Antiplasmodial and antimicrobial activities of South African marine algal extracts

Abstract

Seventy-eight crude organic fractions from nineteen species of marine algae collected from the coast of South Africa were screened for activity against a chloroquine sensitive strain of Plasmodium falciparum (D10), Staphylococcus aureus, Klebsiella pneumoniae, Mycobacterium aurum and Candida albicans. Fifteen crude fractions showed good antiplasmodical activity (IC50 <10 μg/mL). The dichloromethane fraction from Sargassum heterophyllum (Turner) C. Agardh (Sargassaceae) was the most active with an IC50 value of 2.8 μg/mL. Eleven extracts showed MIC values ≤ 1 mg/mL against at least one of S. aureus, K. pneumoniae, M. aurum and C. albicans. The broadest spectrum of antimicrobial activity was exhibited by the aqueous-HP20 fraction of Polysiphonia incompta Harvey (Rhodomelaceae). This study shows that marine algae not only produce antimicrobial compounds but also may be a source of antimalarial lead compounds.