Assessment of Anthelminthic Activity of Plant Extracts on Ancylostoma Ceylanicum and the Development of a Toxicity Bioassay

Soil-transmitted helminthes are intestinal parasites that contribute to major disease burden in people within tropical and impoverished areas. It has been estimated this blood sucking parasite has been responsible for the loss of over one million liters of blood per day. Recently, resistance to current control programs has rendered it necessary to develop new treatments. Earlier projects within the lab have assessed the anthelmintic effects of plant extracts and their enriched fractions on Ancylostoma ceylanicum ex vivo. The plants Dalea ornata and Oemlaria cerasiformis have shown efficacy with adult worms showing either significant decreases in motility or mortality. The additional fractions tested, however, did not display anthelminthic activity. Another important step was to develop an assay testing the toxicity of the extracts to mammalian cells. Three were attempted: a Trypan Blue assay, a Flow Cytometer assay, and a Cell Counting Kit assay. All of them used hamster splenocytes with the extracts at various concentrations. Death and mitosis were monitored over a three to five day period and compared with the control

Evaluation of the toxicity to mammalian cells of plant extracts with anthelminthic activity

Hookworm infection is one of the most common and important tropical diseases in the world, affecting over 700 million people within impoverished areas worldwide. Frequent deworming with benzimidazoles is the current treatment. However, this method has begun to show resistance, rendering it necessary to develop new treatments. Despite the need, research and production has been essentially neglected for the past three decades because drug development for impoverished areas provides little commercial gain. Within Dr. Blaise Dondji’s lab and in collaboration with Dr. Gil Belofsky, the plants Dalea ornata and Oemlaria cerasiformis have already shown in vitro activity against hookworm, but their toxicity remains to be tested. My current plan will be to test the toxicity of the plants to mammalian cells because they must demonstrate their safety before in vivo testing. Safety will be assessed by measuring the death and efficiency of cell division using C2C12 mouse myoblasts and hamster spleen cells

Phenolic Metabolites of Dalea ornata Affect Both Survival and Motility of the Human Pathogenic Hookworm Ancylostoma ceylanicum

Hookworms are ubiquitous human parasites, infecting nearly one billion people worldwide, and are the leading cause of anemia and malnutrition in resource-limited countries. Current drug treatments rely on the benzimidazole derivatives albendazole and mebendazole, but there is emerging resistance to these drugs. As part of a larger screening effort, using a hamster-based ex vivo assay, anthelmintic activity toward Ancylostoma ceylanicum was observed in the crude extract of aerial parts of Dalea ornata. These studies have led to the isolation and characterization of phenolic metabolites 1–10. The structures were determined by 1D and 2D NMR spectroscopy, and the absolute configuration of 1 was assigned using electronic circular dichroism data. The new compound, (2S)-8-(3-methylbut-2-en-1-yl)-6,7,4′-trihydroxyflavanone, was weakly active at 7.3 μM, with 17% reduction in survival of the hookworms after 5 days. The rotenoids deguelin and tephrosin, predictably perhaps, were the most active, with complete worm mortality observed by day 4 (or earlier) at 6.3 and 6.0 μM, respectively. The effects of 1–10 on hookworm motility and on toxicity to hamster splenocytes were also explored as important measures of treatment potential

Phenolic Metabolites of <i>Dalea ornata</i> Affect Both Survival and Motility of the Human Pathogenic Hookworm <i>Ancylostoma ceylanicum</i>

Hookworms are ubiquitous human parasites, infecting nearly one billion people worldwide, and are the leading cause of anemia and malnutrition in resource-limited countries. Current drug treatments rely on the benzimidazole derivatives albendazole and mebendazole, but there is emerging resistance to these drugs. As part of a larger screening effort, using a hamster-based ex vivo assay, anthelmintic activity toward <i>Ancylostoma ceylanicum</i> was observed in the crude extract of aerial parts of <i>Dalea ornata</i>. These studies have led to the isolation and characterization of phenolic metabolites <b>1</b>–<b>10</b>. The structures were determined by 1D and 2D NMR spectroscopy, and the absolute configuration of <b>1</b> was assigned using electronic circular dichroism data. The new compound, (2<i>S</i>)-8-(3-methylbut-2-en-1-yl)-6,7,4′-trihydroxyflavanone (<b>1</b>), was weakly active at 7.3 μM, with 17% reduction in survival of the hookworms after 5 days. The rotenoids deguelin (<b>9</b>) and tephrosin (<b>10</b>), predictably perhaps, were the most active, with complete worm mortality observed by day 4 (or earlier) at 6.3 and 6.0 μM, respectively. The effects of <b>1</b>–<b>10</b> on hookworm motility and on toxicity to hamster splenocytes were also explored as important measures of treatment potential