Topical application of marine briarane-type diterpenes effectively inhibits 12-O-tetradecanoylphorbol-13-acetate-induced inflammation and dermatitis in murine skin

Immunomodulatory and anti-angiogenesis effects of excavatolide B and its derivatives in alleviating atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin condition primarily driven by T helper 2 (Th2) cytokines, resulting in skin barrier defects, angiogenesis, and inflammatory responses. The marine natural product excavatolide B (EXCB), isolated from the Formosan Gorgonian coral Briareum stechei, exhibits anti-inflammatory and analgesic properties. To enhance solubility, EXCB is chemically modified into the derivatives EXCB-61 salt and EXCB-79. The study aims to investigate the therapeutic effects of these compounds on dinitrochlorbenzene (DNCB)-induced skin damage and to elucidate the underlying anti-inflammatory and anti-angiogenesis mechanism. In vitro, using lipopolysaccharide (LPS)-induced RAW 264.7 cells, all compounds at 10 μM significantly inhibited expression of inflammatory proteins (inducible nitric oxide synthase and cyclooxygenase-2), vascular endothelial growth factor (VEGF), and cytokines (interleukin (IL)-1β, IL-6, and IL-17A). In vivo, topical application of these compounds on DNCB-induced AD mice alleviated skin symptoms, reduced serum levels of IgE, IL-4, IL-13, IL-17, and interferon-γ, and moderated histological phenomena such as hyperplasia, inflammatory cell infiltration, and angiogenesis. The three compounds restored the expression of skin barrier-related proteins (loricrin, filaggrin, and claudin-1) and reduced the expression of angiogenesis-related proteins (VEGF and platelet endothelial cell adhesion molecule-CD31) in the tissues. This is the first study to indicate that EXCB, EXCB-61 salt, and EXCB-79 can treat AD disease by reducing inflammation and angiogenesis. Hence, they may be considered potential candidates for the development of new drugs for AD.

Humulus japonicus ameliorates irritant contact dermatitis by suppressing NF‑κB p65‑dependent inflammatory responses in mice

As a type of contact dermatitis (CD), irritant CD (ICD) is an acute skin inflammation caused by external irritants, such as soap, water and chemicals. Humulus japonicus (HJ) is a herbal medicine widely distributed in Asian countries and has anti-inflammatory, antimicrobial and antioxidant effects. The current study aimed to investigate the anti-dermatitis effect of HJ on ICD and determine the molecular basis of this effect using 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced dermatitis mice models and lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Mice were orally administered HJ and luteolin, the major compound in HJ, and topically administered TPA on the right ear to induce dermatitis. Topical application of TPA induced ear redness, oedema and increased infiltration of neutrophils and macrophages, which ameliorated following HJ and luteolin administration. The gene expression levels of inflammatory cell migrating chemokines, chemokine ligand 3 (CCL3) and chemokine (C-X-C motif) ligand 2 (CXCL2), and pro-inflammatory cytokine, IL-1β, were reduced in the ears of HJ- and luteolin-treated mice. HJ and luteolin also inhibited the gene expression of chemokines, CCL3 and CXCL2, and pro-inflammatory cytokines, IL-1β, IL-6 and TNF-α, in LPS-stimulated RAW264.7 cells. Moreover, HJ and luteolin decreased the expression levels of two key inflammatory enzymes, cyclooxygenase-2 (COX2) and inducible nitric oxide synthase (iNOS), and total and active phosphorylation of NF-κB p65. These results suggest that HJ could have a protective effect against ICD by suppressing inflammatory responses; therefore, HJ is a promising therapeutic strategy for ICD treatment.

Marine diterpenoid targets STING palmitoylation in mammalian cells

Natural products are important sources of therapeutic agents and useful drug discovery tools. The fused macrocycles and multiple stereocenters of briarane-type diterpenoids pose a major challenge to total synthesis and efforts to characterize their biological activities. Harnessing a scalable source of excavatolide B (excB) from cultured soft coral Briareum stechei, we generated analogs by late-stage diversification and performed structure-activity analysis, which was critical for the development of functional excB probes. We further used these probes in a chemoproteomic strategy to identify Stimulator of Interferon Genes (STING) as a direct target of excB in mammalian cells. We showed that the epoxylactone warhead of excB is required to covalently engage STING at its membrane-proximal Cys91, inhibiting STING palmitoylation and signaling. This study reveals a possible mechanism-of-action of excB, and expands the repertoire of covalent STING inhibitors.

