (p-mTOR)/mTOR, reduced interleukin 1 beta (IL-1β), increased Beclin 1, LC3II/LC3I, and reduced p62 renal contents. Moreover, it elevated renal SIRT1 gene expression and reduced renal tumor necrosis factor-alpha (TNF-α) and caspase-3 protein expressions.

Conclusion: Beta-carotene exerted renoprotective effect against STZ-induced DN and histopathological alterations through alleviating hyperglycemia, attenuating inflammation, activating AMPK/SIRT1/autophagy pathway, and combating apoptosis.