Activation Of Cyclooxygenase-2 Research Articles

Current challenges for therapy of comorbid patients: a new look at celecoxib. A review

The use of non-steroidal anti-inflammatory drugs (NSAIDs) for a wide range of diseases is increasing, in part due to an increasing elderly population. Elderly patients are more vulnerable to adverse drug reactions, including side effects and adverse effects of drug-drug interactions, often occurring in this category of patients due to multimorbidity and polypharmacy. One of the most popular NSAIDs in the world is celecoxib. It is a selective cyclooxygenase (COX)-2 inhibitor with 375 times more COX-2 inhibitory activity than COX-1. As a result, celecoxib has a better gastrointestinal tract safety profile than non-selective NSAIDs. Gastrointestinal tolerance is an essential factor that physicians should consider when selecting NSAIDs for elderly patients. Celecoxib can be used in a wide range of diseases of the musculoskeletal system and rheumatological diseases, for the treatment of acute pain in women with primary dysmenorrhea, etc. It is also increasingly used as part of a multimodal perioperative analgesia regimen. There is strong evidence that COX-2 is actively involved in the pathogenesis of ischemic brain damage, as well as in the development and progression of neurodegenerative diseases, such as Alzheimer's disease. NSAIDs are first-line therapy in the treatment of acute migraine attacks. Celecoxib is well tolerated in patients with risk factors for NSAID-associated nephropathy. It does not decrease the glomerular filtration rate in elderly patients and patients with chronic renal failure. Many meta-analyses and epidemiological studies have not confirmed the increased risk of cardiovascular events reported in previous clinical studies and have not shown an increased risk of cardiovascular events with celecoxib, irrespective of dose. COX-2 activation is one of the key factors contributing to obesity-related inflammation. Specific inhibition of COX-2 by celecoxib increases insulin sensitivity in overweight or obese patients. Combination therapies may be a promising new area of treatment for obesity and diabetes.

Dihydroartemisinin modulated arachidonic acid metabolism and mitigated liver inflammation by inhibiting the activation of 5-LOX and COX-2

BackgroundDihydroartemisinin (DHA), a derivative of Artemisia annua, has been shown to possess anti-inflammatory properties. Besides, Yes-associated protein 1 (YAP1) plays a crucial role in maintaining liver homeostasis. MethodsThis study used Yap1Flox/Flox, Albumin-Cre mice with hepatocyte-specific Yap1 knockout (referred to as Yap1LKO) and their control mice (Yap1Flox/Flox, referred to as Yap1Flox). The effect of Yap1 on lipid metabolism homeostasis was investigated through non-targeted metabolomic analysis of mouse liver. Subsequently, DHA was administered to Yap1LKO mice to assess its potential as a treatment. Liver pathology was evaluated via H&E staining, and the levels of AST, ALT, and TG were quantified using biochemical assays. The contents of arachidonic acid (AA), prostaglandin E1 (PGE1), and leukotrienes (LT) in the liver were measured using ELISA, while the protein expressions of PLIN2, 5-lipoxygenase (5-LOX), and cyclooxygenase-2 (COX-2) were analyzed through IHC staining. ResultsHepatocyte-specific Yap1 knockout activated the AA metabolic pathway, resulting in increased elevated levels of AA, PGE1, and LT levels, along with inflammatory cytokine infiltration. DHA mitigated the elevation of metabolites such as PGE1 and LT caused by the AA metabolic pathway activation by down-regulating the levels of COX-2 and 5-LOX in the liver of Yap1LKO mice. Moreover, it alleviated the accumulation of lipid vacuoles and reduced triglyceride (TG) and perilipin-2 (PLIN2) levels in the liver of Yap1LKO mice. ConclusionsExcessively low YAP1 expression induces liver inflammation and disturbances in lipid metabolism, whereas DHA modulated AA metabolism and mitigated liver inflammation by inhibiting the activation of 5-LOX and COX-2.

Quantification of COX-2 Level in Alzheimer's Disease Patients to Develop Potential Blood-Based Biomarker for Early Diagnosis and Therapeutic Target.

