EVALUATION OF ANTIPARKINSONS AND MONOAMINE OXIDASE-MAO-B INHIBITORY PROPERTIES OF SENNA OCCIDENTALIS IN RATS

Parkinson’s disease is a progressive neurodegenerative disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra, leading to motor and non-motor dysfunction. The present study was designed to evaluate the antiparkinsonian and monoamine oxidase-B (MAO-B) inhibitory activity of Senna occidentalis in MPTP-induced Parkinsonian rats. Parkinsonism was induced by administration of MPTP (25 mg/kg, i.p.), and animals were divided into five groups: vehicle control, MPTP control, standard drug (Levodopa 12 mg/kg + Benserazide 3 mg/kg), and Senna occidentalis extract at doses of 200 mg/kg and 400 mg/kg (p.o.). Behavioral assessments including rotarod, open field, hole board, forced swimming, and tail suspension tests were performed to evaluate motor coordination, locomotor activity, and behavioral despair. Biochemical parameters such as dopamine levels, MAO-B activity, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx), and nitric oxide (NO) were estimated in brain tissue. MPTP administration produced significant motor impairment, increased oxidative stress, elevated MAO-B activity, and reduced dopamine levels. Treatment with Senna occidentalis significantly improved behavioral performance and biochemical parameters in a dose-dependent manner. The higher dose (400 mg/kg) showed more pronounced neuroprotective effects, comparable to the standard drug. The protective effect may be attributed to the presence of phytoconstituents such as flavonoids, phenolics, alkaloids, and terpenoids, which exert antioxidant and MAO-B inhibitory actions. In conclusion, Senna occidentalis exhibits significant antiparkinsonian activity through modulation of oxidative stress, inhibition of MAO-B enzyme, and restoration of dopaminergic function, suggesting its potential as a neuroprotective agent in Parkinson’s disease. Keywords: Parkinson’s disease, MPTP, Senna occidentalis, MAO-B inhibition, oxidative stress, dopamine, neuroprotection, antioxidant activity.