Suppression of cyclooxygenase-2 and inducible nitric oxide synthase expression by epimuqubilin A via IKK/IκB/NF-κB pathways in lipopolysaccharide-stimulated RAW 264.7 cells

Anti-inflammatory Activities of 7,8-Dihydroxy-4-Methylcoumarin Acetylation Products via NF-κB and MAPK Pathways in LPS-Stimulated RAW 264.7 Cells

Coumarins are phenolic compounds that are characterized by fused benzene and α-pyrone rings. Among coumarin-based compounds, 7,8-dihydroxy-4-methylcoumarin (DHMC) has anti-inflammatory activities, but whether the level of this activity varies according to the degree of acetylation remains unknown. Therefore, we acetylated DHMC to yield monoacetylated 8-acetoxy-4-methylcoumarin (8AMC) and 7,8-diacetoxy-4-methylcoumarin (DAMC). We then compared the anti-inflammatory activities of DHMC with its acetylated derivatives and discovered a novel anti-inflammatory agent. We evaluated whether DHMC, 8AMC, and DAMC could inhibit lipopolysaccharide (LPS)-induced stimulation in RAW 264.7 cells. We found that DHMC, 8AMC, and DAMC induced a dose-dependent downregulation of nitric oxide (NO), prostaglandin E2 (PGE2), pro-inflammatory cytokine, inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2) expression at the mRNA and protein levels. Western blotting showed that DHMC, 8AMC, and DAMC inhibited phosphorylated mitogen-activated protein kinase (MAK), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38, and nuclear factor-kappa B (NF-κB) expression in a concentration-dependent manner. Furthermore, 8AMC was the most effective inhibitor with powerful anti-inflammatory activity. These results indicate that acetylation can improve the anti-inflammatory activity of natural precursors. We also discovered the new anti-inflammatory compounds 8AMC and DAMC.

Investigation of Antioxidant, Anticancer, and Chemopreventive Properties of Hawaiian Grown Māmaki tea (Pipturus albidus)

Objective Māmaki tea ( Pipturus albidus) is a native Hawaiian plant species that is best known for its medicinal uses. It is endemic and only grows on the Hawaiian Islands. We evaluated different extraction methods and investigated antioxidant, anticancer, and/or chemopreventive potential of Māmaki tea. Materials and Methods Fresh Māmaki tea leaves were purchased from Hilo Farmers Market on Big Island. The Ferric Reducing Antioxidant Power (FRAP) assay was used to evaluate the antioxidant activities of selected Hawaii-grown teas, fruits, and vegetables. In addition, chemopreventive assays against tumor necrosis factor (TNF)-α-induced nuclear factor kappa B (NF-κB) and nitric oxide (NO) were performed for these Māmaki tea extracts. Cytotoxicity testing was done using in vitro sulforhodamine B (SRB) assay against lung (LU-1) and breast (MCF-7) cancer cell lines. Results Locally grown red vine Māmaki tea exhibited the highest level (40.0 µM/µg) of antioxidants among the tested locally grown fruits, vegetables, and tea. In addition, when tested at 20 µg/mL, the dehydrated Māmaki tea powders (AS-18), brewed from boiling water, showed the highest NF-κB inhibition (75.0%); and the freeze-dried Māmaki leaf powder (AS-1) brewed using room temperature water had the highest inhibitory activity with 55.5% in the nitrite assay. Furthermore, AS-25, the 100% ethanol extract from dehydrated Māmaki tea leaves exhibited the best anticancer activity with the lowest 71.3% survival of breast cancer cells. Conclusions This work stimulates further studies on the biological properties and medicinal uses of Māmaki tea, and raises community and public awareness to promote Māmaki tea.

Marine Terpenic Endoperoxides

Organic extracts of marine invertebrates, mainly sponges, from seas all over the world are well known for their high in vitro anticancer and antibiotic activities which make them promising sources of compounds with potential use as pharmaceutical leads. Most of the structures discovered so far have a peculiar structural feature in common: a 1,2-dioxane ring. This is a highly reactive heterocycle that can be considered as an endoperoxide function. Together with other structural features, this group could be responsible for the strong biological activities of the substances present in the extracts. Numerous research programs have focused on their structural elucidation and total synthesis since the seventies. As a consequence, the number of established chiral centres and the similarity between different naturally occurring substances is increasingly higher. Most of these compounds have a terpenoid nature, mainly diterpene and sesterterpene, with several peculiar structural features, such as the loss of one carbon atom. Although there are many reviews dealing with the occurrence of marine peroxides, their activities, or potential pharmaceutical uses, no one has focused on those having a terpene origin and the endoperoxide function. We present here a comprehensive review of these compounds paying special attention to their structural features and their biological activity.

