Effects of four species of herbs on immune function of Carassius auratus gibelio

Four species of herbs (dry)-Rheum officinale, Andrographis paniculata, Isatis indigotica and Lonicera japonica-were employed. Each species, at the weight ratio of 1% diet, was decocted three times and every time for 60 min. The three times of solution were concentrated, and mixed with the diets (mixed diets). The Carassius auratus gibelio were fed with the mixed diets, respectively, for 28 d and then stopped to eat normal diet. For the four groups of R.officinale, A.paniculata, I.indigotica and L.japonica, the phagocytic activities of white blood cell in C.auratus gibelio increased notably, and the phagocytosis percentage (PP ) was significantly higher than the control (normal diet) 4 d after the mixed diets were fed (P0.01). The phagocytic index (PI ) was significantly different compared with the control 4 d after the treatment and extremely significantly different 7 d after the treatment. Ten days after the fish stopped feeding the mixed diets, their PP and PI were both significantly higher than control (P0.01). Also, the lysozyme activities in the serum and the body surface mucus increased obviously that after feeding the mixed diets for 7 d, the fish all had extremely significant difference in lysozyme activity compared with control but this significant difference disappeared 10 d after the fish stopped feeding mixed diet (P0.05).