Effects of 5-AzaC on E. histolytica growth and in vitro virulence. (A) and (B) Growth curves for untreated and 5-AzaC treated E. histolytica HM-1:IMSS and E. histolytica 200:NIH strains respectively. On day zero 50,000 trophozoites were inoculated in 15 ml culture tubes and grown with or without 23 μM 5-AzaC. On days two and four (marked by a downward arrow), 50,000 trophozoites were subcultured into fresh media and 5-AzaC added to the appropriate tubes. (C) Monolayer destruction of CHO cells by untreated, three-day, and seven-day 5-AzaC treated trophozoites of E. histolytica strains HM-1:IMSS and 200:NIH. In both parasite strains the 3-day and 7-day 5-AzaC treated parasites showed significantly decreased virulence compared to that with corresponding untreated parasites (p-value < 0.05) (shown by *).