In vitro alpha-amylase and alpha-glucosidase inhibitory activity and in vivo antidiabetic activity of Quercus coccifera (Oak tree) leaves extracts

Quercus species are group of plants known as oak which represent important genus of Fagaceae family. These species are widely distributed in Mediterranean countries. Many of those species used in traditional medicine to treat and prevent various human disorders such as diabetes. Exhausted extraction for Quercus coccifera leaves were carried out using n-hexane, chloroform, methanol, boiled water and microwaved water. Extracts were subjected to phytochemical screening, acute toxicity study, and in vitro and in vivo animal model to evaluate antidiabetic activity of the produced extracts. The highest in vitro activity against α-amylase and α-glucosidase activity was obtained from methanolic extract with an IC(50) of 0.17 and 0.38 µg/ml respectively and better than the positive control acarbose. While the rest of the extract was either with moderate or low activity. Similarly, in the in vivo study, methanolic extract with a concentration of 200 mg/kg/day was able to reduce the blood glucose level for the diabetic mice to 146.8 mg/dL with normal bodyweight and biochemical signs when compared to the normal mice group. While the rest of the extracts were either with moderate or low ability to maintain blood glucose level for diabetic mice with few signs of hepatic and renal toxicity and weight loss. All data were statistically significantly different with p-value of less than 0.001 at confidence interval of 95% with high variance homogeneity. In conclusion, methanolic plant leaves extract of Q. coccifera can possibly be used alone to control the elevation of blood glucose level with a renal and hepatic protective property.