Acute infection with Strongyloides venezuelensis increases intestine production IL-10, reduces Th1/Th2/Th17 induction in colon and attenuates Dextran Sulfate Sodium-induced colitis in BALB/c mice

Helminth infection can reduce the severity of inflammatory bowel disease. However, the modulatory mechanisms elicited by helminth infection are not yet fully understood and vary depending on the experimental model. Herein we evaluated the effect of acute infection of BALB/c mice with Strongyloides venezuelensis on the clinical course of ulcerative colitis induced by Dextran Sulfate Sodium (DSS) treatment of these animals. For the experiments, S. venezuelensis-infected BALB/c mice were treated orally with 4% DSS solution for seven days. As controls, we used untreated S. venezuelensis infected, DSS-treated uninfected, and untreated/uninfected BALB/c mice. During DSS treatment, mice from the different groups were compared with regards to the clinical signs related to the severity of colitis and intestinal inflammation. Mice acutely infected with S. venezulensis and treated with DSS had reduced clinical score, shortening of the colon, and tissue inflammation. Moreover, DSS-treated and infected mice showed reduced IL-4, INF-γ, and IL-17 levels and increase of IL-10 production in the colon and/or in the supernatant of mesenteric lymph nodes cell cultures that resulted in lower eosinophil peroxidase and myeloperoxidase activity in colon homogenates, when compared with DSS-treated uninfected mice. DSS-treated infected mice also preserved the intestine architecture and had normal differentiation of goblet cells and mucus production in the colon mucosa. In conclusion, the data indicate that the clinical improvement reported in DSS-treated infected mice was accompanied by the lower production of Th1/Th2/Th17 pro-inflammatory cytokines, stimulation of IL-10, and induction of mucosal repair mechanisms.

Improvement of the liver pathology by the aqueous extract and the n-butanol fraction of Sida pilosa Retz in Schistosoma mansoni-infected mice

ETHNOPHARMACOLOGICAL RELEVANCE

Sida pilosa Retz (Malvaceae) is a plant used in Africa for the treatment of intestinal helminthiasis, lower abdominal pains and dysmenorrhea.

AIM OF THE STUDY

In order to determine the potential use of S. pilosa in the treatment of schistosomiasis mansoni, we evaluated the schistosomicidal, antioxidant and anti-fibrotic properties of the aqueous extract and the n-butanol fraction of its aerial parts.

MATERIAL AND METHODS

S. pilosa aqueous extract (SpAE) at 100, 200 and 400mg/kg and n-butanol fraction (SpBF) at 50, 100 and 200mg/kg were administered per os to Schistosoma mansoni-infected mice for 4 weeks. Praziquantel (100mg/kg × 5 days) was used as reference drug. After sacrifice, worm burden and egg count, transaminases and proteins levels were evaluated. Malondialdehyde (MDA), lipid hydroperoxydes (LOOH), catalase (CAT), superoxide dismutase (SOD), eosinophil peroxidase (EPO) and myeloperoxidase (MPO) were also measured. The anti-fibrotic effect of the plant was evaluated by the determination of hydroxyproline and γ-interferon (IFN-γ).

RESULTS

The treatment of S. mansoni-infected mice by SpAE or SpBF resulted in a moderate reduction of worm burden and egg load in the liver and intestine. Both SpAE and SpBF significantly reversed the increasing liver proteins, MDA, LOOH and CAT levels induced by the infection. Moreover, SOD activity was improved by SpAE and SpBF. Schistosomiasis mansoni considerably increased the EPO (p<0.001) and MPO activities (p<0.001). SpAE treatment significantly reduced EPO and MPO activities at all doses. SpBF failed to reduce the increasing MPO and decreased EPO only at the highest dose. S. mansoni-infection induced an increase in hydroxyproline content (p<0.001) and a decrease in IFN-γ level (p<0.001). Both SpAE and SpBF significantly reduced hepatic hydroxyproline content, while only SpAE (p<0.05) improved IFN-γ level.

CONCLUSION

These results suggest that the liver pathology in schistosomiasis mansoni is improved by S. pilosa aqueous extract, which disclosed a moderate schistosomicidal, but strong antioxidant and anti-fibrotic activities. The n-butanol fraction was however less active than the aqueous extract.