Sinapic Acid Inhibits the IL-1β-Induced Inflammation via MAPK Downregulation in Rat Chondrocytes

Sinapic Acid Mitigates Pentylenetetrazol-induced Acute Seizures By Modulating the NLRP3 Inflammasome and Regulating Calcium/calcineurin Signaling: In Vivo and In Silico Approaches

Sinapic acid (SA) is a naturally occurring carboxylic acid found in citrus fruits and cereals. Recent studies have shown that SA has potential anti-seizure properties due to its anti-inflammatory, antioxidant, and anti-apoptotic effects. The present study investigated the neuroprotective role of SA at two different dosages in a pentylenetetrazol (PTZ)-induced acute seizure model. Mice were divided into six groups: normal control, PTZ, SA (20 mg/kg), SA (20 mg/kg) + PTZ, SA (40 mg/kg), and SA (40 mg/kg) + PTZ. SA was orally administered for 21 days, followed by a convulsive dose of intraperitoneal PTZ (50 mg/kg). Seizures were estimated via the Racine scale, and animals were behaviorally tested using the Y-maze. Brain tissues were used to assess the levels of GABA, glutamate, oxidative stress markers, calcium, calcineurin, (Nod)-like receptor protein-3 (NLRP3), interleukin (IL)-1β, apoptosis-associated speck-like protein (ASC), Bcl-2-associated death protein (Bad) and Bcl-2. Molecular docking of SA using a multistep in silico protocol was also performed. The results showed that SA alleviated oxidative stress, restored the GABA/glutamate balance and calcium/calcineurin signaling, downregulated NLRP3 and apoptosis, and improved recognition and ambulatory activity in PTZ-treated mice. In silico results also revealed that SA strongly interacts with the target proteins NLRP3 and ASC. Overall, the results suggest that SA is a promising antiseizure agent and that both doses of SA are comparable, with 40 mg/kg SA being superior in normalizing glutathione, calcium and IL-1β, in addition to calcineurin, NLRP3, ASC and Bad.

Ruscogenin attenuates cartilage destruction in osteoarthritis through suppressing chondrocyte ferroptosis via Nrf2/SLC7A11/GPX4 signaling pathway

Osteoarthritis (OA) is a common joint degenerative disease, and chondrocyte injury is the main pathological and physiological change. Ruscogenin (Rus), a bioactive compound isolated from Radix Ophiopogon japonicus, exhibits various pharmacological effects. The aim of this research was to test the role and mechanism of Rus on OA both in vivo and in vitro. Destabilized medial meniscus (DMM)-induced OA model was established in vivo and IL-1β-stimulated mouse chondrocytes was used to explore the role of Rus on OA in vitro. In vivo, Rus exhibited protective effects against DMM-induced OA model. Rus could inhibit MMP1 and MMP3 expression in OA mice. In vitro, IL-1β-induced inflammation and degradation of extracellular matrix were inhibited by Rus, as confirmed by the inhibition of PGE2, NO, MMP1, and MMP3 by Rus. Also, IL-1β-induced ferroptosis was suppressed by Rus, as confirmed by the inhibition of MDA, iron, and ROS, as well as the upregulation of GSH, GPX4, Ferritin, Nrf2, and SLC7A11 expression induced by Rus. Furthermore, the suppression of Rus on IL-1β-induced inflammation, MMPs production, and ferroptosis were reversed when Nrf2 was knockdown. In conclusion, Rus attenuated OA progression through inhibiting chondrocyte ferroptosis via Nrf2/SLC7A11/GPX4 signaling pathway.

Undenatured type II collagen and its role in improving osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease, affecting 32.5 million US adults or 242 million people worldwide. There is no cure for OA. Many animal and clinical trials showed that oral administration of undenatured type II collagen could significantly reduce the incidence of OA or alleviate the symptoms of articular cartilage. Type II collagen is an important component of cartilage matrix. This article reviewed research progress of undenatured type II collagen including its methods of extraction and preparation, structure and characterization, solubility, thermal stability, gastrointestinal digestive stability, its role in improving OA, and the mechanism of its action in improving OA. Type II collagen has been extensively explored for its potential in improving arthritis. Methods of extraction of type II collagen are inefficient and tedious. The method of limited enzymatic hydrolysis is mainly used to prepare soluble undenatured type II collagen (SC II). The solubility, thermal and gastrointestinal digestive stability of SC II are affected by the sources of raw material, pH, salt ions, and temperature. Oral administration of undenatured type II collagen improves OA, whereas its activity is affected by the sources, degree of denaturalization, intervention methods and doses. However, the influence of the structure of undenatured type II collagen on its activity and the mechanism are unclear. The findings in this review support that undenatured type II collagen can be used in the intervention or auxiliary intervention of patients with OA.

