Inflammation: patterns and new concepts

Anti‑inflammatory and antioxidant activity of the traditional herbal formula Gwakhyangjeonggi‑san via enhancement of heme oxygenase‑1 expression in RAW264.7 macrophages

Gwakhyangjeonggi‑san (GHJGS) is a mixture of herbal plants, including Agastache rugosa, Perilla frutescens, Angelica dahurica, Areca catechu, Poria cocos, Magnolia officinalis, Atractylodes macrocephala, Citrus reticulata, Pinellia ternata, Platycodon grandiflorum, Glycyrrhiza uralensis, Ziziphus jujuba and Zingiber officinale. GHJGS has been used for treating diarrhea‑predominant irritable bowel syndrome in traditional Korean medicine. In the present study, the anti‑inflammatory and antioxidant effects of GHJGS were investigated using the RAW 264.7 murine macrophage cell line. GHJGS significantly reduced production of the proinflammatory cytokines, tumor necrosis factor‑α, interleukin‑6 and prostaglandin E2 in lipopolysaccharide (LPS)‑stimulated macrophages. GHJGS markedly suppressed LPS‑induced phosphorylation of mitogen‑activated protein kinases, whereas it had no effect on nuclear factor‑κB activation. Furthermore, GHJGS enhanced expression of heme oxygenase‑1 and prevented the generation of reactive oxygen species in RAW 264.7 cells. These results indicate that GHJGS is a viable therapeutic agent against inflammation and oxidative stress‑associated disorders.

Anticancer activity of essential oils: a review

Natural essential oil constituents play an important role in cancer prevention and treatment. Essential oil constituents from aromatic herbs and dietary plants include monoterpenes, sesquiterpenes, oxygenated monoterpenes, oxygenated sesquiterpenes and phenolics among others. Various mechanisms such antioxidant, antimutagenic and antiproliferative, enhancement of immune function and surveillance, enzyme induction and enhancing detoxification, modulation of multidrug resistance and synergistic mechanism of volatile constituents are responsible for their chemopreventive properties. This review covers the most recent literature to summarize structural categories and molecular anticancer mechanisms of constituents from aromatic herbs and dietary plants.

Synthesis and biological evaluation studies of novel quinazolinone derivatives as antibacterial and anti-inflammatory agents

Some novel 6,8-diiodo-2-methyl-3-substituted-quinazolin-4(3H)-ones bearing sulfonamide derivatives (4-11) were synthesized in good yields and evaluated for their possible antibacterial, anti-inflammatory activities and acute toxicity. The structures of the synthesized compounds were confirmed on the basis of their spectral data and elemental analysis. Their antibacterial activities were evaluated by the agar well diffusion method while their anti-inflammatory activities were evaluated by the carrageenan-induced hind paw edema test. All the tested compounds showed considerable antibacterial activities and high to moderate anti-inflammatory activities that last for 12 h compared to ibuprofen. All the tested compounds showed no toxic symptoms or mortality rates 24 h post-administration at tested anti-inflammatory doses. In addition, LD50 for all tested compounds was higher than that for ibuprofen implying their good safety margin. The obtained results showed that the most active compounds could be useful as a template for future design, modification and investigation to produce more active analogs.

Effect of percutaneous transthoracic lung biopsy on oxidative metabolism in sheep

This study aimed to assess the effect of percutaneous transthoracic lung biopsy on the oxidative metabolism of sheep by measuring the oxidative stress markers of superoxide dismutase (SOD), total glutathione (GSH-t), peroxidase (GSH-Px) and thiobarbituric acid reactive substances (TBARS) in the red cells of these animals. Blood samples were collected from 20 clinically healthy sheep prior to, and 30 min after, percutaneous transthoracic lung biopsy. After biopsy, there was a significant decrease (p < 0.05) in SOD and GSH-Px activity, with no significant change (p ≥ 0.05) in GSH-t and TBARS concentrations. These results showed that percutaneous transthoracic lung biopsy did not significantly affect the oxidative metabolism of sheep 30 min after the procedure, which may be used widely in this species without causing serious tissue damage.  

