Omega polyunsaturated fatty acids and parasitic infections: An overview.

Omega-3 and omega-6 polyunsaturated fatty acids are synthesized from the essential fatty acids alpha-linolenic acid and linoleic acid, respectively. They are pivotal components of all mammalian cells and were found to be useful in prevention and treatment of a variety of health problems owing to their anti-inflammatory and anti-microbial properties. Omega-3 and omega-6 polyunsaturated fatty acids are further metabolized to anti-inflammatory mediators, such as lipoxins, resolvins, and protectins. Moreover, these polyunsaturated fatty acids were found to have in vivo and in vitro protective efficacies against some parasitic infections. Therefore, dietary intake of polyunsaturated fatty acids should be encouraged because of their considerable beneficial effects.

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.

Effect of Mirazid in Schistosoma japonicum-infected mice: parasitological and pathological assessment.

Conflicting reports are found in the literature about the antischistosomal efficacy of Mirazid (MZ), which is a special formulation of myrrh obtained from the stem of the plant Commiphora molmol. This initiated the present study to assess this drug for the first time in experimental schistosomiasis japonicum. Mice were divided into four groups: infected untreated control (I); infected treated with MZ, 500 mg/kg (II); infected treated with MZ, 250 mg/kg (III); and infected treated with praziquantel (PZQ), 200 mg/kg (IV). The drugs were given 7 weeks post-infection for five successive days. All animals were killed 3 weeks posttreatment. Results showed no signs of antibilharzial activity of MZ. Total worms, total tissue egg load, egg developmental stages, and granuloma area were not affected by any of the MZ treatment regimens as compared to the infected untreated group (P > 0.05 for all variables). These results were in contrast to those obtained in PZQ-treated animals in which 82.82 % total worm reduction, 94.62 % egg reduction, and 86.35 % granuloma area reduction were observed. Also, it significantly increased the percentage of dead ova and decreased the percentage of mature ova with complete absence of immature ones in comparison with the control group (P < 0.01 for all variables). In conclusion, the results of the current study raise serious doubts about the antischistosomal activity of MZ.