Sinapic Acid Improves Neurotransmitter Status and Oxidative Stress-Related Changes in Mouse Model of Experimental Parkinsonism

Abstract

Parkinsonism is a progressive neurodegenerative disease of the dopaminergic neurons in the substantia nigra. Oxidative stress is a known causative factor in the death of dopaminergic neurons. Sinapic acid (SNP or SA), a hydroxycinnamic type of the abundantly available plant-derived metabolite, is known for its antioxidant and anti-inflammatory properties. In the present study, we assessed the effects of sinapic acid against 1-methyl-4-phenyl 1,2,3,6-tetrahydropyridine (MPTP) induced Parkinson disease (PD) in a mouse model. The animals were pretreated with vehicle or SNP for a period of 5 days. On Day 5, 45 minutes after giving sinapic acid (SNP/SA) or normal saline (control/vehicle/), MPTP was administered. Motor function was tested using a beam walk test. Dopamine level was measured by HPLC. SNP-pretreated mice showed significant improvement in the levels of dopamine at the striatum and substantia nigra pars compacta regions of the brain. SNP also showed improved antioxidants like glutathione and superoxide dismutase levels. These were also corroborated by the improvement in motor function tests. Sinapic acid, with its antioxidant ability and dopamine-replenishing properties attenuated the pathological features associated with MPTP intoxicated dopaminergic degeneration in experimental PD.