New light on the cell location of avarol within the sponge Dysidea avara (Dendroceratida)

Abstract

Many sponges produce and store secondary metabolites with interesting pharmacological bioactivities. Identification of the cell type(s) responsible for the production and/or storage of these compounds may be a crucial step for the future culture and production of these substances if the biosynthesis is not envisageable and the producer organism is rare or too slow-growing for feasible exploitation. Localisation of these cells within the sponge may also contribute to ascertaining the ecological role of these compounds. The cell type containing the main bioactive metabolite (avarol) and its derivative avarone in the sponge Dysidea avara has been identified by cell isolation in a density gradient and by chromatographic techniques. Preliminary cytological characterisation of the cell types in each particular sponge species under study is required, otherwise the identification of the cells in suspensions is inaccurate. In contrast with the findings reported for other sponge species, the active metabolites of D. avara are not contained within spherulous cells but within choanocytes that line the chambers of the aquiferous system. The possible ecological role of avarol is discussed in the light of its internal position and the biological functions of the cells storing the bioactive compounds.& k w d :

Evaluation of the Activity of the Sponge Metabolites Avarol and Avarone and their Synthetic Derivatives Against Fouling Micro- and Macroorganisms

“…Intrigued by the wide range of biological activities of these metabolites and the fact that avarol (1) is biosynthesized in large amounts by the sponge, implying an important ecological role [36], we decided to investigate their antifouling activity and prepare a number of lipophilic derivatives that would reduce their solubility in sea water and improve their incorporation in a potential antifouling preparation. …”

Environmental Flow Regimes for Dysidea avara Sponges

“…It is the natural source of avarol and related metabolites that have shown antitumoral, antibacterial, antiviral, and anti-inflammatory activities (Müller et al 1985;Minale et al 1974;Uriz et al 1996). Avarol is currently being tested on humans in Germany as an additive to a skin cream for treating psoriasis (Pietschmann et al 2004).…”

Chemical Mediation of Interactions Among Marine Organisms

“…14 Other recent studies of metabolite localization in sponges demonstrate that major secondary metabolites are often not found in the symbionts. 16 " 17 ' 251 " 254 Cell fractionation and Ehrlich staining showed that the defensive furanosesquiterpenes found in Dysidea fragilis were located in large spherular sponge cells. 253 Cell fractionation on Ficoll gradients showed that avarol 62 from Dysidea avara was located within choanocytes.…”