Alzheimer's disease (AD) is a progressive neurodegenerative disease and symptoms develop gradually over many years. The current direction for medication development in AD is focused on neuro-inflammation and oxidative stress. Amyloid-β (Aβ) deposition activates microglia leading to neuro-inflammation and neurodegeneration induced by activation of COX-2 via NFκB p50 in glioblastoma cells. The study aimed to evaluate the concentration of COX-2 and NFκB p50 in serum of AD, mild cognitive impairment (MCI), and geriatric control (GC) and to establish a blood-based biomarker for early diagnosis and its therapeutic implications. Proteins and their mRNA level in blood of study groups were measured by surface plasmon resonance (SPR) and quantitative polymerase chain reaction (qPCR), respectively. The level of protein was further validated by western blot. The binding study of designed peptide against COX-2 by molecular docking was verified by SPR. The rescue of neurotoxicity by peptide was also checked by MTT assay on SH-SY5Y cells (neuroblastoma cell line). Proteins and mRNA were highly expressed in AD and MCI compared to GC. However, COX-2 decreases with disease duration. The peptide showed binding affinity with COX-2 with low dissociation constant in SPR and rescued the neurotoxicity of SH-SY5Y cells by decreasing the level of Aβ, tau, and pTau proteins. It can be concluded that COX-2 protein can serve as a potential blood-based biomarker for early detection and can be a good platform for therapeutic intervention for AD.

Neutrophil extracellular traps promote MASH fibrosis by metabolic reprogramming of HSC.

Metabolic dysfunction-associated steatohepatitis (MASH) fibrosis is a reversible stage of liver disease accompanied by inflammatory cell infiltration. Neutrophils extrude a meshwork of chromatin fibers to establish neutrophil extracellular traps (NETs), which play important roles in inflammatory response regulation. Our previous work demonstrated that NETs promote HCC in MASH. However, it is still unknown if NETs play a role in the molecular mechanisms of liver fibrosis. Following 12 weeks of Western diet/carbon tetrachloride, MASH fibrosis was identified in C57BL/6 mice with increased NET formation. However, NET depletion using DNase I treatment or mice knocked out for peptidyl arginine deaminase type IV significantly attenuated the development of MASH fibrosis. NETs were demonstrated to induce HSCs activation, proliferation, and migration through augmented mitochondrial and aerobic glycolysis to provide additional bioenergetic and biosynthetic supplies. Metabolomic analysis revealed markedly an altered metabolic profile upon NET stimulation of HSCs that were dependent on arachidonic acid metabolism. Mechanistically, NET stimulation of toll-like receptor 3 induced cyclooxygenase-2 activation and prostaglandin E2 production with subsequent HSC activation and liver fibrosis. Inhibiting cyclooxygenase-2 with celecoxib reduced fibrosis in our MASH model. Our findings implicate NETs playing a critical role in the development of MASH hepatic fibrosis by inducing metabolic reprogramming of HSCs through the toll-like receptor 3/cyclooxygenase-2/cyclooxygenase-2 pathway. Therefore, NET inhibition may represent an attractive treatment target for MASH liver fibrosis.

Magnolia kobus DC leaf ethanol extract alleviated lipopolysaccharide-induced acute lung inflammation by suppressing NF-κB and Nrf2 signaling

Introduction: Magnolia kobus DC has been used as herbal medicine to treat coughs and is known to exert biological effects such as anti-inflammatory, antioxidant, and antibacterial properties. We aimed to define the pharmacological effects of M. kobus leaf ethanol extract (MLEE) on acute lung inflammation and explore the underlying mechanisms of action. Methods: For in vitro investigations, RAW 264.7 cells were pretreated with MLEE (1, 10, and 100 μg/mL) and stimulated with lipopolysaccharide (LPS). For in vivo investigations, BALB/c mice were intratracheally administered with LPS for 24 hours after injection of MLEE (0.3, 3, and 30 mg/kg). Hematoxylin and eosin staining was used for histopathology analysis of lung tissue. The phytochemical constituents of MLEE were analyzed using high-performance liquid chromatography. Results: In RAW 264.7 cells, MLEE reduced the activation of the inflammatory mediators (inducible nitric oxide synthase and cyclooxygenase-2) and the nuclear translocation of nuclear factor (NF)-κB and nuclear factor erythroid-2-related factor 2 (Nrf2). The intraperitoneal injection of MLEE (30 mg/kg) attenuated interstitial edema and immune cell infiltration in LPS-induced acute lung inflammation. MLEE also inhibited the activation of cyclooxygenase-2, NF-κB, and Nrf2 in the lung tissue. Conclusion: Taken together, MLEE exerted an anti-inflammatory effect by inhibiting inflammatory and oxidative mediators on acute lung inflammation suggesting that it might be used as a natural drug for treating acute lung inflammatory diseases.

