Phytochemical composition, hypnotic activity, and antinociceptive properties of cumin essential oil collected from various geographical regions.

The quantity and quality of the active components of plants are strongly influenced by environmental factors. In this regard, dried cumin seeds were collected from four different locations (SaadatShahr (P1) and Sarvestan (P2) from Fars Province and Kashmar (P3) and Sabzevar (P4) from Khorasan), and their essential oils were isolated by Clevenger apparatus and evaluated using GC and GC-MS. In addition, the hypnotic and antinociceptive activities of the cumin EO sample, which had the highest yield and quality, respectively, were assessed via the pentobarbital-induced loss of righting test and acetic acid-induced writhing test. Our results showed that the highest amount of EO was present in sample P4 (3.63%), followed by P3 (2.92%), P2 (2.69%), and P1 (2.31%). GC-MS analysis revealed cuminaldehyde (21.31-33.60%), γ-terpinene (13.68-23.29%), p-mentha-1,4-dien-7-al (14.44-20.84%), p-mentha-1,3-dien-7-al (10.06-14.02%), β-pinene (9.32-11.46%), and p-cymene (3.16-7.89%) were the major constituents in all the populations. Generally, the results showed that the seeds harvested from areas with hotter and drier climates (P3 and P4) had higher EO yields and cuminaldehyde concentrations but had moderate amounts of γ-terpinene, β-pinene, and p-cymene. In addition, the hypnotic (100 and 200 mg/kg) and antinociceptive (25, 50, and 100 mg/kg) effects of cumin EO were proven in animal models.