Hostname: page-component-848d4c4894-75dct Total loading time: 0 Render date: 2024-06-01T15:58:54.583Z Has data issue: false hasContentIssue false

Effects of chloroquine on Plasmodium knowlesi in vitro

Published online by Cambridge University Press:  06 April 2009

W. E. Gutteridge
Affiliation:
National Institute for Medical Research, Mill Hill, London NW7 1AA
P. I. Trigg
Affiliation:
National Institute for Medical Research, Mill Hill, London NW7 1AA
P. M. Bayley
Affiliation:
National Institute for Medical Research, Mill Hill, London NW7 1AA

Extract

The binding of chloroquine to DNA isolated from P. knowlesi has been investigated. In the presence of increasing concentrations of malarial DNA, the absorption spectrum of chloroquine exhibited strong hypochromism in the range 325–350 nm, small red shifts of the absorption maxima and an isosbestic point at 300 nm. The fluorescence emission of the drug at 380 nm (excitation 330 nm) was quenched five-fold by malarial DNA. Chloroquine itself protected malarial DNA from thermal denaturation. These data are consistent with binding of the drug to malarial DNA as has been suggested from studies with DNA from bacteria and mammalian cells. The binding affinity for malarial DNA is of the same order as that for mammalian DNA.

The effect of chloroquine on the metabolism of P. knowlesi in culture was also investigated. There was a direct correlation between concentrations of drug which affect the morphology of parasites and those which affect markedly the incorporation of 3H-adenosine into DNA and RNA, 14C-isoleucine incorporation into protein and the formation of lactate as a result of respiration. However, all processes were inhibited to the same extent, indicating that binding to DNA is not the only action of the drug.

The mode of action of chloroquine and the question of resistance to it are discussed.

One of us (P. I. T.) received financial assistance from the World Health Organization. We thank Dr F. Hawking and Dr J. Williamson for many helpful discussions, Dr K. N. Brown for reading through the manuscript, and Miss Jane Dunnett, Mrs A. C. Gutteridge and Mr T. Scott-Finnigan for skilled technical assistance.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1972

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

Allison, J. L., O'Brien, R. L. & Hahn, F. E. (1965). DNA: reaction with chloroquine. Science 149, 1111–13.CrossRefGoogle ScholarPubMed
Cohen, S. N. & Yielding, K. L. (1965). Spectrophotometric studies of the interaction of chloroquine with DNA. Journal of Biological Chemistry 240, 3123–31.CrossRefGoogle Scholar
Fitch, C. D. (1969). Chloroquine resistance in malaria: a deficiency of chloroquine binding. Proceedings of the National Academy of Science 64, 1181–7.CrossRefGoogle ScholarPubMed
Gutteridge, W. E. & Trigg, P. I. (1970). Incorporation of radioactive precursors into DNA and RNA of Plasmodium knowlesi in vitro. Journal of Protozoology 17, 8996.CrossRefGoogle ScholarPubMed
Gutteridge, W. E., Trigg, P. I. & Williamson, D. H. (1971). Properties of DNA from some malarial parasites. Parasitology 62, 209–19.CrossRefGoogle ScholarPubMed
Hahn, F. E., O'Brien, R. L., Ciak, J., Allison, J. L. & Olenick, J. G. (1966). Studies on modes of action of chloroquine, quinacrine and quinine and on chloroquine resistance. Military Medicine 131 (Supplement), 1071–89.CrossRefGoogle ScholarPubMed
Howells, R. E., Peters, W., Homewood, C. A. & Warhurst, D. C. (1970). Theory for the mechanism of chloroquine resistance in rodent malaria. Nature, London 228, 625–8.CrossRefGoogle ScholarPubMed
Macomber, P. B., O'Brien, R. L. & Hahn, F. E. (1966). Chloroquine: physiological basis of drug resistance in Plasmodium berghei. Science 152, 1374–5.CrossRefGoogle ScholarPubMed
Macomber, P. B., Sprinz, H. & Tousimis, A. J. (1967). Morphological effects of chloroquine on Plasmodium berghei in mice. Nature, London 214, 937–9.CrossRefGoogle ScholarPubMed
Polet, H. & Barr, C. F. (1968). Chloroquine and dihydrochloroquine: in vitro studies of their antimalarial effect upon Plasmodium knowlesi. Journal of Pharmacology and Experimental Therapeutics 164, 380–6.Google Scholar
Polet, H., Brown, N. D. & Angel, C. R. (1969). Biosynthesis of amino acids from 14C-U-glucose, -pyruvate and -acetate by erythrocytic forms of Plasmodium knowlesi in vitro. Proceedings of the Royal Society for Experimental Biology and Medicine 131, 1215–18.CrossRefGoogle ScholarPubMed
Schellenberg, K. A. & Coatney, G. R. (1961). The influence of antimalarial drugs on nucleic acid synthesis in Plasmodium gallinaceum and Plasmodium berghei. Biochemical Pharmacology 6, 143–52.CrossRefGoogle ScholarPubMed
Trigg, P. I. & Gutteridge, W. E. (1971). A minimal medium for the growth of Plasmodium knowlesi in dilution cultures. Parasitology 62, 113–23.CrossRefGoogle ScholarPubMed
Trigg, P. I., Gutteridge, W. E. & Williamson, J. (1971). The effects of cordycepin on malarial parasites. Transactions of the Royal Society of Tropical Medicine and Hygiene. (In the Press.)CrossRefGoogle Scholar
Warhurst, D. C. & Hockley, D. J. (1967). Mode of action of chloroquine on Plasmodium berghei and P. cynomolgi. Nature, London 214, 935–6.CrossRefGoogle ScholarPubMed
Warhurst, D. C. & Williamson, J. (1970). Ribonucleic acid from Plasmodium knowlesi before and after chloroquine treatment. Chemical-Biological Interactions 2, 89106.CrossRefGoogle ScholarPubMed