Monoamine Oxidase-B Inhibitor Reduction in Pro-Inflammatory Cytokines Mediated by Inhibition of cAMP-PKA/EPAC Signaling

Mucosal epithelial cell integrity is an important component of innate immunity and it protects the host from an environment rich in microorganisms. Virulence factors from Gram-negative bacteria [e.g. lipopolysaccharide (LPS)] induce significant pro-inflammatory cytokine expression. Monoamine oxidase (MAO) inhibitors reduce cytokine expression in a variety of inflammatory models and may therefore have therapeutic potential for a number of inflammatory diseases. We tested the anti-inflammatory therapeutic potential of a recently developed reversible MAO-B inhibitor (RG0216) with reduced transport across the blood–brain barrier. In an epithelial cell culture model, RG0216 significantly decreased LPS-induced interleukin (IL)-6 and IL-1β gene and protein expression and was as effective as equimolar concentrations of deprenyl (an existing irreversible MAO-B inhibitor). Hydrogen peroxide and modulating dopamine receptor signaling had no effect on cytokine expression. We showed that LPS-induced expression of IL-6 and IL-1β was cAMP dependent, that IL-6 and IL-1β expression were induced by direct cAMP activation (forskolin) and that RG0216 and deprenyl effectively reduced cAMP-mediated cytokine expression. Targeted protein kinase A (PKA) and Exchange Protein Activated by cAMP (EPAC) activation regulated IL-6 and IL-1β expression, albeit in different ways, but both cytokines were effectively decreased with RG0216. RG0216 reduction of LPS-induced cytokine expression occurred by acting downstream of the cAMP-PKA/EPAC signaling cascade. This represents a novel mechanism by which MAO-B selective inhibitors regulate LPS-induced IL-6 and IL-1β expression.

Cav3.2 calcium channels involvement in inflammation and related pain-like symptoms in murine inflammatory models

Background and Purpose T-type calcium channels, mainly the Cav3.2 subtype, are important contributors to the nociceptive signaling pathway. We investigated their involvement in inflammation and related pain-like symptoms. Experimental Approach The involvement of Cav3.2 and T-type channels was investigated using genetic and pharmacological inhibition to assess mechanical allodynia/hyperalgesia and edema development in two murine inflammatory pain models. The location of Cav3.2 involved in pain-like symptoms was studied in mice with Cav3.2 knocked out in C-low threshold mechanoreceptors (C-LTMR) and the use of ABT-639, a peripherally restricted T-type channel inhibitor. The anti-edematous effect of Cav3.2 inhibition was investigated in chimeric mice with immune cells deleted for Cav3.2. Lymphocytes and macrophages from either green fluorescent protein-targeted Cav3.2 or KO mice were used to determine the expression of Cav3.2 protein and the functional status of the cells. Key Results We showed the role of Cav3.2 channels in the development of pain-like symptoms and edema in the two murine inflammatory pain models. For the first time, we provide evidence of the involvement of Cav3.2 channels located on C-LTMRs in inflammatory pain at both peripheral and primary afferent terminals at the spinal level. We showed that Cav3.2 channels located in T cells and macrophages contribute to the inflammatory process. Conclusion and Implications This work highlights the crucial role of Cav3.2 channels in inflammation and related pain and suggests that targeting Cav3.2 channels with pharmacological agents could be an attractive and readily evaluable strategy in a clinical trial to relieve chronic inflammatory pain in affected patients.

The Potential of Vouacapanes from Pterodon Emarginatus Vogel against COVID-19 Cytokine Storm

Purpose: The emergence of the COVID-19 pandemic has led to the search for potential therapeutic responses for various aspects of this disease. Fruits of Pterodon emarginatus Vogel (Fabaceae), sucupira, have been used in Brazilian traditional medicine because of their anti-inflammatory properties, which have been proven in vivo, in vitro, and in silico. Therefore, the aim of this work is to evaluate P. emarginatus oleoresin and isolated diterpenes by in vitro anti-inflammatory models. Methods: In this study, the mechanisms underlying the anti-inflammatory activity of Pterodon emarginatus oleoresin and vouacapanes 6α,19β-diacetoxy-7β,14β-dihydroxyvouacapan (V1), 6α-acetoxy-7β,14β-dihydroxyvouacapan (V2), and methyl 6α-acetoxy-7β-hydroxyvouacapan-17β-oate (V3) were investigated in HaCaT cells. Results: Oleoresin, V2, and V3 inhibited phospholipase A2 (30.78%, 24.96%, and 77.64%, respectively). Both vouacapanes also inhibited the expression of COX-2 (28.3% and 33.17%, respectively). The production of interleukin IL-6 was inhibited by oleoresin by 35.47%. However, oleoresin did not interfere with Nrf-2 expression or IL-8 production. Conclusion: The results support the ethnomedicinal use of P. emarginatus oleoresin as an anti-inflammatory herbal medicine, and also highlight Pterodon emarginatus oleoresin and isolated vouacapanes as an attractive therapeutic approach for COVID-19 through the reduction or chronological control of the inflammatory mediators IL-6, COX-2, phospholipase A2, and INF-y (indirectly) during the SARS-CoV-2 infection process.