Ginsenoside Rh2 and its octyl ester derivative inhibited invasion and metastasis of hepatocellular carcinoma via the c-Jun/COX2/PGE2 pathway

Liver cancer is a topical global health issue. The treatment of liver cancer meets significant challenges in the high recurrence rate and invasive incidence. Therefore, the treatment strategies that target epithelial-mesenchymal transition (EMT) induced by cyclooxygenase 2 (COX2)/ prostaglandin E2 (PGE2) pathway have become epidemic. Ginsenoside Rh2 has been proved to inhibit the EMT. However, the underlying mechanisms remain unclear. Moreover, the octyl ester derivative of Rh2 (Rh2-O) exhibited superior anti-proliferative and immunomodulatory effects than Rh2 in our previous researches, which indicated that Rh2-O might also exert inhibitory effects on invasion and metastasis. The aim of current study is to explore the inhibitory effects of Rh2 and Rh2-O on invasion and metastasis of hepatocellular carcinoma, and to investigate whether these effects are dependent on the c-Jun/COX2/PGE2 pathway. The Huh-7 liver cancer cells and the H22 tumor-bearing mice were treated with Rh2 and Rh2-O. In this paper, the inhibitory effects of Rh2 and Rh2-O on invasion and metastasis were tested by wound healing, trans-well assay and tumor-bearing mice, and the involvement of c-Jun/COX2/PGE2 pathway were verified by exogenous PGE2, activation of COX2 and overexpression of c-Jun. The results showed that Rh2 and Rh2-O could efficiently inhibit the invasion and metastasis in a dose-dependent manner (p<0.05). And the Rh2-O showed stronger effects than Rh2. Moreover, the exogenous PGE2, activation of COX2 by exogenous LPS and the overexpression of c-Jun by transfection all reversed the inhibitory effects of Rh2 and Rh2-O on metastasis or EMT (p<0.05). Rh2 and Rh2-O could inhibit the invasion and metastasis of hepatocellular carcinoma via restraining the EMT, which was mediated by c-Jun/COX2/PGE2 pathway.

Genetic model of selective COX2 inhibition improve learning and memory ability and brain pathological changes in 5xFAD mouse

Alzheimer's disease (AD) is the most common neurodegenerative disease that leads to dementia. Its pathogenesis is very complex, and inflammation is one of the main pathophysiological mechanisms of AD. Non-steroidal anti-inflammatory drugs (NSAIDs), which mainly target cyclooxygenase (COX) activity, are used to reduce the risk of AD, but several side effects limit their application. Here we assess the effect of Cyclooxygenase-2 (COX2) catalytic activity on learning ability and AD pathology using 5x Familial Alzheimer's Disease (FAD) mice with COX2 inhibition (5xFAD/COX2 KO), 5xFAD mice with cyclooxygenase inactivation of COX2 (5xFAD/COX2 Y385F), and 5xFAD mice with peroxidase (POX) inactivation of COX2 (5xFAD/COX2) H374Y), respectively. Our results indicate that learning ability of COX2 KO and mutants is improved compared to 5xFAD mice, further investigations show that Aβ depositions are reduced, microglia and astrocytes homeostasis are changed in COX2 KO and mutants. Especially, there is more responsive microglia in the brain of 5xFAD/COX2 Y385F mice, and Aβ depositions are more effectively cleaned at old age. Taken together, these results identify a role of COX2 Y385F in regulating microglia function and may have important implications for future treatment of AD.

Etoricoxib nanostructured lipid carriers attenuate inflammation by modulating Cyclooxygenase-2 signaling and activation of nuclear factor-κB-p65 pathways in radiation-induced acute cardiotoxicity in rats

