In vitro effect of Nigella sativa oil on adult Toxocara vitulorum

Since the integrity of Toxocara vitulorum cuticle is essential for the nutritive and protective functions, light and scanning electron microscopic studies were undertaken to assess, for the first time, whether the Nigella sativa oil (NSO) had any effect on the cuticle of adult T. vitulorum following incubation in vitro. Differences in response to NSO action were observed, depending on the used concentration. After 24 h incubation with 0.5 mg mL(-1) NSO, the cuticle of the anterior end of worms appeared to be slightly more swollen than normal. This swelling became pronounced and so severe, with lips showed wrinkled cuticular surface and deformed sensory papillae on increasing the concentration to 1.0 mg mL(-1). With the higher concentration of 1.5 mg mL(-1), extensive and severe disorganization of the cuticle and body musculature was observed. Structural alterations in the cuticle as observed in the present investigation were thus, clear indication of nematocidal activity of NSO that could offer a suitable and cheaper alternative for the more expensive anthelmintics.