Evaluation of Antioxidant, Antimicrobial and Cytotoxic Activity of the Bark of Alstonia scholaris

Alstonia scholaris (Family: Apocynaceae) has been investigated for the assessment of the biological activities. The bark of Alstonia Scholaris were extracted with pet ether, chloroform, carbon tetrachloride and methanol extract to afford 0.9 g, 0.8 g, 0.7 g, 3 g respectively for the test. We used crude pet ether, chloroform and carbon tetrachloride extract of the plant for the screening of antimicrobial activity against some selected organisms as bacteria and fungi by disc diffusion method. Out of all samples, chloroform and carbon tetrachloride extract showed strongest zone of inhibition and spectrum of activity. In vitro antioxidant activity of the extract of Alstonia scholaris was estimated by using DPPH free radical scavenging assay method. In DPPH free radical scavenging assay IC50 value of methanolic extract of Alstonia scholaris was found to be 39 g/ml which indicates mild to moderate antioxidant activity while Ascorbic acid was the standard drug. In the bioassay of brine shrimp lethality, the methanol extract showed an average of LC50 0.91 μg/ml. This indicated that the cytotoxicity exhibited by methanolic extract was very significant.