The Protective Effects of Citrus Aurantium Extract in A 6-Hydroxydopamine-Induced Model of Parkinson's Disease in Male Rats

Parkinson's disease (PD) is a commonly diagnosed neurodegenerative disease among the elderly. Considering the limited symptomatic improvement associated with PD treatments, introduction of more effective agents is necessary. Citrus aurantium flower extract (CAE) is recognized as a neuroprotective and hepatoprotective agent with bioactive compounds, such as flavonoids, phenolics, and vitamins. Regarding the mitigating role of CAE against oxidative damage, the neuroprotective effects of CAE were examined in a PD model in this study.

Overall, 60 male rats were classified into 6 groups: sham (SH), control (C), lesion (L), and CAE-treated lesion (200, 400, and 600 mg/ml CAE+L). For the hemi-PD model, 6-hydroxydopamine (12.5 g/L of saline ascorbate) was injected intrastriatally. Intraperitoneal pretreatment with hydroalcoholic CAE (200, 400, and 600 mg/kg/daily) was applied in the E+SH and E+L groups for 1 week presurgery. Two weeks postsurgery, rotational behaviors were examined by apomorphine hydrochloride, and stained neurons were measured in the pars compacta of substantia nigra (SNC).

In comparison with the C group, significant contralateral turning was reported due to apomorphine in the L group two weeks postsurgery (P< 0.0001), while the neuron count on the left SNC reduced (P< 0.05). The rotational behaviors reduced using alcoholic CAE, and reduction in the neuron count of SNC was attenuated in lesion groups (P< 0.05). However, in the SH group, CAE caused no significant effects on apomorphine-induced rotation and neuron count in the SNC. CAE could decrease the number of degenerated neurons in the SNC. Cell count assessment showed that neural cell count significantly increased in 200, 400, and 600 mg/ml CAE groups.

According to the present findings, CAE can be suitable for preventing PD in rats.