Herbs and spices have been used since antiquity for their nutritional and health properties, as well as in traditional remedies for the prevention and treatment of many diseases. Therefore, this study aims to perform a chemical analysis of both essential oils (EOs) from the seeds of () and () and evaluate their antioxidant, antimicrobial, anti-acetylcholinesterase, and antidiabetic activities alone and in combination. Results showed that the EOs mainly constitute monoterpenes with γ-terpinene (31.03%), β-pinene (18.77%), p-cymene (17.16%), and carvone (12.20%) being the major components present in EO and linalool (76.41%), γ-terpinene (5.35%), and α-pinene (4.44%) in EO. In comparison to standards, statistical analysis revealed that EO showed high and significantly different ( < 0.05) antioxidant activity than EO, but lower than the mixture. Moreover, the mixture exhibited two-times greater ferric ion reducing antioxidant power (FRAP) (IC = 11.33 ± 1.53 mg/mL) and equipotent chelating power (IC = 31.33 ± 0.47 mg/mL) than the corresponding references, and also potent activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC = 19.00 ± 1.00 mg/mL), β-carotene (IC = 11.16 ± 0.84 mg/mL), and superoxide anion (IC = 10.33 ± 0.58 mg/mL) assays. Antimicrobial data revealed that single and mixture EOs were active against a panel of pathogenic microorganisms, and the mixture had the ability to kill more bacterial strains than each EO alone. Additionally, the anti-acetylcholinesterase and α-glucosidase inhibitory effect have been studied for the first time, highlighting the high inhibition effect of AChE by (IC = 0.82 ± 0.05 mg/mL), and especially by (IC = 0.68 ± 0.03 mg/mL), as well as the mixture (IC = 0.63 ± 0.02 mg/mL) compared to the reference drug, which are insignificantly different ( > 0.05). A high and equipotent antidiabetic activity was observed for the mixture (IC = 0.75 ± 0.15 mg/mL) when compared to the standard drug, acarbose, which is about nine times higher than each EO alone. Furthermore, pharmacokinetic analysis provides some useful insights into designing new drugs with favorable drug likeness and safety profiles based on a and EO mixture. In summary, the results of this study revealed that the combination of these EOs may be recommended for further food, therapeutic, and pharmaceutical applications, and can be utilized as medicine to inhibit several diseases.