Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T15:04:28.687Z Has data issue: false hasContentIssue false

Drug activity against Onchocerca gutturosa males in vitro: a model for chemotherapeutic research on onchocerciasis

Published online by Cambridge University Press:  05 June 2009

Simon Townson
Affiliation:
CAB International Institute of Parasitology, 395A Hatfield Road, St Albans, Herts AL4 0XU, UK
C. Connelly
Affiliation:
CAB International Institute of Parasitology, 395A Hatfield Road, St Albans, Herts AL4 0XU, UK
A. Dobinson
Affiliation:
CAB International Institute of Parasitology, 395A Hatfield Road, St Albans, Herts AL4 0XU, UK
R. Muller
Affiliation:
CAB International Institute of Parasitology, 395A Hatfield Road, St Albans, Herts AL4 0XU, UK

Abstract

An in vitro system for chemotherapeutic research using adult male Onchocerca gutturosa has been developed as a model for O. volvulus. Using a culture system consisting of medium MEM+10% heat inactivated foetal calf serum (IFCS)+LLCMK2 (monkey kidney) feeder cells in an atmosphere of 5% CO2 in air, we examined the effects of a range of antiparasitic drugs on worm motility. Ivermectin, levamisole, furapyrimidone, Mel W, chloroquine, metrifonate, flubendazole, amoscanate and the Ciba-Geigy compounds CGP 6140, CGP 20′376 and CGI 17658 either immobilized or significantly reduced motility levels at a concentration of 5x10−5M or less within a 7-day period. Worms were affected at very low concentrations by ivermectin (effective conc. to reduce motility levels to 50% of controls, 3.14x10−8M), levamisole (7.95x10−8M), CGP 6140 (8.87x10−9M) and CGP 20′376 (2.78x10−8M). Difficulties were experienced in accurately repeating the immotile endpoint for levamisole due to an inconsistent partial recovery of motility. Over a 7-day period diethylcarbamazine had little effect on motility levels, while suramin caused a slight increase in activity compared to controls at some timepoints. Subsequent experiments demonstrated some differences in drug efficacy depending on the presence or absence of serum and feeder cells in the culture system probably because of drug avidly binding to serum proteins. However, serum and cells were found to be essential ingredients of the culture system to maintain worms in good condition, indicating that new drugs should be evaluated both in the presence and absence of serum and cells. Comparisons were made between the responses of O. gutturosa and Brugia pahangi to certain drugs and these species were found to significantly differ in their sensitivities to ivermectin and a novel compound (Wellcome), indicating that Onchocerca parasites should be used wherever possible for compound identification and development intended for the treatment of onchocerciasis. The in vitro system described here, using male O. gutturosa, provides a basis for further research and a practical alternative to O. volvulus.

