Two new verticillane-type diterpenoids from the formosan soft coral Cespitularia hypotentaculata

Heterolactone and Heterolactams A-M, Verticillane Diterpenoids with Anti-Inflammatory and Hepatoprotective Activities from the Soft Coral Heteroxenia ghardaqensis

Fourteen new verticillane diterpenoids, heterolactone (1) and heterolactams A-M (2-14), were isolated from the soft coral Heteroxenia ghardaqensis. They structurally share the same 6/12 bicyclic carbon skeleton that is not commonly encountered in marine organisms. The structures, including the absolute configurations, were determined by extensive spectroscopic analysis, single-crystal X-ray diffraction analysis, calculated ECD spectra, and DP4+ probability analyses. Compounds 5, 8, and 9 showed anti-inflammatory activities, and 2, 8, and 12 displayed hepatoprotective activities in zebrafish assays.

New verticillane-diterpenoid as potent NF-κB inhibitor isolated from the gum resin of Boswellia sacra

Two new verticillane-diterpenoids (1 and 2) were isolated from the gum resin Boswellia sacra. Their structures were elucidated by physiochemical and spectroscopic analysis, as well as ECD calculation. In addition, the in vitro anti-inflammatory activities of the isolated compounds were evaluated by determining the inhibitory effects on lipopolysaccharide (LPS)-induced NO production in RAW 264.7 mouse monocyte-macrophages. The results showed that compound 1 exhibited significant inhibitory effect on NO generation with an IC₅₀ value of 23.3 ± 1.7 μM suggesting that it might be a candidate for an anti-inflammatory agent. Furthermore, 1 potently inhibited the release of inflammatory cytokines IL-6 and TNF-α induced by LPS in a dose-dependent manner. Using Western blot and Immunofluorescence methods, compound 1 was found to inhibit inflammation mainly by restraining the activation of NF-κB pathway. And in the MAPK signaling pathway, it was found to have inhibitory effects on the phosphorylation of JNK and ERK proteins and have no effect on the phosphorylation of p38 protein.

New Verticillene Diterpenoids, Eudesmane Sesquiterpenoids, and Hydroperoxysteroids from the Further Chemical Investigation of a Taiwanese Soft Coral Cespitularia sp

An investigation of the chemical composition of a Formosan soft coral Cespitularia sp. led to the discovery of one new verticillene-type diterpenoid, cespitulactam M (1); one new eudesmane sesquiterpenoid, cespilamide F (2); and three new hydroperoxysteroids (3-5) along with twelve known analogous metabolites (6-17). In addition, one new derivative, cespitulactam M-6,2'-diacetate (1a), was prepared from compound 1. The structures were determined by detailed spectroscopic analyses, particularly HRESIMS and NMR techniques. Moreover, the in vitro cytotoxicity, anti-inflammatory, and antibacterial activity of 1-17 and 1a were evaluated.

Bioactive Diterpenes, Norditerpenes, and Sesquiterpenes from a Formosan Soft Coral Cespitularia sp

Chemical investigation of the soft coral Cespitularia sp. led to the discovery of twelve new verticillane-type diterpenes and norditerpenes: cespitulins H-O (1-8), one cyclic diterpenoidal amide cespitulactam L (9), norditerpenes cespitulin P (10), cespitulins Q and R (11 and 12), four new sesquiterpenes: cespilins A-C (13-15) and cespitulolide (16), along with twelve known metabolites. The structures of these metabolites were established by extensive spectroscopic analyses, including 2D NMR experiments. Anti-inflammatory effects of the isolated compounds were studied by evaluating the suppression of pro-inflammatory protein tumor necrosis factor-α (TNF-α) and nitric oxide (NO) overproduction, and the inhibition of the gene expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in lipopolysaccharide-induced dendritic cells. A number of these metabolites were found to exhibit promising anti-inflammatory activities.

