ANT VENOMS - CHEMICAL AND PHARMACOLOGICAL PROPERTIES

Stinging ants are now recognized as being of considerable public health significance in both temperate and tropical regions. Many species of ants produce venoms that contain powerful algogens and these secretions may cause severe systemic reactions as well. Venoms of fire ants (Solenopsis species) are fortified with unique necrotoxins that produce conspicuous lesions at the sting sites. The diverse pharmacological properties of ant venoms are mirrored by the varied biological activities that these secretions possess. The poison gland products of selected ant venoms are cytotoxic and hemolytic against a variety of red blood cells. Some venoms are potently bactericidal and fungicidal against a variety of microorganisms. Venoms of Solenopsis and Monomorium species are highly effective contact insecticides and repellents as well. In addition, these secretions can also inhibit enzymes (e.g., Na+ ATPase), uncouple oxidative phosphorylation, reduce mitochondrial respiration, and release histamine from mast cells. The constituents in ant venoms are characterized by far greater structural diversity than has been reported for those of bees and wasps. Some ant venoms are fortified with proteins that include a variety of enzymes (e.g., lipase). Formicine ants produce cytotoxic venoms that contain up to 60% formic acid. Ants in several myrmicine genera synthesize venoms that are dominated by novel alkaloids that include piperidines, pyrrolidines, indolizidines, and pyrrolizidines. Pseudomyrmecine ants generate unique tricyclic alkaloids in their poison gland as further testimony to the biosynthetic versatility of ants. These alkaloidal natural products can serve as useful models for developing new pharmacological agents.