Tiliacora triandra (Colebr.) Diels leaf extract alleviates motor deficit and protects against MPTP-induced neurodegeneration in mice

Parkinson’s disease (PD) is a neurological disorder that results from a gradual loss of dopaminergic neurons in the substantia nigra. One of the most important causes of nigrostriatal degeneration in PD is oxidative stress-induced neuronal death. Tiliacora triandra (Colebr) Diels (T. triandra (TT)), known as Ya-nang in Thai, is a plant that is recognized to have antioxidant, anti-inflammatory, and neuroprotective activities. In this study, we explored the neuroprotective effects of TT leaf extract in a PD model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). TT (100, 200, and 400 mg/kg BW) was orally administered to 9-week-old C57BL/6 mice for 7 days before and 7 days after receiving four injections of 20 mg/kg BW MPTP, with a 2-hour gap between each injection. The results showed that the treatment of TT improved MPTP-induced motor impairment and suppressed the MPTP-induced reductions of tyrosine hydroxylase-positive neurons in the substantia nigra while TT also mitigated MPTP-induced decreasing dopamine (DA) levels in the striatum. TT also alleviated oxidative stress status including decreased malondialdehyde levels and increased the activities of glutathione, catalase, and superoxide dismutase. Our findings suggest that the consumption of TT could offer neuroprotection, potentially delaying or preventing the neurodegenerative process associated with PD in the C57BL/6 mice. However, further research into the safety of the extract should be conducted before proceeding with a study involving human PD.