The Leaf Extracts of and Fermented Culture Broths of Synergistically Cause Apoptotic Cell Death in Promyelocytic Leukemia Cells

Abstract

Toona sinensis is a common edible vegetable that is used in certain Chinese dishes and has importance in folk medicine. The leaf extracts of T sinensis possess and exhibit anticancer efficacy against various cancer cell types. In Taiwanese folklore, Antrodia camphorata , also known as “Niu-Cheng-Zi,” is used in traditional medicine to treat various illnesses. Its fruit and mycelium possess various potent antiproliferative properties. Two studies from our group have reported that T sinensis or A camphorata has the ability to cause apoptosis in various cancer cells. Conversely, underlying molecular mechanisms and any beneficial effects remain unknown. This study shows anticancer efficacy for both T sinensis and A camphorata co-treatments that target HL-60 cells. The combination index values indicate that 40 µg/mL of T sinensis and 25 µg/mL of A camphorata as a combined treatment shows a synergetic effect, which reduces HL-60 cell proliferation. Alternately, this treatment exhibited no cytotoxic effects for human umbilical vein endothelial cells. Western blot data showed that T sinensis and A camphorata as a combined treatment result in augmented expression of apoptosis, cytochrome c release, Bcl-2 inhibition, expression of Bax, Fas, and FasL, as well as the cleavage of Bid in HL-60 cells. Moreover, this combined treatment overshadowed monotherapy in its ability to inhibit uPAR, MMP-9, MMP-2, COX-2 expression, and PGE 2 secretions. Our study strongly implies that this combined treatment offers more beneficial effects to suppress and treat leukemia due to apoptosis-mediated cell inhibition. Further in vivo studies related to the combined treatment could establish its future potential.