Marine sponges Sarcotragus foetidus, Xestospongia carbonaria and Spongia obscura constituents ameliorate IL-1 β and IL-6 in lipopolysaccharide-induced RAW 264.7 macrophages and carrageenan-induced oedema in rats

Marine sponges are prolific producers of an array of diverse chemical structures containing compounds with multiple biological activities. In this study, whole methanol extracts and fractionated compounds from three marine sponges namely Xestospongia carbonaria, Sarcotragus foetidus and Spongia obscura were thoroughly investigated for their antibacterial, antifungal, antioxidant and anti-inflammatory activities. Methanol extracts and fractionated compounds were characterised using high performance liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Extracts were checked for cytotoxicity in RAW macrophages by MTT assay, before using them for the treatment study. Enzyme linked immunosorbent assay kits were used to check the effects on inflammatory mediator's levels (PGE₂, COX-2, IL-6, IL-1β, TNF-α) in vitro. The results demonstrated good anti-inflammatory activity of all the three marine sponges; X. carbonaria, S. foetidus and S. obscura suppressed the levels of anti-inflammatory cytokines in vitro. Reverse transcriptase-polymerase chain reaction confirmed the inhibition of IL-1β and IL-6 genes expression by the isolates of X. carbonaria and S. foetidus, while reducing cytokine levels in lipopolysaccharide-induced inflammation in vitro as well as in carrageenan-induced inflammation in rats. Two semi pure compounds isolated from X. carbonaria and S. foetidus also confirmed suppression of IL-1β and IL-6 genes expression in RAW macrophages.

Human disorders associated with inflammation and the evolving role of natural products to overcome

Inflammation is a biological function which triggered after the mechanical tissue disruption or from the responses by the incidence of physical, chemical or biological negotiator in body. These responses are essential act provided by the immune system during infection and tissue injury to maintain normal tissue homeostasis. Inflammation is a quite complicated process at molecular level with the involvement of several proinflammatory expressions. Several health problems are associated with prolonged inflammation, which effects nearly all major to minor diseases. The molecular and epidemiological studies jagged that the inflammation is closely associated with several disorders with their specific targets. It would be great achievement for human health around the world to overcome on inflammation. Mostly used anti-inflammatory drugs are at high risk of side effects and also expensive. Hence, the plant-based formulations gained a wide acceptance by the public and medical experts to treat it. Due to extensive dispersal, chemical diversity and systematically established biological potentials of natural products have induced renewed awareness as a gifted source for medications. However, today's urgent need to search for cheaper, more potent and safe anti-inflammatory medications to overcome on current situation. The goal of this review to compile an update on inflammation, associated diseases, molecular targets, inflammatory mediators and role of natural products. The entire text concise the involvement of various cytokines in pathogenesis of various human disorders. This assignment discussed about 321 natural products with their promising anti-inflammatory potential discovered during January 2009 to December 2018 with 262 citations.

Natural Products from Sponges

The sponge is one of the oldest multicellular invertebrates in the world. Marine sponges represent one of the extant metazoans of 700–800 million years. They are classified in four major classes: Calcarea, Demospongiae, Hexactinellida, and Homoscleromorpha. Among them, three genera, namely, Haliclona, Petrosia, and Discodemia have been identified to be the richest source of biologically active compounds. So far, 15,000 species have been described, and among them, more than 6000 species are found in marine and freshwater systems throughout tropical, temperate, and polar regions. More than 5000 different compounds have been isolated and structurally characterized to date, contributing to about 30% of all marine natural products. The chemical diversity of sponge products is high with compounds classified as alkaloids, terpenoids, peptides, polyketides, steroids, and macrolides, which integrate a wide range of biological activities, including antibacterial, anticancer, antifungal, anti-HIV, anti-inflammatory, and antimalarial. There is an open debate whether all natural products isolated from sponges are produced by sponges or are in fact derived from microorganisms that are inhaled though filter-feeding or that live within the sponges. Apart from their origin and chemoecological functions, sponge-derived metabolites are also of considerable interest in drug development. Therefore, development of recombinant microorganisms engineered for efficient production of sponge-derived products is a promising strategy that deserves further attention in future investigations in order to address the limitations regarding sustainable supply of marine drugs.

