In the same group of fatty acids we can place bixine, a member of the polyterpene family with 9 conjugated double bonds which we obtain through saponification of the seeds of Bixa orellana and have studied widely. The changes produced in microbes are similar to those with other polyconju gated fatty acids. Changes in connective tissues in animals appear to be particularly interesting. The first reaction to subcutaneous injection of an oily solution of 1 % bixine in rats or mice is an inflammatory process, with the injected material dividing into hundreds of tiny droplets. Some, however, melt away and the unabsorbed injected material again forms one or two big drops. The wall containing the drops is very thin and transparent and appears to be made up of very few connective cells which have extremely long fibrils, representing the highest degree of differentiation of these cells.

The effect upon pain is similar to that of conjugated fatty acids. The second day wound crust pH shows a manifest change toward alkalosis. The effect upon radiation wounds is the same as for conjugated trienes. In animals injected with convulsant doses of thiamine, only a few milligrams of the bixine preparation are required to prevent convulsions. Of all the fatty acid preparations used, bixine appears to be the most efficient in its anti convulsivant action. The iodine number of 430, found in our preparations, confirms, thus, in this case too, the correlation seen between anticonvulsi vant effect and richness in double bonds of the fatty acids.

The distribution of bixine following administration is interesting. Chromatographic study of blood constituents after hydrolysis shows that almost all the bixine is in the red cells, with minimal quantities in plasma. Lesions such as wounds or tumors, after the administration of bixine, become particularly rich in this substance in comparison to normal tissues. Changes in evolution of tumors also are manifest. The administration of this agent often leads to rapid necrosis and edema. In animals and humans, we saw massive tumors become ulcerated in a few days after use of only a few milligrams of the substance. The ulcerating effect of conjugated fatty acids upon tumors reaches its maximum with bixine. In animal tumors which, in successive transplants, had never shown spontaneous ulcerations, the injection into the host of only a few milligrams of bixine in oily solution produced, in addition to ulceration, a change in the tumor which can be considered to correspond to a mutation. Further transplants consistently developed ulcerating tumors and the ulcerative character persisted in succeeding generations. Massive degenerating changes were obtained in organs after repeated subcutaneous injections of suspensions of cells obtained from these organs and treated in vitro with bixine.

The changes toward offbalance D induced in various systemic patterns in humans by bixine are similar to those produced by conjugated fatty acids. However, once induced, these changes are very persistent, and often remain uninfluenced by anti fatty acids. It is this characteristic of resistance to further changes which represents a certain handicap for therapeutic use of this agent.

Fading Response

In contrast to the relatively persistent changes induced by bixine, the striking character of the effects upon pain or systemic manifestations obtained with fatty acid preparations, and especially with the conjugated isomers, is their short duration. Furthermore, at the beginning of their administration, these agents, even in relatively small doses, exert intense effects, but such effects cannot be obtained later without continuously increasing the amount used. After a certain time, even large doses have very little effect.

An explanation of the fading character of the results obtained with these and many other agents can be found in the fact that the organism defends itself against any factor able to influence its balance. In the case of conjugated fatty acids, this defense seems to be provided mainly by the adrenal glands. E. F. Taskier has studied this aspect of adrenal defense in our laboratory and this research is presented in Note 17, Chapter 6. An adren alectomized animal is usually less resistant toward the administration of many agents than a normal or sham operated animal. This drop in resistance is expressed as an adrenal defense index, as the ratio between the minimal lethal dose for the normal and for the adrenalectomized animal. For most fatty acid preparations, this index is between two and three, and becomes greater for the conjugated fatty acids. Fatty acids with three conjugated double bonds, however, have an adrenal defense index of 120. Eleostearic acid is 120 times less toxic for sham operated controls than for adrenalectomized animals, indicating a specific adrenal defense against these acids. Progressively increased intervention of the adrenals would explain the fading effect mentioned above.