Protective Potential of Orange (Citrus sinensis) Peel Extract in Paraquat-Induced Neurotoxicity in Mice

Several studies have evaluated the effectiveness of orange peel extracts (OPE) in reducing oxidative stress and neurodegenerative diseases linked to paraquat (PQ) exposure. This study evaluated the neuroprotective potential of orange peel extract (OPE) in paraquat-induced neurotoxicity in Swiss mice. Thirty male BALB/c albino mice (20-25 g) were divided into six treatment groups (n=5). Group 1 served as the control and received only the vehicle (Tween-20 and distilled water), Groups 2 and 3 were treated with OPE (100 mg/kg and 200 mg/kg, p.o., respectively), Group 4 received PQ (10 mg/kg, i.p., twice per week), while Groups 5 and 6 received OPE (100 mg/kg and 200 mg/kg p.o., respectively) for the first 10 days of the experiment, followed by treatment with PQ (10 mg/kg, i.p., twice per week) for the remaining 10 days of the study. Administration lasted 21 days, thereafter behavioural tests and biochemical evaluations were carried out to assess the behavioural deficits and oxidative stress levels associated with PQ-induced neurotoxicity. The findings demonstrated that OPE at doses of 100 and 200 mg/kg significantly alleviated motor deficits and oxidative stress caused by PQ (10 mg/kg). Locomotor activity and motor coordination were improved (p<0.05) in OPE groups. The results showed that OPE restored PQ-induced elevation of malondialdehyde (MDA), acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities in mice (p<0.05), OPE also restored PQ-induced inhibition or depletion of superoxide dismutase (SOD) and glutathione (GSH). Conclusively, orange peel extract mitigates oxidative stress and restores AChE activity, offering neuroprotective benefits in neurodegenerative diseases.