BackgroundMany modern pharmaceutical researchers continue to focus on the discovery and evaluation of natural compounds for possible therapies for obesity, diabetes, infections, cancer, and oxidative stress. Extraction ofOcimum basilicumseed essential oil and evaluation of its antioxidant, anti-obesity, antidiabetic, antibacterial, and cytotoxic activities were the goals of the current study.MethodO.basilicumseed essential oil was extracted and evaluated for its anticancer, antimicrobial, antioxidant, anti-obesity, and anti-diabetic properties utilizing standard biomedical assays.ResultsO.basilicumseed essential oil showed good anticancer activity against Hep3B (IC5056.23 ± 1.32 µg/ml) and MCF-7 (80.35 ± 1.17 µg/ml) when compared with the positive control, Doxorubicin. In addition, the essential oil showed potent antibacterial (againstKlebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Proteus mirabilis, andPseudomonas aeruginosa) and antifungal (againstCandida albicans) activities. Moreover, as for the anti-amylase test, IC50was 74.13 ± 1.1 µg/ml, a potent effect compared with the IC50of acarbose, which was 28.10 ± 0.7 µg/ml. On the other hand, for the anti-lipase test, the IC50was 112.20 ± 0.7 µg/ml a moderate effect compared with the IC50of orlistat, which was 12.30 ± 0.8 µg/ml. Finally, the oil had a potent antioxidant effect with an IC50of 23.44 ± 0.9 µg/ml compared with trolox (IC50was 2.7 ± 0.5 µg/ml).ConclusionThis study has provided initial data that supports the importance ofO. basilcumessential oil in traditional medicine. The extracted oil not only exhibited significant anticancer, antimicrobial, and antioxidant properties but also antidiabetic and anti-obesity effects, which provided a foundation for future research.