Kinin-mediated inflammation in neurodegenerative disorders

The mediatory role of kinins in both acute and chronic inflammation within nervous tissues has been widely described. Bradykinin, the major representative of these bioactive peptides, is one of a few mediators of inflammation that directly stimulates afferent nerves due to the broad expression of specific kinin receptors in cell types in these tissues. Moreover, kinins may be delivered to a site of injury not only after their production at the endothelium surface but also following their local production through the enzymatic degradation of kininogens at the surface of nerve cells. A strong correlation between inflammatory processes and neurodegeneration has been established. The activation of nerve cells, particularly microglia, in response to injury, trauma or infection initiates a number of reactions in the neuronal neighborhood that can lead to cell death after the prolonged action of inflammatory substances. In recent years, there has been a growing interest in the effects of kinins on neuronal destruction. In these studies, the overexpression of proteins involved in kinin generation or of kinin receptors has been observed in several neurologic disorders including neurodegenerative diseases such Alzheimer's disease and multiple sclerosis as well as disorders associated with a deficiency in cell communication such as epilepsy. This review is focused on recent findings that provide reliable evidence of the mediatory role of kinins in the inflammatory responses associated with different neurological disorders. A deeper understanding of the role of kinins in neurodegenerative diseases is likely to promote the future development of new therapeutic strategies for the control of these disorders. An example of this could be the prospective use of kinin receptor antagonists.

Anti-inflammatory effects of ethanol extract from Orostachys japonicus on modulation of signal pathways in LPS-stimulated RAW 264.7 cells

In this study, powder of Orostachys japonicus A. Berger (O. japonicus) was extracted with 95% ethyl alcohol and fractionated using a series of organic solvents, including n-hexane (hexane), dichloromethane (DCM), ethylacetate (EtOAc), n-butanol (BuOH), and water (H(2)O). We investigated the anti-inflammatory effects of these O. japonicus extracts on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Their effects on the expression of inflammatory mediators and transcription factors were analyzed by Western blotting. DCM fraction significantly inhibited formation of reactive oxygen species (ROS) as well as nitric oxide (NO) in LPS-stimulated RAW 264.7 cells. Phosphorylation of the pro-inflammatory transcription factor complex nuclear factor-kappa B (NF-κB) p65 and expression of inducible nitric oxide synthase (iNOS), one of its downstream proteins, were also suppressed by DCM fraction. These effects were regulated by upsteam proteins in the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase/Akt (PI3K/Akt) signaling pathways. Taken together, our data suggest that O. japonicus could be used as a potential source for anti-inflammatory agents.

The aging process and potential interventions to extend life expectancy

Aging is commonly defined as the accumulation of diverse deleterious changes occurring in cells and tissues with advancing age that are responsible for the increased risk of disease and death. The major theories of aging are all specific of a particular cause of aging, providing useful and important insights for the understanding of age-related physiological changes. However, a global view of them is needed when debating of a process which is still obscure in some of its aspects. In this context, the search for a single cause of aging has recently been replaced by the view of aging as an extremely complex, multifactorial process. Therefore, the different theories of aging should not be considered as mutually exclusive, but complementary of others in the explanation of some or all the features of the normal aging process. To date, no convincing evidence showing the administration of existing "anti-aging" remedies can slow aging or increase longevity in humans is available. Nevertheless, several studies on animal models have shown that aging rates and life expectancy can be modified. The present review provides an overlook of the most commonly accepted theories of aging, providing current evidence of those interventions aimed at modifying the aging process.

The formyl peptide N-formyl-methionyl-leucyl-phenylalanine downregulates the expression of FcgammaRs in interferon-gamma-activated monocytes/macrophages in vitro and in vivo

N-Formyl peptides are cleavage products of bacterial and mitochondrial proteins that have pro-inflammatory activities and play an important role in antibacterial host defence. FcgammaRI is a receptor for the Fc portion of immunoglobulin G expressed in monocytes that mediates cytotoxicity and is upregulated by interferon-gamma (IFN-gamma) and interleukin-10 (IL-10). In this report, we demonstrate that N-formyl-methionyl-leucyl-phenylalanine (FMLP) downregulates the expression of FcgammaRI in IFN-gamma-treated monocytes, but not in IL-10-treated monocytes. We determine that supernatants obtained from monocytes treated with IFN-gamma and then exposed to FMLP induce the downregulation of FcgammaRI in naïve monocytes. This effect is abrogated by the protease inhibitors phenylmethylsulphonyl fluoride and phosphoramidon, which inhibit serine and metalloproteases, respectively. Supernatants from FMLP-treated neutrophils also induce the downregulation of FcgammaRI, when added to naïve monocytes. Similar observations were obtained in vivo in a mouse model of chronic inflammation. In vivo, FMLP also downregulates the expression of FcgammaRs in IFN-gamma-activated macrophages. Our results support the existence of a new mechanism through which FMLP could modulate the activity of monocytes/macrophages during bacterial infections.