Briarane-type diterpenoids, the inhibitors of osteoclast formation by interrupting Keap1-Nrf2 interaction and activating Nrf2 pathway

Chemoinformatic and bioassay-guided fractionation of a gorgonian coral Junceella juncea resulted in the isolation of 45 briarane-type diterpenoids, of which 16 new analogues were characterized. Their structures were identified by extensive analyses of the spectroscopic data. Most isolated briaranes showed significant inhibition against the receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation in bone marrow-derived macrophages cells (BMMs). Praelolide, one of the active analogues, significantly activates nuclear factor erythroid-2-related factor 2 (Nrf2) nucleus translocation, induces the expression of Nrf2-targeted genes, suppresses reactive oxygen species (ROS) production, abrogates the activation of downstream mitogen-activated protein kinase (MAPK)/nuclear factor-κB (NFκB) signaling, and subsequently attenuates osteoclast differentiation. Mechanically, praelolide interacts with Kelch-like ECH-associated protein 1 (Keap1) protein by non-covalent interaction to interrupt the interaction between Keap1 and Nrf2 and thereby to activate the Nrf2 signaling pathway. In addition, praelolide rescues the bone loss in prednisone-induced zebrafish. The present study provided praelolide as a new natural scaffold to remedy osteoclastogenic bone disease.

A Small Molecule Selected from a DNA-Encoded Library of Natural Products That Binds to TNF-α and Attenuates Inflammation In Vivo

Tumor necrosis factor α (TNF-α) inhibitors have shown great success in the treatment of autoimmune diseases. However, to date, approved drugs targeting TNF-α are restricted to biological macromolecules, largely due to the difficulties in using small molecules for pharmaceutical intervention of protein-protein interactions. Herein the power of a natural product-enriched DNA-encoded library (nDEL) is exploited to identify small molecules that interfere with the protein-protein interaction between TNF-α and the cognate receptor. Initially, to select molecules capable of binding to TNF-α , "late-stage" DNA modification method is applied to construct an nDEL library consisted of 400 sterically diverse natural products and pharmaceutically active chemicals. Several natural products, including kaempferol, identified not only show direct interaction with TNF-α, but also lead to the blockage of TNF-α/TNFR1 interaction. Significantly, kaempferol attenuates the TNF-α signaling in cells and reduces the 12-O-tetradecanoylphorbol-13-acetateinduced ear inflammation in mice. Structure-activity-relationship analyses demonstrate the importance of substitution groups at C-3, C-7, and C-4' of kaempferol. The nDEL hit, kaempferol, represents a novel chemical scaffold capable of specifically recognizing TNF-α and blocking its signal transduction, a promising starting point for the development of a small molecule TNF-α inhibitor for use in the clinical setting.

Polyoxygenated Klysimplexane- and Eunicellin-Based Diterpenoids from the Gorgonian Briareum violaceum

Three new polyoxygenated diterpenoids with a rare 4-isopropyl-1,5,8a-trimethylperhydrophenanthrane structure of the klysimplexane skeleton, briarols A‒C (1‒3), and one eunicellin-based diterpenoid, briarol D (4), were isolated from Briareum violaceum, a gorgonian inhabiting Taiwanese waters. The chemical structures of these compounds were determined by employing extensive analyses of NMR and high-resolution electrospray ionization mass spectrometry (HRESIMS) data. Metabolites 1‒3 were found to possess the rarely found skeleton of the diterpenoid klysimplexin T. All isolated compounds showed very weak cytotoxic activity against the growth of three cancer cell lines. A plausible biosynthetic pathway for briarols A‒C from the coexisting eunicellin diterpenoid briarol D (4) was postulated.

