Antidiabetic and anti-hypercholesterolemic effects of flavonoid-rich fractions of Rosmarinus officinalis in streptozotocin-induced diabetes in mice

The aim of the present study was to evaluate the antidiabetic and anti-hypercholesterolemic action of flavonoid-rich fractions of Rosmarinus officinalis L. in streptozotocin-induced diabetic mice. Two fractions were tested, n -butanol (BUT) and diethyl ether (DE) fractions. Both fractions showed a significant decrease in glucose level at a dose of 400 mg/kg body weight, especially the DE fraction, where plasma glucose levels decreased significantly ( p < 0.001) reaching 60.38% as maximum glucose level reduction. BUT fraction reduced significantly ( p < 0.05) the plasma glucose level with 51.93% as maximum glucose level reduction. Similarly, BUT fraction at 400 mg/kg decreased significantly ( p < 0.01) the total cholesterol level with 51.85% of reduction and low-density lipoprotein cholesterol with 45.13% of reduction ( p < 0.05). The histopathological study of the pancreas showed that both fractions regenerated the pancreatic β-cells and increased the islets mass. In conclusion, the DE fraction exhibited a potent antidiabetic effect, while BUT fraction showed both antidiabetic and anti-hypercholesterolemic activities.