Synergistic and Defensive Properties of Emblica officinalis, Terminalia chebula, and Terminalia bellerica Extracts Against Serum/Glucose Deprivation-Induced PC12 Cells Death

[Background]Triphala as a combination of three plant’s fruits including Emblica officinalis Gaertn, Terminalia chebula Retz, and Terminalia bellerica Roxb is valued for its antioxidant properties. It has been routinely used in various medicinal studies.[Objective]In this study, the protective effects of E. officinalis, T. chebula, T. bellerica, and Triphala methanolic extracts on cell viability and reactive oxygen species (ROS) generated in PC12 cells were studied under serum/glucose deprivation (SGD) induced cell injury. Synergistic activity of three extracts was also explored.[Methods]Cells were seeded overnight and then exposed to SGD condition for 18 h. Next, they were pretreated with different concentrations of the four extracts (3 - 250 µg/ml) for 4 h. Cell viability and ROS generation were evaluated by viability assay and flow cytometry, respectively. Synergistic activity of three extracts was analyzed with Compusyn software.[Results]SGD could induce cell toxicity after 18 h (P < 0.001). Pretreatment with extracts reduced SGD toxicity in PC12 cells. A significant raise in ROS generation was seen following SGD-induced toxicity. Pretreatment with T. chebula reversed the increased ROS production following ischemic insult.[Conclusions]These results demonstrated the neuroprotection of these extracts possibly by ROS decrement and synergistic activity of them against SGD-induced toxicity.