Briarane-type diterpenoids suppress osteoclastogenisis by regulation of Nrf2 and MAPK/NF-kB signaling pathway

Excess osteoclastic activity leads to an imbalance in bone remodeling and causes most adult skeletal diseases. Natural products are a promising source to attenuate the osteoporosis and relevant diseases of bone loss. Herein, a bioassay-guided detection of gorgonian corals resulted in junceellolide D (JD), a briarane-type diterpenoid from gorgonian Dichotella gemmacea, showing significant inhibition against the receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation in bone marrow macrophages (BMMs) in vitro. To extend the investigation for structure-activity relationship (SAR), a total of 39 briarane-type analogues were isolated including 28 new compounds, and their structures were determined by extensive analyses of spectroscopic data. The SAR data indicated that JD is the most active to inhibit osteoclast development due to the decreased number of multinucleated tartrate-resistance acid phosphatase positive cells, suppression of the actin ring formation, blockage of bone resorption, and downregulation of osteoclast-specific marker genes. Mechanistically, JD increased the protein stability of nuclear factor (erythroid-derived 2)-related factor-2 (Nrf2) and promoted Nrf2 nuclear translocation followed by activation its downstream antioxidant enzymes, which strongly abolished RANKL-induced generation of reactive oxygen species (ROS). Furthermore, JD inhibits the RANKL-stimulated activation of NF-κB and MAPK signaling pathways. Hence, JD is considered as a promising lead compound for anti-osteoclastogenesis via activating Nrf2 and suppressing NF-κB and MAPK signaling pathways to prevent osteoclast-mediated bone destructive diseases.

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.

XB130 deficiency enhances carcinogen-induced skin tumorigenesis

XB130 is an adaptor protein that functions as a mediator of multiple tyrosine kinases important for regulating cell proliferation, survival, migration and invasion. Formerly predicted as an oncogene, alterations of its expression are documented in various human cancers. However, the exact role of XB130 in tumorigenesis is unknown. To address its function in skin tumorigenesis, a two-stage dimethylbenzanthracene (DMBA)/12-O-tetradecanoylphorbol 13-acetate (TPA) study was performed on XB130 knockout (KO), heterozygous (HZ) and wild-type (WT) littermate mice. DMBA/TPA-treated XB130 KO and HZ males developed a significantly higher number of epidermal tumors that were notably larger in size than did WT mice. Interestingly, DMBA/TPA-treated female mice did not show any difference in tumor multiplicity regardless of the genotypes. The skin tumor lesions of XB130 KO males were more progressed with an increased frequency of keratoacanthoma. Deficiency of XB130 dramatically increased epidermal tumor cell proliferation. The responses to DMBA and TPA stimuli were also individually investigated to elucidate the mechanistic role of XB130 at different stages of tumorigenesis. DMBA-treated male XB130 KO mice showed compensatory p53-mediated stress response. TPA-treated XB130 KO males demonstrated more skin ulceration with more severe edema, enhanced cell proliferation, accumulation of infiltrating neutrophils and increased production of pro-inflammatory cytokine genes compared with WT mice. Enhanced activities of nuclear factor-kappa B pathway, increased protein expression of metalloproteinase-9 and ERK1/2 phosphorylation were found in these KO mice. These findings demonstrate that XB130 acts as a tumor suppressor in carcinogen-induced skin tumorigenesis that may be mediated through inhibiting inflammation.

Briarenones A‒C, New Briarellin Diterpenoids from the Gorgonian Briareum violaceum

Three new eunicellin-derived diterpenoids of briarellin type, briarenones A‒C (1‒3), were isolated from a Formosan gorgonian Briareum violaceum. The chemical structures of the compounds were elucidated on the basis of extensive spectroscopic analyses, including two-dimensional (2D) NMR. The absolute configuration of 1 was further confirmed by a single crystal X-ray diffraction analysis. The in vitro cytotoxic and anti-inflammatory potentialities of the isolated metabolites were tested against the growth of a limited panel of cancer cell lines and against the production of superoxide anions and elastase release in N-formyl-methionyl-leucyl-phenyl-alanine and cytochalasin B (fMLF/CB)-stimulated human neutrophils, respectively.

