Efficacy of Sida pilosa Retz aqueous extract against Schistosoma mansoni – induced granulomatous inflammation in the liver and the intestine of mice: histomorphometry and gastrointestinal motility evaluation

BACKGROUND: The macerate of Sida pilosa aerial parts is used empirically for the treatment of intestinal helminthiasis. Previous studies have shown that Sida pilosa aqueous extract (SpAE) has schistosomicidal, antioxidant, anti-inflammatory and anti-fibrotic activities in Schistosoma mansoni infection. This study was designed to evaluate the effect of SpAE on the granulomatous inflammation induced by S. mansoni in the liver and the intestine of mice by histomorphometry; as well as on the gastrointestinal motility. METHODS: To study the effect of SpAE on the liver and intestine histomorphometry and on the gastrointestinal motility, SpAE was administered at 200 mg/kg per os to S. mansoni-infected mice for 4 weeks. Praziquantel was used as reference drug. Prior to carrying out sacrifice, a batch of mice was subjected to gastrointestinal transit evaluation with 3% charcoal meal. After sacrifying another batch of mice, we performed histological and morphometric analyses of the liver and the ileum. We measured the following: total proteins, transaminases, malondialdehyde, nitrites, superoxide dismutase, catalase and reduced glutathione. The effect of SpAE (4, 8, 16 and 32 mg/mL) on the ileum contractile activity was evaluated either in the absence or in the presence of pharmacological blockers. RESULTS: SpAE induced a significant reduction of hepatosplenomegaly and intestine enlargement. The number of granulomas was reduced by 52.82% in the liver and 52.79% in the intestine, whereas the volume of hepatic granulomas decreased by 48.76% after SpAE treatment. SpAE also reduced (p < 0.001) the ileal muscular layer thickness. The levels of total proteins, transaminases, malondialdehyde, nitrites, superoxide dismutase, catalase and reduced glutathione were restored after treatment of infected mice with SpAE. A normalization of the gastrointestinal transit was also recorded after SpAE treatment. The effect of SpAE on intestinal motility was mediated via intracellular and extracellular calcium mobilization. CONCLUSION: Our findings provide evidence that SpAE improves granulomatous inflammation induced by S. mansoni both in the liver and in the intestine, as well as it re-establishes normal gastrointestinal transit. SpAE may be used for the development of alternative medicine against S. mansoni infection.