Black rice (Oryza sativa L. indica) bran ethanolic extract improved insulin levels and total antioxidant capacity in type 2 diabetic rats

Abstract

Type 2 Diabetes Mellitus (T2DM) showed a decrease in insulin levels and Total Antioxidant Capacity (TAC). Black rice (Oryza sativa L. indica) bran contained a phytochemical constituent that could ameliorate insulin levels and TAC in T2DM. This study aimed to determine the effect of black rice bran ethanolic extract on insulin levels and TAC in T2DM rats. The black rice bran ethanolic extract was prepared using the maceration method. It was a true experimental study with pre-post-test randomized control group design using forty-two male Wistar rats which were divided into six groups: healthy control, T2DM control (C-), T2DM + Metformin (C+) and T2DM + black rice bran ethanolic extract at the doses of 15 mg/200 g BW (T1), 30 mg/200 g BW (T2) and 60 mg/200 g BW (T3). The treatment was given oral gavage for 21 days. The results showed that there was a significant increase in insulin levels and TAC in treatment groups compared with the T2DM control (p<0.05). The improvement in TAC from the treatment of black rice bran ethanolic extract was the same as metformin. It could be concluded that black rice bran ethanolic extract increased insulin levels and TAC in T2DM rats with the most effective dose of 60 mg/200 g BW. The result indicated that black rice bran ethanolic extract at a dose of 60 mg/200 g BW was as effective as metformin in increasing TAC.