Induction of thymic stromal lymphopoietin by a steroid alkaloid derivative in mouse keratinocytes

Thymic stromal lymphopoietin (TSLP) plays critical roles in inducing and exacerbating allergic diseases. Chemical compounds that induce TSLP production can enhance sensitization to antigens and exacerbate allergic inflammation. Hence, identifying such chemicals will be important to prevent an increase in allergic diseases. In the present study, we found, for the first time, that a steroid alkaloid derivative, code no. 02F04, concentration and time dependently induced mRNA expression and production of TSLP in a mouse keratinocyte cell line, PAM212. In particular, the activity of 02F04 was selective to TSLP. As an analogue of the liver X receptor (LXR) endogenous ligand, 02F04 rapidly increased ATP-binding cassette transporter A1 (ABCA1) expression by regulating the nuclear receptor of LXR. However, instead of being inhibited by the LXR antagonist, 02F04-induced TSLP production was delayed and markedly suppressed by inhibitors of phospholipase C (PLC), pan-protein kinase C (PKC), PKCδ, Rho-associated protein kinase (ROCK), extracellular signal-regulated kinase (ERK) 1/2, and IκΒ kinase 2 (IKK2). Treatment with 02F04 caused the formation of F-actin filaments surrounding the nucleus of PAM212 cells, which then disappeared following addition of ROCK inhibitor. 02F04 also induced phosphorylation of ERK1/2 from 2h after treatment, with a maximum at 24h, and increased nuclear factor-κB (NF-κB) promoter activity by 1.3-fold. Taken together, these results indicate that 02F04-induced TSLP production is regulated via distinct signal transduction pathways, including PLC, PKC, ROCK, ERK1/2, and NF-κB but not nuclear receptors. 02F04, with a unique skeletal structure in inducing TSLP production, can represent a potential new tool for investigating the role of TSLP in allergic diseases.

Excavatolide B Attenuates Rheumatoid Arthritis through the Inhibition of Osteoclastogenesis

Osteoclasts are multinucleated giant cells of macrophage/monocyte lineage, and cell differentiation with the upregulation of osteoclast-related proteins is believed to play a major role in the destruction of the joints in the course of rheumatoid arthritis (RA). Pro-inflammatory cytokines, such as interleukin-17A (IL-17A) and macrophage colony-stimulating factor (M-CSF), can be overexpressed in RA and lead to osteoclastogenesis. In a previous study, we found that cultured-type soft coral-derived excavatolide B (Exc-B) exhibited anti-inflammatory properties. In the present study, we thus aimed to evaluate the anti-arthritic activity of Exc-B in in vitro and in vivo models. The results demonstrated that Exc-B inhibits LPS-induced multinucleated cell and actin ring formation, as well as TRAP, MMP-9, and cathepsin K expression. Additionally, Exc-B significantly attenuated the characteristics of RA in adjuvant (AIA) and type II collagen-induced arthritis (CIA) in rats. Moreover, Exc-B improved histopathological features, and reduced the number of TRAP-positive multinucleated cells in the in vivo AIA and CIA models. Immunohistochemical analysis showed that Exc-B attenuated the protein expression of cathepsin K, MMP-2, MMP-9, CD11b, and NFATc1 in ankle tissues of AIA and CIA rats. Level of interleukin-17A and macrophage colony-stimulating factor were also decreased by Exc-B. These findings strongly suggest that Exc-B could be of potential use as a therapeutic agent by inhibiting osteoclast differentiation in arthritis. Moreover, this study also illustrates the use of the anti-inflammatory marine compound, Exc-B, as a potential therapeutic strategy for RA.

Inhibiting MDSC differentiation from bone marrow with phytochemical polyacetylenes drastically impairs tumor metastasis

Myeloid-derived suppressor cells (MDSCs) are implicated in the promotion of tumor metastasis by protecting metastatic cancerous cells from immune surveillance and have thus been suggested as novel targets for cancer therapy. We demonstrate here that oral feeding with polyacetylenic glycosides (BP-E-F1) from the medicinal plant Bidens pilosa effectively suppresses tumor metastasis and inhibits tumor-induced accumulation of granulocytic (g) MDSCs, but does not result in body weight loss in a mouse mammary tumor-resection model. BP-E-F1 is further demonstrated to exert its anti-metastasis activity through inhibiting the differentiation and function of gMDSCs. Pharmacokinetic and mechanistic studies reveal that BP-E-F1 suppresses the differentiation of gMDSCs via the inhibition of a tumor-derived, G-CSF-induced signaling pathway in bone marrow cells of test mice. Taken together, our findings suggest that specific plant polyacetylenic glycosides that target gMDSC differentiation by communicating with bone marrow cells may hence be seriously considered for potential application as botanical drugs against metastatic cancers.

