Biotropic Research International Journal Vol.1 (No.1) June, 2009 Adamu and Dukku . (2009). BRI J: Antischistosomal Effect of Seed Oil of Nigella sativa (Black Caraway) on Schistosoma mansoni. 50 www.Biotropicresearchinternational.com                   ANTISCHISTOSOMAL EFFECT OF SEED OIL OF Nigella sativa (Black caraway) ON Schistosoma mansoni IN MICE. * Adamu, S.U and Dukku, U.H Biological Sciences Programme, Abubakar Tafawa Balewa University,PMB 0248. Bauchi. *Corresponding Author. Email:usmanmodibbo@yahoo.com ABSTRACT Thirty male aalbino mice of about 4-5 weeks old weighing between 20-25gm obtained from Nation Veterinary Research Institute, Vom were challenged individually with 150-200 Schistosma mansoni cercaria obtained from laboratory bred Biomphalaria pfeifferi snails by tail immersion. On fourth week post infection, animals were divided in to three batches of 10 each. The first batch were treated with Praziquantel suspension at 200mg/kg b.w orally, the second batch were treated with 1ml seed oil of Nigella sativa while the third batch remain as untreated blank control and were orally administered with 70% glyreine. All treatments were over 10 days period.100% and 42.5% cure rates with 100% and 36.19% reduction in worm burden were recorded among animal treated with Praziquantel and seed oil of N. sativa respectively. Mortality rates of 10 and 30% were recorded among the seed oil treated group and the blank control respectively. The mean liver weight of all the experimental animals showed no significant statistical difference (P<0.05), there is however significant difference in mean liver score and total worm burden between the Praziquantel , N. sativa and the Blank control.(P<0.05) Key words: Seed oil, Antischistosoamal effect INTRODUCTION Schistosomiasis otherwise known as Bilharziasis is a public health problem with considerable magnitude in man and domestic animals. The disease is caused by a digenetic trematode of the family Schistosomatidae and genus Schistosoma with nineteen recognised species out of which seven are parasites to man (Johnston et al., 1993). Currently it affects over 200 million people in 76 countries of the world with another 600 million at risk (WHO, 1993). Many community-based programmes depend on Praziquantel for treating patients with schistosomiasis and other fluke infections. There is however, loss of Praziquantel efficacy (Charles et al., 2000) and its inaccessibility (Anthony et al., 1993) and high cost requiring hard currency (Kloos and McCollough, 1982) which set back helminthes control efforts. There is the need to screen local plants as other alternative source of schistosome chemotherapeutic agents. This claim is due to the frequent use of plants by most people in the developing third world countries in primary health care (Houghton, 1995,. Cox and Balik, 1994). Plants are known to offer excellent perspective for the discovery of new therapeutic product whose subsequent development may lead to discovery of a safe and therapeutically effective form of useful drugs (Philipson, 1994). In several trials using different plants, promosing antischiostosomal compounds were reported by several workers. In Guinea, the extract from the bark of Pavetta owariensis, Aliou et al., (1986),. Canxi and Enst (1982) roots of Melia azedrach (L); Kucera and Kucerova, (1975) Zingiber officinale (Ginger); Per et al., (2001) stem-bark and root extracts of Abrus precatorius (Fabiaceae) , Istifanus and Adamu, (2001), Leaves extracts of Erythrina