Sumac nanophytosome improves ۶-hydroxydopamine-induced memory impairment in rat model of Parkinson's disease

Parkinson’s disease (PD) is the second prevalent neurodegenerative disease generally characterized by the irreversible loss of dopaminergic neurons. Clinically, PD is manifested as motor symptoms and nonmotor symptoms. The nonmotor symptoms of PD include cognitive impairment.Sumac belongs to the genus Rhus, which contains flavonoid compounds. Studies related to this plant have shown that the extracts of Sumac have antioxidant properties. Water-soluble phytoconstituents such as flavonoids in sumac are poorly absorbed, either because of their large size of molecular or due to their insignificant lipid solubility which resulted in poor bioavailability. Nanophytosomes show more bioavailability as compared to conventional herbal extracts and reaching the systemic circulation. The aim of this study was to investigate the effect of sumac and sumac nano-phytosome extracts on cognitive impairment in animal model of Parkinson's disease.Method: The experiments were conducted using Wistar male rats (۲۰۰–۲۵۰ g). The rats were divided into the following groups: i) Control ii) positive control iii) ۶-OHDA iv) ۶-OHDA infused supplemented with ۴۰mg/kg sumac extract (۶-OHDA + SE) v) ۶-OHDA infused supplemented with ۴۰mg/kg sumac nano phytosome (۶-OHDA + SNP)Parkinson's model was made by the unilateral injection of ۶-OHDA (۱۰ μg in ۲ μl/site) into the right striatum (AP: +۱ mm; L: +۲.۵ mm; D: +۴.۵ mm). After ۲۴ h of injection of ۶-OHDA, the rats in the SE and SNP group were treated with sumac and sumac nano phytosome by gavage (۴۰ mg/kg body weight) for ۲۱ days. Also, Rats in the positive control group received the same dose of Sumac nano phytosome. Rats in the ۶-OHDA group and control group were given normal saline. After last gavage, memory impairment in all groups evaluated by the novel object test.Result: The results showed that injection of ۶-hydroxydopamine decreases discrimination index (p<۰.۰۰۱) and treatment of nano-phytosomes effectively increases cognitive impairment compared with the ۶-OHDA group (p<۰.۰۰۱).Discussion: The present study was aimed to a stable sumac-loaded nano phytosome formulation to improve its antioxidant feature and bioavailability. Furthermore, in this study, the Sumac and sumac nano phytosome probably have been shown to improve cognitive impairment after ۲۱ days in ۶-hydroxydopamine-induced Parkinson's model.

Keywords:

Parkinson’s disease , cognitive impairment , ۶-hydroxydopamine , sumac- nano phytosome