Anti-Inflammatory Potential of Ethyl Acetate Fraction of Moringa oleifera in Downregulating the NF-κB Signaling Pathway in Lipopolysaccharide-Stimulated Macrophages

In the present investigation, we prepared four different solvent fractions (chloroform, hexane, butanol, and ethyl acetate) of Moringa oleifera extract to evaluate its anti-inflammatory potential and cellular mechanism of action in lipopolysaccharide (LPS)-induced RAW264.7 cells. Cell cytotoxicity assay suggested that the solvent fractions were not cytotoxic to macrophages at concentrations up to 200 µg/mL. The ethyl acetate fraction suppressed LPS-induced production of nitric oxide and proinflammatory cytokines in macrophages in a concentration-dependent manner and was more effective than the other fractions. Immunoblot observations revealed that the ethyl acetate fraction effectively inhibited the expression of inflammatory mediators including cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor (NF)-κB p65 through suppression of the NF-κB signaling pathway. Furthermore, it upregulated the expression of the inhibitor of κB (IκBα) and blocked the nuclear translocation of NF-κB. These findings indicated that the ethyl acetate fraction of M. oleifera exhibited potent anti-inflammatory activity in LPS-stimulated macrophages via suppression of the NF-κB signaling pathway.

Role of Antioxidants and Natural Products in Inflammation

Inflammation is a comprehensive array of physiological response to a foreign organism, including human pathogens, dust particles, and viruses. Inflammations are mainly divided into acute and chronic inflammation depending on various inflammatory processes and cellular mechanisms. Recent investigations have clarified that inflammation is a major factor for the progression of various chronic diseases/disorders, including diabetes, cancer, cardiovascular diseases, eye disorders, arthritis, obesity, autoimmune diseases, and inflammatory bowel disease. Free radical productions from different biological and environmental sources are due to an imbalance of natural antioxidants which further leads to various inflammatory associated diseases. In this review article, we have outlined the inflammatory process and its cellular mechanisms involved in the progression of various chronic modern human diseases. In addition, we have discussed the role of free radicals-induced tissue damage, antioxidant defence, and molecular mechanisms in chronic inflammatory diseases/disorders. The systematic knowledge regarding the role of inflammation and its associated adverse effects can provide a clear understanding in the development of innovative therapeutic targets from natural sources that are intended for suppression of various chronic inflammations associated diseases.

Bioactive Extract from Moringa oleifera Inhibits the Pro-inflammatory Mediators in Lipopolysaccharide Stimulated Macrophages

Introduction:

Inflammation is a well-known physiological response to protect the body against infection and restore tissue injury. Nevertheless, the chronic inflammation can trigger various inflammatory associated diseases/disorder. Moringa oleifera is a widely grown plant in most tropical countries and it has been recognized traditionally for several medicinal benefits.

Objectives:

The objective of this study was to investigate the anti-inflammatory properties of M. oleifera extract on lipopolysaccharide (LPS) - stimulated macrophages.

Materials and Methods:

The anti-inflammatory effect of M. oleifera hydroethanolic bioactive leaves extracts was evaluated by assessing the inhibition of nitric oxide (NO) production during Griess reaction and the expression of pro-inflammatory mediators in macrophages.

Results:

Interestingly, we found that M. oleifera hydroethanolic bioactive leaves extract significantly inhibited the secretion of NO production and other inflammatory markers such as prostaglandin E₂, tumor necrosis factor alpha, interleukin (IL)-6, and IL-1β. Meanwhile, the bioactive extract has induced the production of IL-10 in a dose-dependent manner. In addition, M. oleifera hydroethanolic bioactive leaves extract effectively suppressed the protein expression of inflammatory markers inducible NO synthase, cyclooxygenase-2, and nuclear factor kappa-light-chain-enhancer of activated B-cells p65 in LPS-induced RAW264.7 macrophages in a dose-dependent manner.

Conclusion:

These findings support the traditional use of M. oleifera plant as an effective treatment for inflammation associated diseases/disorders.

