Antiproliferative Properties of Extracts from Stachys sieboldii MIQ

Background: The objective of this study was to investigate the antiproliferative effect of Stachys sieboldii MIQ. extracts on cancer cell lines. Methods: Dried S. sieboldii MIQ. was extracted using acetone/methylene chloride (A+M) or methanol (MeOH), and then fractionated using n-hexane, 85% aq. methanol (MeOH), butanol (BuOH) and distilled water. The cytotoxic activity of S. sieboldii MIQ. against AGS human gastric, HT-29 human colon and HT-1080 fibroblast cancer cell lines was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay. Results: The A+M extract showed significantly higher inhibition of cell growth in all three cell lines compared to the MeOH extract (p < 0.05). All the extracts and fractions from S. sieboldii MIQ. decreased the growth of AGS cells, and the effect was concentration-dependent. Among the different fractions, the n-Hexane and 85% aq. MeOH fractions inhibited AGS cell growth by >50% at a concentration of 0.1 mg/mL (p < 0.05). All fractions inhibited the proliferation of HT-29 cancer cell lines (p < 0.05), showing >50% inhibition at a concentration of 0.25 mg/mL. The A+M extract inhibited the growth of the HT-1080 cancer cells by 60% at a concentration of 0.25 mg/mL. The n-Hexane and 85% aq. MeOH fractions showed the highest growth inhibitory effect on the HT-1080 cancer cells (p < 0.05), similar to that observed in the AGS cancer cells. Conclusion: Thus, the n-Hexane and 85% aq. MeOH fractions from S. sieboldii MIQ. likely contain bioactive compounds such as polyphenols and flavonoids that could prevent cancer proliferation. Further research is needed to isolate these important compounds from the extracts.