Analysis of Chemical Composition and Biological Activities of Aloe vera Rind Extract Obtained by Ultrasound-Assisted...

Ultrasound-assisted extraction of Aloe vera rind yielded significantly more extract (ARE) than conventional maceration, and was therefore selected for in-depth analysis. GC-MS profiling identified thieno\[2,3-c]furan-3-carbonitrile, 2-amino-4,6-dihydro-4,4,6,6-tetramethyl as the predominant compound (49.2%). FTIR spectroscopy confirmed functional groups characteristic of phenolic and flavonoid bioactives. Quantification revealed total phenolic content of 16.88 mg gallic acid equivalents (GAE)/g and total flavonoid content of 32.08 mg quercetin equivalents (QE)/g. Antioxidant efficacy was demonstrated via DPPH radical-scavenging and FRAP assays, indicating strong free-radical neutralization and reducing power. Antimicrobial activity assessed by disk diffusion and well diffusion methods showed potent inhibition of Staphylococcus aureus and Listeria innocua, with minimum inhibitory and bactericidal concentrations (MIC/MBC) of 18.75 mg/mL. Pseudomonas aeruginosa was least sensitive (MIC = 75 mg/mL). SEM examination of ARE-treated S. aureus and Escherichia coli revealed pronounced cell-wall disruption and nucleic acid leakage. Additionally, cytotoxicity assays against cancer cell lines yielded an IC50 of 27.37 mg/mL, demonstrating moderate anticancer potential. Overall, ultrasound extraction proves an efficient method for isolating bioactive compounds from Aloe vera rind. The resulting ARE exhibits notable antioxidant, antimicrobial, and anticancer activities, underscoring its promise for development in pharmaceutical formulations and functional food applications.