الفهرس 
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Abstract
Hymenolepis nana is the most common tapeworm of humans, particularly in young children of developing countries. Direct human to human transmission is the most common route of infection with H. nana, particularly in poor hygiene and inadequate sanitation. It is transmitted through the fecal route and does not require an animal intermediate for replication. Immune potentiation of the intestinal immunity, using different immune stimulators, could accelerate the eradication of H. nana. Chitosan is natural polysaccharide which can be produced by deacetylation of chitin. It has strong potential in immune enhancement, anti-inflammatory properties and disease control. Also, Moringa oleifera has been used in traditional medicine. Different parts of this plant have been used in the indigenous system of medicine as an anti-inflammatory, anthelmintic and antioxidant. The target of this study was to examine the anti-helminthic activity and immunomodulation of intestinal immunity in experimental hymenolepiasis following the application of CSP and MOE alone or combined with HNA.
In order to assess such effect the following investigations were done:
Swiss mice were randomly divided into 7 groups. the first functioned as negative uninfected control, the second as positive infected untreated control, third treated with MOE alone (400 mg/kg body weight), fourth treated with CSP alone (500 µg/mouse), fifth was immunized with HNA alone (50 µg/mouse), sixth treated with MOE + HNA and the last treated with CSP + HNA. Mice were orally immunized once a week for four weeks. One week after the last immunization, the mice were challenged with 2000 H. nana eggs/mouse using stomach tube. After 3 weeks of challenge, blood was collected for determination of IgA levels. Small intestines were removed and opened longitudinally to determine the worm burdens, egg output and intestinal wash was collected. Parts of ileum were preserved for histopathological examination, biochemical and mRNA expression.
The main findings were as the following:
Experimental infection of mice with H. nana eggs was done successfully. Treatments with MOE and CSP could significantly reduce adult worm burden (89.3% and 95%, respectively) in intestine and eggs output (97.2% and 77%, respectively) in faeces. However, treatment with HNA didn’t show high contribution in worm reduction (46%).
Histopathological examination of intestinal tissue indicated destruction of normal villous architecture due to H. nana infection. Treatment groups could show few histological alterations and increase in goblet cell number while, immunization with HNA caused less degenerated villi and leukocytic infiltration. Morphometric analysis for the histological changes in intestinal villi and crypts indicated a reversal effect of CSP, CSP + HNA, MOE and MOE + HNA to normal values in comparison to infected and HNA groups.
Histochemical examination of intestinal villi showed a non-significant increase in mast cells or goblet cells in the infected control group in comparison with non-infected controls. Immunization with HNA caused a non-significant increase in MMCs and GCs. Administration of CSP and CSP + HNA increased the intestinal GCs and MMCs number. Only MOE treatment caused significant decrease in MMCs compared to the infected group. Similarly, all the treated groups showed significant increases (P < 0.001) in MUC2 expression.
In the infected mice, there was disturbance in the oxidant/ antioxidant status indicated by increase in TBARS and iNOs and decrease in glutathione content that was reversed in treated groups.
Experimental infection did not show any changes in IgA levels. Immunization with HNA increased serum IgA but did not affect intestinal IgA. Treatment with MOE and HNA + MOE increased both serum and intestinal IgA. CSP and HNA + CSP did not show any significant changes in both serum and intestinal wash.
There was a marked elevation in IL- 4, -5 and IL-9 mRNA expression in MOE and MOE + HNA treated groups versus significant suppression of SCF, TGF-β, IFN-γ. Moreover, CSP and CSP + HNA increased IL-4, -9 and SCF and suppressed IFN-γ, IFN-α and TNF-α expression in comparison to infected group.
In conclusion, CSP could induce protection against H. nana infection by reducing the worm burden and egg outputs. This protective effect could be a result of its anti-inflammatory action, shifting Th1 to Th2 responses by a marked elevation in Th2 cytokines including IL-4, -9 and SCF. This immunomodulation was associated with increased intestinal GCs, MMCs and MUC2. Compared to immunization with HNA, CSP as an adjuvant with HNA achieved higher reduction percentages of adult worms. Also, MOE could induce protection against H. nana infection due to some obvious mechanisms, including polarization of the immune response toward Th2 with a marked elevation in IL- 4, -5 and IL-9 expression. It could increase GCs number, MUC2 expression and IgA levels. IL-9 did not play a role in increasing MMCs number. Compared to immunization with HNA, MOE as an adjuvant with HNA achieved higher reduction percentages of adult worms and eggs.