Contribution to the Study of Leaves: Azadirachta indica A. Juss (Meliaceae): Evaluation of the Antioxidant Activity

Abstract

In Africa, the use of plants for therapeutic purposes is an ancient practice. In recent years, much scientific work has been spent to the chemistry and toxicology of medicinal plants; there is a particular focus on natural antioxidants in relation to their various therapeutic properties. Therefore, the purpose of our study is to determine the antioxidant activity of aqueous and hydroethanol extracts from the leaves of Azadirachta indica A. Juss a plant known for its many pharmacological properties. The leaves of Azadirachta indica A. Juss were oven dried at 60 degrees for 24 hours and reduced to a fine powder. And, the powder is first extracted with distilled water to obtain the aqueous extract, then with a mixture of distilled water and ethanol 50/50 (v / v) to obtain the hydroethanol extract. Antioxidant activity was done through the DPPH test, the FRAP method and the fixation of the radical nitro-oxide (NO). The results revealed that for the DPPH test, the hydro-ethanol extract is more active (IC50=9.9±0.14 mcg/ml) compared to the activity of the water extract (IC50= 11±0.28 mcg/ml). For the FRAP method, we note absorbance of 0.56 and 1.05 respectively for water and hydro-ethanol extract at a concentration (166.7 µg/ml). On the other hand, for the inhibition of radical nitro-oxide (NO), activity is low for the two extracts of Azadirachta indica A. Juss respectively of 36.94±2.1% for the aqueous extract and 26.03±2.52% for the hydroethanol extract. This work highlights the antioxidant properties of Azadirachta indica A. Juss leaf extracts. Which give credit to certain data ethnopharmacological uses of Azadirachta indica A. Juss, but, study benefits must be carried out to support this use especially on toxicology.