Sinapic acid alleviates 5-fluorouracil-induced nephrotoxicity in rats via Nrf2/HO-1 signalling

Fluoropyrimidine 5-fluorouracil (5-FU) is a DNA analogue broadly used in chemotherapy, though treatment-associated nephrotoxicity limits its widespread clinical use. Sinapic acid (SA) has potent antioxidant, anti-inflammatory, and anti-apoptotic effects, we investigated its protective effects against 5-FU-induced nephrotoxicity in a rat model. We designated four treatment groups each Group I (control) received five intraperitoneal saline injections (once daily) from days 17 to 21; Group II received five intraperitoneal injections of 5-FU (50 mg/kg/day) from days 17 to 21; Group III received an oral administration of SA (40 mg/kg) for 21 days and five intraperitoneal injections of 5-FU (50 mg/kg/day) from days 17 to 21; and Group IV received an oral administration of SA (40 mg/kg) for 21 days (n-six rats in each group). blood samples were collected on day 22 from each group. Animals were sacrificed and their kidneys removed, and instantly frozen. 5-FU caused oxidative stress, inflammation, and activation of the apoptotic pathway by upregulating Bax and Caspase-3 and downregulating Bcl-2. However, SA exposure reduced serum toxicity indicators, boosted antioxidant defences, and reduced kidney apoptosis, which was confirmed by histopathological analysis. Therefore, prophylactic administration of SA could inhibit 5-FU-induced renal injuries in rats via suppression of renal inflammation and oxidative stress, primarily through regulation of NF-κB and proinflammatory cytokines, inhibition of renal apoptosis, and restoration of tubular epithelial antioxidant activities and cytoprotective defences.

Overview of Anti-Inflammatory and Anti-Nociceptive Effects of Polyphenols to Halt Osteoarthritis: From Preclinical Studies to New Clinical Insights

Knee osteoarthritis (OA) is one of the most multifactorial joint disorders in adults. It is characterized by degenerative and inflammatory processes that are responsible for joint destruction, pain and stiffness. Despite therapeutic advances, the search for alternative strategies to target inflammation and pain is still very challenging. In this regard, there is a growing body of evidence for the role of several bioactive dietary molecules (BDMs) in targeting inflammation and pain, with promising clinical results. BDMs may be valuable non-pharmaceutical solutions to treat and prevent the evolution of early OA to more severe phenotypes, overcoming the side effects of anti-inflammatory drugs. Among BDMs, polyphenols (PPs) are widely studied due to their abundance in several plants, together with their benefits in halting inflammation and pain. Despite their biological relevance, there are still many questionable aspects (biosafety, bioavailability, etc.) that hinder their clinical application. This review highlights the mechanisms of action and biological targets modulated by PPs, summarizes the data on their anti-inflammatory and anti-nociceptive effects in different preclinical in vitro and in vivo models of OA and underlines the gaps in the knowledge. Furthermore, this work reports the preliminary promising results of clinical studies on OA patients treated with PPs and discusses new perspectives to accelerate the translation of PPs treatment into the clinics.

Sinapic acid ameliorates airway inflammation in murine ovalbumin-induced allergic asthma by reducing Th2 cytokine production

OBJECTIVE

Asthma is a chronic inflammatory airway disease associated with the airway narrowing and obstruction. Sinapic acid (SA), a hydroxycinnamic acid, possesses various pharmacological properties including antioxidant and anti-inflammatory activity. This research evaluated effects of different doses of SA on murine model of ovalbumin (OVA)-induced allergic asthma.

