Browsing by Author "Tilahun, Getachew(Associate Professor )"

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    In Vitro and In Vivo Evaluation of Anthelmintic Activities of Crude Extracts of Selected Medicinal Plants Against Haemonchus Contortus
    (Addis Ababa University, 2005-12) Eguale, Tadesse; Mekonnen, Eyasu (Professor); Tilahun, Getachew(Associate Professor ); Debella, Asfaw (PhD)
    In the current study, in vitro experiments were conducted to determine the possible anthelmintic effects of crude aqueous and hydro-alcoholic extracts of the seeds of Croton macrostachyus, Ekebergia capensis, Coriandrum sativum, Acacia nilotica, Terminalia schimperiana, Jatropha curcas, leaves of Lawsonia inermis, Chenopodium ambrosioides, ripe berries of Hedera helix, and bark of Albizia gummifera on eggs and adult Haemonchus contortus. Aqueous extracts of C. sativum and H. helix were also investigated for toxicity (LD50 determination) in Albino mice and for in vivo anthelmintic activity in sheep infected with H. contortus. Both extract types of C. macrostachyus, E. capensis, C. sativum, J. curcas, A. gummifera and aqueous extract of A. nilotica inhibited hatching of eggs at concentration less than or equal to 2 mg/ml. Based on their ED50, the six most potent extracts were aqueous extract of E. capensis (0.06mg/ml), Hydro-alcoholic extract of C. ambrosioides (0.09mg/ml), aqueous extract of C. macrostachyus and J. curcas (0.1mg/ml) aqueous extract of C. sativum and H. helix (0.12mg/ml), in decreasing order of potency. Hydro-alcoholic extract of A. nilotica, both extracts of T. schimperiana and L. inermis did not inhibit hatching of eggs of H. contortus significantly and in dose dependent manner at all concentrations tested. Hydro-alcoholic extracts of most of the plants have shown better in vitro activity against adult parasites compared to the aqueous extract. Hydro-alcoholic extracts of C. macrostachyus, A. gummifera, C. sativum and H. helix produced mortality of adult H. contortus significantly to the level of 90, 86.67,85 and 66.67% at concentration of 8 mg/ml while aqueous extracts produced only 36.67, 33.33, 45,and 29.17% respectively at the same concentration. Like their activity on eggs, extracts of A. nilotica, T. schimperiana, J. curcas and L. inermis have shown no statistically significant effect on survival of the adult parasites at the concentrations tested, and a few mortality cases recorded were not dose dependent (p<0.05). Oral administration of aqueous extract of C. sativum didn’t produce mortality and no clinical sign of toxicity was detected in mice despite the high dose (15000 mg/kg) given, while intraperitonial (IP) administration caused mortality at lower doses. IP LD50 for C. sativum was 2177.5 mg/kg. Oral LD50 for H. helix was 3846.09 mg/kg. In vitro anthelmintic evaluation was conducted in total of 36 male sheep artificially infected with H. contortus. The sheep were randomly divided into six groups of six animals each. The first four groups were treated with crude aqueous extract of C. sativum (0.45g/kg), C. sativum (0.90g/kg), x H. helix (1.13g/kg), H. helix (2.25g/kg) respectively. The fifth group was treated with albendazole at 3.8mg/kg and the last group was left untreated. Efficacy was tested by faecal egg count reduction (FECR) and total worm count reduction (TWC). On day 2 post treatment, significant FECR was detected in group treated with higher dose of C. sativum, both doses of H. helix (p<0.05) and albendazole (p<0.001) compared to untreated control group. The maximum efficacy of the extracts observed on day 2 post treatment was 46.71% for higher dose of H. helix (2.25g/kg) and 24.79% for higher dose of C. sativum (0.9g/kg). On day 7 post treatment, significant reduction was detected only for higher dose of H. helix (p<0.05) and albendazole (p<0.001). The percentage reduction of FEC of sheep treated with both plant extracts decreased gradually on day 7 and day 14 post treatment, while that of albendazole increased from 97.8 on day 2 to 100% on day 14 post treatment. The percentage of larvae recovered from culturing faeces obtained from group of sheep treated with plant extracts was reduced in dose dependant manner compared to faeces obtained from untreated control group. Significant reduction (p<0.05) in TWC was detected for higher dose of C. sativum and both dose levels of H. helix compared to the untreated group. Reduction in male worm count was significant (p<0.05) in all treatment groups except for lower doses of C. sativum, while significant reduction of female worm count was detected only in the case of higher doses of H. helix. No worm was detected in the group treated with albendazole, indicating significant susceptibility of the strain of parasites employed in the current study. Treatment with both doses of H. helix helped the animals maintain their PCV while PCV of animals treated with C. sativum decreased significantly. Treatment with albendazole showed significant increase in PCV (p<0.05). The overall findings of the current study indicated that most of the plants have potential anthelmintic effect and further in vitro and in vivo evaluation is warranted to make use of these plants in the future.