IN VITRO ANTIMICROBIAL ACTIVITY AND PHYTOCHEMICAL SCREENING OF ALOE VERA LINN.

The in vitro antimicrobial activity of aqueous and methanolic extracts of the roots of Aloe vera was investigated against Bacillus cereus, Escherichia coli, Pseudomonas aerugenosa and Enterobacter aerogens using the agar diffusion method. The methanol extract inhibited the growth of all the presently investigated bacteria with zone of inhibition between 7 - 20 mm at 100 µg/ml whereas, water extract exhibited zone of inhibition ranging from 2-4mm at the concentration of 100 µg/ml. The minimum inhibitory concentration (MIC) of the methanol extract was between 10 and 25 µg/ml while that of aqueous extract ranged from 25 to 60 µg/ml. The minimum bactericidal concentration (MBC) for methanol extract ranged between 20 and 50 µg/ml. The MBC of aqueous extract ranged from 50 to 120 µg/ml. Preliminary phytochemical analyses showed that the extracts contain flavonoids, terpenoids, tannins, saponins, reducing sugars and anthraquinones.