MATERIALS AND METHODS

Allergic asthma induced by sensitizing mice on days 1 and 14 by intraperitoneal injection of OVA. After initial sensitization, between days 21 and 23, mice were challenged for 30 min with an aerosol of 1 % (wt/vol) OVA. Treatment with dexamethasone (3 mg/kg) or SA (25, 50 or 100 mg/kg) were done by oral gavage on days 15-23. Inflammatory cells infiltration and interferon-γ (IFN-γ), interlukin-4 (IL-4), IL-5 and IL-13 levels were evaluated in the bronchoalveolar lavage fluid (BALF). Serum total and OVA-specific immunoglobulin E (IgE) and lung tissue nitric oxide (NO) levels were measured. Histological changes in lung tissue were examined by staining with hematoxylin and eosin (H&E) for cell infiltration, periodic acid-Schiff (PAS) for mucus production and Masson's trichrome for collagen deposition.

RESULTS

Treatment with SA significantly inhibited inflammatory cell infiltration, enhanced IFN-γ level and decreased IL-4, IL-5 and IL-13 levels in BALF. Serum total and OVA-specific IgE levels and NO level in lung tissue were significantly reduced by SA. Histological examination demonstrated that SA significantly attenuated inflammatory cell infiltration and mucus-producing cells in the lung.

CONCLUSION

These data suggest that SA may be a new therapeutic potential to treat allergic asthma through suppressing T-helper 2 immune responses.

Sinapicacid Inhibits Group IIA Secretory Phospholipase A2 and Its Inflammatory Response in Mice

Human Group IIA secreted phospholipase A₂ (sPLA₂-IIA) enzyme plays a crucial role in several chronic inflammatory diseases such asasthma, atherosclerosis, gout, bronchitis, etc. Several studies showed that the antioxidants exert an anti-inflammatory function by inhibiting the sPLA₂-IIA enzyme. Hence, the present study evaluated an antioxidant molecule, sinapic acid, for sPLA₂-IIA inhibition as an anti-inflammatory function. Initially, the antioxidant efficacy of sinapic acid was evaluated, and it showed greater antioxidant potency. Further, sinapic acid inhibited 94.4 ± 4.83% of sPLA₂-IIA activity with an IC₅₀ value of 4.16 ± 0.13 µM. The mode of sPLA₂-IIA inhibition was examined by increasing the substrate concentration from 30 to 120nM and the calcium concentration from 2.5 to 15 mM, which did not change the level of inhibition. Further, sinapic acid altered the intrinsic fluorescence and distorted the far UltraViolet Circular Dichroism (UV-CD) spectra of the sPLA₂-IIA, indicating the direct enzyme-inhibitor interaction. Sinapic acid reduced the sPLA₂-IIA mediated hemolytic activity from 94 ± 2.19% to 12.35 ± 2.57% and mouse paw edema from 171.75 ± 2.2% to 114.8 ± 1.98%, demonstrating the anti-inflammatory efficiency of sinapic acid by in situ and in vivo methods, respectively. Finally, sinapic acid reduced the hemorrhagic effect of Vipera russelli venom hemorrhagic complex-I (VR-HC-I) as an anti-hemorrhagic function. Thus, the above experimental results revealed the sinapic acid potency to be an antioxidant, anti-inflammatory and anti-hemorrhagic molecule, and therefore, it appears to be a promising therapeutic agent.

Modulation of Hair Growth Promoting Effect by Natural Products

A large number of people suffer from alopecia or hair loss worldwide. Drug-based therapies using minoxidil and finasteride for the treatment of alopecia are available, but they have shown various side effects in patients. Thus, the use of new therapeutic approaches using bioactive products to reduce the risk of anti-hair-loss medications has been emphasized. Natural products have been used since ancient times and have been proven safe, with few side effects. Several studies have demonstrated the use of plants and their extracts to promote hair growth. Moreover, commercial products based on these natural ingredients have been developed for the treatment of alopecia. Several clinical, animal, and cell-based studies have been conducted to determine the anti-alopecia effects of plant-derived biochemicals. This review is a collective study of phytochemicals with anti-alopecia effects, focusing mainly on the mechanisms underlying their hair-growth-promoting effects.

