ABSTRACT
OBJECTIVE： To study the repair effect of artificial Isaria cicadae on intestinal mucosal injury induced by 5-fluorouracil （5-FU） in rats. METHODS： Forty SD rats were randomly divided into normal group （normal saline）， model group （normal saline）， artificial I. cicadae high-dose， medium-dose and low-dose groups （3.5， 1.75， 0.875 g/kg）， with 8 rats in each group. Except for normal group， other groups were given intraperitoneal injection of 5-FU （0.25 g/10 mL） 30 mg/kg， once a day， for consecutive 5 days. At the same time， each group was given relevant medicine/normal saline intragastrically， once a day， for consecutive 8 d. After medication， body weight of rat was determined in each group. HE staining was used to observe the pathological change of small intestine. The levels of biobarrier-related factor [endotoxin （ET）， D-lactic acid （D-LA）]， immune barrier related factors （TNF-α， IFN-γ， sIgA， IL-15， G-CSF in serum and MPO， MDA in small intestine） and the levels of mechanical barrier related factors （connexin ZO-1 and Claudin-1） were detected. RESULTS： Compared with normal group， body weight of rats in model group was decreased significantly （P＜0.01）. Intestinal villus exfoliated obviously， the crypt structure was scattered， a large number of inflammatory cells gathered， and intestinal mucosa was seriously damaged. Serum levels of ET and D-LA， the levels of TNF-a， IFN-γ， MPO and G-CSF in serum， MDA level in small intestine were increased significantly （P＜0.01）. Serum levels of sIgA and IL-15 as well as the expressions of ZO-1 and Claudin-1 in small intestine were decreased significantly （P＜0.05 or P＜0.01）. Compared with model group， body weight of rats in artificial I. cicadae high-dose group was increased significantly （P＜0.01）. The pathological changes of the small intestine of rats in each administration group were improved to varying degrees. The intestine morphology of artificial I. cicadae high-dose and medium-dose groups was close to that of the normal group. The levels of and ET， D-LA， TNF-α， IFN-γ， MPO， G-CSF in serum and the level of MDA in intestinal were decreased significantly （P＜0.01）. Serum levels of sIgA and IL-15 in administration groups as well as the expressions of ZO-1 and Claudin-1 in intestinal tissue were increased significantly （P＜0.01）. CONCLUSIONS： Artificial I. cicadae can repair intestinal mucosal damage caused by 5-FU in respects of mechanical barrier， immune barrier， biological barrier.