The Screening Research of NF-κB Inhibitors from Moutan Cortex Based on Bioactivity-Integrated UPLC-Q/TOF-MS

Inflammation is a common and important pathological process, and nuclear factor-κB (NF-κB) is a key mediator of it. Moutan Cortex (MC), the dried root cortex of Paeonia suffruticosa Andr., is widely used as a remedy for the treatment of inflammatory diseases in Asian region. However, there are few studies on the systematic identification of NF-κB inhibitors of MC. In this study, the effect of inhibiting NF-κB activation of MC was assessed at the cellular level using a tumor necrosis factor-α (TNF-α) induced inflammatory model. Subsequently, ultra-performance liquid chromatography-quadrupole/time of flight-mass spectrometry (UPLC-Q/TOF-MS) combined with biological activity assay was established to screen and identify potential anti-inflammatory ingredients in MC. The results revealed that MC significantly inhibited the activation of NF-κB. Seven potential NF-κB inhibitors were screened from MC, including oxypaeoniflorin, paeoniflorin, galloylpaeoniflorin, benzoyloxypaeoniflorin, mudanpioside C, gallic acid, and paeonol. Among them, the NF-κB inhibitor activity of galloylpaeoniflorin, benzoyloxypaeoniflorin, and mudanpioside C is first reported here. In conclusion, the anti-inflammatory activity of MC was associated with the seven components mentioned above. And the bioactivity-integrated UPLC-Q/TOF which contains both chemical and bioactive details is suitable for screening active ingredients from natural medicines.

Lycopene attenuates LPS-induced liver injury by inactivation of NF-κB/COX-2 signaling

AIM

This study aimed to investigate the effect of lycopene on LPS-induced liver injury in mice and its mechanisms.

METHODS

Male C57bl/6 mice were randomly assigned to three groups: sham control group (S-C), LPS control group (L-C), lycopene treatment group (L-T). The mice from the L-T were treated with lycopene for 2 weeks, and the remaining mice with solvent. Afterwards, the mice from the L-C and the L-T received an intraperitoneal injection of LPS (20 mg/kg, dissolved in sterile saline), and the S-C mice were injected with sterile saline. Serum levels of alanine transaminase (ALT) and aspartate aminotransferase (AST) were determined for analysis of liver function. Levels of inflammatory cytokines including tumor necrosis factor (TNF)-α and interleukin (IL)-6, malondialdehyde (MDA) content, and the activity of superoxide dismutase (SOD), were detected in serum. Liver tissues were operated for morphologic analysis and determination of protein by western blot.

RESULTS

Pretreatment with lycopene significantly decreased levels of ALT, AST, and TNF-α and IL-6, reduced MDA content, and increased activity of SOD in serum compared with the L-C mice. Lycopene increased expression of nuclear factor-erythroid 2 related factor 2 (Nrf2), and reduced expression of cyclooxygenase (COX)-2, and phosphorylation of nuclear factor-kappa B (NF-κB) and extracellular regulated protein kinases 1/2 (ERK1/2).

CONCLUSION

The results showed that lycopene attenuates LPS-induced liver injury by reducing NF-κB/COX-2 signaling by upregulation of Nrf2/HO-1 activation.

Expressions of Ras Homolog Gene Family, Member A (RhoA) and Cyclooxygenase-2 (COX-2) Proteins in Early Gastric Cancer and Their Role in the Development of Gastric Cancer

Background

This research focused on detecting the expressions of RhoA and cyclooxygenase-2 (COX-2) proteins in early gastric cancer tissues and to explore their role in the development of gastric cancer.

Material/Methods

Surgically resected gastric cancer tissues and the paired normal paracancerous tissues were collected from 26 patients with early gastric cancer from January 2015 to November 2015. The expressions of RhoA and COX-2 proteins were detected by using RT-PCR and immunohistochemistry techniques, respectively. Cell proliferation and migration experiments were conducted on the RhoA-silenced A6-B9 cells and COX-2-silenced D7-B8 cells so as to discuss their role in the development of gastric cancer.

Results

Relative mRNA expressions of RhoA and COX-2 in the cancer tissues were 0.823±0.021 and 0.892±0.103, respectively, which showed significant differences compared to the normal cancerous tissues (0.295±0.014 and 0.129±0.037) (p<0.05). Immunohistochemical staining indicated that the expressions of RhoA and COX-2 proteins in tumor tissues were significantly upregulated as compared to normal cancerous tissues (p<0.05). Cell cloning and streaking assays showed that silencing of RhoA and COX-2 gene caused a considerable decline in the proliferation and migration capacities of the gastric cancer cells, respectively (p<0.05).

