Effects of Boswellia serrata resin extract on motor dysfunction and brain oxidative stress in an experimental model of Parkinson's disease

Objective: Boswellia serrata oleo-gum resin (frankincense) exerted antioxidant and anti-inflammatory effects against several diseases, such as; asthma, rheumatoid arthritis and irritable bowel syndrome. In the current study, the influences of B. serrata resin extract on motor dysfunction and oxidative stress markers were investigated in the intrastriatal 6-hydroxydopamine (6-OHDA) model of Parkinson's disease (PD). Materials and Methods: The animals were randomly assigned to sham, lesion (6-OHDA), and three lesion groups treated with ethyl alcoholic extract of B. serrata at doses of 125, 250 and 500 mg/kg for 3 weeks. The neurotoxin 6-OHDA (12.5 mu g) was microinjected into the left striatum to induce PD in male rats. Motor behavior was assessed by rotational and elevated narrow beam tests. Oxidative stress markers were measured in striatal and midbrain homogenates. Results: There was a significant increase in contralateral rotations in 6-OHDA group versus sham group (p<0.001), and treatment with B. serrata resin extract at doses of 125 and 250 mg/kg significantly decreased the rotations in comparison to 6-OHDA group (p<0.001 and p<0.001, respectively). The 6-OHDA group also showed considerable elevation in the latency to initiate crossing (p<0.001) and the total time (p<0.001) on narrow beam test. Moreover, treatment with B. serrata extract at doses of 125, 250 and 500 mg/kg caused a significant reduction in the latency and total time (p<0.001, p<0.001, and p<0.01, respectively). Biochemical analysis showed no significant difference in oxidative stress markers levels among the groups. Conclusion: Our findings suggest that B. serrata resin extract acts as an anti-inflammatory and antioxidant agent that protects nigrostriatal dopaminergic neurons and improve motor impairments in PD.