Diosmin ameliorates inflammation, insulin resistance, and fibrosis in an experimental model of non-alcoholic steatohepatitis in rats

Non-alcoholic steatohepatitis (NASH) is becoming of increasing significance due to its growing global prevalence and risk of progression to end-stage liver disease. This study was carried out to investigate the potential anti-inflammatory, insulin sensitizing, and antifibrotic effects of diosmin in an experimental model of NASH induced in rats using high-fat diet (HFD) and 30 mg/kg streptozotocin (STZ). Diosmin was administered orally at dose of 100 mg/kg for 8 weeks. Stained tissue sections were examined for histopathological signs of NASH, collagen deposition, and alpha smooth muscle actin (α-SMA) expression. In addition, insulin resistance, dyslipidemia, inflammation, and fibrosis markers were assessed. HFD/STZ successfully induced different NASH features such as insulin resistance seen by elevated fasting blood glucose levels and homeostasis model assessment for insulin resistance. Moreover, induced rats demonstrated dyslipidemia, a significant elevation in tumor necrosis factor alpha (TNF-α) and interleukin-6 levels, and an imbalance in the oxidative status of the liver. Those events altogether precipitated initiation of liver fibrosis as confirmed by elevated transforming growth factor beta (TGF-β) levels. Treatment with diosmin demonstrated multiple beneficial effects as it significantly ameliorated histopathological NASH findings, lowered TNF-α, interleukin-6, and malondialdehyde levels, improved lipid and glucose metabolism, and lowered hepatic TGF-β, α-SMA, and collagen content compared to untreated rats. The present study represents a drug repositioning scenario as diosmin is widely used for management of blood vessel disorders and is known to be well tolerated. This encourages the extension of our study to the clinical setting to explore diosmin effects in NASH patients.

Keywords: Diosmin; Fibrosis; High-Fat Diet; Insulin Resistance; Non-alcoholic Steatohepatitis; Streptozotocin.