Conclusions

RhoA and COX-2 were upregulated in early gastric cancer tissues, which facilitated the proliferation and migration of gastric cancer cells. Both proteins may be used as potential markers for the diagnosis of early gastric cancer.

Culturable diversity and antimicrobial activity of Actinobacteria from marine sediments in Valparaíso bay, Chile

Marine-derived Actinobacteria are a source of a broad variety of secondary metabolites with diverse biological activities, such as antibiotics and antitumorals; many of which have been developed for clinical use. Rare Actinobacteria represent an untapped source of new bioactive compounds that have been scarcely recognized. In this study, rare Actinobacteria from marine sediments were isolated from the Valparaíso bay, Chile, and their potential to produce antibacterial compounds was evaluated. Different culture conditions and selective media that select the growth of Actinobacteria were used leading to the isolation of 68 bacterial strains. Comparative analysis of the 16S rRNA gene sequences led to identifying isolates that belong to the phylum Actinobacteria with genetic affiliations to 17 genera: Aeromicrobium, Agrococcus, Arthrobacter, Brachybacterium, Corynebacterium, Dietzia, Flaviflexus, Gordonia, Isoptericola, Janibacter, Microbacterium, Mycobacterium, Ornithinimicrobium, Pseudonocardia, Rhodococcus, Streptomyces, and Tessaracoccus. Also, one isolate could not be consistently classified and formed a novel phylogenetic branch related to the Nocardiopsaceae family. The antimicrobial activity of these isolates was evaluated, demonstrating the capability of specific novel isolates to inhibit the growth of Gram-positive and Gram-negative bacteria. In conclusion, this study shows a rich biodiversity of culturable Actinobacteria, associated to marine sediments from Valparaíso bay, highlighting novel rare Actinobacteria, and their potential for the production of biologically active compounds.

Antinociceptive effect of tetrandrine on LPS-induced hyperalgesia via the inhibition of IKKβ phosphorylation and the COX-2/PGE₂ pathway in mice

Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid that is isolated from the Stephania Tetrandra. It is known to possess anti-inflammatory and immunomodulatory effects. We have shown that TET can effectively suppress the production of bacterial lipopolysaccharide (LPS)-induced inflammatory mediators, including cyclooxygenases (COXs), in macrophages. However, whether TET has an antinociceptive effect on LPS-induced hyperalgesia is unknown. In the present study, we investigated the potential antinociceptive effects of TET and the mechanisms by which it elicits its effects on LPS-induced hyperalgesia. LPS effectively evoked hyperalgesia and induced the production of PGE2 in the sera, brain tissues, and cultured astroglia. TET pretreatment attenuated all of these effects. LPS also activated inhibitor of κB (IκB) kinase β (IKKβ) and its downstream components in the IκB/nuclear factor (NF)-κB signaling pathway, including COX-2; the increase in expression levels of these components was significantly abolished by TET. Furthermore, in primary astroglia, knockdown of IKKβ, but not IKKα, reversed the effects of TET on the LPS-induced increase in IκB phosphorylation, P65 phosphorylation, and COX-2. Our results suggest that TET can effectively exert antinociceptive effects on LPS-induced hyperalgesia in mice by inhibiting IKKβ phosphorylation, which leads to the reduction in the production of important pain mediators, such as PGE2 and COX-2, via the IKKβ/IκB/NF-κB pathway.

Inhibitory effect of a callophycin A derivative on iNOS expression via inhibition of Akt in lipopolysaccharide-stimulated RAW 264.7 cells

In previous studies, (R)-2-isobutyl 3-methyl 3,4-dihydro-1H-pyrido[3,4-b]indole-2,3(9H)-dicarboxylate (1), a callophycin A derivative, was found to strongly inhibit nitrite production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, while (R)- or (S)-callophycin A showed only weak inhibition. We currently report additional studies to define the mechanisms underlying the inhibitory action of 1. Expression of inducible nitric oxide synthase (iNOS) was reduced at both protein and mRNA levels. Major upstream signaling molecules and transcription factors regulating iNOS expression were examined, but it was found that 1 did not affect the phosphorylated and total protein levels of p38 mitogen-activated protein kinase (p38 MAPK), Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), and signal transducer and activator of transcription 1 (STAT1), nor did it mediate the degradation of the inhibitor of nuclear factor-κB α-isoform (IκBα). However, starting at early time points, 1 consistently inhibited the phosphorylation of protein kinase B/Akt at serine 473. In addition, 1 suppressed the protein expression of octamer-binding transcription factor-2 (Oct-2) and the expression of microRNA 155 (miR-155). In sum, compound 1 inhibits LPS-induced nitrite production by a unique and complex mechanism. Reduction of iNOS expression is accompanied by inhibition of Akt activation, Oct-2 protein expression, and miR-155 expression.

