Chemical and biological prospection of marine sponges belonging to the class Demospongiae: a review.

Marine sponges belonging to the class Demospongiae have been shown to be promising sources of bioactive compounds, investigated from the perspective of potential medical applications. This review aimed to collect studies on biological activities of clinical importance and the chemical composition of sponge species from that class, highlighting the structure/activity relationship. To carry out this work, collections were carried out in the Science Direct, Pubmed, Scielo and Google Scholar databases, using the following descriptors: antimicrobial marine sponges, antioxidant marine sponges and marine sponges biological activity. The inclusion criteria were considered: (1) publications from the year 2022 onwards; (2) written in English or Portuguesen and (3) with information on biological assays of extracts, fractions or isolated compounds. The following were excluded: (1) duplicate works; (2) works whose content was not within the scope of the study and (3) studies that did not evaluate biological activities. Results demonstrate that 274 compounds were isolated from different metabolic classes, being evaluated in several biological assays. From the analysis of the data, it is concluded that the compounds studied demonstrate promise for the development of medicines for the control of microorganisms and the treatment of tumors, acting through different mechanisms of action.

Chemical Profile, Antioxidant and Antimicrobial Activity of Marine Sponge Species Combined with Multivariate Statistical Analyses: Desmapsamma anchorata, Dysidea etheria and Echinodictyum dendroides.

Marine sponges are sources of bioactive compounds, sparking pharmacological interest. This study aimed to evaluate the chemical profile, antioxidant, and antibacterial activities of the species Desmapsamma anchorata, Dysidea etheria, and Echinodictyum dendroides. The chemical profile was characterized by the identification and quantification of polyphenols. Antioxidant activity was assessed using different methods. Antibacterial and modulatory activities were evaluated through microdilution against pathogenic strains. The polyphenols were found in low abundance in the extracts. In the antioxidant assays, the EACDa and EMDa extracts exhibited better inhibitory results. In the antibacterial evaluation, extracts presented MIC ≥ 1024 µg mL-1. The modulation of the extracts in combination with antibiotics showed significant effects against the multiresistant bacterium Pseudomonas aeruginosa. This study contributes to the deepening of chemical and biological knowledge of sponge species, indicating that their extracts can act as good modulators of bacterial resistance to aminoglycoside antibiotics, warranting further investigation into their mechanisms of action.

In Vivo Effects of Biosilica and Spongin-Like Collagen Scaffolds on the Healing Process in Osteoporotic Rats.

Due to bioactive properties, introducing spongin-like collagen (SPG) into the biosilica (BS) extracted from marine sponges would present an enhanced biological material for improving osteoporotic fracture healing by increasing bone formation rate. Our aim was to characterize the morphology of the BS/SPG scaffolds by scanning electron microscopy (SEM), the chemical bonds of the material by Fourier transform infrared spectroscopy (FTIR), and evaluating the orthotopic in vivo response of BS/SPG scaffolds in tibial defects of osteoporotic fractures in rats (histology, histomorphometry, and immunohistochemistry) in two experimental periods (15 and 30 days). SEM showed that scaffolds were porous, showing the spicules of BS and fibrous aspect of SPG. FTIR showed characteristic peaks of BS and SPG. For the in vivo studies, after 30 days, BS and BS/SPG showed a higher amount of newly formed bone compared to the first experimental period, observed both in the periphery and in the central region of the bone defect. For histomorphometry, BS/SPG presented higher %BV/TV compared to the other experimental groups. After 15 days, BS presented higher volumes of collagen type I. After 30 days, all groups demonstrated higher volumes of collagen type III compared to volumes at 15 days. After 30 days, BS/SPG presented higher immunostaining of osteoprotegerin compared to the other experimental groups at the same experimental period. The results showed that BS and BS/SPG scaffolds were able to improve bone healing. Future research should focus on the effects of BS/SPG on longer periods in vivo studies.

Methanolic Extract and Brominated Compound from the Brazilian Marine Sponge Aplysina fulva Are Neuroprotective and Modulate Inflammatory Profile of Microglia.