The inflammation hypothesis of aging: molecular modulation by calorie restriction

Current evidence strongly indicates that reactive oxygen species (ROS) and reactive nitrogen species (RNS) are widely implicated in the inflammatory process. However, mechanistic information is not readily available on the extent to which ROS/RNS contributes to the proinflammatory states of the aging process. The involvement of the underlying inflammation during the aging process and the molecular delineation of anti-inflammatory action of calorie restriction (CR) is described. Age-related upregulations of NF-kappaB, IL-beta, IL-6, TNFalpha, cyclooxygenase-2, and inducible NO synthase are all attenuated by CR. The suppression of the NF-kappaB activation was accomplished by blocking the dissociation of inhibitory IkappaBalpha and IkappaBbeta by CR. These findings provide underlying molecular insights into the anti-inflammatory action of CR in relation to the aging process. Based on these and other available data, it is suggested that the "Inflammation Hypothesis of Aging" supports the molecular basis of the inflammatory process as a plausible cause of the aging process.

N-formyl-methionyl-leucyl-phenylalanine inhibits both gamma interferon- and interleukin-10-induced expression of FcgammaRI on human monocytes

Three different classes of receptors for the Fc portion of immunoglobulin G (FcgammaRs), FcgammaRI, FcgammaRII, and FcgammaRIII, have been identified on human leukocytes. One of them, FcgammaRI, is a high-affinity receptor capable of induction of functions that include phagocytosis, respiratory burst, antibody-dependent cell-mediated cytotoxicity (ADCC), and secretion of cytokines. This receptor is expressed on mononuclear phagocytes, and this expression is regulated by cytokines and hormones such as gamma interferon (IFN-gamma), IFN-beta, interleukin-10 (IL-10), and glucocorticoids. We have recently demonstrated that the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) is capable of inducing a time-dependent downregulation of both FcgammaRIIIB and FcgammaRII in human neutrophils, altering FcgammaR-dependent functions. Considering the biological relevance of the regulation of FcgammaRI, we investigated the effect of FMLP on the overexpression of FcgammaRI induced by both IFN-gamma and IL-10 on human monocytes. We demonstrate that FMLP significantly abrogated IFN-gamma- and IL-10-induced FcgammaRI expression, although its basal level of expression was not altered. However, other IFN-gamma-mediated effects such as the overexpression of the major histocompatibility complex class II antigens and the enhancement of lipopolysaccharide-induced secretion of tumor necrosis factor alpha were not affected by FMLP treatment. The formyl peptide completely inhibited the IFN-gamma- and IL-10-induced enhancement of ADCC and phagocytosis carried out by adherent cells. The inhibitory effect of FMLP on FcgammaRI upregulation could exert an important regulatory effect during the evolution of bacterial infections.

Pretreatment of mice with lipopolysaccharide (LPS) or IL-1beta exerts dose-dependent opposite effects on Shiga toxin-2 lethality

Haemolytic uraemic syndrome (HUS) has been closely associated with infection with a group of Shiga toxin-producing enterohaemorrhagic Eschericchia coli in young children. Shiga toxins (Stx) have been implicated as pathogenic agents of HUS by binding to the surface receptor of endothelial cells. LPS is a central product of the Gram-negative bacteria and several reports have documented that both LPS and Stx are important for disease development. In this study the reciprocal interactions between LPS and Stx2 are analysed in a mouse model. The results demonstrated that LPS was able to reduce or enhance Stx2 toxicity, depending on the dose and the timing of the injection. The involvement of the main early cytokines induced by LPS, tumour necrosis factor alpha (TNF-alpha) and IL-1beta, in those LPS opposite effects on Stx2 toxicity was evaluated. Stx2 toxicity was enhanced by in vivo injection of murine TNF-alpha and low doses of murine IL-1beta. However, at higher doses of IL-1beta which induced corticosteroid increase in serum, Stx2 lethality was decreased. Considering that dexamethasone and IL-1beta reproduce the LPS protective effects, it is suggested that endogenous corticosteroids secondary to the inflammatory response induced by LPS, mediate the protection against Stx2. It can be concluded that the fine equilibrium between proinflammatory and anti-inflammatory activities strongly influences Stx2 toxicity.