Chitosan oligosaccharides downregulate the expression of E-selectin and ICAM-1 induced by LPS in endothelial cells by inhibiting MAP kinase signaling

The expression of adhesion molecules in endothelial cells elicited by lipopolysaccharide (LPS) is involved in the adhesive interaction between endothelial cells and monocytes in inflammation. In this study, in order to characterize the anti-inflammatory effects of chitosan oligosaccharides (COS) on LPS‑induced inflammation and to elucidate the underlying mechanisms, the mRNA levels of E-selectin and intercellular adhesion molecule-1 (ICAM-1) were measured in porcine iliac artery endothelial cells (PIECs). When these cells were treated with COS, the LPS-induced mRNA expression of E-selectin and ICAM-1 was reduced through the inhibition of the signal transduction cascade, p38 mitogen‑activated protein kinase (MAPK)/extracellular regulated protein kinase 1/2 (ERK1/2) and nuclear factor-κB (NF-κB). Moreover, through the inhibition of p38 MAPK and ERK1/2, COS suppressed the LPS-induced NF-κB p65 translocation. We found that COS suppressed the phosphorylation of p38 MAPK and the translocation of NF-κB p65 into the nucleus in a dose-dependent manner, and inhibited the adhesion of U973 cells to PIECs. Based on these results, it can be concluded that COS downregulate the expression of E-selectin and ICAM-1 by inhibiting the phosphorylation of MAPKs and the activation of NF-κB in LPS-treated PIECs. Our study demonstrates the valuable anti-inflammatory properties of COS.

Peroxy natural products

This review covers the structures and biological activities of peroxy natural products from a wide variety of terrestrial fungi, higher plants, and marine organisms. Syntheses that confirm or revise structures or stereochemistries have also been included, and 406 references are cited.

Suppression of nitric oxide synthase by thienodolin in lipopolysaccharide-stimulated RAW 264.7 murine macrophage cells

The measurement of nitric oxide in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells is used as a model for evaluating the anti-inflammatory or chemopreventive potential of substances. Thienodolin, isolated from a Streptomyces sp. derived from Chilean marine sediment, inhibited nitric oxide production in LPS-stimulated RAW 264.7 cells (IC50 = 17.2 +/- 1.2 microM). At both the mRNA and protein levels, inducible nitric oxide synthase (iNOS) was suppressed in a dose-dependent manner. Mitogen-activated protein kinases (MAPKs), one major upstream signaling pathway involved in the transcription of iNOS, were not affected by treatment of thienodolin. However, the compound blocked the degradation of IkappaBa resulting in inhibition of NF-kappaB p65 nuclear translocation, and inhibited the phosphorylation of signal transducers and activators of transcription 1 (STAT1) at Tyr701. This study supports further exploration of thienodolin as a potential therapeutic agent with a unique mechanistic activity.

Suppression of Nitric Oxide Synthase by Thienodolin in Lipopolysaccharide-stimulated RAW 264.7 Murine Macrophage Cells

The measurement of nitric oxide in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells is used as a model for evaluating the anti-inflammatory or chemopreventive potential of substances. Thienodolin, isolated from a Streptomyces sp. derived from Chilean marine sediment, inhibited nitric oxide production in LPS-stimulated RAW 264.7 cells (IC50 = 17.2 ± 1.2 μM). At both the mRNA and protein levels, inducible nitric oxide synthase (iNOS) was suppressed in a dose-dependent manner. Mitogen-activated protein kinases (MAPKs), one major upstream signaling pathway involved in the transcription of iNOS, were not affected by treatment of thienodolin. However, the compound blocked the degradation of IκBα resulting in inhibition of NF-κB p65 nuclear translocation, and inhibited the phosphorylation of signal transducers and activators of transcription 1 (STAT1) at Tyr701. This study supports further exploration of thienodolin as a potential therapeutic agent with a unique mechanistic activity.