keyholez

To the editor: The snake has been a part of Western medicine since the time of the ancient Sumerians, 4,000 years ago. Ningishzida, their god of healing, was draped with twin snakes, an emblem still in fashion in medical circles today. Snake was an ingredient of a famous theriaca used by Andromachus, physician to Nero, and of a theriaca of Galen, which was in use until the efforts of William Heberden to ban it in 18th century England. It was still quite popular in colonial America, however, and only in the past century have snake and snake oil become synonymous with quackery.

Another kind of oil has come into fashion recently: fish oil has been elevated to the front rank of medical therapeutics because of convincing clinical and laboratory research that documents effects on platelets, white blood cells, and blood vessel walls. Clinical benefits in treating inflammatory disorders, cardiovascular disease, and even cancers are now subjects of serious research. These effects are known to be related to the presence in fish oil of [omega]-3 essential fatty acids, which are precursors of prostaglandin hormones. It is well known that the biology of both plants and animals commonly adapts to cold temperature by producing more of the [omega]-3 unsaturated fatty acids with one more double bond than the [omega]-6 fatty acids.

Since snakes are cold-blooded animals, it seemed plausible to me that they might contain [omega]-3 essential fatty acids. Finding no listing of snake oil in the analytical tables, I sent three specimens of snake to a laboratory for analysis by chromatography and flame ionization (analysis by Dr George Miroff, Monroe Medical Laboratory, Southfields, New York). Table 1 shows the major fatty acids found in snake oil from Chinese snake oil purchased over the counter, subcutaneous fat of a black rattlesnake from southern California (Crotalus viridis), and subcutaneous fat of a red rattlesnake from Arizona (Crotalus tigris).

Chinese snake oil contains almost 20% eicosapentaenoic acid (EPA), about triple the concentration in the American rattlesnakes. I understand the Chinese product includes snake oil from water snakes that feed on fish. This almost certainly would increase the content of EPA in their tissues. In human subjects fed cod liver oil, there was a sevenfold increase of EPA in neutrophils and monocytes. It was also found that arachidonic and docosahexaenoic acid did not increase and that leukotrienes decreased; hence the inference that anti-inflammatory action was due to EPA and that it may work by inhibiting the leukotriene B4-mediated output of neutrophils.

As a concentrated source of EPA, snake oil is a credible anti-inflammatory agent and might indeed confer therapeutic benefits. Since essential fatty acids are known to absorb transdermally, it is not far-fetched to think that inflamed skin and joints could benefit by the actual anti-inflammatory action of locally applied oil just as the Chinese physicians and our medical quacks have claimed.

It is not unusual that an ancient remedy or a folk medicine turns out to have some merit. What is unusual is that this particular therapy, snake oil, has long been our favorite symbol of quackery. I find it humbling that the science of today invests the quackery of yesterday with new credibility. Perhaps our ancestors were wiser than we could appreciate when they wrapped a snake around the staff of Aesculapius.