TOXICOLOGICAL STUDIES ON THE EFFECTS OF CYPRIPEDIUM REGINAE ROOTS ON C. ELEGANS

Intestinal nematode worm infections are among the most common diseases faced by humans in developing countries. An estimated two billion people harbor these infections, as stated by the World Health Organization. Livestock and crops are also widely affected with the parasites. There are already multiple anthelmintic drugs to treat this condition and the most successful has proven to be ivermectin. Unfortunately, an increasing number of livestock has become resistant to anthelmintics worldwide and this is beginning to become an issue in humans as well. The book, Native American Medicinal Plants, by Daniel Moerman, states that Native Americans commonly used lady’s slipper roots to cure intestinal worm infections. This may prove to be a valid alternative to currently used anthelmintics. To test this theory, we conducted a series of experiments that monitored the effects of water-based and ethanol-based extracts from roots of the orchid, Cyprepedium reginae (showy lady’s slipper), on the nematode Caenorhabditis elegans (C. elegans). We developed exposure and observation methods where we exposed synchronized C. elegans to varying dilutions of the extracts in 96 well microtiter plates and observed their survival by counting the number of dead and alive worms every hour over a period of five to six hours. Overall, the worms exposed to a water-based extract showed a survival rate of 83%, whereas worms exposed to a root extract prepared in 75% ethanol showed a much lower survival rate of 30%. To prove that the alcohol was not the active substance killing the worms, our later experiments used an extract prepared from roots ground in 75% ethanol that was evaporated and then resuspended in distilled water. The survival rate in these experiments was 37.3%. Finally, we show that almost three times as many worms died in the group with root extract than in the group without, suggesting that lady's slipper roots are in fact the active ingredient killing the worms. Our data therefore demonstrate that lady’s slipper root extracts prepared in ethanol are effective at killing worms in vitro.