Phtyochemical screening and comparative study of antimicrobial activity of Aloe vera various extracts

The phytochemical screening and comparative study of antimicrobial activity of Aloe vera extracts was carried out. The phytochemical screening revealed the following metabolites: saponins, alkaloids, glycosides, tannins, protein, and flavonoids. While cardiac glyocosides and steroids were absent. The antimicrobial activities of the gel in 10% DMSO, methanol and aqueous extracts of green rind and leaf pulp were carried against some pathogenic clinical isolates, namely, Bacillus subtilis, Staphylococcus aureus, Proteus mirabilis and Candida albicans. The DMSO extract of the gel and the methanol extract of the green rind showed greater potency against tested microorganisms in the order B. Subtilis> S. aureus> C. albicans and S. aureus>C. albicans>B. subtilis>P. mirabilis respectively with different zones of inhibition ranging from 18 to 35 mm gel, 15 to 18 mm for leaf pulp methanol, 20 to 32 mm green rind methanol, also 12 to 14 mm and 14 to 23 mm for leaf pulp aqueous and green rind aqueous respectively. The minimum inhibitory concentration (MIC) of the extracts against organisms ranged from 6.25 to 25 mg/ml while the minimum bactericidal concentration (MBC) was within the range of 12.5 to 50 mg/ml. The study revealed that the green rind methanol extract and gel have greater medicinal potential against B. subtilis. © 2011 Academic Journals.