Public Health and Toxins from Marine Blue-Green Algae

Abstract

Marine blue-green algae belonging to the Oscillatoriaceae are frequently toxic. Lyngbya majuscula, for example, is the causative agent of a severe contact dermatitis that sometimes affects swimmers and bathers at beaches on the windward side of Oahu, Hawaii during the summer months. In August, 1980 an outbreak of this dermatitis occurred and 86 persons with symptoms were reported to the Hawaii Department of Health. The active principles in the blue-green alga are aplysiatoxin and debromoaplysiatoxin, two highly inflammatory acetogenic substances that were first found in the digestive tract of the sea hare Stylocheilus longicauda. A smaller amount of a third inflammatory substance, lyngbyatoxin A, an indole alkaloid that is structurally related to teleocidin B from Streptomyces mediocidicus, is also present in L. majuscula and is responsible in part for the dermatitis. Aplysiatoxin, debromoaplysiatoxin, and lyngbyatoxin A have been shown to be potent tumor promoters in vivo, comparable in potency and biological effects with 12-O-tetradecanoylphorbol-13-acetate (TPA) from Croton oil. The discovery of the cocarcinogenic properties of these toxins suggests that L. majuscula may be an important public health concern.