Effects of piperine on hydrogen peroxide-induced cell death in neuronal cell line cultures

Abstract

Piperine has been widely used in folklore medicine to treat a variety of central nervous system disorders and has marked antioxidant property which may suggest its potential to alleviate oxidative stress-induced neurodegenerative process. The primary objectives of this study were to study beneficial effects of piperine on hydrogen peroxide (H O )-induced cell death in neuronal cell line cultures and investigate possible mechanisms underlying its neuroprotective effects. A cellular model of neurodegeneration induced by H O in N1E-115 cell line cultures was used to investigate the oxidative stress-induced neuronal cell death in this study. MTT reduction and LDH release assays were used to analyze cell survival and death. Lipid peroxidation, cellular GSH contents, and apoptotic cell death were used to analyze possible mechanisms of neuroprotection. Experimental results from this study suggest that piperine possessed bimodal effects on neuronal cell cultures, cytoprotective at lower concentrations and cytotoxic at higher concentrations. Simultaneous exposure with nontoxic concentrations for piperine, in a range of 0.1-10 N, amy be protective against cell injury and apoptotic cell death from exposure to H O in N1E-115 cell line cultures. However, pre[exposure to piperine did not show any beneficial effects. The mechanism of action underlying this beneficial effect of piperine on cultured neurons is unclear at the present time. Possibly, it may involve differen6 direct and indirect actions of piperine, e.g., antioxidation and free radical scavenging, interference with Fenton’s reaction which generates TROS, inhibition of cellular lipid peroxidation, counteraction to ap0optotic cell death cascade. Further studies for clarifying detailed pharmacological properties and potential applications of piperine in experimental research are warranted.