Panax notoginseng saponins R1 enhances the cytotoxicity of cisplatin via gap junction intercellular communication

Objective:To investigate the effect of panax notoginseng saponins R1 on gap junction(GJ) function in HeLa cells transfected with connexin 32 and connexin 26 plasmid and the cytotoxity of cisplatin. Methods:Sulforhodamine B assay was used to determine the inhibitory effect of panax notoginseng saponin R1 on HeLa cells growth for different times.Cells were divided into panax notoginseng saponins R1 10,25,50,100,and 200 mol/L groups,and non-R1 group was taken as the blank control group.After 24,48,and 72 hours the inhibition rate of HeLa cells growth was evaluated;the GJ function of HeLa cells treated with R1 for 48 hours was detected by SL/DT(scrape-loading dye transfer),and distance between cells of lucifer yellow was introduced to reflect the GJ function.The cytotoxity of cisplatin combined with R1 was determined by Standard colony-forming assay,and Surviving Fraction as index was used to evaluate the cytotoxicity of cisplatin. Results:Panax notoginseng saponins R1 suppressed the growth of HeLa cells;R1 up-regulated the GJ of HeLa cells.In the presence of GJ,combination of R1 and cisplatin significantly enhance the cytotoxicity of cisplatin compared with cisplatin treatment group,but in absence of GJ,there was no significant difference between these two groups. Conclusions:R1 enhances the cytotoxicity of cisplatin through enhancement of GJ function.