Origins of prostaglandin E2: involvements of cyclooxygenase (COX)-1 and COX-2 in human and rat systems

Ferroptosis in glioma therapy: advancements in sensitizing strategies and the complex tumor-promoting roles

Ferroptosis, an iron-dependent form of non-apoptotic regulated cell death, is induced by the accumulation of lipid peroxides on cellular membranes. Over the past decade, ferroptosis has emerged as a crucial process implicated in various physiological and pathological systems. Positioned as an alternative modality of cell death, ferroptosis holds promise for eliminating cancer cells that have developed resistance to apoptosis induced by conventional therapeutics. This has led to a growing interest in leveraging ferroptosis for cancer therapy across diverse malignancies. Gliomas are tumors arising from glial or precursor cells, with glioblastoma (GBM) being the most common malignant primary brain tumor that is associated with a dismal prognosis. This review provides a summary of recent advancements in the exploration of ferroptosis-sensitizing methods, with a specific focus on their potential application in enhancing the treatment of gliomas. In addition to summarizing the therapeutic potential, this review also discusses the intricate interplay of ferroptosis and its potential tumor-promoting roles within gliomas. Recognizing these dual roles is essential, as they could potentially complicate the therapeutic benefits of ferroptosis. Exploring strategies aimed at circumventing these tumor-promoting roles could enhance the overall therapeutic efficacy of ferroptosis in the context of glioma treatment.

SINGLE-DOSE, MULTIPLE-DOSE, AND THERAPEUTIC DRUG MONITORING PHARMACOKINETICS OF FIROCOXIB IN ASIAN ELEPHANTS (ELEPHAS MAXIMUS)

Firocoxib is a COX-2-selective nonsteroidal anti-inflammatory drug (NSAID) with limited effects on COX-1, which means it likely has fewer side effects than typically associated with other NSAIDs. This study determined possible doses of firocoxib based on single- and multidose pharmacokinetic trials conducted in 10 Asian elephants (Elephas maximus). Initially, two single oral dose trials (0.01 and 0.1 mg/kg) of a commercially available tablet (n = 6) and paste (n = 4) formulation were used to determine a preferred dose. The 0.1 mg/kg dose was further evaluated via IV single dose (n = 3) and oral multidose trials (tablets n = 6; paste n = 4). Serum peak and trough firocoxib concentrations were also evaluated in Asian elephants (n = 4) that had been being treated for a minimum of 90 consecutive days. Key pharmacokinetic parameters for the 0.1 mg/kg single-dose trials included mean peak serum concentrations of 49 ± 3.3 ng/ml for tablets and 62 ± 14.8 ng/ml for paste, area under the curve (AUC) of 1,332 ± 878 h*mg/ml for tablets and 1,455 ± 634 h*mg/ml for paste, and half-life (T1/2) of 34.3 ± 30.3 h for tablets and 19.9 ± 12.8 h for paste. After 8 d of dosing at 0.1 mg/kg every 24 h, pharmacokinetic parameters stabilized to an AUC of 6,341 ± 3,003 h*mg/ml for tablets and 5,613 ± 2,262 for paste, and T1/2 of 84.4 ± 32.2 h for tablets and 62.9 ± 2.3 h for paste. Serum COX inhibition was evaluated in vitro and ex vivo in untreated elephant plasma, where firocoxib demonstrated preferential inhibition of COX-2. No adverse effects from firocoxib administration were identified in this study. Results suggest administering firocoxib to Asian elephants at a dose of 0.1 mg/kg orally, using either tablet or paste formulations, every 24 h.

Anti-Inflammatory and Immunomodulatory Properties of a Crude Polysaccharide Derived from Green Seaweed Halimeda tuna: Computational and Experimental Evidences

In this study, we investigated for the first time the anti-inflammatory and immunomodulatory properties of crude polysaccharide (PSHT) extracted from green marine algae Halimeda tuna. PSHT exhibited anti-oxidant activity in vitro through scavenging 1, 1-diphenyl-2-picryl hydroxyl free radical, reducing Fe3+/ferricyanide complex, and inhibiting nitric oxide. PSHT maintained the erythrocyte membrane integrity and prevented hemolysis. Our results also showed that PSHT exerted a significant anti-edematic effect in vivo by decreasing advanced oxidation protein products and malondialdehyde levels and increasing the superoxide dismutase and glutathione peroxidase activities in rat's paw model and erythrocytes. Interestingly, PSHT increased the viability of murine RAW264.7 macrophages and exerted an anti-inflammatory effect on lipopolysaccharide-stimulated cells by decreasing pro-inflammatory molecule levels, including nitric oxide, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-α). Our findings indicate that PSHT could be used as a potential immunomodulatory, anti-inflammatory, anti-hemolytic, and anti-oxidant agent. These results could be explained by the computational findings showing that polysaccharide building blocks bound both cyclooxygenase-2 (COX-2) and TNF-α with acceptable affinities.

Xinghamide A, a New Cyclic Nonapeptide Found in Streptomyces xinghaiensis

Xinghamide A (1), a new nonapeptide, was discovered in Streptomyces xinghaiensis isolated from a halophyte, Suaeda maritima (L.) Dumort. Based on high-resolution mass and NMR spectroscopic data, the planar structure of 1 was established, and, in particular, the sequence of nine amino acids was determined with ROESY and HMBC NMR spectra. The absolute configurations of the α-carbon of each amino acid residue were determined with 1-fluoro-2,4-dinitrophenyl-l-and -d-leucine amide (Marfey's reagents) and 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl isothiocyanate, followed by LC-MS analysis. The anti-inflammatory activity of xinghamide A (1) was evaluated by inhibitory abilities against the nitric oxide (NO) secretion and cyclooxygenase-2 (COX-2) expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells.

Herbal melanin modulates PGE2 and IL-6 gastroprotective markers through COX-2 and TLR4 signaling in the gastric cancer cell line AGS

We reported a gastric anti-ulcerogenic effect of the Nigella sativa (L.)-derived herbal melanin (HM) using rat models. However, the molecular mechanisms underlying this HM gastroprotective effect remain unknown. Cyclooxygenase-2 (COX-2)-catalyzed prostaglandin E2 (PGE2) and toll-like receptor 4 (TLR4)-mediated interleukin-6 (IL-6) production and secretion play major roles in gastric mucosal protection. In the current study, the human gastric carcinoma epithelial cell line AGS was used as a model to investigate the effect of HM on TLR4, COX-2, glycoprotein mucin 4 protein and gene expression using immuno-cyto-fluorescence staining, Western blot technology, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Gastroprotective markers PGE2 and IL-6 production and secretion were also assessed using an enzyme-linked immunosorbent assay (ELISA). Bacterial lipopolysaccharides (LPS), well-known inducers of TLR4, COX-2, PGE2 and IL-6 expression, were used as a positive control. We showed that HM upregulated its main receptor TLR4 gene and protein expression in AGS cells. HM increased, in a dose- and time-dependent manner, the secretion of PGE2 and the expression of COX-2 mRNA and protein, which was detected in the nucleus, cytoplasm and predominantly at the intercellular junctions of the AGS cells. In addition, HM enhanced IL-6 production and secretion, and upregulated the mucin 4 gene expression, the hallmarks of gastroprotection. To check whether HM-induced PGE2 and IL-6 through TLR4 signaling and COX-2 generated, AGS cells were pre-treated with a TLR4 signaling inhibitor TAK242 and the COX-2 inhibitor NS-398. A loss of the stimulatory effects of HM on COX-2, PGE2 and IL-6 production and secretion was observed in TAK242 and NS-398-pre-treated AGS cells, confirming the role of TLR4 signaling and COX-2 generated in the HM gastroprotective effects. In conclusion, our results showed that HM enhances TLR4/COX-2-mediated secretion of gastroprotective markers PGE2 and IL-6, and upregulates mucin 4 gene expression in the human gastric epithelial cell line AGS, which may contribute to the promising beneficial gastroprotective effect of HM for human gastric prevention and treatment.

The Role of COX-2 and PGE2 in the Regulation of Immunomodulation and Other Functions of Mesenchymal Stromal Cells

The ability of MSCs to modulate the inflammatory environment is well recognized, but understanding the molecular mechanisms responsible for these properties is still far from complete. Prostaglandin E2 (PGE2), a product of the cyclooxygenase 2 (COX-2) pathway, is indicated as one of the key mediators in the immunomodulatory effect of MSCs. Due to the pleiotropic effect of this molecule, determining its role in particular intercellular interactions and aspects of cell functioning is very difficult. In this article, the authors attempt to summarize the previous observations regarding the role of PGE2 and COX-2 in the immunomodulatory properties and other vital functions of MSCs. So far, the most consistent results relate to the inhibitory effect of MSC-derived PGE2 on the early maturation of dendritic cells, suppressive effect on the proliferation of activated lymphocytes, and stimulatory effect on the differentiation of macrophages into M2 phenotype. Additionally, COX-2/PGE2 plays an important role in maintaining the basic life functions of MSCs, such as the ability to proliferate, migrate and differentiate, and it also positively affects the formation of niches that are conducive to both hematopoiesis and carcinogenesis.