Sinapic Acid Attenuates Rheumatoid Arthritis Through Reducing Inflammation and Oxidative Stress by Downregulating IκB Kinase

Sinapic acid (SA) was reported to protect against inflammation in various types of diseases. However, the role of SA in rheumatoid arthritis remains unclear. This study was designed to investigate the role of SA on rheumatoid arthritis. Rheumatoid arthritis mouse model was established by collagen immunization [collagen-induced arthritis (CIA)]. Histological analysis of articular cartilage tissue was carried out by hematoxylin and eosin (H&E) staining. Serum concentrations of tumor necrosis factor alpha and interleukin 6 were determined through enzyme-linked immunosorbent assay (ELISA). Oxidative damage indexes such as superoxide dismutase activity, malondialdehyde detection, glutathione detection, and catalase were determined by biochemical analysis. The protein levels of related genes were determined using Western blot. In CIA model, SA treatment attenuated paw swelling and clinical score of arthritis, attenuated articular cartilage tissues edema and infiltration of inflammatory cells, suppressed inflammatory cytokines release, and attenuated oxidative damage indexes. Mechanically, SA suppressed immune responses through inhibiting the IκB kinase (IKKs). SA attenuates rheumatoid arthritis through reducing inflammation and oxidative stress by downregulating IKKs.

Ebselen, a multi-target compound: its effects on biological processes and diseases

Ebselen is a well-known synthetic compound mimicking glutathione peroxidase (GPx), which catalyses some vital reactions that protect against oxidative damage. Based on a large number of in vivo and in vitro studies, various mechanisms have been proposed to explain its actions on multiple targets. It targets thiol-related compounds, including cysteine, glutathione, and thiol proteins (e.g., thioredoxin and thioredoxin reductase). Owing to this, ebselen is a unique multifunctional agent with important effects on inflammation, apoptosis, oxidative stress, cell differentiation, immune regulation and neurodegenerative disease, with anti-microbial, detoxifying and anti-tumour activity. This review summarises the current understanding of the multiple biological processes and molecules targeted by ebselen, and its pharmacological applications.

Serumal Lipidomics Reveals the Anti-inflammatory Effect of Flax Lignans and Sinapic Acid in High-Fat-Diet-Fed Mice

Flax lignans (SDG) and sinapic acid (SA) both have the function of antioxidation and anti-inflammation. However, previous studies have focused mainly on biochemical measurements, gene expression analysis, and clinical assessments. There are limited studies that systematically reveal the underlying mechanism of the anti-inflammation effect of SDG or SA from the lipidomic point of view. Herein, the integrated lipidomic profiling platform was used for the analysis of free fatty acids (FFAs), phospholipids (PLs), triacylglycerols (TAGs), and oxylipins in high-fat (HF)-diet-fed mice after SDG or SA administration. Dietary supplementation of SDG or SA downregulated the levels of total TAGs and FFAs in the ApoE^-/- mice model. Furthermore, 28 potential lipids were screened out and considered as key evaluation factors to understand the anti-inflammation function and mechanism of SDG and SA. The results indicated that the anti-inflammatory effect of SDG and SA was principally exerted via regulation of lipid homeostasis.

Anti-inflammatory and analgesic properties of Moroccan medicinal plants: Phytochemistry, in vitro and in vivo investigations, mechanism insights, clinical evidences and perspectives

Moroccan medicinal plants exhibit several pharmacological properties such as antimicrobial, anticancer, antidiabetic, analgesic, and anti-inflammatory effects, which are related to the presence of numerous bioactive compounds, including phenolic acids, flavonoids, and terpenoids. In the present review, we systematically evaluate previously published reports on the anti-inflammatory and analgesic effects of Moroccan medicinal plants. The in vitro investigations revealed that Moroccan medicinal plants inhibit several enzymes related to inflammatory processes, whereas in vivo studies noted significant anti-inflammatory and analgesic effects as demonstrated using different experimental models. Various bioactive compounds exhibiting in vitro and in vivo anti-inflammatory and analgesic effects, with diverse mechanisms of action, have been identified. Some plants and their bioactive compounds reveal specific secondary metabolites that possess important anti-inflammatory effects in clinical investigations. Our review proposes the potential applications of Moroccan medicinal plants as sources of anti-inflammatory and analgesic agents.

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Anti-inflammatory and analgesic effects of Moroccan medicinal plants were highlighted.

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Chemical nature of Moroccan medicinal plants with anti-inflammatory and analgesic effects was reported.

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Insights into anti-inflammatory mechanisms of bioactive compounds were highlighted.

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Toxicological investigations of Moroccan medicinal plants were reviewed.

