Protective Roles of Hop Proanthocyanidins on Alcohol-Induced SH-SY5Y Cell Damage

The present study examined whether hop proanthocyanidins (PACs) or polyphenols could effectively protect alcohol-induced toxicity in human neuroblastoma SH-SY5Y cells. An in-vitro experiment indicated that alcohol could damage the SH-SY5Y cells. The degree of damage was correlated with the alcohol concentration. Cell damage was measured by cell viability, using the MTT assay, and cell apoptosis (programmed cell death) using the TUNEL assay. The results showed that 4 g/L alcohol in-vitro reduced cell viability to 71.7% and caused 34.7% cell apoptosis. Using this model, pre-treatments with 50-75 mg/L hop PACs retained 91% cell viability and inhibited cell apoptosis to below 15%. In addition, it was speculated that the mechanism underlying this neuroprotective effect of PACs might be closely associated with intracellular reactive oxygen species (ROS) levels. This in-vitro experiment demonstrated that the addition of 50-75 mg/L of PACs protected the nerve cells from the damage caused by 4 g/L of alcohol. To date, the impacts of PACs in the brains of humans are not known, however, if blood alcohol concentrations reach 4-5 g/L, severe central nervous system depression, coma, and possibly death can result. Responses of the SH-SY5Y cells might lend an indication of potential neuroprotective effects of hop PACs in alcohol-induced neurotoxicity.