Antiprotozoal Activities of Lyngbya MajuscuIa, Abudefduf Sexfasciatus and Thallassodendron Ciliatum.

Abstract

Methanol (MeOH) extracts of the pan-tropic marine Cyanophyte Lyngbya majuscula, Thallassodendron ciliatum (sea grass) and gill extracts of the Striptail damsel Abudefduf sexfasciatus were examined for in-vitro antiprotozoal activity against Ochromonas danica cultured in hemin enriched media at room temperature using a 50% serial dilution technique. Respiratory inhibition at the 660 nm wavelength was shown to be proportional to the concentration of the extracts with R2 values of 0.992, 0.996 and 0,542 for L. majuscula,Asexfasciatus and T. ciliatum respectively. T. ciliatum exhibited lower inhibition potential where as Asexfasciatus had the highest. Malnourished O. danica at the elevated dilutions of 75% were especially susceptible. In addition to the anticipated antibiosis, rhodamine toxicity and brine shrimp anemia bioassay suggest a role by haemolysin toxins of L. majuscula and A.sexfasciatus in the 24 hour respiratory inhibition process.