Developing anti-tumor activity products from culturing Cordyceps militaris in Radix astragali

Radix astragalus is widely used in China. Radix astragalus was demonstrated to have various bioactivities such as lymphocyte proliferation, immune-regulation, anti-tumor activity, and anti-liver injury. This study used Radix astragali (RA) as the medium for culturing Cordyceps militaris to investigate the anti-tumor activity of the fermentation broth. It was found that the product from culturing C. militaris in RA medium had a better anti-tumor activity than that culturing in synthetic medium. The fermentation broth inhibited the growth of four tumor cells including human gastric cancer AGS cells, human breast cancer MCF-7 cells, human hepatocellular carcinoma Hep G2 cells and murine colorectal adenocarcinoma CT26 cells with IC50 465μg/mL, 37μg/mL, 25μg/mL, and 20μg/mL, respectively. To validate the anti-tumor activity, the BALC/c mice were implanted with CT26 cells and then fed with various dosages of the fermentation product. It was found that 20 mg/kg body weight (BW)/day group had no significant anti-tumor activity as compared to the control group. The dosage of 100 mg/kg BW/day and 200 mg/kg BW/day group inhibited the tumor volume by 43.81% and 48.89%. Tumor weight was also reduced by 31.21% and 39.48% compared to the control group. Besides, the fermentation broth didn’t impose serious side effect on the vital organs of the mice as compared to the chemotherapeutic drug 5-FU. After constituent analyses, the results showed that saponins and isoflavonoids of Astragalus were not the major anti-tumor components. Through HPLC isolation, when cordycepin combined with peak 2 had the strongest anti-tumor activity.