Evaluation of the Protective Effects of Noscapine on Paraquat-Induced Parkinson's Disease in Rats.

Parkinson's disease (PD) is a degenerative central nervous system disease pathologically attributed to dopaminergic neuron damage in the substantia nigra. Noscapine is a natural alkaloid with several benefits, including anti-inflammatory, neural protection, and anti-oxidant effects. Hence, the current study evaluated the protective effects of Noscapine against paraquat (PQ)-induced Parkinson's disease model in rats. Male Wistar rats were into six groups: sham and PQ-induced models treated with vehicle, vitamin-E (20 mg/kg/d), or Noscapine (6, 18, and 55 mg/kg/d) for four weeks. Meanwhile, the rats were assessed for weight and food consumption (FC) daily and PD-associated behavior changes using rotarod, bar, and parallel bar tests every week. The animals were ethically sacrificed at the end of the study, and biochemical, immunological, and histopathological markers were measured in the brain. As a result, the levels of weight, FC, parallel bar, and rotarod test (both speed and latency), number of neurons, total thiol content, and interleukin-10 (IL-10) were significantly reduced. In contrast, the levels of dark neurons, TNF-α, bar test, and malondialdehyde (MDA) were markedly increased in the PQ-vehicle group compared to the sham group (P < 0.001-0.5). In contrast, comedication with Noscapine significantly reversed the histological damages and improved deteriorated behavioral, biochemical, and immunological parameters in a dose-dependent manner compared to the PQ-vehicle group (0.001-0.05). Taken together, it was determined that using Noscapine has antiparkinsonian effects and improved behavioral tests, catalepsy, bradykinesia, and motor dysfunction and has a protective impact on the brain's neurons through its anti-oxidant and anti-inflammatory properties.