In-vitro and In-vivo Evaluation of Anti-trypanosomal Activity of Carica papaya Seed Extracts and Fractions in Albino Wister Rats

Aims: This study presents baseline data on the In-vitro and In-vivo evaluation of anti-trypanosomal activity of Carica papaya seed extracts and fractions in Albino Wister rats.

Study Design: Mention the design of the study here.

Place and Duration of Study Sample: Department of Biochemistry, Modibbo Adama University of Technology, Yola, between June 2009 and July 2010.

Methodology: 56 Wister rats of both sexes were randomly divided into 8 groups (I – VIII) of 7 rats each were used for this study. Four concentrations (100, 200, 400 and 800 mg/kg) of different extracts of seed carica papaya were screened for trypanocidal activity against Trypanosoma brucei In vitro and In vivo. The effect of the extracts was evaluated for trypanocidal activity in rats infected and not infected with the parasite. Administration of the extract and the drugs was orally daily for 5 consecutive days from day 7 of post infection. Level of parasitemia and body weight was taken daily for 21 days.

Results: The extracts inhibited parasite motility and totally eliminated the organisms at the concentrations used In vitro. The extract also showed promising in vivo trypanocidal activity. The observed In vitro and In vivo trypanocidal activities may be due to the presence of bioactive compounds present in the extracts as seen in this study. The extract also improved the observed decreases in haematological parameters of the treated rats, which may be due to their ability to decrease parasite load. The LD50 was estimated to be ≥2,000 mg/Kg (v/v) for acute oral toxicity test (because all the rats survived at the end of the 14-day observation period). This is an indication of very low toxicity, implying that the extract could be administered with some degree of safety. A significant decreased (p<0.05) were observed in weight of rats at 100 mg/kg, 200 mg/kg 400 mg/kg 800 mg/kg negative control and prophylactic at four to eight days of infections, while significantly increased (p<0.05) were observed in weight of rats for berenil control and normal control.

Conclusion: The decrease in weight of rats could be as a result of loss of appetite due to severe fever and also the trypanosome.