Phytochemical analysis, antimicrobial and antioxidant activities of Aidia borneensis leaf extracts

Abstract

Pharmacological evaluation of Aidia borneensis has not been widely reported yet. This study aimed to evaluate its phytochemical constituents and its antimicrobial and antioxidant activities. Phytochemical compositions of Soxhlet-extracted methanol extract and ultrasonic-extracted aqueous extract were determined by gas chromatography mass spectrometry analysis. Antibacterial and antifungal activities were evaluated by the agar-well diffusion method, and antioxidant activities were determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Methanol extract was predominantly characterized by coumaran (21.12%) and palmitic acid (6.34%), and aqueous extract by catechol (15.48%) and coumaran (9.13%). Concentration-dependent antibacterial activities of methanol extract were observed against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, whereas aqueous extract only showed a growth-inhibiting effect against E. coli. Methanol extract also exhibited antifungal activities against Candida albicans and Saccharomyces cerevisiae but not against Aspergillus brasiliensis. No antifungal activity was shown by the aqueous extract. Aqueous extract revealed significantly higher radical scavenging activity, hence, low IC50 value (6.0 µg/ml), compared to methanol extract (14.6 µg/ml) and the reference standard, Trolox (9.1 µg/ml). This study provides scientific support on the medicinal properties of A. borneensis in terms of its phytochemical constituents and its antimicrobial and antioxidant activities.