Inhibitory effect of pyridoxine hydrochloride combined with chemotherapeutics on mice hepatoma cell line H22

Objective To observe the inhibitory effect of pyridoxine hydrochloride (PN) combined with common chemotherapeutics on mice hepatoma cells H22 in vitro. Methods MTT assay was used to determine the effects of PN in combination with 10 different antineoplastic agents on H22 cells, and immuno-histochemistry was used to observe the distribution of PN in H22 cells and morphologic changes of the cells before and after PN treatment. Results After 24 hours incubation with 5 mmol/L PN, the treated cells expanded apparently with nucleus chipping. PN entered the tumor cell and was mainly condensed in cytoplasma and H22 cells were sensitive to PN. When administered concomitantly with chemotherapic agents, most of the combinations showed antagonistic effects while a few of the combinations were additive. For instance, doxorubicin (ADM) used in combination with PN inhibited cell proliferation with an IR value (IR=0.63) much lower than ADM alone (IR=0.71, P 0.9), and the IR value (IR=0.60) in combined group was higher than that (IR=0.40) in ICTX group(P<0.05). Conclusion PN treatment could increase the intracellular PLP level and result in growth inhibition and cell death, and combined administration of PN and ICTX might be a potential method to improve efficacy and to reduce toxic effects while a co-administration of PN and ADM should be avoided. Key words: Liver neoplasms; Cell line, tumor; Hydrochloride pyridoxine; Vitamin B6; MTT assay