In vitro Anthelmintic Activity of Bidens pilosa Linn. (Asteraceae) Leaf Extracts against Haemonchus contortus Eggs and Larvae.

Haemonchus contortus is a major health and welfare problem for small ruminants, responsible for economic losses through reduced productivity and increased mortality. The in vitro efficacy of Bidens pilosa was determined against this gastrointestinal nematode (GIN). Fresh eggs, embryonated eggs and larvae (L1 and L2) were incubated at room temperature in infused aqueous extract, macerated aqueous and ethanolic leaf extract of B. pilosa at concentrations of 0.625, 1.25, 2.5, 3.75 and 5 mg/ml for 48, 6 and 24 hours, respectively. Distilled water and 1.5% Tween 80 were used as negative controls. They did not affect development of eggs and larvae whereas extracts showed a concentration dependent activity eventhough aqueous extracts exhibited a weak activity on the different developmental stages of H. contortus compared to ethanolic extract. Ethanolic extract was more potent on larvae than on eggs. It inhibited 92.5±7.5% and 67.4±7.4% egg embryonation and egg hatch at 5 mg/ml, with IC50 values of 2.1 mg/ml and 3.3 mg/ml respectively and induced 100±0% and 89.8±3.2% L1 and L2 larvae mortality at 5 mg/ml with LC50 values of 1.8 and 1.96 mg/ml respectively. The overall findings of the current study indicated that the evaluated medicinal plant in occurrence B. pilosa possess potential anthelmintic effect and further in vivo and toxicity evaluation are indispensable to validate its use as anthelmintic for the control of GIN.

In vivo Anthelmintic Activity of Terminalia glaucescens (Combretaceae) Extracts against Gastrointestinal Nematodes of Sheep.

Background: Gastrointestinal nematodes (GIN) are a major threat to sheep productivity and endanger animal welfare worldwide particularly in developing countries. They cause loss of production through mortality, weight loss, reduced milk, meat and wool production. Thus, parasitism is an important limiting factor or constraint in livestock production. Aim: To evaluate the anthelmintic activity of organic and aqueous extracts of stem bark of Terminalia glaucescens against gastrointestinal nematodes of sheep using varieties of in vivo tests. Materials and Methods: Thirty (30) West African Dwarf Djallonke sheep acquired natural infection with gastrointestinal nematodes of both sexes, aged 6-10 months old and weighing between 9-13kg, use in bioassay were distributed into 5 groups (n=6). Two experiments using methanol (Groups A to E) and hot water extracts ( Groups A’ to E’) were simultaneously carried out. Groups A & A’ received 1.25% dimethyl sulfoxide (DMSO) and distilled water 1ml/10 kg bwt respectively, Groups B & B’ received Albendazole at 6.25mg/kg bwt, Groups C & C’, D & D’ and E & E’ received doses of 125, 250 and 500 mg/kg bwt of each extract. Sheep were subjected to different treatment with single dose of synthetic drug and double doses of plant extracts. Results: Methanol extract for all the doses tested was active in vivo on the adults of GIN, and reduced significantly (p<0.05) the faecal egg count (FEC) and total warm count (TWC) of the nematodes. The dose rate 500mg/kg showed the highest nematicidal activity of 77, 6% FEC and 73, 5% TWC reduction 14 days post-treatment. For hot water extract, these numbers were 65, 3% and 62, 1% for FEC and TWC respectively at the same dose for the same period of treatment. Conclusion: These results suggest the possible use of this medicinal plant in the control of gastrointestinal nematodes in sheep and justify their use in traditional veterinary practices; hence a toxicological study of the extract of this plant is required.

In vitro anthelminthic efficacy of Dichrocephala integrifolia (Asteraceae) extracts on the gastro-intestinal nematode parasite of mice: Heligmosomoides bakeri (Nematoda, Heligmosomatidae)

<p><b>OBJECTIVE</b>To evaluate the ovicidal and larvicidal activities of aqueous and ethanolic extracts of leaves of Dichrocephala integrifolia (D. integrifolia) against the eggs (fresh and embryonnated), the first and second larval stages of Heligmosomoides bakeri. In order to verify if this medicinal plant possesses active compounds capable of inhibiting the embryonation and hatching of eggs or to induce the mortality of larvae (L1 and L2).</p><p><b>METHODS</b>dried extracts were diluted in distilled FIV water to obtain five different concentrations: 625, 1,250, 2,500, 3,750 and 5,000 µg/mL. Fresh eggs obtained from artificially infected mice feces were exposed to these different concentrations for 48 h. Time of contact for embryonated eggs was 6 h while L1 and L2 larvae were exposed for 24 h. Distilled water (placebo) and 1.5% DMSO were used as negative controls.</p><p><b>RESULTS</b>Distilled water, and 1.5% DMSO had no effect on embryonation, hatching and larval survival. Aqueous extracts of D. integrifolia showed a weak activity against all stages of the parasite at all concentrations tested. On the contrary, the ethanolic extract of D. integrifolia inhibited the embryonation of 87.5% of fresh eggs, the hatching of 81.1% of embryonated eggs and induced the mortality of 98.1% and 98% of L1 and L2 larvae respectively at 5,000 µg/mL.</p><p><b>CONCLUSIONS</b>The results of the present study indicate that the ethanolic extracts of D. integrifolia contained compounds with ovicidal and larvicidal properties. In spite of these results, in vivo tests, studies on toxicity and mechanism of action of active compounds are also needed to validate the utilisation of this medicinal plant by population of Dschang-Cameroon to treat gastro-intestinal parasites.</p>

Acute and sub-acute toxicity of ethanolic extract of Canthium mannii Hiern stem bark on Mus musculus.

Acute and sub-acute toxicity of ethanolic extract (ETE) of C. mannii was assessed on white mice (Mus musculus). After 48 h of extract administration, no death was registered. It was deduced that the LD50 was indisputably higher than 16 g/kg body weight. The sub-acute toxicity test was based on the daily administration of three doses of ETE (300, 600 and 1200 mg/kg body weight) for four weeks; 1% DMSO served as negative control. As for the first experiment, no sign of toxicity was registered. Conversely, the sub acute doses stimulated and increased the weight-rate of mice after 7 days of treatment. Except for the spleen weight, the doses administrated did not modify the weight index. It was observed that, sub-acute doses induced and increased (a) the food (particularly) and water consumption according to time and (b) the number of red and white blood cells. It was thought that, ETE can stimulate the haematopoietic function. Finally, no time variation of the activity of alanine aminotransferase and aspartate aminotransferase enzyme was observed in the serum of euthanized mice. The results showed the innocuity of ETE of C. mannii and thus validated his utilization in cameroonian traditional pharmacopoea.