Preliminary investigation of the neuroprotective potentials of <i>Crossyne guttata</i> in MPP⁺-induced toxicity in SH-SY5Y

Abstract

Parkinson's disease (PD) is a movement disorder caused by the gradual and sustained loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). There is presently no permanent treatment for PD, thus the need for more investigations into complementary and alternative medicine capable of inhibiting neuronal damage. This study investigates the potential neuroprotective activity of Crossyne guttata, a plant commonly found in the western and southern Cape of South Africa in 1-methyl-4-phenylpyridinium (MPP⁺)-induced, in vitro model of PD, using the SH-SY5Y neuroblastoma cells.

Methodology: The optimal concentration of Crossyne guttata aqueous extract (CGE) that showed no toxicity on cells and the concentration of MPP⁺ that reduced cell viability to about 50% was determined using the 3-(4,5-dimethyithiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Following this SH-SY5Y cells were pretreated with 10 μg/ml of CGE for 2 hours before the addition of 2000 μM of MPP⁺ and cell survival was determined. Furthermore, morphological changes associated with treatments were observed under the light microscope.

Results: Results show that CGE did not reduce cell viability in the cells at all concentrations tested, while MPP⁺ showed a dose-dependent reduction in cell viability. Also, pretreatment of cells with CGE extract improved cell survival as well as cell morphology by inhibiting toxicity induced by MPP⁺.

Conclusion: Findings from this study suggest that CGE may be a potential neuroprotective agent in PD and thus make a case for further investigation into the mechanism(s) of action as well as bioactive components of the plant eliciting such effects.

Keywords: Crossyne guttata, Medicinal plants, 1-methyl-4-phenylpyridinium (MPP⁺), Cell viability