Triptolide exhibits anti-inflammatory effects on adipocytes and macrophages by inhibition of AMPK/mTOR pathway

Obesity is a growing global health problem and chronic over-nutrition disease with lipid accumulation that results in low-grade chronic inflammation in the microenvironment of adipose tissue. Triptolide is a diterpene lactone compound extracted from the roots of the Chinese herb TWHF and possesses a therapeutic potential due to its immunosuppressive and anti-inflammatory properties. In this study, we built obesity-related inflammatory models of adipocytes using LPS, Ma-CM and raw264.7 macrophages, while the obesity-related inflammatory models of macrophages were built using LPS and Ad-CM system. We used these inflammatory models to investigate the anti-inflammatory property of triptolide. Treatment of triptolide (0.005, 0.010, 0.020 and 0.040 μ M) inhibited LPS-induced or macrophages conditioned medium-stimulated activation of AMPK/mTOR signaling pathway (p < 0.05). The results showed that triptolide reduced the release of chemokines MCP-1, RANTES, EOTAXIN and KC in LPS, Ma-CM or RAW264.7 macrophages-stimulated 3T3-L1 adipocytes. Triptolide also diminished MCP-1, RANTES, EOTAXIN, KC and TNF-α in Ad-CM stimulated RAW264.7 macrophages, while expression of MCP-1, RANTES, TNF-α, GM-CSF and IL-6 was decreased in LPS stimulated RAW264.7 macrophages (p < 0.05). These results demonstrate that triptolide is not only effective against inflammatory response of RAW264.7 macrophages or 3T3-L1 adipocytes, but also disrupts the crosstalk between macrophages and adipocytes, particularly by inhibiting secretion of pro-inflammatory mediators through inhibiting the activation of AMPK/mTOR signaling pathway. Triptolide might benefit to ameliorate obesity-induced inflammatory diseases.

ANTI-INFLAMMATORY PERSPECTIVES OF DIVERSE NATURAL RESOURCES

irritants. It is characterized by redness, swollen joints, joint pain, stiffness, and loss of joint function. Inflammation is currently treated by NSAIDs. Unfortunately, these drugs cause an increased risk of blood clots resulting in heart attacks and strokes. Therefore, the developments of potent anti-inflammatory drugs from natural products are now under consideration. Natural products are a rich source for the discovery of new drugs because of their chemical diversity. A natural product from medicinal plants plays a major role to cure many diseases associated with inflammation. The conventional drug available in the market to treat inflammation produces various side effects. Due to these side effects, there is a need for the search for newer drugs with fewer or no side effects. There are hundreds of phytoconstituents reported to have many pharmacological activities although most of these reports are of academic interest and very few find an entry in clinical trials. The present review is directed towards the compilation of data on promising phytochemicals from herbal plants that have been tested in inflammatory models using modern scientific systems

Anti-Inflammatory, Antipyretic, and Analgesic Properties of Potamogeton perfoliatus Extract: In Vitro and In Vivo Study

Natural antioxidants, especially those of plant origins, have shown a plethora of biological activities with substantial economic value, as they can be extracted from agro-wastes and/or under exploited plant species. The perennial hydrophyte, Potamogeton perfoliatus, has been used traditionally to treat several health disorders; however, little is known about its biological and its medicinal effects. Here, we used an integrated in vitro and in vivo framework to examine the potential effect of P. perfoliatus on oxidative stress, nociception, inflammatory models, and brewer’s yeast-induced pyrexia in mice. Our results suggested a consistent in vitro inhibition of three enzymes, namely 5-lipoxygenase, cyclooxygenases 1 and 2 (COX-1 and COX-2), as well as a potent antioxidant effect. These results were confirmed in vivo where the studied extract attenuated carrageenan-induced paw edema, carrageenan-induced leukocyte migration into the peritoneal cavity by 25, 44 and 64% at 200, 400 and 600 mg/kg, p.o., respectively. Moreover, the extract decreased acetic acid-induced vascular permeability by 45% at 600 mg/kg, p.o., and chemical hyperalgesia in mice by 86% by 400 mg/kg, p.o., in acetic acid-induced writhing assay. The extract (400 mg/kg) showed a longer response latency at the 3 h time point (2.5 fold of the control) similar to the nalbuphine, the standard opioid analgesic. Additionally, pronounced antipyretic effects were observed at 600 mg/kg, comparable to paracetamol. Using LC-MS/MS, we identified 15 secondary metabolites that most likely contributed to the obtained biological activities. Altogether, our findings indicate that P. perfoliatus has anti-inflammatory, antioxidant, analgesic and antipyretic effects, thus supporting its traditional use and promoting its valorization as a potential candidate in treating oxidative stress-associated diseases.