SUMMARY

Hydroethanolic extracts of Moringa oleifera effectively inhibit the NO production in LPS induced inflammatory model.

M. oleifera crude extracts successfully modulate the production of pro-inflammatory mediators in LPS stimulated macrophages.

M. oleifera extracts suppressed the expression of inflammatory mediators in LPS stimulated macrophages.

Higher Caffeinated Coffee Intake Is Associated with Reduced Malignant Melanoma Risk: A Meta-Analysis Study

Background

Several epidemiological studies have determined the associations between coffee intake level and skin cancer risk; however, the results were not yet conclusive. Herein, we conducted a systematic review and meta-analysis of the cohort and case-control studies for the association between coffee intake level and malignant melanoma (MM) risk.

Methods

Studies were identified through searching the PubMed and MEDLINE databases (to November, 2015). Study-specific risk estimates were pooled under the random-effects model.

Results

Two case-control studies (846 MM patients and 843 controls) and five cohort studies (including 844,246 participants and 5,737 MM cases) were identified. For caffeinated coffee, the pooled relative risk (RR) of MM was 0.81 [95% confidential interval (95% CI) = 0.68–0.97; P-value for Q-test = 0.003; I² = 63.5%] for those with highest versus lowest quantity of intake. In the dose-response analysis, the RR of MM was 0.955 (95% CI = 0.912–0.999) for per 1 cup/day increment of caffeinated coffee consumption and linearity dose-response association was found (P-value for nonlinearity = 0.326). Strikingly, no significant association was found between the decaffeinated coffee intake level and MM risk (pooled RR = 0.92, 95% CI = 0.81–1.05; P-value for Q-test = 0.967; I² = 0%; highest versus lowest quantity of intake).

Conclusions

This meta-analysis suggested that caffeinated coffee might have chemo-preventive effects against MM but not decaffeinated coffee. However, larger prospective studies and the intervention studies are warranted to confirm these findings.

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 and Analgesic Effects of the Marine-Derived Compound Excavatolide B Isolated from the Culture-Type Formosan Gorgonian Briareum excavatum

In recent years, several marine-derived compounds have been clinically evaluated. Diterpenes are secondary metabolites from soft coral that exhibit anti-inflammatory, anti-tumor and cytotoxic activities. In the present study, we isolated a natural diterpene product, excavatolide B, from cultured Formosan gorgonian Briareum excavatum and investigated its anti-inflammatory activities. We found that excavatolide B significantly inhibited the mRNA expression of the proinflammatory mediators, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in lipopolysaccharide (LPS)-challenged murine macrophages (RAW 264.7). We also examined the anti-inflammatory and anti-nociceptive effects of excavatolide B on intraplantar carrageenan-induced inflammatory responses. Excavatolide B was found to significantly attenuate carrageenan-induced nociceptive behaviors, mechanical allodynia, thermal hyperalgesia, weight bearing deficits and paw edema. In addition, excavatolide B inhibited iNOS, as well as the infiltration of immune cells in carrageenan-induced inflammatory paw tissue.

Coffee drinking and cutaneous melanoma risk in the NIH-AARP diet and health study

BACKGROUND

Cutaneous melanoma is the fifth most common cancer in the United States. Modifiable risk factors, with the exception of exposure to ultraviolet radiation (UVR), are poorly understood. Coffee contains numerous bioactive compounds and may be associated inversely with melanoma. However, previous epidemiological evidence is limited.

METHODS

Coffee intake was assessed at baseline with a food frequency questionnaire in the National Institutes of Health-AARP prospective cohort study. Among 447 357 non-Hispanic whites who were cancer-free at baseline, 2904 incident cases of malignant melanoma were identified during 4 329 044 person-years of follow-up, with a median of 10.5 years of follow-up. Multivariable-adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for coffee intake and subsequent melanoma risk with non-coffee drinkers as the reference group. Statistical tests were two-sided, and P values less than .05 were interpreted as statistically significant.

RESULTS

The highest category of coffee intake was inversely associated with malignant melanoma (≥4 cups/day: HR = 0.80, 95% CI = 0.68 to 0.93, P trend = .01). This association was statistically significant for caffeinated (≥4 cups/day: HR = 0.75, 95% CI = 0.64 to 0.89, P trend = .01) but not for decaffeinated coffee (P trend = .55).

