A new herbal formula BP10A exerted an antitumor effect and enhanced anticancer effect of irinotecan and oxaliplatin in the colon cancer PDTX model

BP10A is a novel two-herb medicine formula, consisting of Descurainiae sophia Semen and Peucedani praer-uptorum Radix. This study was done to evaluate the antitumor efficacy of BP10A and its effect on the efficacy of the anticancer drugs oxaliplatin and irinotecan (CPT-11) in a colon tumor xenograft model. Chemical constituents from the ethanol extracts of BP10A were characterized with the ultra-performance liquid chromatography (UPLC) and each constituent was quantified with the UPLC-diode array detector method. Our study showed that BP10A exerted the cytotoxic effects in two colorectal cancer cell lines and its combination treatments with oxaliplatin or CPT-11 remarkably increased the in vitro cytotoxicity of each cancer drug assessed by the Ez-cytox assay. The in vivo antitumor activity of BP10A was evaluated in three colon cancer patient-derived tumor xenograft (PDTX) models with different genetic backgrounds. Oral administration with BP10A (250 and 500 mg/kg, daily) delayed tumor growth by 34-70% in the all PDTX models. Similarly, intraperitoneal injection of oxaliplatin (6 mg/kg) or CPT-11 (20 mg/kg) also suppressed tumor growth by 31.8-60.5% or by 24.3-50.4%, respectively. Furthermore, the combination treatment of BP10A with oxaliplatin or CPT-11 remarkably enhanced the antitumor activity of each anti-cancer drug and delayed tumor growth by 47.1-74.6% or by 74.4-82.9%, respectively. In accordance with the antitumor activity, the Ki-67 expression for tumor cell proliferation and the CD31 for angiogenesis were decreased, and TUNEL staining for tumor cell apoptosis was remarkably increased by the co-treatment of BP10A and the anticancer drugs as well as by each treatment of BP10A, oxaliplatin or CPT-11. Conclusively, BP10A has a strong tumor inhibitory effect against colon cancer and a synergistic effect with anticancer drugs, suggesting that BP10A could be considered as a good therapeutic candidate for the treatment of colon cancer.