Exploring the global animal biodiversity in the search for new drugs -Amphibians

Abstract

Many breakthrough drugs have been developed from plants with medicinal properties on the basis of ethnopharmacological information. In the search for structurally novel and mechanistically unique lead compounds, drug discovery and development progams are now also paying attention to the myriad of bioactive molecules provided by the animal biodiversity. A well-known example emerging from these efforts is the breakthrough angiotensin-converting enzyme inhibitor captopril used for the treatment of hypertension and congestive heart failure. Captopril has been developed as an analogue of bradykinin in the venom of the Brazilian pit viper Bothrops jararaca (Viperidae) following the observation that the latter agent lowered blood pressure by vasodilation. In the mean time, dozens of clinically useful and potentially therapaeutically applicable compounds from animal origin have been identified. The skin gland secretions of amphibians have been refined during millions of years of evolution to highly efficient defensive chemicals. These compounds have remarkable pharmacological activities and may also represent a treasure chest of potentially novel drugs against pathophysiological conditions. This paper addresses the importance of bioactive compounds in the skin secretions of frogs, toads, salamanders, newts, and caecilians, and elaborates on the therapeutic potential of some of them as anti-alzheimer, cardiotonic, antidiabetic, anti-HIV, analgesic, antimicrobial, and antiparasitic compounds.