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L-DOPA (L-3,4-dihydroxyphenylalanine) relieves symptoms of Parkinson disease (PD), but long-term use can cause serious side effects. Resveratrol (3,5,4′-trihydroxy-trans-stilbene, RV), a polyphenolic compound derived from grapes and red wine that has antioxidant activity, has been shown to have neuroprotective effects. RV was investigated to enhance the therapeutic effect of L-DOPA in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mouse model of Parkinson disease. Mice received a saline or RV injection (10 mg/kg/day), then 2 h later, saline or MPTP (15 mg/kg/day) was administered for 7 consecutive days. Saline or L-DOPA (5 or 8 mg/kg/day) was injected post-administration of MPTP for the last 2 consecutive days. Our results indicated that RV alleviated MPTP-induced loss of dopaminergic neurons and attenuated astroglial activation in the nigrostriatal pathway. In parallel, RV reduced the expression of α-synuclein in the striatum. In addition, RV also increased levels of the anti-apoptotic signalling molecule Bcl-2, reduced levels of the pro-apoptotic signalling molecule Bax, and reduced activation of caspase-3 in the striatum. Specifically, RV significantly reduced motor dysfunction in MPTP-treated mice. Furthermore, the RV-treated group showed less IL-1β and an enhanced pAkt/Akt ratio, which promoted dopamine neuron survival in the striatum. We found that the effects of co-administration of RV with L-DOPA (5 mg/kg) were equivalent to those of administration of 8 mg/kg L-DOPA in MPTP-induced PD mice. Therefore, with fewer side effects, L-DOPA can be effectively used in the treatment of PD over a long period of time.

Parkinson's disease (PD) is a common neurodegenerative disorder disease, causing the phenomenon of shaking, rigidity, slowness of movement and dementia. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) can lead to some Parkinson's-like symptoms by destroying dopaminergic neurons in the substantia nigra of the brain. It has been thus used to establish PD models in various animal studies. Here, mice receive MPTP injections (20 mg/kg/day) for seven days and the behavioral tests are performed on the eighth day. This model is adapted efficiently in the study of PD. The behavioral tests here include the cylinder test and the open field test. The cylinder experiment is used to detect the animals' ability to lift their front paws when put into a different environment. As the PD model mice show arching-the mouse arches its back-the number of paw liftings decrease. This test is easy to execute. The open field test is used to detect the amount of time the mice spend on running, walking, and remaining immobile. We analyze animals' movements in open field using software and obtain data. Lastly, we use L-DOPA, one of the most commonly used PD drugs, as one example to show how to apply this model to the study of PD drugs. Our results indicate that MPTP neurotoxicity induces motor deficit which can be mitigated by L-DOPA.