RESULTS
Effect of KRG Extract on the Cell Viability in Primary Cultured Rat Cortical Cells
In order to evaluate if KRG extract exhibits cytotoxicity in primary cultured rat cortical cells, we have examined the viability of cells after exposure to KRG extract at concentrations ranging from 0.1–10 mg/mL for the time periods of 6, 12 and 24 h. As can be seen in Fig. 1, KRG extract did not elicit any cytotoxicity at any time periods of exposure at the concentrations up to 3 mg/mL. However, it significantly reduced the viability of cells at 10 mg/mL in a time-dependent manner (Fig. 1). Based on these findings, the remaining experiments were performed using the concentrations of KRG extract below 10 mg/mL.