The current investigation aimed to explore the potential of etoricoxib nanostructured lipid carriers (ET-NLCs) as an anti-inflammatory drug in radiation-exposed rats, with a focus on assessing its efficacy in reducing inflammation while minimizing cardiac toxicity compared to conventional etoricoxib (ET) treatment. The ET-NLCs were prepared by the low-temperature melt emulsification solidification technique. Various techniques were employed to characterize the NLCs. Rats were exposed to gamma-irradiation (6 Gy) to induce cardiac inflammation and injury, followed by oral administration of ET or ET-NLCs (10 mg/kg b.w.) for 14 consecutive days. Results demonstrated a significant increase in the levels of malondialdehyde (MDA), cyclooxygenase-2 (COX-2), nuclear factor kappa-B p65 (NF-κB-p65), and poly ADP-ribose polymerase (PARP-1) in the heart tissues of gamma-irradiated rats compared to the control group. This increase was accompanied by a reduction in the activity of antioxidant enzymes. However, treatment with ET and ET-NLCs exhibited a positive impact on these levels. Interestingly, the efficacy of ET-NLCs in mitigating radiation-induced inflammation in heart tissue was found to be superior to that of ET. In conclusion, the study suggests that the utilization of NLCs as a drug delivery system for ET may not only enhance its therapeutic efficacy but also help reduce the cardiovascular risks associated with ET, specifically focused on individuals who had been exposed to gamma radiation. These findings open new avenues for further research in the development of effective and safer therapeutic strategies for managing inflammatory diseases and their impact on cardiovascular health.

Immunomodulatory Effect of Benincasa hispida Extract Fermented by Bacillus subtilis CJH 101 on RAW 264.7 Macrophages

This study aimed to confirm the immunomodulatory effects of fermented Benincasa hispida extract (HR1901-BS) on RAW 264.7 macrophages. B. hispida was fermented for 72 h using Bacillus subtilis CJH 101. To evaluate the efficacy of HR1901-BS in enhancing macrophage function, we measured and compared the levels of macrophage activation-related markers in HR1901-BS-stimulated RAW 264.7 cells. We evaluated the effects on nitric oxide (NO) production and the release of pro-inflammatory cytokines (interleukin IL-1β, IL-6, and tumor necrosis factor TNF-β) in the RAW 264.7 cell line. We confirmed that HR1901-BS affected macrophage activation by inducing a significantly high dose-dependent NO production and increasing the release of pro-inflammatory cytokines in RAW 264.7 macrophages. It also suggested that the immunomodulatory effect by HR1901-BS occurred mainly as a result of the activation of cyclooxygenase-2 (COX-2), inducible NO synthase (iNOS), and mitogen-activated protein kinase (MAPK)/nuclear factor-κB (NF-κB) pathways. Our results indicate that HR1901-BS is a promising candidate as a functional material that enhances immune responses through macrophage activation.

Translational Selenium Nanoparticles to Attenuate Allergic Dermatitis through Nrf2-Keap1-Driven Activation of Selenoproteins.

Easy recurrence and strong treatment side effects significantly limit the clinical treatment of allergic dermatitis. The human trace element selenium (Se) plays essential roles in redox regulation through incorporation into selenoproteins in the form of 21st necessary amino acid selenocysteine, to participates in the pathogenesis and intervention of chronic inflammatory diseases. Therefore, based on the safe and elemental properties of Se, we construct a facile-synthesis strategy for antiallergic selenium nanoparticles (LET-SeNPs), and scale up the production by employing a spray drying method with lactose (Lac-LET-SeNPs) or maltodextrin (Mal-LET-SeNPs) as encapsulation agents realizing larger scale production and a longer storage time. As expected, these as-prepared LET-SeNPs could effectively activate the Nrf2-Keap1 signaling pathway to enhance the expression of antioxidative selenoprotein at mRNA and protein levels, then inhibit mast cell activation to achieve efficient antiallergic activity. Interestingly, LET-SeNPs undergo metabolism to seleno-amino acids to promote biosynthesis of selenoproteins, which could suppress ROS-induced cyclooxygenase-2 (COX-2) and MAPKs activation to suppress the release of histamine and inflammatory cytokines. Allergic mouse and Macaca fascicularis models further confirm that LET-SeNPs could increase the Se content and selenoprotein expression in the skin, decrease mast cells activation and inflammatory cells infiltration, and finally exhibit the high therapeutic effects on allergic dermatitis. Taken together, this study not only constructs facile large-scale synthesis of translational Se nanomedicine to break through the bottleneck problem of nanomaterials but also sheds light on its application in the intervention and treatment of allergies.