Neurodegenerative diseases involve neuroinflammation and a loss of neurons, leading to disability and death. Hence, the research into new therapies has been focused on the modulation of the inflammatory response mainly by microglia/macrophages. The extracts and metabolites of marine sponges have been presented as anti-inflammatory. This study evaluated the toxicity of an extract and purified compound from the Brazilian marine sponge Aplysina fulva as well as its neuroprotection against inflammatory damage associated with the modulation of microglia response. PC12 neuronal cells and neonatal rat microglia were treated with the methanolic extract of A. fulva (AF-MeOH, 0.1-200 µg/mL) or with its purified dimethyl ketal of 3,5-dibromoverongiaquinol (AF-H1, 0.1-100 µM). Cytotoxicity was determined by MTT tetrazolium, Trypan blue, and propidium iodide; microglia were also treated with the conditioned medium (CM) from PC12 cells in different conditions. The microglia phenotype was determined by the expression of Iba-1 and CD68. AF-MeOH and AF-H1 were not toxic to PC12 or the microglia. Inflammatory damage with Escherichia coli lipopolysaccharide (LPS, 5 µg/mL) was not observed in the PC12 cells treated with AF-MeOH (1-10 µg/mL) or AF-H1 (1-10 µM). Microglia subjected to the CM from PC12 cells treated with LPS and AF-MeOH or AF-H1 showed the control phenotype-like (multipolar, low-CD68), highlighting the anti-neuroinflammatory and neuroprotective effect of components of this marine sponge.

3D printed scaffolds of biosilica and spongin from marine sponges: analysis of genotoxicity and cytotoxicity for bone tissue repair.

Biosilica (BS) and spongin (SPG) from marine sponges are highlighted for their potential to promote bone regeneration. Moreover, 3D printing is introduced as a technology for producing bone grafts with optimized porous structures, allowing for better cell attachment, proliferation, and differentiation. Thus, this study aimed to characterize the BS and BS/SPG 3D printed scaffolds and to evaluate the biological effects in vitro. The scaffolds were printed using an ink containing 4 wt.% of sodium alginate. The physicochemical characteristics of BS and BS/SPG 3D printed scaffolds were analyzed by SEM, EDS, FTIR, porosity, evaluation of mass loss, and pH measurement. For in vitro analysis, the cellular viability of the MC3T3-E1 cell lineage was assessed using the AlamarBlue® assay and confocal microscopy, while genotoxicity and mineralization potential were evaluated through the micronucleus assay and Alizarin Red S, respectively. SEM analysis revealed spicules in BS, the fibrillar structure of SPG, and material degradation over the immersion period. FTIR indicated peaks corresponding to silicon oxide in BS samples and carbon oxide and amine in SPG samples. BS-SPG scaffolds exhibited higher porosity, while BS scaffolds displayed greater mass loss. pH measurements indicated a significant decrease induced by BS, which was mitigated by SPG over the experimental periods. In vitro studies demonstrated the biocompatibility and non-cytotoxicity of scaffold extracts. .Also, the scaffolds promoted cellular differentiation. The micronucleus test further confirmed the absence of genotoxicity. These findings suggest that 3D printed BS and BS/SPG scaffolds may possess desirable morphological and physicochemical properties, indicating in vitro biocompatibility.

Polyurethane sponges bearing cucurbituril adsorb Cr(III) and Pb(II) ions from contaminated water samples.

