Possible involvement of nitric oxide mechanism in the neuroprotective effect of rutin against immobilization stress induced anxiety like behaviour, oxidative damage in mice.

Dietary supplements are widely used to manage stress and related consequences. However, the exact pathological mechanism and cellular cascades involved in the action of these supplements are not properly understood so far. Therefore, the present study has been designed to explore the neuroprotective mechanism of rutin against immobilization stress-induced anxiety-like behavioural and oxidative damage in mice. Laboratory Animal Centre A-strain (laca) mice were used in the present study. Rutin (20, 40, and 80 mg/kg), l-arginine (100 mg/kg), l-nitroarginine methyl ester (l-NAME) (5 mg/kg) and vitamin-E (50 mg/kg) were administered for 5 days before 6h immobilization stress on 6th day. Various behavioural parameters (mirror chamber test, locomotor activity) followed by biochemical parameters (lipid peroxidation, nitrite concentration, reduced glutathione and catalase) in brain and then serum corticosterone level were assessed. 6 h immobilization stress produced anxiety-like behavioural in mirror chamber test, raised corticosterone level and oxidative stress (as evidenced by rise in lipid peroxidation, nitrite concentration, depletion of reduced glutathione and catalase activity) significantly as compared to naive group. 5 days pre-treatment with rutin (40 and 80 mg/kg) causes a significant attenuation of locomotor activity, corticosterone level, oxidative stress as compared to control. Further, l-arginine (100 mg/kg) pre-treatment significantly reversed the protective effect of rutin (40 mg/kg) in 6 h immobilized animals. However, l-NAME (5 mg/kg) pre-treatment with rutin (40 mg/kg) potentiated their protective effect which was significant as compared to their effect per se. The present study suggests the involvement of nitric oxide mechanism in the neuroprotective effect of rutin against immobilization stress-induced anxiety-like behaviour and oxidative damage in mice.