INHIBITION OF REVERSE-TRANSCRIPTASE ACTIVITY BY EXTRACTS OF CULTURED BLUE-GREEN-ALGAE (CYANOPHYTA)

Lipophilic and hydrophilic extracts of over 900 strains of cultured bl ue-green algae (cyanophyta) were examined in vitro for their ability t o inhibit the reverse transcriptases (RT) of avian myeloblastosis viru s (AMV) and human immunodeficiency virus, type 1 (HIV-1). Eighteen (2. 0 %) aqueous extracts showed activity against AMV and HIV RTs. The max imal level of RT inhibition achieved by some of the active extracts wa s equivalent to that measured for 3'-azido-2',3'-di-deoxythymidine (AZ T) at 668 ng/ml. Examination of partially purified fractions prepared by C18 column chromatography demonstrated that the RT inhibition obser ved could not be attributed entirely to the degradation of transcript DNA, template RNA, or enzyme protein in the reaction mixture. Thus, th ese results indicate that cultured blue-green algae may represent a no vel source of compounds that inhibit RT activity, including that of HI V-1.