Schistosoma mansoni is one of the parasites causing schistosomiasis, a disease which threatens millions of people all over the world. Traditional chemical drugs are not fully effective against schistosomaisis due to the evolving drug resistant worm strains, so exploring new remedies derived from natural products is a good way to fight schistosomiasis. In the present investigation two natural products, Nigella sativa oil and Chroococcus turgidus extract were used separately or in a combination to explore their effect on S. mansoni. The infected mice treated with Chroococcus turgidus extract or/and sativa seed oil showed a significant decrease in the total worm burden. The total number of deposited eggs by females of S. mansoni was significantly decreased in the liver of mice treated with Chroococcus turgidus extract or/and sativa seed oil. However, in the intestine, the number of eggs was significantly reduced in mice treated with algal extract and those treated with both algal extract and oil. Fecundity of female S. mansoni showed a significant decrease from mice treated with algal extract or/and sativa seed oil. According to SEM investigations the tegmental surface, oral and ventral suckers of worms also showed considerable changes; as the tubercles lost their spines, some are swollen and torn out. The suckers become edematous and enlarged while the tegmental surface is damaged due to the treatment with Chroococcus turgidus extract or/and sativa seed oil. In conclusion, the Nigella sativa oil and Chroococcus turgidus extract are promising natural compounds that can be used in fighting schistosomiasis.
Keywords: Black seed; Chroococcus turgidus; Cyanophyte; Electron microscopy; Schistosoma.