Chemical profiling and anti-psoriatic activity of marine sponge (Dysidea avara) in induced imiquimod-psoriasis-skin model

Since Marine sponge Dysidea avara is regarded as a source of anti-inflammatory compounds, we decided to evaluate its potential anti-psoriatic activity in a psoriasis Imiquimod-induced in the mouse model. Psoriatic mice were treated with three different methanolic extracts of Dysidea avara compared with betamethasone-treated mice in in- vivo studies. Clinical skin severity was assessed with the psoriasis area index (PASI), whilst ELISA detected the expression of TNF-α, IL-17A, and IL-22. Dysidea avara activity was studied by employing GC-MS (to distinguish compounds), HPTLC (for skin permeation and accumulation), and SEA DOCK to predict single compound potential anti-inflammatory activity. After 7 days of treatment, mice treated with Dysidea avara displayed a dose-dependent, statistically significant improvement compared to controls (p< 0.001). In line with the clinical results, ELISA revealed a statistically significant decrease in IL-22, IL-17A, and TNF-α after treatment; the same SEA DOCK analysis suggests a possible anti-psoriatic activity of the extracts.

Investigating the Antiparasitic Potential of the Marine Sesquiterpene Avarone, Its Reduced Form Avarol, and the Novel Semisynthetic Thiazinoquinone Analogue Thiazoavarone

The chemical analysis of the sponge Dysidea avara afforded the known sesquiterpene quinone avarone, along with its reduced form avarol. To further explore the role of the thiazinoquinone scaffold as an antiplasmodial, antileishmanial and antischistosomal agent, we converted the quinone avarone into the thiazinoquinone derivative thiazoavarone. The semisynthetic compound, as well as the natural metabolites avarone and avarol, were pharmacologically investigated in order to assess their antiparasitic properties against sexual and asexual stages of Plasmodium falciparum, larval and adult developmental stages of Schistosoma mansoni (eggs included), and also against promastigotes and amastigotes of Leishmania infantum and Leishmania tropica. Furthermore, in depth computational studies including density functional theory (DFT) calculations were performed. A toxic semiquinone radical species which can be produced starting both from quinone- and hydroquinone-based compounds could mediate the anti-parasitic effects of the tested compounds.

­Reproductive strategies of two common sympatric Mediterranean sponges:Dysidea avara(Dictyoceratida) andPhorbas tenacior(Poecilosclerida)

Despite their abundance in benthic ecosystems, life cycles and reproductive features of most sponge species remain unknown. We have studied the main reproductive features of two demosponges,Dysidea avaraandPhorbas tenacior,belonging to phylogenetically distant groups: Orders Dictyoceratida and Poecilosclerida, respectively. Both sponges are abundant and share habitat in the Mediterranean rocky sublittoral. They brood parenchymella larvae with different morphology and behaviour. Sampling was conducted monthly over a two-year period in a locality where both species coexist. The two species reproduced in spring-summer, and presented species-specific reproductive features despite being subject to the same environmental conditions.D. avarahas a shorter reproductive period thanP. tenacior, ending before the peak of temperature in summer, while the reproductive period ofP. tenaciorlasts until beginning of autumn. Brooding larvae were present in June-July inD. avara, and in August-October inP. tenacior. Larval size, reproductive effort and number of larvae produced (measured the month with the maximum production) were significantly higher inD. avarathan inP. tenacior. A higher reproductive effort and larval traits point to a more opportunistic life strategy inD. avarathan inP. tenacior.A lack of overlap in the timing of larval release, as well as different reproductive traits, may reduce competition and facilitate the coexistence of these two sympatric and abundant sponges.

Changes and stability of a Mediterranean hard bottom benthic community over 25 years

During the last decades, the Mediterranean shallow-water benthic communities have experienced significant changes in taxa composition and distribution. These variations were related to a complex set of anthropogenic stressors as well as to mass mortality events starting from 1999 and related to the current climatic changes. To evaluate the effect of these changes on long-living species with a limited larval dispersal capacity, a quantitative and qualitative monitoring of the shallow-water hard bottom community structure was performed over a pluri-decennial interval of time. The aim of this work was the comparison of the quali-quantitative occurrence and seasonal cycles of several benthic taxa living on a rocky cliff of the Portofino Promontory (eastern Liguria, Mediterranean Sea), from 15 to 20 m depth. The studied community, within a Lithophyllo–Halimedetum tunae association, was analysed by sets of photographs repeated, exactly in the same site, at 25 years of distance (1987/88 and 2012/13). The results suggest that the macroalgal coverage of the surveyed cliff suffered, during the monitored span of time, a significant depletion in quali-quantitative terms, while the overall sponge coverage remained almost unvaried. Nevertheless, a discrete analysis of the most common sponge species present in the study area showed significant variations, with some taxa now more abundant (Axinella spp. and Agelas oroides), some virtually stable (Cliona viridis and the complex of red encrusting sponges), and others drastically depleted (Chondrosia reniformis, Phorbas tenacior, Acanthella acuta, Ircinia spp., Dysidea avara and Petrosia ficiformis). Finally, some sponge species showed clear seasonal cycles indicating recruitment periods and post-recruit mortalities.

Bioactive sesquiterpene quinols and quinones from the marine sponge Dysidea avara

Reports the isolation, structure determination, and cytotoxic and NF-κB inhibitory activities of eight sesquiterpene quinols and quinones from Dysidea avara.