To study the effect of Pseudostellaria heterophylla polysaccharide(PHPS)on the intestinal immune response of immunosuppressed mice induced by the model antigen ovalbumin(OVA),84 male ICR mice were randomly divided into 7 groups:PBS control group(PBS group),cyclophosphamide control group(CY group),OVA alone immunization group(OVA-CY group),aluminum adjuvant control group(OVA-CY-AL group),OVA-CY-PHPS low,medium,and high dose groups(OVA-CY-PHPS-L group,OVA-CY-PHPS-M group,OVA-CY-PHPS-H group).In order to establish immunosuppressed mouse models,excluding the PBS group,all the mice were intraperitoneally injected with cyclophosphamide(CY,50mg/kg)at 1st-3rd and 18th days.The mice in the OVA-CY-PHPS-L group,OVA-CY-PHPS-M group,and OVA-CY-PHPS-H group were given corresponding doses of PHPS(50mg/kg,100mg/kg,200mg/kg)by gavage at the 4th-8th and 19th-23rd days,while the other mice were given equal volumes of double distilled water by gavage in the PBS group,CY group,OVA-CY group,and OVA-CY-AL group;The first and second immunizations were performed by subcutaneously injecting 100μg OVA(0.2mL/animal)into the groin of mice in OVA-CY-PHPS-L group,OVA-CY-PHPS-M group,OVA-CY-PHPS-H group,and OVA-CY group at the 9th and 24th days.The mice in the PBS group and CY group were received subcutaneous injection with 0.2mL/animal of sterile PBS,while those in OVA AL group were received with 0.2mL/animal of OVA/aluminum adjuvant mixture into the groin(OVA 100μg+Alum 200μg).On the 38th day,the mice in each group were dissected and their tissue were made in pathological sections,and the intestinal lesions were observed in duodenum,jejunum,and ileum.Image Pro Plus 6.0 software was used to calculate the villus height,crypt depth,and lymphocyte count in the intestinal epithelium of each intestinal segment;The content of IL-6,TNF-α and immunoglobulin A(SIgA)antibody in various intestinal segments of mice in each group were detected by ELISA method;qRT-PCR was used to detect the relative transcription levels of cytokine mRNA in various intestinal segments of mice in each group.The results showed that compared with the OVA-CY group,all doses of PHPS could improve the sparsity,swelling,and rupture of intestinal villi in immunosuppressed mice.Low doses of PHPS could significantly increase the villus height and V/C ratio(P＜0.05)in the duodenum and jejunum of immunosuppressed mice,while low and high doses of PHPS could significantly increase the villus height and V/C value in the ileum of immunosuppressed mice(P＜0.05);Compared with the OVA-CY group,high-dose PHPS significantly increased the number of lymphocytes in the jejunal epithelium in immunosuppressed mice(P＜0.05),while low-dose and high-dose PHPS significantly increased the number of lymphocytes in the jejunal epithelium in immunosuppressed mice(P＜0.05);Compared with the OVA-CY group,all doses of PHPS significantly increased IL-6 content in the duodenum of immunosuppressed mice and TNF-α content in various intestinal segments and enhanced SIgA antibody level(P＜0.05);Compared with the OVA-CY group,PHPS could significantly upregulate the relative transcription level of mRNA for IL-6 and TNF-α in various intestinal segments in immunosuppressed mice(P＜0.05).The above results indicate that PHPS can to some extent repair damage to the intestinal mucosal structure,regulate the cytokine secretion and gene transcription,enhance the intestinal mucosal immune function,and thus improve the immune response ability of immunosuppressed mice to OVA.This study provides reference for the role of PHPS in regulating intestinal immunity and further study on PHPS.
NETL
NSTL
万方数据
