4-Nonylphenol
(NP) is an emerging concern contaminant which is widely spread in the
aquatic ecosystem. Nigella sativa seed (NSS) has multifaceted therapeutic values. This
study aimed to give insight into the potential protective effect of NSS on NP-induced
haematotoxicity in Clarias gariepinus through evaluation of haematological parameters,
oxidant/antioxidant balance of blood lysate and histopathological investigation of
blood smear. One hundred and fifty fish were divided into five groups (30/group). First
group served as control which did not received NP exposure and fed basal diet without
NSS supplementation. The other four groups were exposed to NP at a dose of
0.1 mg L−1 and fed diets supplemented with NSS at levels of 0, 10, 25 and 50 g/kg diet,
respectively. Macrocytic hypochromic anaemia, thrombocytopenia, leucopenia, neutrophilia,
lymphopenia, monocytosis and eosinophilia were observed following NP exposure
together with increase in morphological erythrocyte alterations and micronuclei
formation. Elevation in total peroxide and malondialdehyde and depletion in total antioxidant
capacity of blood lysate were reported. We concluded that supplementation
of NSS markedly ameliorated the previously listed manifestations, and the most effective
doses were 25 and 50 g/kg feed.