Experimental validation of Vitex negundo leaves hydroalcoholic extract for neuroprotection in haloperidol induced parkinson’s disease in rat

Parkinsonism is a neurodegenerative disease, mainly imbalance in dopamine and acetylcholine neurotransimitter in mid brain, which manifestation of dysfunctions of extrapyramidal like akinesia, tremor, rigidity and catalepsy etc., even cognitive and memory loss. The current study is framed to evaluate the effect of Vitex negundo (VNL) leaf extract in Haloperidol induced PD in rats. In vitro studies of antioxidant capacity were checked via DPPH and NO assays and identified its Acetylcholinesterase (AChE) inhibitory activity. Secondly the In vivo study of anti-PD activity in Haloperidol induced in rats were evaluated by Rotarod, morris water maze (MWM), cooks pole climb (CPC), actophotometer, novel object recognition (NOR), and T-maze were utilized to assess extrapyramidal, cognitive and memory function. Thirdly, changes in biomarker level viz. (AChE), butyrylcholinesterase. (BChE) in hippocampus and cortex, reduced glutathione (GSH), malondialdehyde (MDA), total protein (TP), superoxide dismutase (SOD), catalase (CAT), and dopamine level in the whole brain were measured. Finally, histopathology of hippocampus and cortex was examined at 40x magnification to access restoring integrity and maintaining the architecture of neuronal cell in the treatment group compared to control group and L-DOPA as a standard treatment group. V. negundo showed potent antioxidant potency on scavenging of DPPH (IC 50 84.81 μg/ml) and NO (IC 50 133.20 μg/ml) and possess AChE inhibitory potency (IC 50 114.35 μg/ml) by in vitro studies. The Rotarod, MWM, CPC, Actophotometer, NOR, T-maze demonstrated that Haloperidol group administration declines performance time, ELT, TL and decreases locomotion, cognitive and memory respectively. The treatment of VNL 100, 200, and 400 mg/kg p.o. significantly ( p < 0.05 to p < 0.0001) reversed. Whole brain AChE, BChE, and MDA level were significantly raised and GSH, TP, SOD, CAT and Dopamine were significantly declined in Haloperidol treated group rats, especially V. negundo 400 mg/kg p.o. highly significantly ameliorate the Haloperidol group altered pathological changes through the restoration of the cholinergic function, enhancing the antioxidant defense and by increasing the dopaminergic function. The current study provides validation of V. negundo for its anti-PD activity and could be a valuable source for the treatment of PD in future. Graphical abstract