Antioxidative and anti-inflammatory effect of ethanol extracts from Magnolia kobusDC on LPS-induced in vitroand in vivomodel

Abstract Magnolia kobusDC (M. kobus) has biological effects such as antioxidant, anti-inflammatory and antibacterial properties in its flower, bud, and stem bark extracts. Despite of diverse effectiveness of M. kobus, the pharmacological effects supporting inhibition of oxidation and inflammation on acute lung inflammation states have not been studied yet. The purpose of this study was to evaluate the pharmacological activity of M. kobusleaf ethanol extract (MkDE) by antioxidant and anti-inflammatory effects on acute lung inflammatory diseases. The antioxidant and anti-inflammatory effects of MkDE was evaluated using ROS detection assay, NO assay, qPCR, ELISA, and Western blot on LPS-induced macrophages. The therapeutic effect of MkDE was investigated in vivooxidative and inflammatory responses by histological observations, qPCR, ELISA, and Western blot using the LPS-induced acute lung inflammation mouse model. MkDE decreased ROS production and protein of Nrf2. MkDE showed a protective effect against H 2O 2as well as a decrease in NO production. MkDE reduced the levels of pro-inflammatory cytokines and chemokine, the activation of COX-2 and iNOS, and NF-κB translocation in LPS-induced macrophage. The intraperitoneal injection of MkDE showed to decrease the lung/body weights, infiltrated inflammatory cells into the lung alveoli, pro-inflammatory mediators, and serum released proteins. Furthermore, MkDE inhibited the activation of Nrf2, COX-2 and NF-κB in LPS-induced acute lung tissue. MkDE exhibits the pharmacological effect by reducing oxidative and inflammatory mediators on LPS-induced macrophages and acute lung inflammation mouse model. Taken together, MkDE might be used to treat acute lung disease.

Classic Phytochemical Antioxidant and Lipoxygenase Inhibitor, Nordihydroguaiaretic Acid, Activates Phospholipase D through Oxidant Signaling and Tyrosine Phosphorylation Leading to Cytotoxicity in Lung Vascular Endothelial Cells.

Nordihydroguaiaretic acid (NDGA), a dicatechol and phytochemical polyphenolic antioxidant and an established inhibitor of human arachidonic acid (AA) 5-lipoxygenase (LOX) and 15-LOX, is widely used to ascertain the role of LOXs in vascular endothelial cell (EC) function. As the modulatory effect of NDGA on phospholipase D (PLD), an important lipid signaling enzyme in ECs, thus far has not been reported, here we have investigated the modulation of PLD activity and its regulation by NDGA in the bovine pulmonary artery ECs (BPAECs). NDGA induced the activation of PLD (phosphatidic acid formation) in cells in a dose- and time-dependent fashion that was significantly attenuated by iron chelator and antioxidants. NDGA induced the formation of reactive oxygen species (ROS) in cells in a dose- and time-dependent manner as evidenced from fluorescence microscopy and fluorimetry of ROS and electron paramagnetic resonance spectroscopy of oxygen radicals. Also, NDGA caused a dose-dependent loss of intracellular glutathione (GSH) in BPAECs. Protein tyrosine kinase (PTyK)-specific inhibitors significantly attenuated NDGA-induced PLD activation in BPAECs. NDGA also induced a dose- and time-dependent phosphorylation of tyrosine in proteins in cells. NDGA caused in situ translocation and relocalization of both PLD1 and PLD2 isoforms, in a time-dependent fashion. Cyclooxygenase (COX) inhibitors were ineffective in attenuating NDGA-induced PLD activation in BPAECs, thus ruling out the activation of COXs by NDGA. NDGA inhibited the AA-LOX activity and leukotriene C4 (LTC4) formation in cells. On the other hand, the 5-LOX-specific inhibitors, 5, 8, 11, 14-eicosatetraynoic acid and kaempferol, were ineffective in activating PLD in BPAECs. Antioxidants and PTyK-specific inhibitors effectively attenuated NDGA cytotoxicity in BPAECs. The PLD-specific inhibitor, 5-fluoro-2-indolyl deschlorohalopemide (FIPI), significantly attenuated and protected against the NDGA-induced PLD activation and cytotoxicity in BPAECs. For the first time, these results demonstrated that NDGA, the classic phytochemical polyphenolic antioxidant and LOX inhibitor, activated PLD causing cytotoxicity in ECs through upstream oxidant signaling and protein tyrosine phosphorylation.

Smart Farming Enhances Bioactive Compounds Content of Panax ginseng on Moderating Scopolamine-Induced Memory Deficits and Neuroinflammation.