Assessing the Anti-inflammatory Effects of Bacopa-Derived Bioactive Compounds Using Network Pharmacology and In Vitro Studies

Bacopa monnieri is reported as a potent Indian medicinal plant that possesses numerous pharmacological activities due to the presence of various bioactive compounds. These pharmacological activities were used in the ancient medicine system to cure inflammatory conditions. Bacopa has the ability to reduce acute pain and inflammation by inhibiting the enzyme cyclo-oxygenase-2 (COX-2) and reducing COX-2-arbitrated prostanoid mediators. Moreover, the anti-inflammatory property may also be associated with the neuroprotective activity of Bacopa. Considering this importance, the current pilot study focused on the anti-inflammatory potential of various phytocompounds of bacopa and their interaction with inflammation responsible genes such as COX2, iNOS, LOX, STAT3, CCR1, and MMP9 through pharmacology analysis of its systems. Docking results revealed that, quercetin (QR) showed significant binding energies with inflammatory genes. Hence, we selected QR as a potential phytocompound for further in vitro experiments. This existing study aimed to evaluate the efficacy of QR as a potent anti-inflammatory compound against lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The in vitro analysis concludes that QR effectively reduces the production of nitric oxide (NO) in LPS-induced RAW264.7 cells and downregulates the expression of COX-2 and iNOS genes due to the inhibitory potential of QR on LPS-stimulated NO production.

Anti-Inflammatory Activity of Essential Oil from Zingiber ottensii Valeton in Animal Models

Zingiber ottensii (ZO) Valeton, a local plant in Northern Thailand, has been widely used in traditional medicine. Many studies using in vitro models reveal its pharmacological activities, including the anti-inflammatory activity of ZO essential oil, extracted from ZO rhizomes. However, the scientific report to confirm its anti-inflammatory activity using animal models is still lacking. The present study aimed to evaluate the anti-inflammatory activity and explore the possible mechanisms of action of ZO essential oil in rats. The results revealed that ZO essential oil significantly reduced the ear edema formation induced by ethyl phenylpropiolate. Pre-treatment with ZO essential oil significantly reduced the carrageenan-induced hind paw edema and the severity of inflammation in paw tissue. In addition, pre-treatment with ZO essential oil exhibited decreased COX-2 and pro-inflammatory cytokine TNF-α expression in paw tissue, as well as PGE₂ levels in serum. On this basis, our study suggests that ZO essential oil possesses anti-inflammatory activity in animal models. Its possible mechanisms of action may involve the inhibition of TNF-α expression as well as the inhibition of COX-2 and PGE₂ production. These findings provide more crucial data of ZO essential oil that may lead to new natural anti-inflammatory product development in the future.

Impact of phosphorylation of heat shock protein 27 on the expression profile of periodontal ligament fibroblasts during mechanical strain

PURPOSE

Orthodontic tooth movement is a complex process involving the remodeling of extracellular matrix and bone as well as inflammatory processes. During orthodontic treatment, sterile inflammation and mechanical loading favor the production of receptor activator of NF-κB ligand (RANKL). Simultaneously, expression of osteoprotegerin (OPG) is inhibited. This stimulates bone resorption on the pressure side. Recently, heat shock protein 27 (HSP27) was shown to be expressed in the periodontal ligament after force application and to interfere with inflammatory processes.

METHODS

We investigated the effects of phosphorylated HSP27 on collagen synthesis (COL1A2 mRNA), inflammation (IL1B mRNA, IL6 mRNA, PTGS2 protein) and bone remodeling (RANKL protein, OPG protein) in human periodontal ligament fibroblasts (PDLF) without and with transfection of a plasmid mimicking permanent phosphorylation of HSP27 using real-time quantitative polymerase chain reaction (RT-qPCR), western blot and enzyme-linked immunosorbent assays (ELISAs). Furthermore, we investigated PDLF-induced osteoclastogenesis after compressive strain in a co-culture model with human macrophages.

RESULTS

In particular, phosphorylated HSP27 increased gene expression of COL1A2 and protein expression of PTGS2, while IL6 mRNA levels were reduced. Furthermore, we observed an increasing effect on the RANKL/OPG ratio and osteoclastogenesis mediated by PDLF.

CONCLUSION

Phosphorylation of HSP27 may therefore be involved in the regulation of orthodontic tooth movement by impairment of the sterile inflammation response and osteoclastogenesis.

Lagerstroemia ovalifolia Exerts Anti- Inflammatory Effects in Mice of LPSInduced ALI via Downregulating of MAPK and NF-κB Activation

Lagerstroemia ovalifolia Teijsm. & Binn. (LO) (crape myrtle) has reportedly been used as traditional herbal medicine (THM) in Java, Indonesia. Our previous study revealed that the LO leaf extract (LOLE) exerted anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Based on this finding, the current study aimed to evaluate the protective effects of LOLE in a mouse model of LPS-induced acute lung injury (ALI). The results showed that treatment with LPS enhanced the inflammatory cell influx into the lungs and increased the number of macrophages and the secretion of the inflammatory cytokines in the bronchoalveolar lavage fluid (BALF) of mice. However, these effects were notably abrogated with LOLE pretreatment. Furthermore, the increase of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and monocyte chemoattractant protein-1 (MCP-1) expression in the lung tissues of mice with ALI was also reversed by LOLE. In addition, LOLE significantly suppressed the LPS-induced activation of the MAPK/NF-κB signaling pathway and led to heme oxygenase-1 (HO-1) induction in the lungs. Additionally, in vitro experiments showed that LOLE enhanced the expression of HO-1 in RAW264.7 macrophages. The aforementioned findings collectively indicate that LOLE exerts an ameliorative effect on inflammatory response in the airway of ALI mice.

Rosa davurica Pall. improves DNCB-induced atopic dermatitis in mice and regulated TNF-Alpa/IFN-gamma-induced skin inflammatory responses in HaCaT cells

PURPOSE

Rosa davurica Pall., is mainly distributed in Korea, Japan, northeastern China, southeastern Siberia, and eastern Asia. It has been extensively used to treat various kinds of diseases by reason of the significant antioxidant, antiviral and anti-inflammatory activities. However, the pharmacological mechanism of Rosa davurica Pall. in atopic dermatitis (AD) is still ill defined and poorly understood. This study was to examine the anti-inflammatory effects and its mechanism on AD of Rosa davurica Pall. leaves (RDL).

METHODS

To evaluate the therapeutic potential of RDL against AD, we have investigated the effects of RDL on the inflammatory reactions and the productions of inflammatory chemokines and cytokines that were induced by tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ) in HaCaT cells. Futhermore, we examined the effects of RDL on the signaling pathways of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB). For the in-vivo studies, RDL extract was topically applied to the dinitrochlorobenzene (DNCB)-induced AD mice, then its therapeutic effect was evaluated physiologically and morphologically.

RESULTS

After the stimulation of HaCaT cells with TNF-α/IFN-γ, RDL considerably reduced the release of inflammatory mediators such as nitric oxide (NO), PEG₂ and other cytokines. RDL also reduced the phosphorylations of MAPK and NF-κB in TNF-α/IFN-γ-stimulated HaCaT cells. In vivo topical application of RDL to DNCB-induced AD mice significantly reduced the dorsal skin and ear thickness, clinical dermatitis severity, and mast cells. Treatment with RDL also markedly decreased the levels of serum IgE, IL-6 and the number of WBCs in the blood.

CONCLUSION

Our studies indicate that RDL inhibits the AD-like skin lesions by modulating skin inflammation. Consequently, these results suggest that RDL may be served as a possible alternative therapeutic treatment for skin disorder such as AD.

Poly-dispersed Acid-Functionalized Single-Walled Carbon Nanotubes (AF-SWCNTs) Are Potent Inhibitor of BCG Induced Inflammatory Response in Macrophages

The present study is focused on the modulation of Mycobacterium bovis BCG-induced inflammatory response by poly-dispersed acid-functionalized single-walled carbon nanotubes (AF-SWCNTs) in macrophages. Flow cytometric and confocal microscopy studies indicated that both BCG and AF-SWCNTs were efficiently internalized by RAW 264.7 and MH-S macrophage cell lines and were essentially localized in the cytoplasmic area. BCG-induced production of reactive oxygen species (ROS) and nitric oxide by the two cell lines was significantly inhibited by AF-SWCNTs. Using RT-PCR technique, a marked decline was observed in the expression of BCG-induced pro-inflammatory genes COX-2, iNOS, TNF-α, IL-6, and IL-1β upon treatment with AF-SWCNTs. Results of gelatin zymography indicated that the AF-SWCNTs treatment also induced a marked decline in BCG-induced release of matrix metalloproteinases MMP-2 and MMP-9 by the two macrophage cell lines. The anti-inflammatory effect of AF-SWCNTs in downregulating BCG-induced inflammatory response was further validated in murine peritoneal macrophages. Treatment with AF-SWCNTs led to a steep decline in BCG-induced NO production in murine peritoneal macrophages in vitro as well as in vivo. Peritoneal macrophages isolated from mice treated with BCG and AF-SWCNTs had a significantly lower intracellular expression of COX-2 as compared to the peritoneal macrophages derived from mice treated with BCG alone. Taken together, our results demonstrate a potent anti-inflammatory effect of AF-SWCNTs in alleviating BCG-induced inflammatory responses in macrophages in vitro and in vivo.