Pharmacological and Biochemical evaluation of anti-arthritic activity of Justicia gendarussa extract in FCA induced arthritis in Wistar rats

The present study is carried out to evaluate anti-inflammatory and anti-arthritic potential of Justicia gendarussa. Leaves and stem extracted with ethanol and chloroform. These extract is tested against in-vitro (HRBC membrane stabilization method and Inhibition of protein denaturation method) and in-vivo (Carrageenan induced paw edema model) anti-inflammatory models. To assess the anti-arthritic activity, FCA induced arthritis model is used. Assessment of arthritis is done by paw volume, joint diameter, body weight, biochemical parameters, hematological parameters (Hb, RBC, WBC, ESR). The effect of in-vitro anti-inflammatory model depends on concentration. Both test extract and standard Diclofenac sodium has been shown concentration dependent effect. The maximum anti-inflammatory effect of the test extract achieved at 2000μg/ml. The test (JGLE, JGLC, JGSE) has been shown inhibition of paw edema induced by carrageenan at 50mg/kg body weight. The extract JGLE, JGLC, JGSE at 50mg/kg body weight and 100mg/kg body weight orally showed the significant (P< 0.05) and dose dependent inhibitory effect against FCA induced arthritis model. Diclofenac sodium 20mg/kg body weight orally is used as a standard. JGLE exhibit more significant and most promising anti-arthritic and anti-inflammatory effect than other extracts these effects support the traditional role of J. gendarussa in arthritis and other inflammatory condition.

Expression of CYP24A1 and other multiple sclerosis risk genes in peripheral blood indicates response to vitamin D in homeostatic and inflammatory conditions

Although genetic and epidemiological evidence indicates vitamin D insufficiency contributes to multiple sclerosis (MS), and serum levels of vitamin D increase on treatment with cholecalciferol, recent metanalyses indicate that this vitamin D form does not ameliorate disease. Genetic variation in genes regulating vitamin D, and regulated by vitamin D, affect MS risk. We evaluated if the expression of vitamin D responsive MS risk genes could be used to assess vitamin D response in immune cells. Peripheral blood mononuclear cells (PBMCs) were isolated from healthy controls and people with MS treated with dimethyl fumarate. We assayed changes in expression of vitamin D responsive MS risk (VDRMS) genes in response to treatment with 25 hydroxy vitamin D in the presence or absence of inflammatory stimuli. Expression of CYP24A1 and other VDRMS genes was significantly altered in PBMCs treated with vitamin D in the homeostatic and inflammatory models. Gene expression in MS samples had similar responses to controls, but lower initial expression of the risk genes. Vitamin D treatment abrogated these differences. Expression of CYP24A1 and other MS risk genes in blood immune cells indicate vitamin D response and could enable assessment of immunological response to vitamin D in clinical trials and on therapy.

Malyngamide F Possesses Anti-Inflammatory and Antinociceptive Activity in Rat Models of Inflammation

Objective. Inflammation and pain are involved in the pathophysiology of various clinical conditions. This investigation aims to probe the analgesic and anti-inflammatory activity of Maltoamide F. Methods. The possible toxicity of Maltoamide F was evaluated by an acute toxicity test. To assess the anti-inflammatory and antinociceptive effects of Maltoamide F on rats, the models of carrageenan-caused paw edema, xylene-induced ear edema, arachidonic-acid- (AA-) induced ear edema, formalin-caused plantar edema, and cotton-pellet-induced granuloma were established. Levels of TNF-α, PGE-2, and IL-6 were detected by enzyme-linked immunosorbent assay (ELISA). Results. Maltoamide F was safe at oral doses of 1–10 mg/kg for rats. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) notably reduced carrageenan-induced edema percentage of paws in rats and decreased levels of PGE-2, IL-6, and TNF-α in homogenates of foot tissues. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) reduced levels of PGE-2, IL-6, and TNF-α in foot tissues of formalin-induced rats. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) repressed AA-induced increase of ear thickness in rats and reduced levels of PGE-2, IL-6, and TNF-α in homogenates of ear tissues. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) reduced xylene-induced weight of ear edema in rats and reduced levels of PGE-2, IL-6, and TNF-α in homogenates of ear tissues. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) reduced levels of PGE-2, IL-6, and TNF-α in homogenates of cotton ball granuloma of cotton-pellet-induced rats. Conclusions. Maltoamide F possessed anti-inflammatory and analgesic activity in inflammatory models of rats.