In Vitro Antimicrobial Activity of the Oil Obtained From the Seeds of Citrullus Colocynthis (Bitter Apple)

Abstract The phytochemical and antimicrobial analysis of the crude extract of oil gotten from the seeds of Citrullus colocynthis were carried out using standard methods. The result of the photochemical screening showed that the oil extract of Citrullus colocynthis contains alkaloids, flavonoids, saponins, tannins, terpenoids and anthraquinone. The bacterial activity of Citrullus colocynthis oil extract was assessed against a panel of pathogenic bacteria such as Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Staphylococcus aureus. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) results shows that the microorganisms show zone of inhibition of 4.5 mm for Escherichia coli, 4.6 for Pseudomonas aeruginosa, 5.9 for Salmonella typhi, and 6.1 mm for Staphylococcus aureus. Notably, Staphylococcus aureus and Pseudomonas aeruginosa exhibited larger zones of inhibition compared to Escherichia coli and Salmonella typhi. Thin Layer Chromatography (TLC) revealed three spots of the isolated compound, while MIC and MBC/MFC values were determined. Synergistic effects were assessed in combination with standard antibiotics, and mechanisms of action were investigated through chemical analysis. The research uncovered the antimicrobial potential of Citrullus colocynthisseed oil, offering promising insights for further exploration and potential clinical applications. The FTIR spectrum of the isolated compound revealed characteristic peaks, including a strong absorption at 2855.1 cm-1 indicative of alkanes (C-H) and another at 3011.7 cm1 for C=C in aromatics. The presence of a broad absorption at 2922.2 cm-1 suggested the presence of C-H groups, consistent with a reported absorption at 3420 cm-1. Compound gotten from the GCMS analysis which include 1-Decene and Mesitylene have been used in the synthesis of medicine such as asthma, cancer, tuberculosis and jaundices for their antimicrobial and anti-inflammatory properties.