IN VITRO EVALUATION OF ANTIMICROBIAL ACTIVITIES OF ALOE VERA (L.) LEAF EXTRACT ON SELECTED HUMAN SKIN PATHOGENS

Aloe vera is one of a medicinal plant that used traditionally to treat a number of diseases. Hence, this study was conducted to evaluate antimicrobial activities of Aloe vera (L.) leaf and gel extract in different solvents like Ethanol, Petroleum ether and Distilled water (aqueous) against selected human skin pathogens namely; Streptococcus pyogenes, Streptococcus agalactiae and Aspergillus flavus. Disc diffusion method was used to achieve antimicrobial assay. Minimum inhibitory, bactericidal and fungicidal concentration of the extracts were determined by using broth dilution method. The current result showed the inhibitory activity of the gel extracts and the leaf did not inhibit the microbes. The best antimicrobial effect was recorded for petroleum ether gel extracts against Aspergillus flavus (19.7mm), Streptococcus pyogenes (16.2mm) and Streptococcus agalactiae (14 mm). Ethanol extracts showed moderate inhibition against Aspergillus flavus (15mm), Streptococcus pyogenes (13mm) and Streptococcus agalactiae (10.5mm). Aqueous extract showed lowest inhibitory activities with zone diameter of 13, 11 and 7.16mm against Aspergillus flavus, Streptococcus pyogenes and Streptococcus agalactiae respectively. The Minimum inhibitory concentration of both ethanol and petroleum ether extracts were 25mg/ml and 50mg/ml for aqueous extract against Aspergillus flavus and Streptococcus pyogenes. Streptococcus agalactiae was inhibited at 25, 50 and 75mg/ml of petroleum ether, ethanol and aqueous extracts respectively. The Minimum bactericidal concentration value of petroleum ether, ethanol and aqueous extracts for Streptococcus pyogenes were 25, 50, and 75mg/ml respectively. Streptococcus agalactiae was killed at 50, 75 and 100mg/ml of petroleum ether, ethanol, and aqueous extracts respectively. Aspergillus flavus showed Minimum fungicidal concentration at a concentration of 25mg/ml for both ethanol and petroleum ether and 75mg/ml for aqueous extracts. Over-all the results of this study showed the antimicrobial effectiveness of Aloe vera gel extract in different solvents against tested pathogens and the gel part is recommended in order to treat skin diseases caused by Aspergillus flavus, Streptococcus pyogenes and Streptococcus agalactiae rather than the fiber part of Aloe vera.