The aqueous extract of Gerrardanthus macrorhizus caudex enhanced doxorubicin acvity in MCF-7 human breast cancer cells

Abstract

Gerrardanthus macrorhizus (GM) caudex, is tradionally used in cancer therapy by the Tetun people in Belu District, East Nusa Tenggara Province, Indonesia, where it is known as “akar batu”. This study aimed to explore the cytotoxic effects of G. macrorhizus caudex aqueous extract, as well as its combinaon with doxorubicin, on MCF-7 cells. Also inves-gated were the possible mechanisms of interacon through cell cycle progression and apoptosis inducon. Single treatments of 5–320 µg/mL of the extract showed morphological alteraons in MCF-7 cells, but did not show any cytotoxic effect. Combining the extract with doxorubicin resulted in a synergisc cytotoxic effect. Doxorubicin concentraons equivalent to 1/12, 1/8, and 1/5 fold of the IC50 combined with 20 µg/mL decreased viability to 48%. We then explored the combinaon effect of doxorubicin 0.4 µM with GM 5 and 20 µg/mL using a flow cytometer. A low concentraon of the extract (5 µg/mL) combined with 0.4 µM of doxorubicin resulted in slight cell cycle modulaon by G1, G2M arrested and apoptosis inducon. The combinaon of doxorubicin and a higher concentraon of the extract (20 µg/mL) did not show cell cycle modulaon, and led to necrosis. Therefore, G. macrorhizus caudex at low concentraons has the potenal to be developed further as a co-chemotherapeuc agent.