The influence of the medium on the toxicity of certain alkaloids towards protozoa / by T.A. Henry and H.C. Brown.

  • Thomas Anderson Henry
Date:
[1923.]
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Licence: Public Domain Mark

Credit: The influence of the medium on the toxicity of certain alkaloids towards protozoa / by T.A. Henry and H.C. Brown. Source: Wellcome Collection.

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    TPTE INFLUENCE OF TPTE MEDIUIM ON TOXICrPY OK CElCrAIN ALKAI/IIDS TOWAKDS PKOTOZOA. HY T. A. HENRY, D.Sc. l)n'e('iov of the etIconic Chcmwol Rcscacch Tjoborofoi'irs. AND H, C. RROWX, C.I.E.. M.B., li.Cn, (Camb.), ^^ajor T.M.S. (rrt.). Wellcome Bureau of Scientific Bcaearch. Paper presented at a Meeting of the Boyal Society of Tropical Medicine and Hygiene, Thursday, 17th May, 1923. In a previous paper (Brown, 1922) it was shown that in vitro conessine, the principal alkaloid of Holandiena (Wrightia) antidysenterica bark (Pyman, 1919) was as toxic to free-living amoebae as emetine. It has now been found that the toxicity of both alkaloids towards protozoa is greatly increased in presence of alkali. This is only one out of a number of recent laboratory and clinical observations indicating that the action of alkaloids on protozoa is enhanced in an alkaline medium. Thus Acton (1922) found that quinine is more toxic to Paramsecium in presence of alkali, and, in the same year, Iriye found that the action of emetine on amoebae was intensified under like conditions. This year, Hinton has made practical use of these observations, and finds that quinine gives better results in malaria when administered with alkalis than when given alone. The data recorded in the present paper are derived solely from experiments in vitro, but as Hellards and 1jp:iva (192-1) have pointed out : “ In chemotherapeutic work on amoebic dysentery tests for toxicity of a druR for Ijimax amaebie are not without value for pui'poses of obtain- ing general orientation. Obviously the results cannot lie applied to Entaniceha histolytica any more than the effects of experiments on lower animals can be applied directly to man. It is also pertectl) cleai that the
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