Granulocytic Myeloid-Derived Suppressor Cell Exosomal Prostaglandin E2 Ameliorates Collagen-Induced Arthritis by Enhancing IL-10+ B Cells

The results of recent studies have shown that granulocytic-myeloid derived suppressor cells (G-MDSCs) can secrete exosomes that transport various biologically active molecules with regulatory effects on immune cells. However, their roles in autoimmune diseases such as rheumatoid arthritis remain to be further elucidated. In the present study, we investigated the influence of exosomes from G-MDSCs on the humoral immune response in murine collagen-induced arthritis (CIA). G-MDSCs exosomes-treated mice showed lower arthritis index values and decreased inflammatory cell infiltration. Treatment with G-MDSCs exosomes promoted splenic B cells to secrete IL-10 both in vivo and in vitro. In addition, a decrease in the proportion of plasma cells and follicular helper T cells was observed in drainage lymph nodes from G-MDSCs exosomes-treated mice. Moreover, lower serum levels of IgG were detected in G-MDSCs exosomes-treated mice, indicating an alteration of the humoral environment. Mechanistic studies showed that exosomal prostaglandin E2 (PGE2) produced by G-MDSCs upregulated the phosphorylation levels of GSK-3β and CREB, which play a key role in the production of IL-10⁺ B cells. Taken together, our findings demonstrated that G-MDSC exosomal PGE2 attenuates CIA in mice by promoting the generation of IL-10⁺ Breg cells.

Celecoxib substituted biotinylated poly(amidoamine) G3 dendrimer as potential treatment for temozolomide resistant glioma therapy and anti-nematode agent

Glioblastoma multiforme (GBM) is a one of the most widely diagnosed and difficult to treat type of central nervous system tumors. Resection combined with radiotherapy and temozolomide (TMZ) chemotherapy prolongs patients' survival only for 12 - 15 months after diagnosis. Moreover, many patients develop TMZ resistance, thus important is search for a new therapy regimes including targeted drug delivery. Most types of GBM reveal increased expression of cyclooxygenase-2 (COX-2) and production of prostaglandin E2 (PGE₂), that are considered as valuable therapeutic target. In these studies, the anti-tumor properties of the selective COX-2 inhibitor celecoxib (CXB) and biotinylated third generation of the poly(amidoamine) dendrimer substituted with 31 CXB residues (G3BC31) on TMZ -resistant U-118 MG glioma cell line were examined and compared with the effect of TMZ alone including viability, proliferation, migration and apoptosis, as well as the cellular expression of COX-2, ATP level, and PGE₂ production. Confocal microscopy analysis with the fluorescently labeled G3BC31 analogue has shown that the compound was effectively accumulated in U-118 MG cells in time-dependent manner and its localization was confirmed in lysosomes but not nuclei. G3BC31 reveal much higher cytotoxicity for U-118 MG cells at relatively low concentrations in the range of 2-4 µM with compared to CBX alone, active at 50-100 µM. This was due to induction of apoptosis and inhibition of proliferation and migration. Observed effects were concomitant with reduction of PGE₂ production but independent of COX-2 expression. We suggest that investigated conjugate may be a promising candidate for therapy of TMZ-resistant glioblastoma multiforme, although applicable in local treatment, since our previous study of G3BC31 did not demonstrate selectivity against glioma cells compared to normal human fibroblasts. However, it has to be pointed that in our in vivo studies conducted with model organism, Caenorhabditis elegans indicated high anti-nematode activity of G3BC31 in comparison with CXB alone that confirms of usefulness of that organism for estimation of anti-cancer drug toxicity.

Recent Updates on Anti-Inflammatory and Antimicrobial Effects of Furan Natural Derivatives

The furan nucleus is found in a large number of biologically active materials. In recent years, many natural furan derivatives were isolated and their biological effects were investigated. In this review, we focused on the anti-inflammatory and antimicrobial effects of some natural furans and discussed their effects on the immune system. Our investigation revealed that furan natural derivatives have effective antioxidant activities and exert regulatory effects on various cellular activities by modifying some signaling pathways such as MAPK (mitogen-activated Protein Kinase) and PPAR-ɣ (peroxisome proliferator-activated receptor gamma). The antimicrobial activity of these natural compounds was performed through selective inhibition of microbial growth and modification of enzymes. Further studies are needed for isolation and detection of different furan derivatives from natural compounds and investigation of their precise mechanisms for revealing health beneficial effects of these compounds.

Acetylsalicylic acid-like analgesic effects of Trametes versicolor in Wistar rats

The aim of the present study was to investigate the analgesic effects and mechanism of action of Trametes versicolor (Tv) mycelium powder. Wistar rats were randomly divided into the following three or four groups: i) Saline group, fed saline; ii) Tv 500 group, fed 500 mg/kg Tv; iii) ASA 50 group, fed 50 mg/kg acetylsalicylic acid (ASA); and iv) ASA 100 group, fed 100 mg/kg ASA. Chemical formalin tests and thermal hot plate tests were used to investigate the analgesic effects of each group. ELISAs were performed to detect cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) plasma levels, and high-performance liquid chromatography (HPLC) was used for quality control the active component, oleanolic acid (OA) in Tv that had the analgesic effect. The OA content in aqueous Tv extract was found to be 11.92 % by HPLC assays. The licking frequencies in the early phase and late phase of the formalin test were significantly lower in the Tv 500 and ASA 100 groups than the saline group. The licking time in the late phase were also significantly lower in the Tv 500 and ASA 100 groups than the saline group. The plasma levels of COX-2 and PGE2 were decreased significantly in the Tv 500 and ASA 100 groups compared with that of the saline group at 60 min in the formalin test. In addition, oral feeding with 500 mg/kg Tv may effectively reduce physical pain triggered by hot plates in Wistar rats. Taken together, the acetylsalicylic acid-like analgesic effects of Tv in Wistar rats may be associated with the reduction of the plasma COX-2 and PGE2 levels.

Mechanisms underlying N3-PUFA regulation of white adipose tissue endocrine function

Omega-3 polyunsaturated fatty acids (N3-PUFA) are widely reported to improve obesity-associated metabolic impairments, in part, through the regulation of adipokine and cytokine secretion from white adipose tissue (WAT). However, the precise underlying molecular mechanisms by which N3-PUFA influence WAT endocrine function remain poorly described. Available evidence supports that N3-PUFA and related bioactive lipid mediators regulate several intracellular pathways that converge on two important transcription factors: PPAR-γ and NF-κB. Further, N3-PUFA signaling through GPR120 appears integral for the regulation of adipokine and cytokine production. This review collates insights from in vitro and in vivo studies using genetic and chemical inhibition of key signaling proteins to describe the pathways by which N3-PUFA regulate WAT endocrine function. Existing gaps in knowledge and opportunities to advance our understanding in this area are also highlighted.

Synedrella nodiflora (Linn.) Gaertn. inhibits inflammatory responses through the regulation of Syk in RAW 264.7 macrophages

Synedrella nodiflora (Linn.) Gaertn. (S. nodiflora) has long been used for the treatment of inflammatory diseases, including liver disease, asthma, rheumatism and earache, in tropical countries throughout America, Asia and Africa. However, the biological effects of S. nodiflora have not been extensively studied at the molecular level. Notably, it remains unclear how S. nodiflora exerts anti-inflammatory activity. In the present study, the anti-inflammatory mechanism of a methanol extract of S. nodiflora (MSN) in RAW 264.7 macrophages activated by lipopolysaccharide (LPS) was investigated. Non-cytotoxic concentrations of MSN (≤400 µg/ml) decreased the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which resulted in a decrease in nitric oxide and prostaglandin E₂ (PGE₂) production. The mRNA expression of pro-inflammatory cytokines such as interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α was reduced upon MSN treatment. In addition, the activation of spleen tyrosine kinase (Syk) and Akt was suppressed by MSN. Taken together, these findings recommend the traditional medicinal application of S. nodiflora in the treatment of several inflammation-associated diseases and indicate the possibility of MSN as a novel therapeutic reagent of inflammation-related diseases.

Effects of Helichrysum bracteatum flower extracts on UVB irradiation-induced inflammatory biomarker expression

Background

The present study aimed to investigate the anti-inflammatory activity of Helichrysum bracteatum (H. bracteatum) flower extracts in vitro.

Methods

H. bracteatum flowers were extracted with water, ethanol and 1,3-butylene glycol, and the anti-oxidative activities of the extracts were measured using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The inhibition of the expression of inflammation-related genes, including tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2), was evaluated in vitro using reverse transcription-PCR in ultraviolet B (UVB)-irradiated human epidermal keratinocytes (HEKa cells). To investigate the inhibitory effects of H. bracteatum flower extracts on UVB-induced inflammatory responses in HEKa cells, the production of nitric oxide (NO) and TNF-α was measured using enzyme-linked immunosorbent assays. Results were expressed as the mean ± standard deviation; statistical significance was calculated using the Student’s t-test.

Results

The DPPH assay results showed that H. bracteatum flower extracts have good anti-oxidative effects and inhibited the expression of inflammation-related genes IL-6, COX-2 and TNF-α. Moreover, the production of NO and TNF-α was inhibited by H. bracteatum flower extracts.

