Effect of omega-3 fatty acids administered as monotherapy or combined with artemether on experimental Schistosoma mansoni infection.

Schistosomiasis is on the top list of endemic diseases in sub-Saharan Africa. Praziquantel is the drug of choice for treatment of human schistosomiasis. Yet, the sole dependence on the drug raises concerns about the potential for increased drug resistance, which would subsequently result in searching for alternative preventive chemotherapy options, ideally among natural compounds. Therefore, we conducted this work to assess the effect of omega-3 polyunsaturated fatty acids [(ω-3) PUFAs] monotherapy or combined therapy with artemether (ART) against Schistosoma mansoni infection in a mouse model. A total of 42 mice were divided into 4 groups and infected with 50 ± 5 S. mansoni cercariae for 10 weeks. Mice were treated orally with either (ω-3) PUFAs as 273 mg/ kg, 4 times/ week throughout the experiment, ART as a single dose of 400 mg/ kg, 3 weeks post-infection, or combined ART + (ω-3) PUFAs using the same respective treatment regimen, while infected untreated mice were served as controls. The study explored that combined administration of (ω-3) PUFAs and ART has the best schistosomicidal efficacy as it significantly reduced liver and spleen indices, worm count, egg burdens, and granulomas count as well as diameter. Besides, the combined regimen was associated with a significant decrease in both hepatic nitric oxide and serum interleukin-4 level. The results highlighted the possibility of using (ω-3) PUFA combined with ART as a novel anti-schistosomal combination therapy. However, further researches should be conducted to clarify the possible synergistic mechanism/s between the two natural compounds.

Prevention and treatment of Schistosoma mansoni-induced liver fibrosis in mice.

The present study was designed to examine the potential preventive and curative effects of curcumin, resveratrol, imatinib, rosiglitazone, losartan and bosentan (BOS) on Schistosoma mansoni-induced liver fibrosis in mice. Induction of liver fibrosis was produced in male Swiss mice by subcutaneous injection of S. mansoni cercariae per mouse. Mice were left for 28 days before starting the experiment then mice were divided into two main groups. The first group was further subdivided into experimental groups and started drug treatment at day 28 after infection and continued for 2 weeks in order to evaluate the potential preventive effects of the mentioned drugs on S. mansoni-induced liver fibrosis. The second group of mice were left for 2 weeks and then treated with praziquantel for two consecutive days to eradicate the worms and so stop egg disposition and further fibrosis development. Mice were then subdivided into the experimental groups and drug treatment was started for 2 weeks to evaluate their efficacy to decrease the developed fibrosis. At the end of the experiment period, mice were killed and serum was collected for the estimation of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin and albumin. Liver tissue was taken for the estimation of hepatic hydroxyproline content and histopathological examination to confirm the biochemical results. Results of the study indicate that curcumin and imatinib have potent antifibrotic activity both in suppressing and reversing S. mansoni-induced liver fibrosis, while resveratrol has beneficial effects only in suppressing the development of S. mansoni-induced liver fibrosis.