Protective effect of montelukast against quinolinic acid/malonic acid induced neurotoxicity: possible behavioral, biochemical, mitochondrial and tumor necrosis factor-α level alterations in rats

The present study has been designed to explore the protective effect of montelukast (leukotriene receptor antagonist) against intrastriatal quinolinic acid (QA; 300 nmol) and malonic acid (MA; 6 μmol) induced Huntington's like symptoms in rats. Quinolinic acid has been reported to induce excitotoxicity by stimulating the N-methyl-d-aspartate receptor, causing calcium overload which in turn leads to the neurodegeneration. On the other hand, MA, being a reversible inhibitor of mitochondrial enzyme complex-II, leads to energy crisis and free radical generation. Recent studies have reported the therapeutic potential of leukotriene receptor antagonists in different neurodegenerative disorders. However, their exact role is yet to be established. The present study accordingly, is an attempt to investigate the effect of montelukast against QA and MA induced behavioral, biochemical and molecular alterations in rat striatum. Oxidative stress, mitochondrial enzyme complex and tumor necrosis factor-alpha (TNF-α) were evaluated on day 21st and 14th post intrastriatal QA and MA treatment, respectively. Findings of the present study demonstrate significant alteration in the locomotor activity and motor coordination as well as oxidative burden (increased lipid peroxidation, nitrite concentration and decreased endogenous antioxidants), mitochondrial enzyme complex (I, II and IV) activities and TNF-α level, in both intrastriatal QA and MA treated animals. Further, montelukast (0.4, 0.8 mg/kg p.o.) treatment for 21 and 14 days respectively, attenuated the behavioral alterations, oxidative stress, mitochondrial dysfunction and TNF-α level in these models of Huntington's disease in a significant manner. In conclusion, the present study emphasizes the neuroprotective potential of montelukast in the therapeutic management of Huntington like symptoms.