Effects of Nigella sativa Aqueous Seed Extract on Larval Stages of Schistosoma haematobium

Abstract

Aims: To determine the lethal effect of Nigella sativa seed extract concentrations on the egg viability and cercaria infectivity of Shistosoma haematobium in Nkalagu, Ishielu Local government area of Ebonyi State, Nigeria. Study Design: The study was carried out using standard parasitological and malacological techniques. Snail hosts were picked from waterbodies in the study sites for cercaria shedding, viability and potency for transmission while urine samples were collected from pupils in sampled schools closely located near the water bodies. Methodology: The urine samples were screened for the eggs of Schistosoma haematobium. Eggs and viable cercaria of S. haematobium extracted, were tested to determine the lethal effects of Nigella sativa (N. sativa) aqueous seed extract. Results: The egg viability test for Schistosoma haematobium showed that there was a statistical difference in the number of viable, calcified, and resistant eggs tested (p < 0.05) but recorded a significant difference at different time durations (p > 0.05). High morphological and tegumental changes in eggs of S. haematobium occurred at high concentrations and more extended periods of exposure to N. sativa aqueous seed extract. The reverse was observed at lower concentrations and shorter periods of exposure to the extract. This was the same case with cercaria upon exposure to N. sativa aqueous seed extract. The result also revealed that difference in mortality was statistically significant (p < 0.05) at different concentrations but not with time (p < 0.05) at various percentage dilutions. Conclusion: The current result on the cercaricidal activity of N. sativa suggests that this plant has a potential inhibitory effect on Schistosoma parasites and intermediate snail hosts. Therefore, there is a need for public awareness programs on the use of N. sativa seed due to its antiparasitic properties and its relevance against urinary schistosomiasis infection in endemic communities.