Modulation of oxidative/nitrosative stress and mitochondrial protective effect of Semecarpus anacardium in diabetic rats.

Objectives: Oxidative and nitrosative stress play an important role in the complications of diabetes mellitus. Free radicals are produced when there is an electron leak in the mito-chondria and a change in the mitochondrial membrane potential. The present study was undertaken to investigate the role of Semecarpus anacardium in protecting the mito-chondria by modulating the production of reactive oxygen species and reactive nitrogen species in diabetic rats.

Methods: Diabetes was induced using streptozotocin at a dose of 50 mg/kg body weight and, starting 3 days after the induction, Semecarpus anacardium nut milk extract was administered for 21 days. The same duration of study was used for control, diabetes-induced and drug control groups, together with a group treated with metformin. After the experimental period, the animals were sacrificed and the levels of superoxide, hydrogen peroxide, nitrate and nitrite were estimated. Changes in mitochondrial membrane potential, intracellular reactive oxygen species and intracellular calcium were also determined. Confocal laser microscopic images were taken for mitochondria isolated from the liver and kidneys.

Key Findings: The results of the study revealed that Semecarpus anacardium was able to decrease the production of reactive oxygen and nitrogen species, and reverse the changes in mitochondrial membrane potential and the influx of calcium into the mitochondria.

Conclusions: The mitochondrial protective effect may be mediated by scavenging of free radicals and complexing of metal ions by virtue of the antioxidative effect of Semecarpus anacardium.