Different Macrophage Type Triggering as Target of the Action of Biologically Active Substances from Marine Invertebrates

Macrophages play a fundamental role in the immune system. Depending on the microenvironment stimuli, macrophages can acquire distinct phenotypes characterized with different sets of the markers of their functional activities. Polarization of macrophages towards M1 type (classical activation) is involved in inflammation and the related progression of diseases, while, in contrast, alternatively activated M2 macrophages are associated with the anti-inflammatory mechanisms. Reprogramming macrophages to switch their phenotypes could provide a new therapeutic strategy, and targeting the M1/M2 macrophage balance is a promising current trend in pharmacology. Marine invertebrates are a vast source of the variety of structurally diverse compounds with potent pharmacological activities. For years, a large number of studies concerning the immunomodulatory properties of the marine substances have been run with using some intracellular markers of immune stimulation or suppression irrespective of the possible application of marine compounds in reprogramming of macrophage activation, and only few reports clearly demonstrated the macrophage-polarizing activities of some marine compounds during the last decade. In this review, the data on the immunomodulating effects of the extracts and pure compounds of a variety of chemical structure from species of different classes of marine invertebrates are described with focus on their potential in shifting M1/M2 macrophage balance towards M1 or M2 phenotype.

Immuno-Modulatory and Anti-Inflammatory Effects of Dihydrogracilin A, a Terpene Derived from the Marine Sponge Dendrilla membranosa

We assessed the immunomodulatory and anti-inflammatory effects of 9,11-dihydrogracilin A (DHG), a molecule derived from the Antarctic marine sponge Dendrilla membranosa. We used in vitro and in vivo approaches to establish DHG properties. Human peripheral blood mononuclear cells (PBMC) and human keratinocytes cell line (HaCaT cells) were used as in vitro system, whereas a model of murine cutaneous irritation was adopted for in vivo studies. We observed that DHG reduces dose dependently the proliferative response and viability of mitogen stimulated PBMC. In addition, DHG induces apoptosis as revealed by AnnexinV staining and downregulates the phosphorylation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), signal transducer and activator of transcription (STAT) and extracellular signal–regulated kinase (ERK) at late time points. These effects were accompanied by down-regulation of interleukin 6 (IL-6) production, slight decrease of IL-10 and no inhibition of tumor necrosis factor-alpha (TNF-α) secretion. To assess potential properties of DHG in epidermal inflammation we used HaCaT cells; this compound reduces cell growth, viability and migration. Finally, we adopted for the in vivo study the croton oil-induced ear dermatitis murine model of inflammation. Of note, topical use of DHG significantly decreased mouse ear edema. These results suggest that DHG exerts anti-inflammatory effects and its anti-edema activity in vivo strongly supports its potential therapeutic application in inflammatory cutaneous diseases.

Chemical and biological profile of Cespitularia species: A mini review

Soft corals belonging to the genus Cespitularia have been well recognized as a rich source of bioactive secondary metabolites especially diterpenoids. This review furnishes an overview of all naturally isolated compounds from Cespitularia genus as, diterpenoids, nitrogen-containing diterpenes, sesquiterpenoids and steroids as well as biological activities of these species. Cespitularia species have been studied for their anticancer, immunomodulatory, antiviral, antimicrobial, and anti-inflammatory activities. This work is the first review published on this topic.

Marine Diterpenoids as Potential Anti-Inflammatory Agents

The inflammatory response is a highly regulated process, and its dysregulation can lead to the establishment of chronic inflammation and, in some cases, to death. Inflammation is the cause of several diseases, including rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis, and asthma. The search for agents inhibiting inflammation is a great challenge as the inflammatory response plays an important role in the defense of the host to infections. Marine invertebrates are exceptional sources of new natural products, and among those diterpenoids secondary metabolites exhibit notable anti-inflammatory properties. Novel anti-inflammatory diterpenoids, exclusively produced by marine organisms, have been identified and synthetic molecules based on those structures have been obtained. The anti-inflammatory activity of marine diterpenoids has been attributed to the inhibition of Nuclear Factor-κB activation and to the modulation of arachidonic acid metabolism. However, more research is necessary to describe the mechanisms of action of these secondary metabolites. This review is a compilation of marine diterpenoids, mainly isolated from corals, which have been described as potential anti-inflammatory molecules.

Anti-inflammatory activities of natural products isolated from soft corals of Taiwan between 2008 and 2012

This review reports details on the natural products isolated from Taiwan soft corals during the period 2008–2012 focusing on their in vitro and/or in vivo anti-inflammatory activities. Chemical structures, names, and literature references are also reported. This review provides useful and specific information on potent anti-inflammatory marine metabolites for future development of immune-modulatory therapeutics.