There are several examples of bio-active molecules isolated from animal sources, say, snakes, bees, toads, leeches and some mammals, which have found medicinal applications. These applications have been highlighted in this article.
Thus some of the snake venoms have pain relieving action. This property has been exploited in alleviating the extreme pain of the patients in the terminal stages of cancer. Cobra venom (cobrotoxin), for example, is reported to be a superior alternative to morphine in its pain relieving action. The toxins, derived from vipers, have been employed in the treatment of arthritis and rheumatism. Crotalus toxin (i.e. the venom derived from rattle snake and pit vipers) is claimed to be useful in the treatment of the periodic throbbing headache (migraine). Snake venoms usually produce two different types of effects, namely, enhance the blood clotting or inhibit it. Based on this property the patients afflicted with haemophilic disorder (i.e. prolonged bleeding following even minor injuries) can be treated with blood clotting venoms. These also find application as haemostatic agents in surgery and in the treatment of other hemorrhagic conditions. Likewise the anti-coagulant action of some snake venoms has been successfully employed in the case of patients having the formation of blood clots (thrombosis) in their veins and arteries. These venoms are also described to be useful in the case of ‘angina pectoris; - a condition when the patient has a severe but temporary attack of cardiac pain. An interesting use of the venom derived from rattle snake is in the treatment of epilepsy.