title: Contribution to in vitro screening of Egyptian plants for schistosomicidal activity.
abstract: BACKGROUND
  This study is a continuation of our previous work in which a bioassay screening of 346 methanol extracts from 281 Egyptian plant species was carried out for in vitro schistosomicidal activity.
  
  
  OBJECTIVE
  Another 309 methanol extracts from 278 plant species were subjected to the bioassay screening using the same technique on viable Schistosoma mansoni Sambon (Schistosomatidae) mature worms in specialized culture medium (Roswell Park Memorial Institute medium 1640) in a trial to discover a source for a schistosomiasis drug from Egyptian flora.
  
  
  METHODS
  The methanol plant extracts were tested in vitro against viable S. mansoni mature worms in culture medium. Viability of worms was examined after exposure to 100 μg/ml of the extract in the medium for 24 h. Negative (dimethyl sulfoxide) and positive (praziquantel) controls were simultaneously used. Extracts showing schistosomicidal activity were further subjected to determination of their (Lethal concentration) LC₅₀ and LC₉₀ values.
  
  
  RESULTS
  Confirmed in vitro antischistosomal activity was found in 42 extracts. Of these, 14 plant species possessed considerably high antischistosomal activity (LC₅₀ ≤ 15 µg/ml), viz. Callistemon viminalis (Soland. Ex Gaertn) Cheel, C. rigidus R.Br., C. speciosus (Sims.) DC, C. citrinus Stapf, Eucalyptus citriodora Hook, E. rostrata Dehnh., Eugenia edulis Vell, E. javanica Lam syn. Syzygium samarangense (Blume) Merril, Melaleuca leucadendron (L.) L., M. stypheloides Sm. (all belong to Myrtaceae), Cryptostegia grandiflora R.Br. (Asclepiadaceae), Zilla spinosa (L.) Prantl (Cruciferae), Ficus trijuja L. (Moraceae) and Fagonia mollis Delile (Zygophylacae).
  
  
  CONCLUSIONS
  These species may represent additional natural sources of bioactive material that deserve further investigation for drug discovery against schistosomiasis.
authors: Theodor Bilharz Research Institute, Schistosome Biological Supply Center, Cairo, Imbaba, Egypt. fouadyousif@hotmail.com
authors: Fouad
authors: F
authors: Yousif
authors: Gamila
authors: G
authors: Wassel
authors: Loutfy
authors: L
authors: Boulos
authors: Therese
authors: T
authors: Labib
authors: Khaled
authors: K
authors: Mahmoud
authors: Salwa
authors: S
authors: El-Hallouty
authors: Samia
authors: S
authors: El Bardicy
authors: Soheir
authors: S
authors: Mahmoud
authors: Fatem
authors: F
authors: Ramzy
authors: Lamiaa
authors: L
authors: Gohar
authors: May
authors: M
authors: El-Manawaty
authors: Mohamed A M
authors: MA
authors: El Gendy
authors: Walid
authors: W
authors: Fayad
authors: Bassem
authors: B
authors: El-Menshawi
mesh_terms: D000818:Animals; D055808:Drug Discovery; D004534:Egypt; D005260:Female; D020128:Inhibitory Concentration 50; D008297:Male; D000432:Methanol / Q000737:chemistry; D027822:Myrtaceae / Q000737:chemistry; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010944:Plants / Q000737:chemistry*; D012550:Schistosoma mansoni / Q000187:drug effects* / Q000254:growth & development; D012556:Schistosomicides / Q000302:isolation & purification / Q000494:pharmacology*; D012997:Solvents / Q000737:chemistry
chemical_list: D010936:Plant Extracts; D012556:Schistosomicides; D012997:Solvents; D000432:Methanol