Conclusions

These findings indicate that H. bracteatum flower extracts have efficacy against UVB-induced inflammation-related gene expression.

Topical Spilanthol Inhibits MAPK Signaling and Ameliorates Allergic Inflammation in DNCB-Induced Atopic Dermatitis in Mice

Atopic dermatitis (AD) is a recurrent allergic skin disease caused by genetic and environmental factors. Patients with AD may experience immune imbalance, increased levels of mast cells, immunoglobulin (Ig) E and pro-inflammatory factors (Cyclooxygenase, COX-2 and inducible NO synthase, iNOS). While spilanthol (SP) has anti-inflammatory and analgesic activities, its effect on AD remains to be explored. To develop a new means of SP, inflammation-related symptoms of AD were alleviated, and 2,4-dinitrochlorobenzene (DNCB) was used to induce AD-like skin lesions in BALB/c mice. Histopathological analysis was used to examine mast cells and eosinophils infiltration in AD-like skin lesions. The levels of IgE, IgG1 and IgG2a were measured by enzyme-linked immunosorbent assay (ELISA) kits. Western blot was used for analysis of the mitogen-activated protein kinase (MAPK) pathways and COX-2 and iNOS protein expression. Topical SP treatment reduced serum IgE and IgG2a levels and suppressed COX-2 and iNOS expression via blocked mitogen-activated protein kinase (MAPK) pathways in DNCB-induced AD-like lesions. Histopathological examination revealed that SP reduced epidermal thickness and collagen accumulation and inhibited mast cells and eosinophils infiltration into the AD-like lesions skin. These results indicate that SP may protect against AD skin lesions through inhibited MAPK signaling pathways and may diminish the infiltration of inflammatory cells to block allergic inflammation.

A novel nanoformulation of α-eleostearic acid restores molecular pathogenesis of hypersensitivity

AIM

The present work provides first-time empirical and molecular interaction evidence to establish the higher biofunctionality of a therapeutic lipid, α-eleostearic acid (ESA), encapsulated in a novel and thoroughly characterized biocompatible nanoemulsion (NE) system (particle size <200 nm).

MATERIALS & METHODS

A novel methodology was employed to fabricate novel formulations of ESA. Molecular biological tools and assays were used to arrive at definite conclusions.

RESULTS

The proinflammatory profile was found to be significantly mitigated in the hypersensitized rats administered with the ESA-NE formulation more emphatically as compared with ESA-conventional emulsion in both in vivo and ex vivo models.

CONCLUSION

The novel ESA-NE formulation shows a lot of palpable promise for clinical applications.

Anti-inflammatory and Antioxidant Properties of Probiotic Bacterium Lactobacillus mucosae AN1 and Lactobacillus fermentum SNR1 in Wistar Albino Rats

The potent antioxidant probiotic strains Lactobacillus mucosae AN1 and Lactobacillus fermentum SNR1 were assessed for anti-inflammatory properties in carrageenan (acute) and complete Freund’s adjuvant-induced inflammation (chronic) models in the present study. The two probiotic strains were administered orally along with feed to the Wistar albino male rats as whole cell as well as microencapsulated form. The following experiments were performed to evaluate the anti-inflammatory properties of probiotic strains and the results were observed that the encapsulated and unencapsulated probiotic strains have exhibited statistically significant decrease in paw thickness. Percentage of inhibition in paw thickness of microencapsulated probiotic bacteria (Group VIII), unencapsulated strains (Group IX) were revealed 85 ± 13% and 77 ± 25%, respectively. In Hematoxylin and Eosin staining, results were revealed that the probiotic strains were exhibited anti-inflammatory effects on inflammation-induced paw tissues. qRT-PCR studies revealed upregulation of anti-inflammatory cytokine genes and down-regulation pro-inflammatory cytokine genes in probiotic-treated rat paw tissues. Further, the expression of anti-inflammatory and pro-inflammatory cytokines were examined using immunohistochemistry and ELISA methods. The probiotic administered rat paw tissue in different groups have exhibited the low level of lipid peroxides formation and higher anti-oxidant activities when compared to the control and inflammation control tissues.

Combined Effects of PVT1 and MiR-146a Single Nucleotide Polymorphism on the Lung Function of Smokers with Chronic Obstructive Pulmonary Disease

Non-coding RNAs play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). This study was performed to investigate the role of PVT1 and miR-146a single nucleotide polymorphisms (SNPs) in the lung function of COPD smokers. Real-time PCR and Western blot analyses were performed to measure the expression of miR-146 and PVT1 SNPs and determine the effect of these SNPs on the pathogenesis of COPD. A total of 100 COPD smokers were enrolled in this study and divided into four groups as follows: Rs2910164CC/GC + Rs13281615GG; Rs2910164CC/GC + Rs13281615GA/AA; Rs2910164GG + Rs13281615GG; and Rs2910164GG + Rs13281615GA/AA. No obvious differences in terms of age, sex, and body height and weight were found among the four groups. However, the Rs2910164GG + Rs13281615GA/AA was associated with the highest stage of the Global Initiative for Chronic Obstructive Lung Disease and the highest values of the forced vital capacity, forced expiratory volume, and diffusing capacity of carbon monoxide, while the lowest values of these parameters were observed in the Rs2910164CC/GC + Rs13281615GG group. In addition, the highest and lowest COX2 levels were observed in the Rs2910164GG + Rs13281615GA/AA and Rs2910164CC/GC + Rs13281615GG groups, respectively. PVT1 directly and negatively regulated the miR-146a expression, which in turn directly and negatively regulated COX2 expression. Thus, the combined actions of SNP in PVT1 Rs13281615 and miR-146a Rs2910164 affected the lung function in COPD smokers.

Xenobiotica-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models

Studies on the metabolic fate of medical drugs, skin care products, cosmetics and other chemicals intentionally or accidently applied to the human skin have become increasingly important in order to ascertain pharmacological effectiveness and to avoid toxicities. The use of freshly excised human skin for experimental investigations meets with ethical and practical limitations. Hence information on xenobiotic-metabolizing enzymes (XME) in the experimental systems available for pertinent studies compared with native human skin has become crucial. This review collects available information of which—taken with great caution because of the still very limited data—the most salient points are: in the skin of all animal species and skin-derived in vitro systems considered in this review cytochrome P450 (CYP)-dependent monooxygenase activities (largely responsible for initiating xenobiotica metabolism in the organ which provides most of the xenobiotica metabolism of the mammalian organism, the liver) are very low to undetectable. Quite likely other oxidative enzymes [e.g. flavin monooxygenase, COX (cooxidation by prostaglandin synthase)] will turn out to be much more important for the oxidative xenobiotic metabolism in the skin. Moreover, conjugating enzyme activities such as glutathione transferases and glucuronosyltransferases are much higher than the oxidative CYP activities. Since these conjugating enzymes are predominantly detoxifying, the skin appears to be predominantly protected against CYP-generated reactive metabolites. The following recommendations for the use of experimental animal species or human skin in vitro models may tentatively be derived from the information available to date: for dermal absorption and for skin irritation esterase activity is of special importance which in pig skin, some human cell lines and reconstructed skin models appears reasonably close to native human skin. With respect to genotoxicity and sensitization reactive-metabolite-reducing XME in primary human keratinocytes and several reconstructed human skin models appear reasonably close to human skin. For a more detailed delineation and discussion of the severe limitations see the Conclusions section in the end of this review.

Asatone Prevents Acute Lung Injury by Reducing Expressions of NF-κB, MAPK and Inflammatory Cytokines

Asatone is an active component extracted from the Chinese herb Radix et Rhizoma Asari. Our preliminary studies have indicated that asatone has an anti-inflammatory effect on RAW 264.7 culture cells challenged with lipopolysaccharide (LPS). Acute lung injury (ALI) has high morbidity and mortality rates due to the onset of serious lung inflammation and edema. Whether asatone prevents ALI LPS-induced requires further investigation. In vitro studies revealed that asatone at concentrations of 2.5–20[Formula: see text][Formula: see text]g/mL drastically prevented cytotoxicity and concentration-dependently reduced NO production in the LPS-challenged macrophages. In an in vivo study, the intratracheal administration of LPS increased the lung wet/dry ratio, myeloperoxidase activity, total cell counts, white blood cell counts, NO, iNOS, COX, TNF-[Formula: see text], IL-1[Formula: see text], and IL-6 in the bronchoalveolar lavage fluid as well as mitogen-activated protein kinases in the lung tissues. Pretreatment with asatone could reverse all of these effects. Asatone markedly reduced the levels of TNF-[Formula: see text] and IL-6 in the lung and liver, but not in the kidney of mice. By contrast, LPS reduced anti-oxidative enzymes and inhibited NF-[Formula: see text]B activations, whereas asatone increased anti-oxidative enzymes in the bronchoalveolar lavage fluid and NF-[Formula: see text]B activations in the lung tissues. Conclusively, asatone can prevent ALI through various anti-inflammatory modalities, including the major anti-inflammatory pathways of NF-[Formula: see text]B and mitogen-activated protein kinases. These findings suggest that asatone can be applied in the treatment of ALI.

