Antimicrobial activity of various extracts of the sea urchin Tripneustes gratilla (Echinoidea)

Abstract

The recent appearance of a growing number of bacteria resistant to conventional antibiotics has stimulated the search for novel antimicrobial agents or lead compounds from a variety of sources, including natural sources  crustaceans, molluscs and echinoderms, with particular interest on their secondary metabolites with desirable antimicrobial properties (Haug et al, 2002, Casas et al, 2010).

Antimicrobial activity in several species of echinoderms collected from Gulf of California, Mexico, Caribbean and Coast of Norway has been reported (Rinehart et al, 1981; Bryan et al, 1994; Haug et al, 2002). In addition, a variety of antimicrobial factors, including steroidal glycosides (Andersson et al, 1989), polyhydroxylated sterols (Iorizzi et al, 1995), naphthoquinone pigments (Service and Wardlaw, 1984), lysozymes (Canicatti and Roch, 1989; Stabili and Pagliara, 1994), complement like substances (Leonard et al, 1990) and antimicrobial peptides (Beauregard et al, 2001) have also been isolated from echinoderms. These findings suggest that marine echinoderms are a potential source of new types of antibiotics for pharmaceutical development.Tripneustes gratilla (Echinoidea) collected from the Kenyan Coast.

Unfortunately, in most of these studies on antimicrobial activity in echinoderms, whole bodies or body walls have been tested for activity. Recently, Haug et al. (2002) observed wide differences in antibacterial activities between different extracts and organs/tissues, as well as between species, of three echinoderms.

Whether the same antibacterial factors are responsible for the activity in all organs or tissues remains unclear. The present work focused on screening and comparing antimicrobial and hemolytic activities in different organs/tissues of the sea urchin