Potential use of Herbal Anthelmintics as Alternative Antiparasitic Drugs for Small Holder Farms in Developing Countries

Abstract

Helminth control programs, base on improvement of farm management and regular anthelmintic treatment, are often impracticable in developing countries due to relatively high price of modern anthelmintics for the smallholder. For centuries farmers have used traditional medicinal plants to treat the parasites. Medicinal plants may become good alternatives for modern synthetic anthelmintics in smallholder farms if their efficacy can be proofed scientifically under controlled studies. Study on the possible use of traditional herbal anthelmintic in our laboratory has been done in three phases. The first screening of plant materials was done by dose titration study in rodent using Hymenolepis spp (cestode), Heligmosomoides polygyrus (strongyloid) and Aspiculuris tetraptera (pinworm) as parasite models. Dose titration trial in second phase study was carried out using target parasite such as Ascaridia galli (chicken) and Haemonchus contortus (sheep) to get appropriate dose for treatment in the following field trials. A number of plant materials have been screened for anthelmintic properties including Carica papaya, Morinda citrifolia, Ananas comosus, Coleus blumei, Codiaceum variegatum and Leucana leucocephala. Results of the studies revealed that papaya seed showed high efficacy against parasite models Aspiculuris tetraptera and Hymenolepis nana in mice. A high effiucay against H. nana was also found in Coleus blumei, Codiaceum variegatum Papaya latex has shown high efficacy against ascarid in chicken and pigs, but it caused high toxicity when given to ruminants. Thereby the latex can be considered to be used as a narrow spectrum anthelmintic in monogastric animals. Morinda citrifolia fruit posses potency as broad spectrum anthelmintic as it showed high efficacy against Haemonchus contortus and Hymenolepis nana. No anthelmintic effect was found when testing Leucana leucocephala seed extract.