In Vitro Anti-Diabetic and Anti-Oxidant Activities of Geum Species from Iran

Medicinal plants have been considered as important sources of potent free radical scavengers as well as digestive enzymes inhibitors. Several plants are used in traditional and modern medicine for their biological properties such as anti-oxidant and anti-diabetic activity. The aim of this study was to investigate the anti-diabetic and anti-oxidant activities of roots and aerial parts from three of five native Iranian herbaceaous Geum species, including G. iranicum, G. kokanicum and G. urbanum. The Geum species and their bio-active substances are getting a lot of attention due to their various biological effects, such as anti-oxidant, anti-diabetic, anti-tumor and anti-microbial activities.

The anti-diabetic activity of the Geum species was evaluated via α-glucosidase and α-amylase inhibition assays. The anti-oxidant effect was analyzed using the free radical scavenging method and the total phenolics content was determined via a colorimetric assay.

Based on our study, all the examined species revealed moderate to high anti-diabetic and anti-oxidant effects. Geum kokanicum roots showed the highest α-glucosidase inhibition activity (91.0%±1.7) at the concentration of 500 µg/mL and DPPH radical scavenging potential (IC50: 11.6±0.5 μg/mL).

The results demonstrated in-vitro anti-diabetic property of G. kokanicum, so detailed investigation to isolate the active compounds is suggested.