Water contamination with toxic metals causes harmful effects on the environment and to human health. Although cucurbiturils have carboxyl groups in their portal that can interact with metal ions, there is a lack of studies about their use as metal adsorbent. This scenario has motivated conduction of the present study, which addresses the use of cucurbit[6]uril (CB[6]) and cucurbit[8]uril (CB[8]) for adsorbing Pb and Cr from water samples, in free forms and immobilized in poly(urethane) sponges. The adsorption kinetics revealed that CB[8] leads to faster adsorption compared to CB[6], with equilibrium achieved in 8 h for CB[8] and 48 h for CB[6] for both metals, and achieved up to 80% of decrease in metal concentration. The Langmuir isotherm model provided a better description of adsorption for Cr and Pb in CB[6] and Pb in CB[8] with a maximum concentration adsorbed of 32.47 mg g-1 for Pb in CB[6], while the Dubinin-Radushkevich model was more suitable for Cr adsorption in CB[8]. Sponges containing CB[6] and CB[8] have proven to be efficient for Pb and Cr remediation in tannery effluent samples, reducing Cr and Pb concentration by 42 and 33%, respectively. The results indicate that CB[6] and CB[8], whether used in their pure form or integrated into sponges, exhibit promising potential for efficiently adsorbing metals in aqueous contaminated environments.

Unveiling microbial guilds and symbiotic relationships in Antarctic sponge microbiomes.

Marine sponges host diverse microbial communities. Although we know many of its ecological patterns, a deeper understanding of the polar sponge holobiont is still needed. We combine high-throughput sequencing of ribosomal genes, including the largest taxonomic repertoire of Antarctic sponge species analyzed to date, functional metagenomics, and metagenome-assembled genomes (MAGs). Our findings show that sponges harbor more exclusive bacterial and archaeal communities than seawater, while microbial eukaryotes are mostly shared. Furthermore, bacteria in Antarctic sponge holobionts establish more cooperative interactions than in sponge holobionts from other environments. The bacterial classes that established more positive relations were Bacteroidia, Gamma- and Alphaproteobacteria. Antarctic sponge microbiomes contain microbial guilds that encompass ammonia-oxidizing archaea, ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, and sulfur-oxidizing bacteria. The retrieved MAGs showed a high level of novelty and streamlining signals and belong to the most abundant members of the main microbial guilds in the Antarctic sponge holobiont. Moreover, the genomes of these symbiotic bacteria contain highly abundant functions related to their adaptation to the cold environment, vitamin production, and symbiotic lifestyle, helping the holobiont survive in this extreme environment.

Baseline metal and metalloid contamination in two marine sponge species, Hymeniacidon heliophila and Desmapsamma anchorata, from southeastern Brazil.

Sponges are not routinely employed as metal bioindicators in Brazil. In this sense, this study reports baseline metal and metalloid concentrations, determined by inductively coupled plasma mass spectrometry, for two Demospongiae sponge species, Hymeniacidon heliophila and Desmapsamma anchorata, sampled from two Southeastern Brazil areas. Sponges from Ilha Grande Bay, an Environmental Protection Area, exhibited higher Al, As, Cd, Co, Cr, Fe, and Ni levels compared to Vermelha Beach, a metropolitan area in the Rio de Janeiro city. Several strong correlations were noted between elemental pairs, indicating common contamination sources and/or similar metabolic detoxification routes. Comparisons of the means determined herein for each study site to other reports indicate mostly lower Ag, As, Co, Cd, and Cu levels, while Al levels were higher than other studies, and Cr, Ni, and Fe were within reported ranges. These baseline data further knowledge on metal pollution in Desmspongiae members, which are still limited.

Evaluating the secondary bioactive metabolites in Geodia corticostylifera / Avaliação dos metabólitos bioativos secundários em Geodia corticostylifera

Ophiactis savignyi could be discovered all over the world in tropical marine environments. People could have aided in the spread of O. savignyi, particularly in the western and eastern populations of Panama's Isthmus. The brittle star Ophiactis savignyi, often known as savigny's brittle star, coexists alongside the sponge Geodia corticostylifera. The focus of this research has been to assess the functional relevance of G. corticostylifera secondary metabolites as antifoulant against mussels, protection against generalist fish, and chemical cues to affiliated brittle stars. Both in flow-through and static seawater laboratory studies, O. savignyi which has previously been connected with sponges, was given both treated and control mimics at the same time. The sponge extract was also tested for its ability to protect fish against predators and fouling. Deterrence test using chemicals indicated that the normal level of the sponge extract may also suppress generalist fish predation in the field as well as the mussel Perna perna's normal attachment in clinical contexts. According to the findings, G. corticostylifera crude extract has many roles in the aquatic environments, apparently being accountable for this sponge's tighter relationship with O. savignyi, which protects the ophiuroid and inhibits epibionts on itself.

