title: Antitrypanosomal activity of Verbascum sinaiticum Benth. (Scrophulariaceae) against Trypanosoma congolense isolates.
abstract: BACKGROUND
  African Trypanosomiasis is a neglected tropical disease with a large impact on the livelihood of the rural poor in Sub-Saharan Africa. The available drugs for managing this disease are old, expensive and are facing the problem of drug resistance. Thus, the aim of this study was to evaluate in vivo antitrypanosomal efficacy of aqueous and absolute methanol leaf extracts of Verbascum sinaiticum Benth. against Trypanosoma congolense field isolate.
  
  
  METHODS
  Verbascum sinaiticum (Local name 'qetetina') is a biennial plant, and 60-150 cm tall. It is traditionally used to treat wound, stomachache, viral infection, cancer, sunstroke, fever, abdominal colic, diarrhea, hemorrhage, anthrax, and hepatitis. The efficacy of aqueous and absolute methanol leaf extracts of V. sinaiticum was evaluated in a randomized experiment with Swiss albino mice infected with T. congolense field isolate. The extracts were administered at doses of 100, 200 and 400 mg/kg by intraperitoneal injection for seven days at 12 Days Post-Infection (DPI) when the peak parasitaemia level was approximately 10(8) trypanosomes/ml. Parasitaemia, Packed Cell Volume (PCV), mean survival time and change in body weight were used as indices for monitoring the efficacy of the extracts. Diminazene (28 mg/kg) was used as a positive control while 2 % Tween was used as the negative control. Phytochemicals screening were conducted following standard methods.
  
  
  RESULTS
  The extracts showed no toxicity effect in Swiss albino mice and had LD50 above 2000 mg/kg. The phytochemicals screened in V. sinaiticum were alkaloids, flavonoids, glycoside, saponins, steroids, phenolic compounds, and tannins. The mice treated with absolute methanol leaf extract of V. sinaiticum at 400 mg/kg dose had significantly lower mean parasitaemia (7.20 ± 0.16) (p < 0.001) as compared to the negative control group (8.82 ± 0.12) on day 14 of treatment. Animals treated with the same dose had significant (p < 0.001) higher PCV value and body weight and as well as the highest mean survival time of 40.20 ± 0.31 days as compared to the negative control at the end of the observation period.
  
  
  CONCLUSIONS
  This study established that Verbascum sinaiticum had trypanocidal activity. The crude extracts have partially eliminated trypanosomes in a dose-dependent manner. The study can be a basis for future in-depth analysis of the biologically active chemicals.
authors.affiliation: Department of Pharmacology and Clinical Pharmacy, Faculty of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
authors.forename: Ermias
authors.initials: E
authors.lastname: Mergia
authors.affiliation: Department of Pharmacology and Clinical Pharmacy, Faculty of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
authors.forename: Workineh
authors.initials: W
authors.lastname: Shibeshi
authors.affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Addis Ababa University, Addis Ababa, Ethiopia.
authors.forename: Getachew
authors.initials: G
authors.lastname: Terefe
authors.affiliation: Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia. tilahunmt@yahoo.com.
authors.forename: Tilahun
authors.initials: T
authors.lastname: Teklehaymanot
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use / Q000633:toxicity; D014344:Trypanocidal Agents / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use / Q000633:toxicity; D014348:Trypanosoma congolense / Q000187:drug effects*; D014353:Trypanosomiasis, African / Q000188:drug therapy / Q000469:parasitology*; D032265:Verbascum / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D014344:Trypanocidal Agents
keywords: Ethiopia; In vivo; Phytochemical; Trypanosoma congolense; Verbascum sinaiticum