The effect of nobiletin on performance of rats in forced swimming and elevated plus maze tests in intranigral lipopolysaccharide rat model of Parkinson's disease

Anti-inflammatory property of nobiletin (NOB) is proven and neuroinflammation is involved in triggering and progression of neurodegenerative disorder such as Parkinson's disease (PD). PD is a neurodegenerative disorder characterized by motor and non-motor features including psychiatric symptoms such as depression and anxiety. The purpose of this study to investigate whether oral nobiletin administration at a dose of 10 mg/kg has the ability to alleviate non-motor behavioural changes including depression and anxiety-like behaviors in LPS-induced model of PD in rat. For this purpose, 32 male Wistar rats (195-245 g) were divided into four groups (n=8) as follows: Sham-operated group, nobiletin-treated sham-operated group (sham+NOB), lesion group (LPS) and nobiletin-treated lesion group (LPS+NOB). LPS (5 μg/kg) rat was unilaterally injected into the SN of rat brains through standard stereotaxis, according to the atlas of Paxinos and Watson (to generate a neuroinflammatory model of PD), with or without NOB (10 mg/kg administrated daily for 1 week after surgery, via gavage). Behavioral assessment was carried out one week after surgery by assessment of performance in forced swimming and elevated plus maze tests. NOB-treated LPS group showed significant decrease in immobility time and insignificant increase in the percentage of open arm spending time as compared with LPS group which demonstrate the anti-depressant like effect of NOB in inflammatory model of PD in rats. Taken together, this study demonstrated that nobiletin as an anxiolytic and anti-depressive agent in the LPS-induced rat model of Parkinson’s disease.