Anti‑inflammatory effect of quercetin and galangin in LPS‑stimulated RAW264.7 macrophages and DNCB‑induced atopic dermatitis animal models

Flavonols are compounds that have been shown to possess potent anti-inflammatory effects in cellular and animal models of inflammation. In the present study, the anti-inflammatory effects and mechanisms of two natural flavonols, quercetin and galangin, in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages were investigated. It was identified that quercetin and galangin markedly reduced the production of nitric oxide (NO), inducible NO synthase and interleukin-6, and the nuclear translocation of nuclear factor-κB (NF-κB). In addition, LPS-induced activation of extracellular signal-regulated kinase 1/2 (Erk1/2) and c-Jun N-terminal kinase (JNK) was suppressed by quercetin and galangin. Taken together, these data implied that NF-κB, Erk1/2 and JNK may be potential molecular targets of quercetin and galangin in an LPS-induced inflammatory response. Subsequently, the effects of oral administration of quercetin or galangin, either alone or in combination, in a 2,4-dinitrochlorobenzene-induced atopic dermatitis (AD) mouse model were investigated. As a result, measurements of ear thickness and the levels of serum immunoglobulin E, and histological analysis revealed that the two flavonols led to a decrease in inflammation, whereas, in combination, they were even more effective. These results suggested that quercetin and galangin may be promising therapeutic agents for AD. Additionally, their combination may be a novel therapeutic strategy for the prevention of AD.

Leaves of Raphanus sativus L. Shows Anti-Inflammatory Activity in LPS-Stimulated Macrophages via Suppression of COX-2 and iNOS Expression

Raphanus sativus L. (RS) is a cruciferous vegetable that is widely consumed in Korea. The anticancer activity of leaves of RS (RSL) extract has been investigated; however, no studies focused on its anti-inflammatory effects. Therefore, the aim of the current study was to evaluate the anti-inflammatory effects of RSL extract. In brief, RSL powder was fractionated into n-hexane, chloroform, ethyl acetate, n-butanol, and water-soluble fractions. Lipopolysaccharide (LPS)-stimulated RAW264.7 cells were treated with each fraction for initial screening. It was found that the chloroform fraction significantly inhibited nitric oxide release in LPS-stimulated RAW264.7 cells with a half maximal inhibitory concentration value of 196 μg/mL. In addition, the mRNA and protein expression levels of inducible nitric oxide synthase, measured using reverse transcriptase-polymerase chain reaction and western blotting, respectively, were reduced in a concentration-dependent manner. Moreover, the inflammatory cyclooxygenase-2 enzyme expression decreased. Furthermore, the expression of nuclear factor-kappa B (NF-κB), the key regulator of the transcriptional activation of the inflammatory cytokine genes, was reduced by the RSL chloroform fraction. Therefore, the results of our study suggest that RSL exhibits anti-inflammatory effects in LPS-stimulated macrophages via NF-κB inactivation.

Amelioration of an LPS-induced inflammatory response using a methanolic extract of Lagerstroemia ovalifolia to suppress the activation of NF-κB in RAW264.7 macrophages

Lagerstroemia ovalifolia Teijsm. & Binn. has traditionally been used as an herbal medicine and possesses anti-inflammatory properties. However, the mechanisms underlying its anti-inflammatory effects remain poorly understood. For this purpose, we aimed to investigate the effects of methanolic extract of L. ovalifolia (LOME) on nitric oxide (NO) and prostaglandin E2 (PGE2) production, as well as the underlying molecular mechanisms responsible for these effects, in lipopolysaccharide (LPS)‑stimulated RAW264.7 macrophages. We examined the effects of LOME on the production of NO and PGE2 in LPS-stimulated RAW264.7 cells. To explore the anti-inflammatory mechanisms of LOME, we measured the mRNA or protein expression of the pro‑inflammatory mediators induced by LOME in the LPS-stimulated RAW264.7 cells. LOME significantly inhibited the production of NO, PGE2, interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α) in LPS-stimulated RAW264.7 cells. Moreover, LOME suppressed the mRNA and protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and inhibited the phosphorylation of the mitogen-activated protein kinases (MAPKs), with a reduction in the nuclear translocation of nuclear factor (NF)-κB in LPS-stimulated RAW264.7 cells. Taken together, these findings suggest that LOME may exert anti-inflammatory effects in vitro in LPS-stimulated RAW264.7 macrophages and thus, may have potential for use as an adjuvant treatment of inflammatory diseases.

Finasteride Enhances the Generation of Human Myeloid-Derived Suppressor Cells by Up-Regulating the COX2/PGE2 Pathway

Myeloid-derived suppressor cells (MDSCs) have been known to be a key factor in the regulation of the immune system under numerous conditions such as tumors, infections, autoimmune diseases, and transplantations. In contrast to the proposed deleterious role of MDSCs in tumors and infections, MDSCs with their suppressive function are now proved to have the beneficial potential of suppressing the autoimmune response and promoting tolerance to transplantation. Therefore, the expansion of MDSCs could be a promising therapeutic strategy for many diseases. In this study, we aimed to identify FDA-approved drugs that could aid in the expansion of functional MDSCs. We performed a high-throughput screening (HTS) of FDA-approved drugs based on the in vitro human MDSC-differentiation system and identified finasteride (FIN) to have the best potency to aid the generation of human MDSCs. The FIN-induced MDSCs were quite similar to monocytic MDSCs with regard to their surface phenotype, morphology, immunosuppressive function, and related gene expression. Next, we aimed to determine the mechanism of action of FIN and found that FIN induced the expansion of MDSCs through up-regulation of the COX2/PGE2 pathway by enhancing the activity of COX2 promoter. In addition, the administration of indomethacin (IND), a COX2 inhibitor, abrogated the effect of FIN. Based on these results, we suggested that FIN could find applications in the future in the expansion of MDSCs. Further development of FIN-like compounds could be a novel strategy for generating functional MDSCs for immunosuppressive therapies in various immune disorder conditions.

Studies on anti-inflammatory and analgesic properties of Lactobacillus rhamnosus in experimental animal models

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used for the treatment of inflammatory diseases. However, constant use of NSAID may lead to some side effects like gastrointestinal ulcers, bleeding and renal disorders. This study evaluates analgesic and anti-inflammatory activities of Lactobacillus rhamnosus in female Wistar rats.

METHODS

Diclofenac sodium was used as a standard drug for comparison. L. rhamnosus, drugs and vehicle were administered orally. Acetic acid-induced writhing test and carrageenan-induced paw edema model were used for evaluation. Paw edema and number of writhes were measured subsequently. Pro-inflammatory (interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α and IL-17) and anti-inflammatory (IL-4 and IL-10) cytokines were estimated in serum after 24 h.

RESULTS

Results showed that L. rhamnosus significantly decreased the paw thickness at t=24 h by 28.66 % while drug decreased by 19.33 %. Also, L. rhamnosus treatment and standard drug showed a protection of 66.66 % and 41.66 %, respectively. L. rhamnosus and diclofenac sodium treatment significantly down-regulated pro-inflammatory and up-regulated anti-inflammatory cytokines at p<0.0001. Overall, protection provided by L. rhamnosus was more pronounced in comparison to diclofenac sodium.

CONCLUSIONS

The present study clearly suggests that L. rhamnosus suppressed carrageenan-induced paw edema after second phase and decreased the acetic acid-induced writhings. It ameliorated the inflammatory pathways by down-regulating pro-inflammatory cytokines. However, additional clinical investigations are needed to prove the efficacy of L. rhamnosus in treatment/management of inflammatory joint diseases.

Anti-inflammatory Effects of Novel Polysaccharide Sacran Extracted from Cyanobacterium Aphanothece sacrum in Various Inflammatory Animal Models

The goal of this study was to investigate the topical anti-inflammatory effects of the megamolecular polysaccharide sacran extracted from cyanobacterium Aphanothece sacrum using various inflammatory animal models. Sacran showed potent anti-inflammatory effects with optimum effective concentrations at 0.01 and 0.05% (w/v). Sacran markedly inhibited paw swelling and neutrophil infiltration in carrageenan-induced rat paw edema. Additionally, 6,7-dimethoxy-1-methyl-2(1H)-quinoxalinone-3-propionyl-carboxylic acid (DMEQ)-labeled sacran had the ability to penetrate carrageenan-induced rat paw skin rather than normal skin. Also, sacran significantly suppressed kaolin-induced and dextran-induced rat paw edema throughout the duration of the study. Furthermore, sacran significantly suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema and mRNA expression levels of cyclooxygenase (COX)-2 as well as pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6. Safety of sacran solution was verified by negligible cytotoxicity in HaCaT cells. These results suggest that sacran may be useful as a therapeutic agent against inflammatory skin diseases with no life-threatening adverse effects.

