The use of emetine dihydrochloride, an active ingredient in ipecac syrup, alone or with cisplatin therapy inhibited proliferation of bladder tumor cells in a recent study.
Once used to induce vomiting after poison ingestion, ipecac syrup is no longer recommended for that purpose now that studies have shown that vomiting after swallowing poison is not helpful and is sometimes harmful, according to information from Loyola University Health System in Maywood, Illinois. But as Loyola researcher Kimberly E. Foreman, PhD, and fellow investigators explained in their new report for The Journal of Urology, emetine dihydrochloride also demonstrated modest anticancer efficacy in clinical trials in the 1970s.
Although these findings were not pursued at the time, recent studies have found that emetine dihydrochloride, a natural alkaloid, induced apoptosis (programmed cell death) in leukemia cell lines, an effect enhanced by cisplatin. Current cisplatin-based therapies for stage IV bladder cancer are associated with a 5-year survival rate of 4% to 20%, “underscoring the need to develop novel therapies for these patients,” wrote Foreman’s group, which sought to determine the antiproliferative effects of emetine with and without cisplatin on bladder cancer cells.
The scientists tested emetine, cisplatin, or both in human bladder cancer cell lines and in normal human urothelial cell cultures. Each agent alone inhibited bladder cell proliferation, but worked with moderate to strong synergism when used together. Emetine appeared to primarily induce growth arrest rather than apoptosis of the cancer cells. It had little effect on the normal urothelial cells.
These results suggest that therapy combining emetine and cisplatin-based chemotherapy may benefit persons with bladder cancer, concluded Foreman and coauthors.