Ophiactis savignyi pode ser descoberta em todo o mundo em ambientes marinhos tropicais. A população pode ter contribuído para a propagação de O. savignyi, particularmente as populações ocidentais e orientais do istmo do Panamá. A estrela-quebradiça O. savignyi, muitas vezes conhecida como estrela-quebradiça de Savignyi, coexiste com a esponja Geodia corticostylifera. O foco desta pesquisa foi avaliar a relevância funcional dos metabólitos secundários de G. corticostylifera como anti-incrustante contra mexilhões, proteção contra peixes generalistas e sinais químicos para estrelas-quebradiças afiliadas. Em estudos de laboratório com fluxo contínuo e estático de água do mar, O. savignyi, que anteriormente havia se ligado a esponjas, recebeu mimetizadores tratados e controle ao mesmo tempo. O extrato de esponja também foi testado por sua capacidade de proteger os peixes contra predadores e incrustações. Testes de dissuasão usando produtos químicos indicaram que o nível normal de extrato de esponja também pode suprimir a predação de peixes generalistas no campo, bem como a fixação normal do mexilhão Perna perna em ambientes clínicos. De acordo com os achados, o extrato bruto de G. corticostylifera tem diversas funções em ambientes aquáticos, aparentemente responsáveis ​​pela relação mais próxima dessa esponja com O. savignyi, protegendo o ofiuroide e inibindo os epibiontes.

Ultrastructure of oogenesis in two tropical oviparous Demospongiae (Porifera): Cinachyrella apion and Tethya maza.

Reproduction is a key step for propagation of any species. Consequently, gametogenesis is crucial, as it links one generation to the other. Oogenesis is influenced by different factors, but it is usually related to the quality and quantity of the food and the capacity of the female to convert these resources into egg production. In Demospongiae (Porifera), oocytes vary in several aspects (e.g., origin, size, and vitellogenic pathways). However, data on oocyte morphology is still fragmentary, and the ultrastructural organization of reproductive cells has been investigated only in a few species, mainly of viviparous sponges. Here, we aimed to comprehend the oogenesis of two tropical oviparous demosponges (Cinachyrella apion and Tethya maza) using light and electron microscopy. In both species, oocytes seemed to originate from archaeocytes. Oocytes of C. apion were surrounded by a collagenous matrix and nurse cells containing many lipid vesicles. The increase of biosynthetic organelles, concomitantly with the presence of yolk vesicle in the ooplasm, indicated that the vitellogenesis was carried out through the mixed pathway. The oocytes of T. maza were surrounded by a follicle cell membrane and nurse cells containing yolk vesicles. The absence of characteristic biosynthetic organelles in the egg of this species indicated that vitellogenesis occured through the heterosynthetic pathway. The oogenesis of C. apion is similar to other species of the genus, while the follicle membrane and nurse cells surrounding the oocytes of T. maza are not observed in any other species of Tethya. These accessory cells were considered to have a trophic role during the oogenesis of the studied species. Moreover, the presence of these accessory cells may have ecological significance, as they accelerate the egg's production through trophic support of the growing oocyte.

Different Species of Marine Sponges Diverge in Osteogenic Potential When Therapeutically Applied as Natural Scaffolds for Bone Regeneration in Rats.

