Effects of Tanacetum polycephalum Essential Oil on Depression: Enhancement of Hippocampal Antioxidant Capacity

Background and aims: Depression is a complex, persistent, and debilitating condition that affects individuals worldwide. This study aimed to investigate the antidepressant properties of essential oil derived from Tanacetum polycephalum. Methods: Fifty-six mice were randomly assigned to seven groups: (1) the control group, which received normal saline (10 mL/kg); (2) the depressed model group, which received reserpine (5 mg/kg); (3 to 6) groups that received reserpine in combination with T. polycephalum essential oil at doses of 25, 50, 75, and 100 mg/kg, respectively; and (7) the positive control group, which was administered Fluoxetine (20 mg/kg) alongside reserpine. All injections were administered via the intraperitoneal route. Depression was assessed using the forced swimming test (FST), Splash test, and open field test (OFT). Levels of malondialdehyde (MDA) and total antioxidant capacity (TAC) were measured in hippocampal and serum samples. Results: The administration of reserpine significantly prolonged the duration of immobility in the FST (P<0.001), whereas T. polycephalum essential oil significantly reduced this duration across all four doses tested (P<0.05, P<0.001). In the Splash test, both the duration and frequency of licking were significantly reduced in the reserpine group (P<0.001), while all doses of T. polycephalum essential oil significantly increased both the duration and frequency of licking (P<0.001). The reserpine group exhibited a significant reduction in the number of line crossings, rearing, and grooming behaviors (P<0.01). Notably, T. polycephalum essential oil at doses of 50, 75, and 100 mg/kg significantly enhanced these behaviors (P<0.001). Furthermore, reserpine treatment resulted in a significant decrease in TAC and an increase in MDA levels in both the hippocampus and serum. In contrast, T. polycephalum essential oil at various doses significantly increased TAC and decreased MDA levels (P<0.001). Conclusion: Tanacetum polycephalum essential oil exhibited significant efficacy in alleviating depression-like behaviors induced by reserpine. This effect is likely associated with its capacity to reduce oxidative stress parameters. The findings underscore its potential as a natural antidepressant agent. Further research is warranted to validate its therapeutic applications.