Effect of calcitonin gene-related peptide antagonist on the cardiovascular events, mortality, and prostaglandin E2 production by nitrate-induced tolerant rats with acute myocardial infarction

Background

Anti-ischemic effects of NO releasing by nitroglycerin (NTG) and the release of calcitonin gene-related peptide (CGRP) are involved in the decrease of vascular remodeling in different cardiovascular diseases. Using a nitrate-free period is still generally required to prevent nitrate tolerance and should be used as the first-line option to maintain adequate symptom control and on an individual basis. Personalized anti-ischemic concerns require the urgent change of paradigm from interventional measures to predictive, preventive, and personalized treatment with organic nitrates and its combination with drugs that may improve prognosis and drugs that can be added for patients who remain symptomatic despite therapy with the other classes of agents. The purpose of this study was to evaluate the influence of human calcitonin gene-related peptide antagonist (CGRP_8-37) on cardiohemodynamic events, prostaglandin E₂ (PGE₂) plasma concentration, the severity of ventricular arrhythmias, and mortality occurring during acute myocardial infarction (AMI) in NTG-tolerant and nontolerant rats.

Methods

In the pilot study of efficacy of calcitonin gene-related peptide antagonist (CGRP_8-37), 58 male Wistar rats were included. All procedures were performed according to protocols approved by the General Animal Care and Use Committee. Adult male rats underwent surgery to induce AMI by ligating the left anterior descending coronary artery or SHAM. ECG was used to confirm myocardial ischemia. In each experiment, a rat was maintained under anesthesia for the duration of the experiment. At the end of the experiment, the rat was killed by an overdose of pentobarbital. All animals in accordance with the received pharmacological agent were randomized into three groups: I—received only NTG, 50 mg/kg daily, s.c. injections b.i.d. 3 days prior to AMI; II—received NTG by the same dose, route, and frequency of administration + CGRP antagonist (CGRP_8-37), 10 μg/kg two times daily by a similar period of administration; and III—served as control (C) group without preliminary tolerance to NTG.

Results

Subcutaneous injections of NTG (50 mg/kg) 30 min prior to AMI in NTG-tolerant animals (group I) and in NTG-tolerant rats + CGRP antagonist (group II) caused minor changes in blood pressure and heart period that was accompanied before NTG s.c. administration with blunted baroreflex sensitivity in response to i.v. administration of sodium nitroprusside in these groups of rats (0.66 ± 0.05 and 0.56 ± 0.04 ms/mmHg, P < 0.05, respectively) in comparison to C (group III) animals (0.9 ± 0.1 ms/mmHg). AMI 1 h duration was associated with a high incidence of ventricular arrhythmia and significant mortality in group I (70 %) and especially in group II (90 %) animals at 72 h after reperfusion as compared with group III rats (56 %), that correlated to a decrease of PGE₂ plasma content in group II (2.2 ± 0.4 ng/ml, P < 0.001) and group I (3.6 ± 0.2 ng/ml, P < 0.01) vs. control group of rats (4.8 ± 0.3 ng/ml).

Conclusions

CGRP could be involved in the mechanism of nitrate tolerance via the inhibition of release of the potent vasodilator CGRP leading to exacerbation of acute myocardial ischemia. The influence of CGRP antagonist could enhance this condition.

4,7-Dimethoxy-5-methyl-1,3-benzodioxole from Antrodia camphorata inhibits LPS-induced inflammation via suppression of NF-κB and induction HO-1 in RAW264.7 cells

Several benzenoid compounds have been isolated from Antrodia camphorata are known to have excellent anti-inflammatory activity. In this study, we investigated the anti-inflammatory potential of 4,7-dimethoxy-5-methyl-1,3-benzodioxole (DMB), one of the major benzenoid compounds isolated from the mycelia of A. camphorata. DMB significantly decreased the LPS-induced production of pro-inflammatory molecules, such as nitric oxide (NO), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in RAW264.7 cells. In addition, DMB suppressed the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose dependent manner. Moreover, DMB significantly suppressed LPS-induced nuclear translocation of nuclear factor-κB (NF-κB), and this inhibition was found to be associated with decreases in the phosphorylation and degradation of its inhibitor, inhibitory κB-α (IκB-α). Moreover, we found that DMB markedly inhibited the protein expression level of Toll-like receptor 4 (TLR4). Furthermore, treatment with DMB significantly increased hemoxygenase-1 (HO-1) expression in RAW264.7 cells, which is further confirmed by hemin, a HO-1 enhancer, significantly attenuated the LPS-induced pro-inflammatory molecules and iNOS and TLR4 protein levels. Taken together, the present study suggests that DMB may have therapeutic potential for the treatment of inflammatory diseases.

A combinational effect of acetaminophen and oriental herbs on the regulation of inflammatory mediators in microglia cell line, BV2

The mechanism of Western medicine that is commonly used for pain relief is well-known. However, very little is known for oriental herbs, and even less is known for mixture of the two. We investigated the combinational effect of 3 kinds of oriental herbs, usually used for the control of headache, and acetaminophen to relieve headache in microglia cell line, BV2. Lipopolysaccharide (LPS) stimulation induced to produce nitrite and increased the expression of inflammation-related factors like inducible nitric oxide synthase and cyclooxygenase-2 (COX-2) in murine microglia cell line, BV2. Oriental herbs such as Angelica tenuissima, Angelica dahurica, and Scutellaria baicalensis reduced the production of nitric oxide and the expression of COX-2. Moreover, a treatment of acetaminophen combined with oriental herbs was more decreased the COX-2 expression, and its product, prostaglandin E2 production in BV2 cells. Therefore, a combined treatment of oriental herbs such as A. tenuissima, A. dahurica, and S. baicalensis and Western medicine like acetaminophen has a synergistic effect on the decrease of LPS-induced inflammation in microglia.

Evaluation of anti-inflammatory activity of probiotic on carrageenan-induced paw edema in Wistar rats

OBJECTIVE

Probiotic strain Lactobacillus sporogenes and Bifidobacteria bifidum were used to assess the anti-inflammatory properties in Carrageenan induced acute inflammatory model.

METHODS

Non-encapsulated and encapsulated Probiotic strain of Bifidobacteria bifidum and Lactobacillus sporogenes was given orally. Diclofenac sodium was used as standard drug at a concentration of 150 mg/kg of body weight. Edema was induced with 1% carrageenan to all the groups except group A after half an hour of the oral treatments. Paw thickness was checked at t = 1, 2, 4 and 24 h. Stair climbing score and motility score were assessed at t = 24 h.

RESULTS

Non-encapsulated and encapsulated Probiotic Bifidobacteria and Lactobacillus showed a statistically significant decrease in paw thickness at P < 0.05. The percentage inhibition in paw thickness of non-encapsulated and encapsulated probiotic L. sporogenes and B. bifidum is 37 ± 3% and 43 ± 2% after 24 h of treatment. They both significantly increased stair climbing and motility score.

CONCLUSION

Probiotic B. bifidum and L. sporogenes significantly decreased the inflammatory reactions induced by carrageenan.

Herb-drug interactions between Scutellariae Radix and mefenamic acid: Simultaneous investigation of pharmacokinetics, anti-inflammatory effect and gastric damage in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellariae Radix (SR), the dried root of Scutellariae baicalensis Georgi, has a lot in common with non-steroidal anti-inflammatory drugs (NSAIDs). Their similarities in therapeutic action (anti-inflammation) and metabolic pathways (phase II metabolisms) may lead to co-administration by patients with the potential of pharmacokinetic and/or pharmacodynamic interactions. The current study aims to investigate the potential interactions between SR and an NSAID, mefenamic acid (MEF), on the overall pharmacokinetic dispositions, anti-inflammatory effects and adverse effects in rats.

MATERIALS AND METHODS

The current study simultaneously monitored the pharmacokinetic and pharmacodynamic interactions in a single animal. Four groups of Sprague-Dawley rats (n=7 each) received oral doses of a standardized SR extract (300mg/kg, twice daily), MEF (40mg/kg, daily), combination of SR extract and MEF, and vehicle control, respectively, for 5 days. On Day 5, blood samples were collected after first dose over 24h for the determination of (1) plasma concentrations of SR bioactive components, MEF and its metabolites by LC-MS/MS, and (2) prostaglandin E2 (PGE2) production and cyclooxygenase-2 (COX-2) gene expression by ex vivo analyses using LPS-stimulated RAW264.7 macrophage cells, ELISA and real time-PCR. After the rats were sacrificed, stomachs were isolated to assess their gross mucosal damage. Statistical comparisons were conducted using ANOVA and t-test.

RESULTS

Minimal pharmacokinetic interaction between SR extract and MEF was observed. Co-administration of SR extract and MEF did not significantly alter the plasma concentration-time profile or the pharmacokinetic parameters such as Cmax, AUC0→24, Tmax or clearance. Pharmacodynamic interaction via the COX-2 pathway was observed. The PGE2 level in LPS-stimulated RAW264.7 cells treated with plasma collected from control group over the 24h sampling (AUC0→24[PGE2]) was 191981±8789pg/mlhr, which was significantly reduced to 174,780±6531 and 46,225±1915pg/mlhr by plasma collected from rats administered with SR extract and MEF, respectively. Co-administration of SR extract and MEF further potentiated the PGE2 inhibition, with an AUC0→24[PGE2] of 37013±2354pg/mlhr (p<0.05, compared to SR or MEF group). By analyzing the COX-2 gene expression, SR extract significantly prolonged the COX-2 inhibitory effect of MEF over the 24h (p<0.05). Furthermore, the MEF-induced stomach ulcer after the 5-day treatment, as evidenced by the increased gross ulcer index and sum of lesion length (p<0.05, compared to control), could be alleviated by co-administration with SR extract (p<0.05).