A highly porous structure, and an inorganic (biosilica) and collagen-like organic content (spongin) makes marine sponges potential candidates to be used as natural scaffolds in bone tissue engineering. The aim of this study was to characterize (through SEM, FTIR, EDS, XRD, pH, mass degradation and porosity tests) scaffolds produced from two species of marine sponges, Dragmacidon reticulatum (DR) and Amphimedon viridis (AV), and to evaluate the osteogenic potential of these scaffolds by using a bone defect model in rats. First, it was shown that the same chemical composition and porosity (84 ± 5% for DR and 90 ± 2% for AV) occurs among scaffolds from the two species. Higher material degradation was observed in the scaffolds of the DR group, with a greater loss of organic matter after incubation. Later, scaffolds from both species were surgically introduced in rat tibial defects, and histopathological analysis after 15 days showed the presence of neo-formed bone and osteoid tissue within the bone defect in DR, always around the silica spicules. In turn, AV exhibited a fibrous capsule around the lesion (19.9 ± 17.1%), no formation of bone tissue and only a small amount of osteoid tissue. The results showed that scaffolds manufactured from Dragmacidon reticulatum presented a more suitable structure for stimulation of osteoid tissue formation when compared to Amphimedon viridis marine sponge species.

3D Printed Scaffolds Manufactured with Biosilica from Marine Sponges for Bone Healing in a Cranial Defect in Rats.

The inorganic part of marine sponges, called Biosilica (BS), presents an osteogenic potential and the ability of consolidating fractures. Moreover, 3D printing technique is highly effective for manufacturing scaffolds for tissue engineering proposals. Thus, the aims of this study were to characterize the 3D rinted scaffolds, to evaluate the biological effects in vitro and to investigate the in vivo response using an experimental model of cranial defects in rats. The physicochemical characteristics of 3D printed BS scaffolds were analyzed by FTIR, EDS, calcium assay, evaluation of mass loss and pH measurement. For in vitro analysis, the MC3T3-E1 and L929 cells viability was evaluated. For the in vivo evaluation, histopathology, morphometrical and immunohistochemistry analyses were performed in a cranial defect in rats. After the incubation, the 3D printed BS scaffolds presented lower values in pH and mass loss over time. Furthermore, the calcium assay showed an increased Ca uptake. The FTIR analysis indicated the characteristic peaks for materials with silica and the EDS analysis demonstrated the main presence of silica. Moreover, 3D printed BS demonstrated an increase in MC3T3-E1 and L929 cell viability in all periods analyzed. In addition, the histological analysis demonstrated no inflammation in days 15 and 45 post-surgery, and regions of newly formed bone were also observed. The immunohistochemistry analysis demonstrated increased Runx-2 and OPG immunostaining. Those findings support that 3D printed BS scaffolds may improve the process of bone repair in a critical bone defect as a result of stimulation of the newly formed bone.

Effect of extracts from several sponges of Yucatan Coast on Giardia lamblia and preliminary chemical investigation of the bioactive extract of Haliclona (Reinera) tubifera.

In this study, twenty-four organic extracts from six marine sponge species, collected at shallows of Yucatan, Mexico, were evaluated against Giardia lamblia trophozoites and Vero cells. The dichloromethane and hexane extracts of Haliclona tubifera exhibited the highest antigiardiasic activity (IC50 = 1.00 and 2.11 µg/mL, respectively), as well as high selectivity (SI = 41.8 and > 47.4, respectively), while ethyl acetate and methanol extracts of Cinachyrella alloclada, and methanol extract of Suberites aurantiaca showed moderate activity. Contrastingly, the extracts of Halichondria magniculosa and Oceanapia nodosa were considered non actives. Consequently, the dichloromethane extract of H. tubifera were subject to an exploratory chemical study, isolating cholesterol, two benzaldehyde derivatives, three benzoic acid derivatives, cytosine, and thymine.

Guidelines on Designing MicroRNA Sponges: From Construction to Stable Cell Line.

Single microRNA (miRNA) can be inhibited using antagomiR which efficiently knocks down a specific miRNA. However, the effect is transient and often results in subtle phenotype. Here we report a guideline on designing miRNA sponges inhibiting a miRNA family. As a model system, we targeted miR-30 family, known as tumor suppressor miRNAs in multiple tumors. To achieve an efficient knockdown, we generated perfect and bulged-matched miRNA binding sites (MBS) and introduced multiple copies of MBS. The protocol here demonstrates the miRNA sponge as a useful tool to examine the functional impact of inhibition miRNAs.

