Preliminary screening of two marine algae and sea grass harvested from Sri Lankan waters against the LPS-induced inflammatory responses in RAW 264.7 macrophages and in vivo zebrafish embryo model

Abstract

The present study was designed to investigate the secondary metabolites from under-explored marine flora inhabiting the coastal areas of Sri Lanka for evaluating their anti-inflammatory properties. The hexane, chloroform, ethyl acetate and aqueous solvent fractions obtained from 80 % methanol extracts of two marine algae; Chaetomorpha antennina, Gracilaria edulis and the sea grass; Halophila ovalis harvested from the Kalpitiya area of Sri Lanka were screened for anti-inflammatory properties using LPS stimulated RAW 264.7 macrophages and by in vivo zebrafish embryo model. The chloroform fraction of G. edulis (GEMC), and hexane fractions of G. edulis (GEMH) and C. antennina (CAMH) demonstrated the best anti-inflammatory activity against LPS induced NO production in RAW 264.7 macrophages. The anti-inflammatory effects in RAW 264.7 macrophages were mediated through the inhibition of iNOS, COX-2 and PGE2 expression. Moreover, GEMH, GEMC and CAMH solvent fractions also exerted pronounced anti-inflammatory activity against LPS induced NO production, ROS production and cell death in the zebrafish model. The active components responsible for the anti-inflammatory activity could be identified with further purification of the solvent fractions.