In Vitro Antimicrobial Activity of the Oil Obtained from the Seeds of Citrullus Colocynths (Bitter Apple)

The phytochemical and antimicrobial analysis of the crude extract of oil gotten from the seeds of Citrullus colocynths were carried out using standard methods. The result of the photochemical screening showed that the oil extract of Citrullus colocynths contains alkaloids, flavonoids, saponins, tannins, terpenoids and anthraquinone. The bacterial activity of Citrullus colocynths 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 show that the microorganisms show zone of inhibition of 4.5 mm for Escherichia coli, 4.6 mm for Pseudomonas aeruginosa, 5.9 mm for Salmonella typhi and 6.1 mm for Staphylococcus aureus at a concentration of 200 mg/ml, 400 mg/ml and 600 mg/ml. 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 also determined with a concentration of 600 to 700 µg/cm3. 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 colocynths seed 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.