Efficacy of collagen-only scaffolds compared to polymer-associated collagen and nanomaterials in skin wound repair ­ a review

Wound healing remains a clinical problem, with cases of atrophic, hypertrophic, or keloid scars. Three-dimensional scaffolds have been used to restore skin function, facilitating cell migration, adhesion, and proliferation. Collagen is the most common, presenting low antigenicity, decreased inflammation, and replacement by autologous tissue. It is used as sheets/films, sponges, membranes, sprays, and hydrogels of various origins. This integrative literature review aimed to evaluate the application of unassociated collagen scaffolds for skin wound healing and compare them to collagen associations with nanomaterials and polymers. Properties such as applications in humans and other unconventional models cause burns, partial and full-thickness wounds, and others. Scaffold, biomaterials, collagen, wound, injury, repair, and healing were among the descriptors. We found 3,098 articles published between 1995 and 2022 (Mendeley platform), including clinical/experimental trials. After exclusion, 26 studies were identified and analyzed. Autologous and heterologous collagens are the most used in the clinic and favor wound closure by improving re-epithelialization and reducing inflammation but may present challenges in aesthetic acceptance and loss of repair function in the wound site. Furthermore, collagen integration with other nanomaterials improved wound repair and experimental models.

Antimicrobial and cytotoxic effects of marine sponge extracts Agelas clathrodes, Desmapsamma anchorata and Verongula rigida from a Caribbean Island.

Although marine sponges are known for their antimicrobial, antifungal and cytotoxic activity, very few studies have been carried out on endemic species of Martinique. Martinique is part of the Agoa Sanctuary, a marine protected area that includes the exclusive economic zones (EEZ) of the French Caribbean islands, making it an abundant source of marine species. To highlight the potential of this area for the discovery of marine biomolecules with antipathogenic and antitumor activities, we tested the aqueous and ethanolic extracts of sponge species Agelas clathrodes, Desmapsamma anchorata and Verongula rigida. Five bacterial strains: Bacillus cereus (CIP 78.3), Escherichia coli (CIP 54.127), Pseudomonas aeruginosa (CIP A22), Staphylococcus aureus (CIP 67.8) and Staphylococcus saprophyticus (CIP 76125) were evaluated, as well as four tumor cell lines: breast cancer (MDA-MB231), glioblastoma (RES259) and leukemia (MOLM14 and HL-60). Antimicrobial activity was evaluated using the disc diffusion technique by determining the minimum inhibitory and minimum bactericidal concentrations. Tumor cytotoxic activity was determined in vitro by defining the minimum concentration of extracts that would inhibit cell growth. Ethanolic extracts of Agelas clathrodes were bactericidal for Staphylococcus aureus and Staphylococcus saprophyticus strains, as well as strongly cytotoxic (IC50 < 20 µg/mL) on all cancer cell lines. Verongula rigida also showed strong cytotoxic activity on cell lines but no antimicrobial activity. These results are innovative for this species on these bacterial lines, highlighting the potential of sponge extracts from this area as bioactive compounds sources.

Fluxes of the Amazon River plume nutrients and microbes into marine sponges.

Sponges have co-evolved with microbes for over 400 myr. Previous studies have demonstrated that sponges can be classified according to the abundance of microbes in their tissues as Low Microbial Abundance (LMA) and High Microbial Abundance (HMA). While LMA sponges rely mainly on water column microbes, HMA appear to rely much more on symbiotic fermentative and autotrophic microbes maintained in their tissues. However, it is unclear if this pattern holds when comparing different species of tropical sponges under extreme nutrient conditions and sediment loads in the water column, such as the Great Amazon Reef System (GARS), which covers an area of ~56,000 km2 off the Amazon River mouth. Sponges are the major GARS benthic components. However, these sponges' microbiome across the GARS is still unknown. Here, we investigated water quality, isotopic values (δ13C and δ15N), metagenomic and lipidomic profiles of sponges obtained from different sectors throughout the GARS. >180 million shotgun metagenomic reads were annotated, covering 22 sponge species. Isotopic and lipidomic analyses suggested LMA sponges rely on the Amazon River Plume for nutrition. HMA sponges (N = 15) had higher Roseiflexus and Nitrospira abundance, whereas LMA sponges (N = 7) had higher Prochlorococcus and Pelagibacter abundance. Functional data revealed that the LMA sponge microbiomes had greater number of sequences related to phages and prophages as well as electron transport and photophosphorylation which may be related to photosynthetic processes associated with the Prochlorococcus and Synechococcus found in the LMA. The higher phages abundance in LMA sponges could be related to these holobionts' reduced defense towards phage infection. Meanwhile, HMA sponge microbiomes had higher Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR abundance, which may be involved in defense against phage infection. This study sheds light on the nutrient fluxes and microbes from the Amazon River plume into the sponge holobionts.

