Evaluation of Total Phenolic Contents and in vitro Antioxidant Activity of Prosopis africana Leaf Extracts

Abstract

Prosopis africana belongs to the Family Leguminoceae, is used in ethnomedicine to treat different ailments including, diarrhea, bacillary dysentery, malaria, male sterility and Cancer. Antioxidants from natural sources are effective in the treatment of many diseases including garthritis, atherosclerosis, ischemia and reperfusion injury of many tissues, gastritis, diabetics, central nervous system injury, acquired immunodeficiency syndrome (AIDS) and cancer. This work was aimed at extracting and screening the extracts for, total phenolic contents and antioxidant activity of the Prosopis africana. The plant material was extracted with absolute ethanol to obtained the crude ethanol extract which was macerated with different solvents in increasing order of polarity to obtained different fractions such as n-hexane, chloroform, ethylacetate and methanol. The results of total phenolic contents of the extract shows that methanol fraction (PA-05) showed the highest amount of phenolic compounds with the 285.92 ±0.22 mg/ml of GAE, followed by ethylacetate (PA-04) with the value of 268.49 ±0.12 mg/ml of GAE. n-Hexane fraction (PA-02) showed the lowest amounts of phenolic compounds. The results of antioxidant activity on the other hand, shows that methanol fraction (PA-05) was having the highest IC₅₀ value of 6.39 µg/ml, competing with Ascorbic acid (positive control) with the IC₅₀ value of 6.24 µg/ml. But, n-hexane fraction (PA-02) has the lowest IC₅₀ value of 81.75 µg/ml, followed by chloroform fraction having the IC₅₀ value of 76.22 µg/ml. Generally, the methanol fraction was found to be very effective in both phenolic contents and antioxidant activity among other fractions and the crude extracts.