Philippine E-Journals

Antibacterial Activity of the Semi-Purified Fractions of Jatropha curcas Leaves Extract in Combination with Gentamicin against Staphylococcus aureus

Joyce Ann Arellano | Ma. Nievel Adio | Christian Andrew Almalbis | Celine Altamia | Junila Lou Amboboyog | Jessa Mae Arellano | Pauline Arellano | Fernan Brian Balili | Melissa June Paderog

 

Abstract:

Antibiotic resistance is an increasing threat to public health. Urgent action is needed to halt the development of resistance, and to accelerate new and improved treatments for bacterial infection. The extracts of many Jatropha species including Jatropha curcas have shown to display potent cytotoxic, anti-tumor and antimicrobial activities in different assays. Thus, this study was conducted to identify the antibacterial activity of the bioactive band of the semi-purified fraction from hexane, methanol, and water sub-extracts of J. curcas leaves against Staphylococcus aureus ATCC 25923 in combination with gentamicin. Secondary plant metabolites of the mature leaves of J. curcas were extracted using hexane and underwent partitioning with water and methanol. The antibacterial activity of the methanol and hexane sub-extracts was investigated using microbroth susceptibility assay and confirmed using TLC agar overlay method. Thin layer chromatography profiling was then performed, and presence of antibacterial plant metabolites were screened using TLC color forming reagents. The antibacterial activity of the phytochemicals was evaluated through bioautography against the test pathogen. Pencil column chromatography of the methanol sub-extract was further performed to separate the bioactive band and it was combined with gentamicin to investigate if the sub-extract enhanced the activity of the antibiotic. Results of this study suggests that J. curcas methanolic sub-extract contain phenolic antibacterial compounds that are highly polar in nature and are UV active at 254 and 365 nm wavelengths. Pencil column chromatography resulted to 15 methanolic PC fractions in which fractions 13, 13- DCM, and 13-methanol contains the bioactive band. Microbroth susceptibility screening of PC fractions 13- DCM and 13-methanol in combination with gentamicin, suggests that the fractions either enhance or decrease the activity of the antibiotic depending on concentration. Hence, this study concluded that J. curcas leaves is a potential source of antibacterial compounds that may be used as single agent, however, should not be used in combination with gentamicin drug.