Effect of combination of cisplatin with brassinosteroids on the growth of cancer cells

Abstract

In this work, the effect of brassinosteroids on the antitumor activity of classical cytostatic cisplatin in tumor cell lines A549 (human lung carcinoma) and Hep G2 (human hepatocellular carcinoma) was evaluated. Natural brassinosteroids 24-epibrassinolide and 28-homocastasterone, as well as their synthetic analogues (22S,23S)-24-epibrassinolide and (22S,23S)-28-homocastasterone were used. All four compounds with cisplatin inhibited the growth of cancer cells more effectively than cisplatin alone. Combinations with low concentrations of synthetic brassinosteroids were more effecient, and at 1 µM decreased the IC50 of cisplatin by almost 2 times. The results suggest a possible benefit of combinations of classical antitumor drugs with brassinosteroids in overcoming the negative effects of chemotherapy by reducing their effective doses.