Investigation of antidiabetic and antioxidant activities of Rhododendron luteum and Rhododendron caucasicum plant extracts

Diabetes Mellitus, in which insulin deficiency occurs, is a metabolic disease that continues with defects in fat and protein metabolism, including carbohydrate metabolism. It has been reported in various studies that the plant can be used against the treatment of diabetes and that these plants exhibit antidiabetic activity by lowering the glucose dose in the blood. In antidiabetic activity determination studies, inhibition test of alpha-amylase and alpha-glucosidase enzymes, which are involved in carbohydrate degradation mechanism, are performed. Antidiabetic and antioxidant properties of Rhododendron luteum and Rhododendron caucasicum plants were determined. Alpha-amylase and alpha-glucosidase enzyme inhibition spectrophotometric methods were determined for the determination of total polyphenolic content, total flavonoid content, iron reducing power, DPPH radical scavenging activity and antidiabetic activity of flower and leaf extracts of these plant species. The highest total polyphenol text of studied plant extracts was 439.42 ± 2.16 mg gallic acid equivalent in Rhododendron caucasicum leaf sample per gram sample, highest flavonoid content loaded in Rhododendron luteum flower extract as 11.25 ± 0.027 mg quercetin equivalent, the most DPPH Sweeping activity was determined as EC50: 9.16 ± 0.55 µg / mL in Rhododendron caucasicum leaf extract. The highest iron reducing power source was determined as 382.71 ± 3.17 mg trolox equivalent in Rhododendron caucasicum leaf extract. Rhododendron luteum flower extract was accepted as the highest activity with alpha-amylase inhibition activity IC50: 792.52 ± 10.49 µg / mL. In the determination of alpha-glucosidase enzyme inhibition activity, Rhododendron caucasicum leaf extract was determined as the highest activity inhibition activity with IC50: 235.59 ± 1.27 µg / mL. It was observed that Rhododendron luteum and Rhododendron caucasicum plants, which are perennial plants belonging to the Ericaceae family, have antioxidant properties and also inhibit alpha glucosidase and alpha amylase enzymes.