Structure-Activity Relationship of Cytotoxic Natural Products from Indonesian Marine Sponges.

Indonesian marine natural products have been one of the most promising sources in the race to obtain potential drugs for cancer treatment. One of the primary producers of cytotoxic compounds is sponges. However, there are still limited sources of comprehensive reviews related to the relationship between the structure of isolated compounds and their cytotoxic activity. This review remarks the attempt to provide a preliminary guidance from the perspective of structure-activity relationship and its participation on marine natural products research. This guidance is segregated by the compound's classes and their cytotoxic targets to obtain and organized a reliable summary of inter-study of the isolated compounds and their cytotoxicity. Structure-activity relationship is well-known for its ability to tune the bioactivity of a specific compound, especially on synthetic organic chemistry and in silico study but rarely used on natural product chemistry. The present review is intended to narrow down the endless possibilities of cytotoxicity by giving a predictable structure-activity relationship for active compounds. In addition, bioactive framework leads were selected by uncovering a noticeable structure-activity relationship with the intervention of cytotoxic agents from natural sources, especially Indonesian marine sponge.

Antifouling Diterpenoids from the Sponge Dendrilla antarctica.

Two nor-diterpenes, 9,11-dihydrogracilin A (1) and the previously unreported 9,11-dihydrogracillinone A (2), were isolated from the sponge Dendrilla antarctica. The sponge was collected by trawling at a depth of 49 m, from the research vessel Puerto Deseado, near the coast of Tierra del Fuego, farther north than the reported habitat for this species. Since these compounds were particularly abundant and the sponge was free from epibionts, both 1 and 2 were included in soluble-matrix paints and tested for antifouling activity in the ocean. The results obtained from these experiments clearly indicated a potent antifouling activity for both compounds against a variety of colonizing organisms, and established a probable role as natural antifoulants for these abundant secondary metabolites and other structurally related compounds previously isolated from Dendrilla spp.

Comparison of Different Methods for Spongin-like Collagen Extraction from Marine Sponges (Chondrilla caribensis and Aplysina fulva): Physicochemical Properties and In Vitro Biological Analysis.

This study aimed to compare different protocols (Protocol 1: P1; Protocol 2: P2; Protocol 3: P3; Protocol 4: P4) for the extraction of spongin-like collagen (SC) from marine sponges. The SEM micrographs demonstrated a fibrillar structure for the extracts from Chondrilla caribensis and the nodular/particulate aggregates for Aplysina fulva. FTIR showed for all samples peaks similar to collagen for both species. For C. caribensis, the extracts obtained using P2, P3, and P4 protocols presented higher values of extraction yield, TPQ, and GAGs. P2 and P4 showed higher values of SC concentration and for antioxidant analysis. For A. fulva, P2, P3, and P4 provided a higher extraction yield besides an increase in the antioxidant assay. For both species, no difference was observed for Col quantification and TPQ analysis; also, higher values of GAGs were found using P2 and P4. Fibroblast proliferation observed for C. caribensis was lower for P1 on day 1 and for P2 and P3 on day 3 (for 50%) compared to the control group. There was a significant reduction in fibroblast cell proliferation for all A. fulva extracts evaluated. It can be concluded that protocols P2 and P4 were more efficient for extracting SC from C. caribensis.