Type
Research Papers
Copyright
Copyright © Cambridge University Press 1987

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Albiez, E. J., Kaiser, A., Walter, G., Newland, H.S., White, A. T., Greene, B. M., Taylor, H. R. & Buttner, D. W. (1987) Effects of high doses of DEC in onchocerciasis. Tropical Medicine and Parasitology, 38, 60.Google Scholar
Awadzi, K., Schulz-Key, H., Howells, R. E., Haddock, D. R. W. & Gilles, H. M. (1982) The chemotherapy of onchocerciasis. VIII. Levamisole and its combination with the benzimidazoles. Annals of Tropical Medicine and Parasitology, 76, 459471.CrossRefGoogle ScholarPubMed
Bianco, A. E., Nwachukwu, M. A., Townson, S., Doenhoff, M. J. & Muller, R. L. (1986) Evaluation of drugs against Onchocerca microfilariae in an inbred mouse model. Tropical Medicine and Parasitology, 37, 3945.Google Scholar
Comley, J. C. W., Rees, M. J., Lees, G. M., Hayes, D. J., Murgatroyd, R. C. & Selwood, D. (1987) In vitro leakage of incorporated [U-14C] adenine — a method for monitoring the extent of drug induced injury in cultured filarial parasites. Tropical Medicine and Parasitology, 38, 64.Google Scholar
Copeman, D. B. (1979) An evaluation of the bovine Onchocerca gibsoni — Onchocerca gutturosa model as a tertiary screen for drugs against Onchocerca volvulus in man. Tropenmedizin und Parasitologie, 30, 469474.Google Scholar
Court, J. P. & Lees, G. M. (1983) Improvement of in vitro culture conditions of B. pahangi four day old developing larvae for use in an antifilarial drug assay. Tropenmedizin und Parasitologie, 34, 162169.Google Scholar
Court, J. P., Martin-Short, M. & Lees, G. M. (1986) A comparison of the response of Dipetalonema viteae and Brugia pahangi adult worms to antifilarial agents in vitro. Tropical Medicine and Parasitology, 37, 375380.Google ScholarPubMed
Devaney, E. & Howells, R. E. (1984) The microfilaricidal activity of ivermectin in vitro and in vivo. Tropenmedizin und Parasitologie, 35, 4749.Google ScholarPubMed
Friedheim, E. A. H. (1961) Quelques observations concernant le pentylthiarsaphenyl-melamine (Mel W) dans le traitement des filarioses a O. volvulus et W. bancrofti. Annales del la Société Belge de Médecine Tropicale, 41, 367373.Google Scholar
Goodwin, L. G. (1984) Chemotherapy. In: Recent Advances in Research on Filariasis. Transactions of the Royal Society of Tropical Medicine and Hygiene, 78, (Supplement), 18.CrossRefGoogle Scholar
Howells, R. E., Mendis, A. M. & Bray, P. G. (1983) The mode of action of suramin on the filarial worm Brugia pahangi. Parasitology, 87, 2948.CrossRefGoogle ScholarPubMed
Jenkins, D. C., Topley, P. & Rapson, E. B. (1987) Fasciola hepatica in vitro: increased susceptiblity to fasciolicides in a defined serum-free medium. Parasitology, 95, 165171.CrossRefGoogle Scholar
Mendis, A. H. W. & Townson, S. (1985) Evidence for the occurrence of respiratory electron transport in adult Brugia pahangi and Dipetalonema viteae. Molecular and Biochemical Parasitology, 14, 337354.CrossRefGoogle ScholarPubMed
Nowak, M., Hutchinson, G. W. & Copeman, D. B. (in press) In vitro drug screening in isolated male Onchocerca gibsoni using motility suppression. Tropical Medicine and Parasitology.Google Scholar
O'Dowd, A. B., Holmes, L. S., Court, J. P. & Mendis, A. H. W. (1985) The effect of some metabolic inhibitors on the lactic acid output by intact Brugia pahangi. Tropical Medicine and Parasitology, 36, 27.Google Scholar
Rapson, E. B., Chilwan, A. S. & Jenkins, D. C. (1986) Acetylcholinesterase secretion — a parameter for the interpretation of in vitro anthelmintic screens. Parasitology, 92, 425430.CrossRefGoogle ScholarPubMed
Rivas-Alcala, R., Mackenzie, C. D., Gomez-Rojo, E., Green, B. M. & Taylor, H. R. (1984) The effects of diethylcarbamazine, mebendazole and levamisole on Onchocerca volvulus in vivo and in vitro. Tropenmedizin und Parasitologie, 35, 7177.Google ScholarPubMed
Staniunas, R. J. & Hammerberg, B. (1982) Diethylcarbamazine-enhanced activation of complement by intact microfilariae of Dirofilaria immitis and their in vitro products. Journal of Parasitology, 68, 809816.CrossRefGoogle ScholarPubMed
Striebel, H. P., Gallay, J. J., Gelzer, J., Jenny, E. F., Rao, V. R., Reddy, A. B. & Subramanyam, D. (1986) Three new chemotherapeutic agents with potent antifilarial activity. Tropical Medicine and Parasitology, 37, 91.Google Scholar
Townson, S., Connelly, C. & Muller, R. (1986) Optimization of culture conditions for the maintenance of Onchocerca gutturosa adult worms in vitro. Journal of Helminthology, 60, 323330.CrossRefGoogle ScholarPubMed
Townson, S., Holmes, L., Court, J. & Ham, P. (1984) The in vitro culture and drug responses of Onchocerca lienalis infective larvae in the presence and absence of mammalian cells. Parasitology, 89, lxx-lxxi.Google Scholar
WHO (1983) Onchocerciasis Chemotherapy Project. Report of a scientific working group on the biochemistry of filarial and allied parasites. Publ. by the World Health Organization, OCP/OCT/83.1.Google Scholar
WHO (1985a) 10 years of onchocerciasis control. Review of the work of the Onchocerciasis Control Programme in the Volta River basin area from 1974 to 1984. Publ. by the World Health Organization, OCP/GVA/85.1B.Google Scholar
WHO (1985b) Report of the 11th meeting of the scientific working group on filariasis on review of filaricide screening methods and results in relation to synthetic chemistry, biochemistry and toxicology held jointly with the Onchocerciasis Chemotherapy Project. Publ. by the World Health Organization, TDR/FIL-SWG(11).85.3.Google Scholar
Williams, J. F., Mackenzie, C. D., Guderian, R., Bennett, J. L. & Vande Waa, B. (1987) Antifilarial activity of chloroquine and other aminoquinolines. Tropical Medicine and Parasitology, 38, 75.Google Scholar