ABSTRACT

Some herbal remedies are said to have antioxidant activity, reducing oxidative stress in cells and are therefore useful in the treatment of many diseases such as diabetes. This study consisted of the evaluation of the antioxidant activity in vitro and in vivo of an aqueous extract of Vernonia amygdalina (EAVa) in healthy rats and diabetic rats. The antioxidant power of EAVa, evaluated in vitro by assaying the anti-free radical activity by the 2,2-diphenyl-1-picrylhydrazyl test, shows that this extract (IC₅₀ = 26.07 ?g/mL), just like gallic acid (IC₅₀ = 2.13 ?g/mL), reduces this free radical, and therefore has an antioxidant power. The study of antioxidant activity in vivo on rats shows that EAVa, at a dose of 1200 mg/kg BW, strengthens the antioxidant balance in healthy animals and decreases the state of oxidative stress induced by the injection. streptozotocin (STZ). In fact, the injection of STZ disrupts the oxidative defense system in rats. In pathological changes caused by the presence of oxygen radicals, EAVa causes depletion of hepatic glutathione levels and increased levels of liver malondialdehyde, catalase and superoxide dismutase. EAVa thus maintains the balance of the antioxidant balance of liver cells, which allows it to be used against diseases associated with oxidative stress, and therefore the pathological state of diabetes. This antioxidant power of the aqueous extract of Vernonia amygdalina would justify the use of this plant in the prevention and treatment of diabetes and associated pathologies.

Keywords: Diabetes, antioxidant, Vernonia amygdalina, hepatic glutathione, catalase, malondialdehyde, superoxide dismutase.