Determination of antibacterial and antioxidant activity of Spondias mombin stem bark extracts

Abstract

Plants have been used throughout history in traditional medicine, and remain a promising source of pharmaceuticals. Spondias mombin, an ethnomedicinal plant recognized for its efficacy in treating various diseases, is also the source of numerous therapeutic agents. Previous studies on the bark of this plant revealed its abundance of beneficial compounds along with several pharmacological properties. Although widely available in Bangladesh, limited scientific studies have been reported on this plant. Therefore, this thesis aims to investigate the antibacterial and antioxidant activity of locally sourced S. mombin stem bark extracts. The ethanolic bark extract was subjected to solvent partitioning with chloroform, ethyl acetate, hexane, and methanol. Then thin-layer chromatography, Kirby-Bauer disk diffusion test, and DPPH free radical scavenging assay were conducted on the solvent partitions. The ethyl acetate partition extract exhibited mild antibacterial activity against Acinetobacter baumanni ATCC 19606, E. coli ATCC 25922, Klebsiella pneumonia and Salmonella typhi. Additionally, all four partition extracts displayed very strong antioxidant activities, with the ethyl acetate extract demonstrating the strongest activity and the lowest IC50 value of 4.74 μg/mL. Visualization of the TLC plates showed the presence of several compounds in the chloroform, hexane, and ethyl acetate partitions which may be of medicinal value. Therefore, these findings underscore the importance of further research into this plant for therapeutic purposes.