CONCLUSIONS

Co-administration of SR extract and MEF potentiated the anti-inflammatory effects, alleviated the MEF-induced stomach adverse effect while having minimal pharmacokinetic interactions. Our findings provide insight for combination therapy of SR extract and MEF against inflammatory diseases.

Rhododendron album Blume inhibits iNOS and COX-2 expression in LPS-stimulated RAW264.7 cells through the downregulation of NF-κB signaling

Rhododendron album Blume (RA) has traditionally been used as an herbal medicine and is considered to have anti-inflammatory properties. In the present study, we screened RA extracts with anti-inflammatory properties. The biological effects of an RA methanol extract (RAME) on inflammation were investigated in lipopolysaccharide (LPS)-stimulated mouse RAW264.7 cells. We investigated the effects of RAME on the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated RAW264.7 cells. To explore the anti-inflammatory mechanisms of RAME, we measured the mRNA and protein expression of pro-inflammatory mediators induced by RAME in the LPS-stimulated RAW264.7 cells by RT-PCR and western blot analysis, respectively. RAME significantly inhibited the production of NO, PGE2, interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α in the LPS-stimulated RAW264.7 cells. It also suppressed the mRNA and protein expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and mitogen-activated protein kinases (MAPKs) with a concomitant decrease in the nuclear translocation of nuclear factor-κB (NF-κB) in the LPS-stimulated RAW264.7 cells. These results indicate that RAME inhibits LPS-induced inflammatory responses. These effects were considered to be strongly associated with the suppression of NF-κB activation. We therefore suggest that RAME may be prove to be an effective therapeutic agent for the treatment of inflammatory diseases.

Xenobiotic-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models

The exposure of the skin to medical drugs, skin care products, cosmetics, and other chemicals renders information on xenobiotic-metabolizing enzymes (XME) in the skin highly interesting. Since the use of freshly excised human skin for experimental investigations meets with ethical and practical limitations, information on XME in models comes in the focus including non-human mammalian species and in vitro skin models. This review attempts to summarize the information available in the open scientific literature on XME in the skin of human, rat, mouse, guinea pig, and pig as well as human primary skin cells, human cell lines, and reconstructed human skin models. The most salient outcome is that much more research on cutaneous XME is needed for solid metabolism-dependent efficacy and safety predictions, and the cutaneous metabolism comparisons have to be viewed with caution. Keeping this fully in mind at least with respect to some cutaneous XME, some models may tentatively be considered to approximate reasonable closeness to human skin. For dermal absorption and for skin irritation among many contributing XME, esterase activity is of special importance, which in pig skin, some human cell lines, and reconstructed skin models appears reasonably close to human skin. With respect to genotoxicity and sensitization, activating XME are not yet judgeable, but reactive metabolite-reducing XME in primary human keratinocytes and several reconstructed human skin models appear reasonably close to human skin. For a more detailed delineation and discussion of the severe limitations see the “Overview and Conclusions” section in the end of this review.

The fish oil ingredient, docosahexaenoic acid, activates cytosolic phospholipase A₂ via GPR120 receptor to produce prostaglandin E₂ and plays an anti-inflammatory role in macrophages

Docosahexaenoic acid (DHA) is one of the major ingredients of fish oil and has been reported to have anti-inflammatory properties mediated through the GPR120 receptor. Whether cytosolic phospholipase A2 (cPLA2 ) and lipid mediators produced from cPLA2 activation are involved in the anti-inflammatory role of DHA in macrophages has not been reported. We report here that DHA and the GPR120 agonist, GW9508, activate cPLA2 and cyclooxygenase 2 (COX-2), and cause prostaglandin E2 (PGE2) release in a murine macrophage cell line RAW264.7 and in human primary monocyte-derived macrophages. DHA and GW9508 activate cPLA2 via GPR120 receptor, G protein Gαq and scaffold protein β-arrestin 2. Extracellular signal-regulated kinase 1/2 activation is involved in DHA- and GW9508-induced cPLA2 activation, but not p38 mitogen-activated protein kinase. The anti-inflammatory role of DHA and GW9508 is in part via activation of cPLA2 , COX-2 and production of PGE2 as a cPLA2 inhibitor or a COX-2 inhibitor partially reverses the DHA- and GW9508-induced inhibition of lipopolysaccharide-induced interleukin-6 secretion. The cPLA2 product arachidonic acid and PGE2 also play an anti-inflammatory role. This effect of PGE2 is partially through inhibition of the nuclear factor-κB signalling pathway and through the EP4 receptor of PGE2 because an EP4 inhibitor or knock-down of EP4 partially reverses DHA inhibition of lipopolysaccharide-induced interleukin-6 secretion. Hence, DHA has an anti-inflammatory effect partially through induction of PGE2.

Mechanical stress is a pro-inflammatory stimulus in the gut: in vitro, in vivo and ex vivo evidence

Aims

Inflammatory infiltrates and pro-inflammatory mediators are found increased in obstructive and functional bowel disorders, in which lumen distention is present. However, what caused the low level inflammation is not well known. We tested the hypothesis that lumen distention- associated mechanical stress may induce expression of specific inflammatory mediators in gut smooth muscle.

Methods

Static mechanical stretch (18% elongation) was applied in vitro in primary culture of rat colonic circular smooth muscle cells (RCCSMCs) with a Flexercell FX-4000 Tension Plus System. Mechanical distention in vivo was induced in rats with an obstruction band placed in the distal colon.

Results

In the primary culture of RCCSMCs, we found that static stretch significantly induced mRNA expression of iNOS, IL-6, and MCP-1 in 3 hours by 6.0(±1.4), 2.5(±0.5), and 2.2(±0.5) fold (n = 6∼8, p<0.05), respectively. However, gene expression of TNF-α, IL-1β, and IL-8 was not significantly affected by mechanical stretch. In the in vivo model of colon obstruction, we found that gene expression of iNOS, IL-6, and MCP-1 is also significantly increased in a time-dependent manner in the mechanically distended proximal segment, but not in the sham controls or distal segments. The conditioned medium from the muscle strips of the stretched proximal segment, but not the distal segment or control, significantly induced translocation and phosphorylation of NF-κB p65. This treatment further increased mRNA expression of inflammatory mediators in the naïve cells. However, treatment of the conditioned medium from the proximal segment with neutralizing antibody against rat IL-6 significantly attenuated the activation of NF-κB and gene expression of inflammatory mediators.

Conclusions

Our studies demonstrate that mechanical stress induces gene expression of inflammatory mediators i.e. iNOS, IL-6, and MCP-1 in colonic SMC. Further ex vivo study showed that mechanical stress functions as a pro-inflammatory stimulus in the gut.

Evaluation of hemostatic and anti-inflammatory activities of extracts from different Lagochilus species in experimental animals: comparison of different extractives and sources

Different members of Lagochilus genus have been used in folkloric medicine to treat hemorrhages and inflammation. However, only a few species of them have received scientific attention supporting their efficacy. Here, the hemostatic and antiinflammatory activities of five Lagochilus species were determined and compared by using in vivo assays. The results showed that the extracts of Lagochilus lanatonodus and Lagochilus diacanthophyllus showed better hemostatic activities among five species. The high doses of L. lanatonodus extracts were able to shorten the values of thrombin time, activated partial thromboplastin time and prothrombin time in a rat model. Moreover, the extracts of L. lanatonodus and L. diacanthophyllus showed strong inhibitory effects on the acute phase of inflammation in both xylene-induced ear edema mouse model and carrageenan-induced paw edema rat model. In parallel, the treatment of these extracts modulated the expressions of those inflammatory parameters, that is, nitric oxide, prostaglandin E2 , inducible nitric oxide synthase, malondialdehyde and superoxide dismutase. L. lanatonodus and L. diacanthophyllus showed better hemostatic and antiinflammatory activities in several test models: these results therefore supported the folkloric utilization. L. lanatonodus was found to be the most active Lagochilus species.

Influence of mefenamic acid on the intestinal absorption and metabolism of three bioactive flavones in Radix Scutellariae and potential pharmacological impact

CONTEXT

Mefenamic acid (MEF) and the dried root of Scutellaria baicalensis Georgi (Radix Scutellariae, RS) share a high possibility of combined medication to treat inflammation.

OBJECTIVE

The present study investigates the impact of MEF on absorption/disposition of three major components in RS (baicalein, B; wogonin, W; oroxylin A, OA) and further pharmacological changes.

MATERIALS AND METHODS

The apparent permeability (P(app)) and percentage of metabolism of B, W and OA at 10 μΜ were measured at the absence/presence of MEF (100 μΜ) in the Caco-2 cell monolayer model. A modified whole blood assay was employed to quantify prostaglandin E₂ (PGE₂) 4, 6 and 8 h post-oral administration with water suspension of MEF at 40 mg/kg and RS at 200 mg/kg.

