title: Extracts of Euphorbia hirta Linn. (Euphorbiaceae) and Rauvolfia vomitoria Afzel (Apocynaceae) demonstrate activities against Onchocerca volvulus microfilariae in vitro.
abstract: BACKGROUND
  Onchocerciasis transmitted by Onchocerca volvulus is the second major cause of blindness in the world and it impacts negatively on the socio-economic development of the communities affected. Currently, ivermectin, a microfilaricidal drug is the only drug recommended for treating this disease. There have been speculations, of late, concerning O. volvulus resistance to ivermectin. Owing to this, it has become imperative to search for new drugs. World-wide, ethnomedicines including extracts of Euphorbia hirta and Rauvolfia vomitoria are used for treating various diseases, both infectious and non-infectious.
  
  
  METHODS
  In this study extracts of the two plants were evaluated in vitro in order to determine their effect against O. volvulus microfilariae. The toxicity of the E. hirta extracts on monkey kidney cell (LLCMK2) lines was also determined.
  
  
  RESULTS
  The investigations showed that extracts of both plants immobilised microfilariae at different levels in vitro and, therefore, possess antifilarial properties. It was found that all the E. hirta extracts with the exception of the hexane extracts were more effective than those of R. vomitoria. Among the extracts of E. hirta the ethyl acetate fraction was most effective, and comparable to that of dimethanesulphonate salt but higher than that of Melarsoprol (Mel B). However, the crude ethanolic extract of E. hirta was found to be the least toxic to the LLCMK2 compared to the fractionated forms.
  
  
  CONCLUSIONS
  Extracts from both plants possess antifilarial properties; however, the crude extract of E. hirta was found to be least toxic to LLCMK2.
authors.affiliation: Department of Microbiology, University of Ghana Medical School, University of Ghana, Legon, Ghana. skwakuattah@yahoo.com
authors.forename: Simon K
authors.initials: SK
authors.lastname: Attah
authors.forename: Patrick F
authors.initials: PF
authors.lastname: Ayeh-Kumi
authors.forename: Archibald A
authors.initials: AA
authors.lastname: Sittie
authors.forename: Isaac V
authors.initials: IV
authors.lastname: Oppong
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Nyarko
mesh_terms: D000818:Animals; D000969:Antinematodal Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002460:Cell Line; D004351:Drug Resistance / Q000187:drug effects; D028481:Euphorbia; D000882:Haplorhini; D007559:Ivermectin / Q000494:pharmacology / Q000627:therapeutic use; D007668:Kidney / Q000187:drug effects; D008842:Microfilariae / Q000187:drug effects*; D017181:Onchocerca volvulus / Q000187:drug effects*; D009855:Onchocerciasis / Q000517:prevention & control; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D011926:Rauwolfia
chemical_list: D000969:Antinematodal Agents; D010936:Plant Extracts; D007559:Ivermectin