The effect of chloroquine on the male worms of Onchocerca volvulus in-vitro

Chloroqunie is a well-known anti-malaria drug commonly used in the tropics. Chloroquine was in this study, tested on adult male worms of Onchocerca volvulus to assess its possible effect. Male worms were mechanically isolated from nodules of untreated onchocerciasis patients. After 24hours incubation in a drug-free Minimum Essential Medium (MEM), they were transferred to fresh media containing varying concentrations of the drugs (0.3ug/ml, 0.5ug/ml,1ug/ml and 2ug/ml) for 24 and 48 hours respectively. The viability of the worms was assessed using two techniques: (a) measurement of motility using a micromotility meter and (b) determination of the rate of reduction to the MTT tetrezolium salt to Formazan. Heat-killed male worms were used as control. The motility of the worms decreased significantly 24 hours after exposure to the drugs and motility indices remained very low ill the end of the experiment. He M readings of the treated worm were indicative of viable but metabolically weak worms. Chloroquine showed the tendency of macrofilaricidal activity, and is an avenue that needs urgent exploration, in order to bring to an end the menace of the filarial parasite O. volvulus. br> The Nigerian Journal of Parasitology Vol. 24 2003: 71-7