International Journal of Pharmaceutical Science Invention ISSN (Online): 2319 – 6718, ISSN (Print): 2319 – 670X www.ijpsi.org || Volume 4 Issue 1|| January 2015 || PP.47-54 www.ijpsi.org 47 | Page Evaluation of the Biocidal Activity of Alkaloids, Saponins and Volatile Oil Extracted from Nigella Sativa Seeds against Miracidia and Cercariae of Schistosoma mansoni 1 Khaled Abo-Zeid, 2,3 Mohamed Shohayeb 1 Department of parasitology, College of Medicine, Taif University, Saudi Arabia 2 Pharmaceutical Biotechnology Unit, College of pharmacy Taif University, Saudi Arabia 3 Department of Microbiology, Faculty of pharmacy Tanta University, Egypt ABSTRACT: Schistosomiasis is one of the most fatal diseases of humans. In Saudi Arabia, it is found in Jazan, Bishah, Aseer, Madina, Al-Bahah and Taif. In this study, the lethal properties of Nigella sativa alkaloids, saponins and volatile oil were tested in vitro against Schistosoma mansoni aquatic stages; miracidia and cercariae. The three bioactive constituents exerted a lethal effect on both miracidia and cercariae at concentrations below 1 ppm. Miracidia were more sensitive than cercariae to the lethal effect of three tested constituents. The volatile oil of N. sativa, was the most active constituent against both miracidia and cercariae. At 0.39 and 50ppm it killed 100% of the miracidia after 25 and 0.5 min and cercariae after 90 and 5 min respectively. Therefore it may be concluded that, the antimiracidial and anticercarial activity of sativa seeds could be attributed at least in part to its contents of volatile oil, saponins and alkaloids.Therefore, these three active constituents might be recommended for use in programs for controlling schistosomiasis. KEYWORDS: Schistosoma mansoni; Nigella sativa; alkaloids; volatile oil; saponins; cercariae; miracidia I. INTRODUCTION Schistosomiasis or bilharziasis is an ancient parasitic disease of man. Eggs of schistosoma have been recovered from Egyptian mummies several thousand years old [1]. Schistosomiasis is caused by a blood fluke of the genus Schistosoma, of which three species, namely S. mansoni, S. haematobium and S. japonicum, are the main causative agent of the disease in man [2]. Schistosomiasis is a fatal disease of humans which comes as the second parasitic disease after malaria in terms of overall morbidity and mortality. It is estimated that 200 million people are infected with schistosoma, of whom 20 million have severe disease [3]. Schistosomiasis is endemic in 54 countries in South America, Africa and Asia [4] and it is a major threat to public health in some Middle East countries like, Iraq, Sudan, Egypt, Yemen, and Saudi Arabia [1, 4-7] Both S. mansoni, S. haematobium are endemic in Saudi Arabia. According to the Ministry of Health, the prevalence of schistosomiasis in Saudi Arabia was 2.9/ 100,000 persons [8]. The highest prevalence was reported in Jazan, Bishah, Aseer, Al-Bahah and Taif. S. mansoni is more prevalent in Taif, Al- Bahah, Aseer, Bishah, Najran, Makkah Al- Mukarramah and Al- Medina [8] and it is presumably, transmitted by rodents, baboon monkeys and infected humans [9-11]. After the eggs of schistosoma parasite in faeces of hosts get into water, the ripe miracidia hatch out and invade the intermediate host freshwater snail where they form sporocysts. Cercariae are formed in sporocysts and emerge from the snails in water and search for humans or animals to penetrate their skin [12]. Therefore, to control schistosomiasis, the life cycle the life cycle of schistosoma should be interrupting for instance by killing cercaiae and miracidia [13-15]. The use of chemical compounds to control the aquatic snails, miracidia or cercariae, is not recommended because of their adverse effects on the environment [16]. Several plants that can decrease the shedding of cercariae and to kill both cercariae and miracidia have been reported. Phytolacca dodecandra (Phytolaccaceae) is considered as a natural efficient alternative to chemicals for controlling schistosomiasis [17,18] and it was environmentally acceptable [19]. Other examples include Tetrapleura tetraptera, which is used in South-west Nigeria under the name Aridan [20 ]; Ambrosia maritima L. (Damsisa) which is widely distributed throughout the Mediterranean region and was used to control of bilharziasis in Egypt [21,22] and M. thonningii which is highly active against both S. mansoni miracidia and cercariae [23]. The black seed, Nigella sativa L. is widely uses in folk medicine especially amongst Muslims as it was narrated that the prophet of Islam, Muhammad (peace be upon him), said “ it is a cure from all ailments” [24]. The crude oil of N. sativa hindered the penetration of skin by cercariae [25], and its ingestion by infected albino mice lead to topographic changes in adult worms [26]. In vitro, crushed N. sativa seeds and crude extracts were found to be active against S. mansoni miracidia, cercariae, and the adult worms ([27]. In this study, we purified the alkaloids, saponins and volatile oil of N. sativa and evaluated their lethal effect on cercariae and miracidia.