Korean ginseng (Panax ginseng) is a traditional herbal supplement known to have a variety of pharmacological activities. A smart farm system could provide potential standardization of ginseng seedlings after investigating plant metabolic responses to various parameters in order to design optimal conditions. This research was performed to investigate the effect of smart-farmed ginseng on memory improvement in a scopolamine-induced memory deficit mouse model and an LPS-induced microglial cell model. A smart farming system was applied to culture ginseng. The administration of its extract (S2 extract) under specific culture conditions significantly attenuated cognitive and spatial memory deficits by regulating AKT/ERK/CREB signaling, as well as the cortical inflammation associated with suppression of COX-2 and NLRP3 induced by scopolamine. In addition, S2 extract improved the activation of iNOS and COX-2, and the secretion of NO in LPS-induced BV-2 microglia. Based on the HPLC fingerprint and in vitro data, ginsenosides Rb2 and Rd were found to be the main contributors to the anti-inflammatory effects of the S2 extract. Our findings suggest that integrating a smart farm system may enhance the metabolic productivity of ginseng and provides evidence of its potential impact on natural bioactive compounds of medicinal plants with beneficial qualities, such as ginsenosides Rb2 and Rd.

Systematic review on combination pharmacotherapy: methodological rigor but no pharmacology.

Systematic review on combination pharmacotherapy: methodological rigor but no pharmacology.

Nickel and aluminium mixture elicit memory impairment by activation of oxidative stress, COX-2, and diminution of AChE, BDNF and NGF levels in cerebral cortex and hippocampus of male albino rats

This study evaluated nickel and aluminium-induced neurotoxicity, as a binary metal mixture. Twenty-eight male Sprague Dawley albino rats were weight-matched and divided into four groups. Group 1 (control) received deionized water. Group 2 and 3 received Aluminium (1 mg/kg) and Nickel (0.2 mg/kg) respectively, while Group 4 received Ni and Al mixture HMM three times a week orally for 90 days. Barnes maze tests was performed. Rats were sacrificed under pentobarbital anaesthesia, cerebral cortex and hippocampus were separated, and metal levels were measured using Atomic Absorption Spectroscopy (AAS). Malondialdehyde (MDA), catalase (CAT), glutathione content (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), Brain Derived Neurotrophic Factor (BDNF), Nerve growth factor NGF, cyclo-oxygenase COX-2 and Acetylcholinesterase (AChE) were assayed using ELISA kits. Ni/Al binary mixture exposed rats showed a shorter latency period (though not significant) of 3.21 ± 1.40 s in comparison to 3.77 ± 1.11 (Ni only) and 3.99 ± 1.16(Al only). Ni/Al mixture gp had the lowest levels of Mg in both the hippocampus and frontal cortex when compared with the individual metals. In the hippocampus Al only exposed rats significantly showed p < 0.05 higher iron and Ca levels in comparison to Ni/Al mixture. Al alone significantly showed p < 0.05 lower levels of Fe but higher Ca than the Ni/Al mixture group. Exposure to Al only showed lower levels of BDNF in comparison to Ni/Al combination, whereas Ni/Al mixture gp had lower levels of NGF in comparison to the individual metals in the hippocampus. In the frontal cortex Ni only, group showed significantly lower BDNF in comparison to Ni/Al mixture whereas the mixture showed significantly lower NGF when compared with Al only group. There were higher levels of COX-2 in the Ni/Al mixture than individual metal treated rats in both hippocampus and frontal cortex. AChE levels in the Ni/Al mixture group was higher than Ni or Al only gps in the hippocampus whereas in the frontal cortex, Ni/Al exposed rats showed significantly lower AChE levels in comparison to Al only group. Ni, Al and Ni/Al mixture exhibited memory impairment by activation of oxidative stress, COX-2, and diminution of AChE, BDNF and NGF levels in cerebral cortex and hippocampus. The BDNF-COX-2 AChE signalling pathway may be involved in the neurotoxicity of Ni and Al.

Aspirin mediates protection from diabetic kidney disease by inducing ferroptosis inhibition.

