Possible neuroprotective mechanisms of action involved in the neurobehavioral property of naringin in mice.

Flavonoids are naturally occurring bioactive phytochemical metabolites widely known to prevent and suppress several human diseases, and are important sources of therapeutic compounds from plants. Evidence derived from previous studies suggests that naringin, a neuroactive flavonoid possess functional beneficial neurobehavioral effects including anxiolytic, antidepressant and memory enhancing properties. However, literature search revealed that no studies have been carried out to evaluate the possible biochemical mechanisms involved in the neurobehavioral property of naringin alone following repeated treatment. Hence, this study was designed to evaluate the possible neuro-biochemical mechanisms involved in the neurobehavioral property of naringin following repeated administration in mice. The effects of naringin (2.5, 5 and 10 mg/kg), diazepam (2 mg/kg), imipramine (15 mg/kg) and donepezil (1 mg/kg) or vehicle on neurobehavioral and biochemical effects were evaluated in mice following repeated intraperitoneal injection for 7 consecutive days. Neurobehavioral activities consisting of open-field (locomotor), elevated-plus maze (anxiolytic), forced swim and social interaction (antidepressant and social preference), and Y-maze (memory enhancing) tests were assessed. Thereafter, brains levels of biomarkers of oxidative, nitrosative and cholinergic parameters were determined. Repeated treatment with naringin produced increased locomotor activity, and demonstrated antidepressant-like effects evidenced by decreased immobility time in forced swim test and increased % social preference in the social interaction test relative to controls. Also, naringin induced anxiolytic-like effect and increased cognitive performance in mice. Mechanistically, naringin significantly increased the activities of superoxide dismutase and catalase, and glutathione concentration relative to vehicle-controls. However, naringin significantly decreased malondialdehyde and nitrite contents, and reduced brain acetylcholinesterase activity in mice brains in a significant manner relative to controls. Taken together, these findings suggest that treatment with naringin might be useful to produce functional behavioral effects via mechanisms related to enhancement of cholinergic transmission, antioxidant defense systems, inhibition of lipid peroxidation and nitrosative processes.

Evaluation of the Neurobehavioral Properties of Naringin in Swiss Mice.

OBJECTIVES: This study was carried out to investigate the neurobehavioral properties of naringin, a flavonoid compound formed from naringenin on behavioral models in mice. METHOD: The neurobehavioral property of naringin (2.5, 5 and 10 mg/kg) administered intraperitoneally (i.p.) was assessed on novelty-induced rearing, locomotor behavior using open field test; anxiolytic effect was evaluated using hole-board, light and dark box, and elevated-plus maze paradigms. The anti-depressant-like property was also assessed using forced swim test (FST), tail suspension test (TST) and social interaction test (SIT). The cognitive enhancing effect of naringin was evaluated using Y-maze test. RESULTS: Intraperitoneal administration of naringin (2.5 and 5 mg/kg) demonstrated significant (p<0.05) increase in rearing behavior but not the spontaneous motor activity in comparison to control. In the anti-depressant test, naringin (2.5, 5 and 10 mg/kg, i.p.) significantly decreased the duration of immobility in the FST and TST, and increased the % social interaction preference in the SIT relative to controls, suggesting anti-depressant-like and increased social behaviors. Moreover, naringin also exhibited anxiolytic and memory enhancing properties in mice. CONCLUSION: These findings suggest that naringin possesses anti-depressant- and anxiolytic-like activities as well as memory enhancing effect in mice.