Neuroprotective effect of osthole on MPP+-induced cytotoxicity in PC12 cells via inhibition of mitochondrial dysfunction and ROS production.

BACKGROUND

The 1-methyl-4-phenylpyridinium ion (MPP(+)), an inhibitor of mitochondrial complex I, has been widely used as a neurotoxin because it causes a severe Parkinson's disease-like syndrome accompanied by increased levels of intracellular reactive oxygen species (ROS) and apoptotic death. In the present study, we investigated the protective effects of osthole, a coumarin compound extracted from the plant-derived medicine Cnidium monnieri, on MPP(+)-induced cytotoxicity in cultured rat adrenal pheochromocytoma (PC12) cells.

METHODS

PC12 cells were treated with MPP(+) 2h after treated with different concentrations of osthole. 24h later, the cell viability, the release of lactate dehydrogenase, the activity of caspase-3 and cytochrome c, the expression ratio of Bax/Bcl-2 and the generation of intracellular ROS were detected.

RESULTS

We found that pretreatment with osthole on PC12 cells significantly reduced the loss of cell viability, the release of lactate dehydrogenase, the activity of caspase-3 and cytochrome c, the increase in Bax/Bcl-2 ratio and the generation of intracellular ROS induced by MPP(+). Moreover, our HPLC analysis of cell extracts confirmed that extracellular osthole does penetrate the cell membrane. Thus osthole may function as an intracellular antioxidant to reduce oxidative stress induced by MPP(+).

CONCLUSIONS

Therefore, the present study supports the notion that osthole may be a promising neuroprotective agent for the treatment of neurodegenerative disorders such as Parkinson's disease.