Diabetic kidney disease (DKD) progression can be predicted by abnormalities in the tubulointerstitial lining, and their treatment may be useful for preventing the disease. DKD is a progressive disease that contributes to renal tubular cell death, but its underlying mechanisms remain unclear. Ferroptosis is a novel term linked to lipid hydroperoxidation, and it plays an important role in the pathogenesis of DKD. Overexpression of cyclooxygenase-2 (COX2), an enzyme of the proximal tubule, causes cellular redox damage in DKD. It remains unknown whether COX2 exacerbates tubular damage by accelerating ferroptosis in the kidneys of diabetic mice. HK-2 cells cultured in high glucose exhibited ferroptosis, which was inhibited by ferroptosis inhibitors. Additionally, alterations in the sensors of ferroptosis metabolism, such as glutathione peroxidase 4 (GPX4) activity, lipid hydroperoxidation, reduced glutathione (GSH) levels and changes in mitochondrial morphology, were observed in high glucose-cultured HK-2 cells. Diabetic mice manifested tubular injury and deranged renal physiological indices, which were mitigated by ferrostatin-1 (Fer-1). Importantly, these perturbations were ameliorated by downregulating COX2. In addition, the increased COX2 was observed to be elevated in the daibetic kindney. To explore the relevance of COX2 to ferroptosis, HK-2 cells that knocked down from COX2 exhibited decreased ferroptosis sensitivity under high glucose conditions. In RSL-3-treated HK-2 cells, ferroptosis was improved by downregulating COX2 by treatment with aspirin, which was confirmed in high glucose-cultured HK-2 cells. Furthermore, the ferroptosis changes were also suppressed by decreasing COX2 in diabetic mice treated with aspirin, which retarded DKD progression. In conclusion, our results demonstrated that ferroptosis in renal tubular cells contributes to DKD development and that diabetes-related ferroptosis was inhibited through the downregulation of COX2 by aspirin, thus retarding the progression of DKD. Our findings support a renoprotective mechanism by which aspirin inhibits COX2 activation, identify COX2 as a potential target of ferroptosis, and establish that ferroptosis in renal tubular cells is an integral process in the pathogenesis of DKD regulated by COX2 expression profiles.

Papain ameliorates monocyte-platelet aggregate formation-mediated inflammatory responses in monocytes by upregulating miRNA-146a transcription.

MicroRNA-146a (miRNA-146a) is a nuclear factor κB (NF-κB)-inducible and inflammation-sensitive miRNA, while papain elicits anti-inflammatory effects by inhibiting monocyte-platelet aggregate (MPA)-mediated NF-κB pathway activation in monocytes. This study aimed to demonstrate the underlying effects of papain on MPA formation-initiated miRNA-146a expression and subsequent action in monocytes. THP-1 cells were exposed to papain, miRNA-146a mimic and inhibitor, NF-κB inhibitor (BAY11-7082), and platelets. Flow cytometry was used to measure the MPA formation-initiated monocyte activation. Levels of miRNA-146a, cyclooxygenase 2 (COX-2) mRNA and protein, and monocyte chemoattractant protein 1 (MCP-1) were analyzed in monocytes by RT-PCR, western blot, and ELISA. The NF-κB inhibitor and miRNA-146a mimics upregulated miRNA-146a expression but suppressed subsequent monocyte activation and expression of COX-2 and MCP-1. Following exposure to papain, the enhanced miRNA-146a transcription induced by MPA-formation was found along with significant inhibition of monocyte activation in a dose-dependent manner. However, the inhibitory tendency was significantly reversed by miRNA-146a inhibitors. Expression of COX-2 mRNA and protein, as well as MCP-1, was inhibited in monocytes by papain, whereas miRNA-146a inhibitors promoted COX-2 and MCP-1 expression. Our findings suggest that papain can inhibit MPA formation-mediated expression of inflammatory mediators in activated monocytes by upregulating miRNA-146a transcription.

Capric Acid Behaves Agonistic Effect on Calcitriol to Control Inflammatory Mediators in Colon Cancer Cells.

Inflammation prompts cancer development and promotes all stages of tumorigenesis. Calcitriol is a nutraceutical essential regulator for host health benefits. However, the influence of calcitriol on inflammatory mediators involved in cancer cells is not clear. This study aimed to assess the sensitivity of calcitriol alone and combined with capric acid, and identify the possible influence of calcitriol on inflammatory mediators. The colorectal cancer cell line (HCT116) was induced by LPS/TNF-α and the inflammation and metastatic mediators (IL-1β, IL-6, IL-17) were quantified in calcitriol and capric acid supplemented colon cancer cells. The mRNA and protein expression of MMP-2, NF-κB and COX-2 were quantified. The significant reduction in MMP-2 expression was confirmed at combination treatment by zymogram analysis. Our findings demonstrated the anti-inflammatory and anti-metastatic potentials of capric acid and calcitriol in individual exposure in a combination of human colon cancer cell lines (HCT116). These abilities may be due to the inhibition of COX-2 mediators and NF-κB transcription factor and reciprocally regulated MMP-2 and MMP-9 signaling pathways. These findings elucidate the activation of COX-2 and NF-κB via disruption of the cellular outer matrix could be considered a novel molecular target suitable for colorectal cancer therapy. This study confirmed that capric acid activates calcitriol sensitization in colon cancer cells and could be used as a successful supplement for intestinal diseases and colon aberrations.

