Effectiveness of a novel herbal agent MB-6 as a potential adjunct to 5-fluoracil-based chemotherapy in colorectal cancer ☆,☆☆

Abstract Natural products, such as fermented soybeans, have been used to treat various physical conditions, including cancer. MB-6 is a botanical preparation composed of fermented soybean extract, green tea extract, Antrodia camphorata mycelia, spirulina, grape seed extract, and curcumin extract. Based on this, we hypothesized that MB-6 would increase the effectiveness of chemotherapy in patients with colon cancer. In a rodent study, MB-6, in combination with leucovorin/5-fluorouracil chemotherapy, increased the survival rate and life span of colon cancer tumor-bearing BALB/c mice as compared with treatment with chemotherapy alone. In a proof-of-concept clinical study, 72 patients with metastatic colorectal cancer were randomized to receive leucovorin, 5-fluorouracil, and oxaliplatin in combination with either MB-6 or placebo for 16 weeks. The primary outcome was the best overall response, and secondary outcomes included progression-free survival, overall survival, and adverse effects. Up to 77 weeks after treatment, there was follow-up with the patients. No significant difference in the best overall response rate and overall survival was observed between the 2 groups. Patients in the MB-6 group had a significantly lower disease progression rate than patients in the placebo group, during the study period (0.0% vs 15.8%, P = .026). The placebo group had a significantly higher incidence of adverse events at least grade 4 compared with the MB-6 group (28.9% vs 2.9%, respectively, P = .004) and a significantly higher occurrence of increased serum creatinine compared with the MB-6 group (29% vs 5.9%, P = .014). MB-6 is a promising botanical supplement that may increase the effectiveness of chemotherapy in patients with metastatic colorectal cancer.