Background and aim: Huang-lian-jie-du-tang (HLJDT; Japanese name, oren-gedoku-to) is a traditional Chinese medicine prescription known to possess anti-inflammatory activity. Our study reports here for the first time the anticancer effect of HLJDT in two human liver cancer cell lines, Hep G2 and PLC/PRF/5.
Methods: Inhibition of cell proliferation by HLJDT was measured by sodium 3'-(1-(phenylamino-carbonyl)-3,4-tetrazolium)-bis(4-methoxy-6-nitro) benzene-sulfonic acid hydrate (XTT) assay. Clonogenic assay was used to elucidate the possible differences in long-term effects of HLJDT on human liver cancer cells. Cell cycle distribution was determined by flow cytometry. Apoptosis was detected using electrophoresis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick endlabeling (TUNEL) assay. Protein expressions were determined by immunoblot assay. The activity of nuclear factor-kappa B (NF-kappaB) was determined by Trans-AM ELISA kit. In vivo tumor activity was assessed by xenograft study.
Results: HLJDT significantly increased the expression of inactivated phospho-Cdc2 and phospho-Cdc25C, and decreased the levels of cyclin A, cyclin B1, Cdc2, and Cdc25C, thereby contributing to cell-cycle arrest. HLJDT increased the expression of Bax and Bak, but decreased the level of Bcl-2 and Bcl-XL, and subsequently triggered the mitochondrial apoptotic pathway. In addition, HLJDT also inhibited cell-survival signaling by enhancing the amount of IkappaBalpha in the cytoplasm, reducing the level and activity of NF-kappaB in the nucleus, and subsequently attenuating the expression of Bcl-XL in Hep G2 and PLC/PRF/5 cells(.) The inhibitory effect mediated by HLJDT on cell growth was also demonstrated in a nude mouse model, in which the liver cancer cells induced tumor xenograft shrank considerably following treatment with HLJDT.
Conclusions: Taken together, these results suggest a potential anticancer effect of HLJDT against human liver cancer cells.