The present invention relates to a pharmaceutical composition comprising snake powder that is derived from the Tzabcan “Crotalus durissus” rattlesnake. The snake powder is prepared by continuously baking the body of the rattlesnake until it completely dehydrates. Then, the dehydrated body is pulverized into a fine granular powder. The present invention included an in vitro method of inhibiting cancer cell growth utilizing the snake powder exhibited. Accordingly, the snake powder can be applied for the development of drugs which are effective for the treatment of various types of cancers.
