Evaluation of Cytotoxicity and Presence of Secondary Metabolites of Selected Macroalgae Along Loreto Dinagat Island

Abstract

The use of macroalgae as a substitute for synthetic drugs is gaining popularity. Macroalgae is a simple and fascinating species that is a treasure chest of natural chemicals and beneficial ingredients and can be found in some areas of marine environment. This study was undertaken to evaluate the toxicity effect through brine shrimp bioassay and presence of the secondary metabolites through phytochemical screening of ethanolic extract in selected macroalgae collected along the intertidal zone in selected areas of the Barangays in Loreto Dinagat Islands. A total of ten macroalgae were collected containing two samples for red algae, four samples for green algae and four samples brown algae. Screening of phytochemical constituents showed positive results for flavonoids, anthraquinones, saponins, tannins, steroids and alkaloids. The toxicity levels of each selected macroalgae were dose-dependent. Three of the samples of macroalgae were identified as highly toxic, and seven of the selected macroalgae were identified as moderately toxic. The result of the present study confirmed that some of the macroalgae present in Loreto Dinagat Islands were rich sources of phytoconstituents which can be isolated and further screened for various biological activities. This study also supports the use of the macroalgae in the treatment of diseases in traditional medicine and also recommends the physicchemical characterization and further biological evaluation of the macroalgae.