Effect of cocaine on the growth of lupinus alba

Abstract

The effects of cocaine and its decomposition products were studied on the growth of seedlings of the plant Lupinus alba. The seeds were soaked in water and allowed to sprout in a suitable medium, following which the length of the straight roots grown by this plant was measured and the effects of cocaine and other chemicals on the growth of the roots were investigated. The plants were placed in solutions of nutrient salts (Shive solution) and the various drugs were added to such solutions. Controls were made on seedlings suspended in Shive solution diluted one half with distilled water. It was found that the effect of cocaine and its decomposition products on the growth of lupinus was very different from the effect of the same substances on animal tissues. Whereas cocaine is very toxic for animal tissues such as smooth and skeletal muscle, nerves, etc., it required strong solutions of this alkaloid, namely 2 per cent. of cocaine hydrochloride to inhibit the growth of the seedlings. Ecgonin hydrochloride inhibited growth in concentrations of .0055 per cent., while benzoyl ecgonin was much less toxic, requiring 2 1/2 per cent. concentration to affect the growth. Methyl alcohol was found to be very little toxic to the roots of the lupinus, requiring 4.8 per cent. to produce an inhibition of growth. Contrary to expectation the most toxic decomposition product of cocaine was found to be sodium benzoate, a compound which is practically non-toxic for animal tissues. Sodium benzoate was found to be deleterious to the Zupinus root in concentrations of 0.007 per cent.; while the ester me thyl-benzoate was found to produce inhibition in concentrations of 0.014 per cent. Various simple mixtures of ecgonin, sodium benzoate, methyl alcohol, benzoyl ecgonin, etc., were also studied and the effects of these will be described in the complete paper in the Journal of General Physiology.