CONCLUSIONS

Higher coffee intake was associated with a modest decrease in risk of melanoma in this large US cohort study. Additional investigations of coffee intake and its constituents, particularly caffeine, with melanoma are warranted.

Topical atorvastatin ameliorates 12-O-tetradecanoylphorbol-13-acetate induced skin inflammation by reducing cutaneous cytokine levels and NF-κB activation

Atorvastatin is a 3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitor used in the treatment of atherosclerosis and dyslipidemia. Studies have evaluated the utility of statins in the treatment of skin inflammation but with varied results. In the present study, we investigated the effect of atorvastatin on TNF-α release and keratinocyte proliferation in vitro and in acute and chronic 12-O-tetradecanoylphorbol-13-acetate (TPA) induced skin inflammation in vivo. Atorvastatin significantly inhibited lipopolysacharide induced TNF-α release in THP-1 cells and keratinocyte proliferation in HaCaT cells. In an acute study, topical atorvastatin showed dose dependent reduction in TPA induced skin inflammation with highest efficacy observed at 500 µg/ear dose. In chronic study, topical atorvastatin significantly reduced TPA induced ear thickness, ear weight, cutaneous cytokines, MPO activity and improved histopathological features comparable to that of dexamethasone. Atorvastatin also inhibited TPA stimulated NF-κB activation in mouse ear. In conclusion, our results suggest that atorvastatin ameliorates TPA induced skin inflammation in mice at least in part, due to inhibition of cytokine release and NF-κB activation and may be beneficial for the treatment skin inflammation like psoriasis.

Klymollins T-X, bioactive eunicellin-based diterpenoids from the soft coral Klyxum molle

Five new eunicellin-based diterpenoids, klymollins T–X (1–5), along with two known compounds (6 and 7) have been isolated from the soft coral Klyxum molle. The structures of these new metabolites were elucidated by extensive spectroscopic analysis and by comparison with related known compounds. Compound 5 was found to exert significant in vitro anti-inflammatory activity against LPS-stimulated RAW264.7 macrophage cells. Furthermore, compounds 4 and 7 were shown to exhibit cytotoxicity against a limited panel of human cancer cell lines.

Briarane diterpenoids isolated from gorgonian corals between 2011 and 2013

The structures, names, bioactivities and references of 138 briarane-type diterpenoids, including 87 new compounds, are summarized in this review. All the briarane-type compounds mentioned in this review article were obtained from gorgonian corals including the genus Briareum, Dichotella, Junceella and Verrucella. Some of these compounds showed potential bioactivities.

A pseudopterane diterpene isolated from the octocoral Pseudopterogorgia acerosa inhibits the inflammatory response mediated by TLR-ligands and TNF-alpha in macrophages

Several diterpenoids isolated from terrestrial and marine environments have been identified as important anti-inflammatory agents. Although considerable progress has been made in the area of anti-inflammatory treatment, the search for more effective and safer compounds is a very active field of research. In this study we investigated the anti-inflammatory effects of a known pseudopterane diterpene (referred here as compound 1) isolated from the octocoral Pseudopterogorgia acerosa on the tumor necrosis factor- alpha (TNF-α) and TLRs- induced response in macrophages. Compound 1 inhibited the expression and secretion of the inflammatory mediators TNF-α, interleukin (IL)-6, IL-1β, nitric oxide (NO), interferon gamma-induced protein 10 (IP-10), ciclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS) and monocyte chemoattractant protein-1 (MCP-1) induced by LPS in primary murine macrophages. This effect was associated with the inhibition of IκBα degradation and subsequent activation of NFκB. Compound 1 also inhibited the expression of the co-stimulatory molecules CD80 and CD86, which is a hallmark of macrophage activation and consequent initiation of an adaptive immune response. The anti-inflammatory effect was not exclusive to LPS because compound 1 also inhibited the response of macrophages to TNF-α and TLR2 and TLR3 ligands. Taken together, these results indicate that compound 1 is an anti-inflammatory molecule, which modulates a variety of processes occurring in macrophage activation.

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.