The study of positive effect of astragalus on immune function in mice bearing colon cancer

Objective To investigate the positive effect of astragalus on immune function in mice bearing colon cancer.Methods Orthotopic colon cancer model was established in nude mice.Forty model mice were then treated with 5-fluorouracil and randomly divided into astragalus group(n=20) and saline group(n=20).Astragalus group and saline group received astragalus injection and 0.9% saline intraperitoneal injection respectively.After treatment,the following parameters including tumor size and weight,T lymphocyte subsets,CD4/CD8 ratio,NK cell killing activity,CTL killing activity,and the number of dead mice on day 35 in the two groups of mice were analyzed and compared.Results Tumor size(936±158 mm3) in astragalus group was significantly less than that in saline group(1493±364 mm3).Compared with saline group,immune functions were enhanced in astragalus group which were indicated by the percentage of CD3 and CD4(90.34±4.62% vs 55.19±7.18%),CD4/CD8 ratio(3.56±0.61 vs 2.38±0.46),NK cell killing activity(34.92±3.62 vs 21.92±4.68) and CTL killing activity(36.92±5.69 vs 25.61±4.91).Astragalus group mortality was significantly lower(10%) than saline group(40%).The above differences were all statistically significant(P0.05).Conclusion Astragalus has a positive regulatory role in immune depressed mice treated with 5-fluorouracil for colon cancer.