RESULTS

In the presence of MEF, Papp of B, W and OA were increased from 1.69 ± 0.89 × 10⁻⁶, 1.57 ± 0.10 × 10⁻⁶ and 3.09 ± 0.70 × 10⁻⁶ cm/sec to 5.24 ± 0.27 × 10⁻⁶, 6.08 ± 0.19 × 10⁻⁶ and 4.13 ± 0.38 × 10⁻⁶, whereas their percentage of metabolism was decreased from 72.75 ± 2.44%, 73.27 ± 3.25% and 89.84 ± 2.99% to 21.11 ± 0.69%, 17.90 ± 5.55% and 45.44 ± 3.38%. PGE2 level was much lower in the co-administration group (49.04 ± 2.03 pg/ml) than in the MEF group (73.13 ± 3.03 pg/ml) or RS group (494.37 ± 11.75 pg/ml) 4 h post MEF dosing, suggesting a synergic effect.

DISCUSSION AND CONCLUSION

Co-administration of MEF and RS could induce potential alterations in their pharmacokinetic profiles and anti-inflammatory effects.

Osteocytes: master orchestrators of bone

Osteocytes comprise the overwhelming majority of cells in bone and are its only true "permanent" resident cell population. In recent years, conceptual and technological advances on many fronts have helped to clarify the role osteocytes play in skeletal metabolism and the mechanisms they use to perform them. The osteocyte is now recognized as a major orchestrator of skeletal activity, capable of sensing and integrating mechanical and chemical signals from their environment to regulate both bone formation and resorption. Recent studies have established that the mechanisms osteocytes use to sense stimuli and regulate effector cells (e.g., osteoblasts and osteoclasts) are directly coupled to the environment they inhabit-entombed within the mineralized matrix of bone and connected to each other in multicellular networks. Communication within these networks is both direct (via cell-cell contacts at gap junctions) and indirect (via paracrine signaling by secreted signals). Moreover, the movement of paracrine signals is dependent on the movement of both solutes and fluid through the space immediately surrounding the osteocytes (i.e., the lacunar-canalicular system). Finally, recent studies have also shown that the regulatory capabilities of osteocytes extend beyond bone to include a role in the endocrine control of systemic phosphate metabolism. This review will discuss how a highly productive combination of experimental and theoretical approaches has managed to unearth these unique features of osteocytes and bring to light novel insights into the regulatory mechanisms operating in bone.

Oligonol supplementation attenuates body temperature and the circulating levels of prostaglandin E2 and cyclooxygenase-2 after heat stress in humans

Oligonol, a phenolic production from lychee, has been reported to exhibit anti-oxidative and anti-inflammatory effects. This study investigated the effect of Oligonol supplementation on circulating levels of prostaglandin E2 (PGE2) and cyclooxygenase (COX)-2, as well as body temperature, after heat stress in 17 healthy human male volunteers (age, 21.6±2.1 years). All experiments were performed in an automated climate chamber (26.0°C±0.5°C, relative humidity 60%±3.0%, air velocity less than 1 m/sec) between 2 and 5 p.m. Subjects ingested an Oligonol (100 mg)-containing beverage or placebo beverage before half-body immersion into hot water (42°C±0.5°C for 30 min). Tympanic and skin temperatures were measured and mean body temperatures were calculated. Serum concentrations of PGE2 and COX-2 were analyzed before, immediately after, and 60 min after immersion. Oligonol intake significantly prevented elevation of tympanic (temperature difference: 0.17°C at Post, P<.05; 0.17°C at Re-60, P<.05) and mean body temperatures (temperature difference: 0.18°C at Post, P<.05; 0.15°C at Re-60, P<.05), and lowered concentrations of serum PGE2 (increased by 13.3% vs. 29.6% at Post, P<.05) and COX-2 (increased by 15.6% vs. 21.8% at Post, P<.05), compared to placebo beverage. Our result suggests that Oligonol has the potential to suppress increases in body temperature under heat stress, and this is associated with decreases in serum levels of PGE2 and COX-2.

Diphlorethohydroxycarmalol, Isolated from Ishige okamurae, Increases Prostaglandin E2 through the Expression of Cyclooxygenase-1 and -2 in HaCaT Human Keratinocytes

Prostaglandin (PG) E2, the most abundant prostaglandin in the human body, is synthesized from arachidonic acid via the actions of cyclooxygenase (COX) enzymes. PGE2 exerts homeostatic, cytoprotective, inflammatory, and in some cases anti-inflammatory effects. Also, it has been reported that PGE2 is involved in hair growth. Diphlorethohydroxycarmalol (DPHC) is a phlorotannin compound isolated from the brown algae Ishige okamurae, with various biological activities in vitro and in vivo. In this study, the biological effect and mechanism of action of DPHC on prostaglandin synthesis in HaCaT human keratinocytes was examined. The results showed that, in these cells, DPHC significantly and dose-dependently induced PGE2 synthesis by increasing the protein and mRNA levels of COX-1 and COX-2. Interestingly, DPHC-induced COX-1 expression preceded that of COX-2. Also, while both rofecoxib and indomethacin inhibited PGE2 production, the latter was seems to be the more potent. From above results, we can expect that DPHC has some beneficial effects via increasing of PGE2 production.

Downregulation of pro-inflammatory mediators by a water extract of Schisandra chinensis (Turcz.) Baill fruit in lipopolysaccharide-stimulated RAW 264.7 macrophage cells

Schisandra chinensis has a long-standing history of medicinal use as a tonic, a sedative, an anti-tussive, and an anti-aging drug. Nevertheless, the antagonistic effects of S. chinensis against lipopolysaccharide (LPS)-stimulated responses have not yet been studied. In this study, we investigated whether water extract of S. chinensis fruit (WESC) has the ability to attenuate the expression of pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor-α (TNF-α) in LPS-stimulated RAW 264.7 macrophage cells. WESC inhibited the expression of LPS-induced pro-inflammatory mediators, namely, NO, PGE2, and TNF-α. Furthermore, gene expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-α was inhibited both at mRNA and protein synthesis levels, without any cytotoxic effect. Moreover, WESC significantly suppressed LPS-induced DNA-binding activity of NF-κB by inhibiting degradation of IκBα. It was found that pyrrolidine dithiocarbamate (PDTC), a specific NF-κB inhibitor, downregulates the expression of these pro-inflammatory genes to be closely regulated by NF-κB activity. Furthermore, we found that WESC retains dephosphorylation of Akt in response to LPS, and consequently suppressed the DNA-binding activity of NF-κB in RAW 264.7 macrophage cells. LY294002, a specific Akt inhibitor, attenuated LPS-induced pro-inflammatory gene expression via suppression of NF-κB activity. Taken together, our results indicate that WESC downregulates the expression of pro-inflammatory genes involved in the synthesis of NO, PGE2, and TNF-α in LPS-stimulated RAW 264.7 macrophage cells by suppressing Akt-dependent NF-κB activity.

Ginsenoside Rd inhibits the expressions of iNOS and COX-2 by suppressing NF-κB in LPS-stimulated RAW264.7 cells and mouse liver

Ginsenoside Rd is a primary constituent of the ginseng rhizome and has been shown to participate in the regulation of diabetes and in tumor formation. Reports also show that ginsenoside Rd exerts anti-oxidative effects by activating anti-oxidant enzymes. Treatment with ginsenoside Rd decreased nitric oxide and prostaglandin E₂ (PGE₂) in lipopolysaccharides (LPS)-challenged RAW264.7 cells and in ICR mouse livers (5 mg/kg LPS; LPS + ginsenoside Rd [2, 10, and 50 mg/kg]). Furthermore, these decreases were associated with the down-regulations of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 and of nuclear factor (NF)-κB activity in vitro and in vivo. Our results indicate that ginsenoside Rd treatment decreases; 1) nitric oxide production (40% inhibition); 2) PGE₂ synthesis (69% to 93% inhibition); 3) NF-κB activity; and 4) the NF-κB-regulated expressions of iNOS and COX-2. Taken together, our results suggest that the anti-inflammatory effects of ginsenoside Rd are due to the down-regulation of NF-κB and the consequent expressional suppressions of iNOS and COX-2.

Heat acclimation affects circulating levels of prostaglandin E2, COX-2 and orexin in humans

We examined serum levels of prostaglandin E2 (PGE2), cyclooxygenase (COX)-2 and orexin before and after heat acclimation (HA) to test the hypothesis that decreased basal body temperature due to HA correlate with circulating levels of these key thermoregulatory molecules. Nine healthy human male volunteers were recruited (age, 21.9±2.7 years). The subjects were exposed to half-body immersion in hot water (42±0.5°C) at the same time of day (2-5p.m.) on alternate days for 3 weeks. The HA protocol included 10 bouts of 30min immersion. All experiments were performed in an automated climate chamber (temperature, 26.0±0.5°C; relative humidity, 60±3.0%; air velocity, <1m/s). Tympanic and skin temperatures were measured, and mean body temperature was calculated. The difference in body weight was used to estimate total sweat loss. Serum levels of PGE2, COX-2 and orexin were analyzed before and after HA. Body temperature decreased significantly (P<0.05) after HA, whereas sweat volume increased significantly (P<0.01). Serum PGE2, COX-2 and orexin concentrations decreased significantly compared to those at pre-acclimation (P<0.001, P<0.01, P<0.01, respectively). Our data suggest that decreased basal body temperature after HA is associated with decreases in thermoregulatory molecules, such as PGE2, COX-2 and orexin.