Behavioral and Biochemical Evaluation of Anti-Depressive and Oxidative Stress-Ameliorating Effects of Amber Extract in Adult Male ICR Mice

Amber, a plant resin, exhibits an anti-stress effect and is used in traditional medicine. Recently, it has been speculated that amber may possess an anti-depressive effect. However, there is no evidence to support this efficacy. Thus, this study investigated the anti-depressive and oxidative-stress-ameliorating effects of amber extract in mice subjected to restraint stress. Mice were treated with amber extract (25 and 50 mg/kg, p.o.) and bupropion (10 mg/kg, p.o.) as positive control. Mice were then subjected to a tail suspension test, and their immobility time, body weight before and after stress, levels of stress-related hormones and neurotransmitters, and oxidative stress parameters were assessed. Amber supplementation did not affect the body weight of mice in any of the groups. Amber extract (25 and 50 mg/kg) demonstrated an anti-depressive effect by significantly decreasing the immobility time and adrenocorticotropin-hormone and corticosterone-hormone levels. Moreover, amber extract at a dose of 25 mg/kg increased the levels of dopamine and serotonin. Additionally, superoxide dismutase, catalase, and glutathione levels increased, whereas the malondialdehyde content decreased with amber supplementation. These findings confirm that amber may possess an anti-depressive effect and hence can be a useful alternative therapy for preventing and managing depression.