Anoxia/reoxygenation enhances spontaneous contractile activity via TRPA1 channel and COX2 activation in isolated rat whole bladder.

Bladder ischemia/reperfusion is an important etiologic factor for overactive bladder disease. The occurrence of this disease is closely associated with enhanced spontaneous contractile activity of the bladder. However, the relationship between bladder ischemia/reperfusion and altered spontaneous bladder contractions (SBC) remains poorly studied. Therefore, the present study investigated whether ischemia/reperfusion affects SBC ex vivo. SBC was measured using isolated whole bladder preparations from rats. The preparations were exposed to anoxia (95% N2 ) for 0.5-6 h, followed by reoxygenation (95% O2 ) in Krebs medium. Anoxia followed by reoxygenation significantly enhanced the amplitude of SBC without affecting its frequency in an anoxic duration-dependent manner. The 5 h anoxia/reoxygenation-induced enhancement of SBC amplitude was completely suppressed by an antioxidant combination of L(+)-ascorbate/D, L-α-tocopherol, or N-acetyl cysteine. Additionally, the enhanced SBC amplitude was inhibited in a concentration-dependent manner by the nonselective TRP antagonist ruthenium red, or selective TRPA1 antagonists HC-030031 or AP-18. A similar inhibitory effect was obtained after repeated treatment with the TRPA1 agonist allyl isothiocyanate, as it induced acute desensitization of TRPA1 channels. Further, the enhanced SBC amplitude was significantly diminished by the nonselective cyclooxygenase (COX) inhibitor indomethacin or selective COX2 inhibitor NS-398, but not by the selective COX1 inhibitor SC-560 and 5-lipoxygenase inhibitor MK-886. The study findings reveal that the spontaneous contractile activity of the bladder is significantly enhanced in response to anoxia/reoxygenation, and that oxidative stress and activation of TRPA1 and COX2 (the resulting production of prostaglandins) are involved in the enhanced SBC activity.

Research progress on mechanism of Carthamus tinctorius in ischemic stroke therapy

Carthamus tinctorius is proved potent in treating ischemic stroke. Flavonoids, such as safflower yellow, hydroxysafflor yellow A(HSYA), nicotiflorin, safflower yellow B, and kaempferol-3-O-rutinoside, are the main substance basis of C. tinctorius in the treatment of ischemic stroke, and HSYA is the research hotspot. Current studies have shown that C. tinctorius can prevent and treat ischemic stroke by reducing inflammation, oxidative stress, and endoplasmic reticulum stress, inhibiting neuronal apoptosis and platelet aggregation, as well as increasing blood flow. C. tinctorius can regulate the pathways including nuclear factor(NF)-κB, mitogen-activated protein kinase(MAPK), signal transducer and activator of transcription protein 3(STAT3), and NF-κB/NLR family pyrin domain containing 3(NLRP3), and inhibit the activation of cyclooxygenase-2(COX-2)/prostaglandin D2/D prostanoid receptor pathway to alleviate the inflammatory development during ischemic stroke. Additionally, C. tinctorius can relieve oxidative stress injury by inhibiting oxidation and nitrification, regulating free radicals, and mediating nitric oxide(NO)/inducible nitric oxide synthase(iNOS) signals. Furthermore, mediating the activation of Janus kinase 2(JAK2)/STAT3/suppressor of cytokine signaling 3(SOCS3) signaling pathway and phosphoinositide 3-kinase(PI3 K)/protein kinase B(Akt)/glycogen synthase kinase-3β(GSK3β) signaling pathway and regulating the release of matrix metalloproteinase(MMP) inhibitor/MMP are main ways that C. tinctorius inhibits neuronal apoptosis. In addition, C. tinctorius exerts the therapeutic effect on ischemic stroke by regulating autophagy and endoplasmic reticulum stress. The present study reviewed the molecular mechanisms of C. tinctorius in the treatment of ischemic stroke to provide references for the clinical application of C. tinctorius.