Abstract

Neelofar Khanam*, G. K. Sharma

ABSTRACT

The present study evaluates the antibacterial potential of Aloe vera L. whole leaf and inner gel extracts derived from both in vivo grown and in vitro regenerated plants. A range of clinically significant bacterial strains, including Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhi, Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumonia, Bacillus subtilis, and Bacillus cereus, were selected to assess antimicrobial efficacy. Various solvent extracts (n-hexane, chloroform, ethyl acetate, methanol, and aqueous) were prepared and tested using the disc diffusion method, followed by determination of minimum inhibitory concentrations (MIC) through agar dilution. The results demonstrated that most solvent extracts exhibited significant antibacterial activity against the tested pathogens, whereas aqueous extracts showed no inhibitory effect. Among all extracts, ethyl acetate fractions displayed the highest antibacterial efficacy, producing larger zones of inhibition and lower MIC values, followed by methanol, chloroform, and n-hexane extracts. Notably, in vitro regenerated plant extracts, particularly inner gel, showed greater antibacterial activity compared to in vivo samples. Pseudomonas aeruginosa exhibited resistance to most extracts, while other pathogens showed varying degrees of sensitivity. The enhanced antibacterial activity may be attributed to the presence of bioactive phytochemicals such as flavonoids, alkaloids, phenolics, and glycosides. The findings indicate that Aloe vera L. possesses broad-spectrum antibacterial properties effective against both Gram-positive and Gram-negative bacteria. This study highlights the potential of Aloe vera L. as a natural source for developing alternative antimicrobial agents, particularly in the context of increasing antibiotic resistance.