Sinapic Acid Reduces Oxidative Stress and Pyroptosis via Inhibition of BRD4 in Alcoholic Liver Disease

Alcoholic liver disease (ALD) is one of the main causes of death in chronic liver disease. Oxidative stress and pyroptosis are important factors leading to ALD. Bromodomain-containing protein 4 (BRD4) is a factor that we have confirmed to regulate ALD. As a phenolic acid compound, sinapic acid (SA) has significant effects in antioxidant, anti-inflammatory and liver protection. In this study, we explored whether SA regulates oxidative stress and pyroptosis through BRD4 to play a protective effect in ALD. Male C57BL/6 mice and AML-12 cells were used for experiments. We found that SA treatment largely abolished the up-regulation of BRD4 and key proteins of the canonical pyroptosis signalling in the liver of mice fed with alcohol, while conversely enhanced the antioxidant response. Consistantly, both SA pretreatment and BRD4 knockdown inhibited oxidative stress, pyroptosis, and liver cell damage in vitro. More importantly, the expression levels of BRD4 and pyroptosis indicators increased significantly in ALD patients. Molecule docking analysis revealed a potent binding of SA with BRD4. In conclusion, this study demonstrates that SA reduces ALD through BRD4, which is a valuable lead compound that prevents the ALD process.

Changes of type II collagenase biomarkers on IL-1β-induced rat articular chondrocytes

Osteoarthritis (OA) is characterized by progressive degeneration of cartilage, formation of cartilage at the cartilage edge, and remodeling of the subchondral bone. Pro-inflammatory cytokines [e.g., interleukin (IL)-1β] that induce inflammation and promote chondrocyte damage induce OA. Currently, the diagnosis of OA is commonly based on imaging examinations (e.g., X-ray) and evaluations of clinical symptoms; however, biomarkers that can effectively diagnose OA are currently not available. By studying the mechanism underlying OA cartilage injury and changes in the concentrations of the biomarkers procollagen type II carboxy-terminal propeptide (PIICP), collagen type-II C-telopeptide fragments (CTX-II), and type II collagen cleavage neoepitope (C2C) during pathogenesis, the present study established a theoretical basis for the evaluation and early diagnosis of OA. In an experiment, 10 ng/ml IL-1β was used to the treat chondrocyte-induced OA models in vitro for 0, 12, 24 and 48 h. Western blotting was used to detect the expression levels of matrix metalloproteinase (MMP)-3, MMP-13, and inducible nitric oxide synthase (iNOS) protein at each time-point. The concentrations of CTX-II, C2C, and PIICP in the cell culture supernatant were detected by ELISA kit. A biochemical kit was used to detect changes of nitric oxide (NO) in the cell culture supernatant. In addition, chondrocytes were treated with 10 ng/ml IL-1β for 0, 30, 60 and 90 min and the translocation and phosphorylation of the NF-κB pathway were investigated by western blotting. Following IL-1β stimulation, the NF-κB pathway was activated to increase the expression levels of MMPs and iNOS synthesis downstream of the pathway, resulting in an increased degradation of type II collagen (Col II). To sum up, pro-inflammatory IL-1β induced an OA chondrocyte model. During the development of OA, the expression of MMPs and NO increased and Col II was degraded.

Sinapic Acid Inhibits IL-1β-Induced Apoptosis and Catabolism in Nucleus Pulposus Cells and Ameliorates Intervertebral Disk Degeneration

Background

Low back pain (LBP) is a very common condition and leads to serious pain, disability, and price tag all over the world. Intervertebral disk degeneration (IDD) is one of the major reasons that contributed to LBP. The levels of interleukin 1 beta (IL-1β) increase significantly in degenerative disks. IL-1β also accelerates IDD. Sinapic acid (SA) has the effect of anti‐inflammatory, antioxidant and antimicrobial. However, the effect of SA on IDD has never been studied. Therefore, the aim of this study was to figure out whether SA has protective effect on nucleus pulposus (NP) cells and further explore the possible underlying mechanism.

Methods

The nucleus pulposus (NP) tissues of rats were collected and cultured into NP cells. The NP cells were stimulated by IL-1β and treated with SA. In vitro treatment effects were evaluated by ELISA, Western blot assay, immunofluorescence, TUNEL method and real-time PCR. We conducted percutaneous needle puncture in the rat tail to build intervertebral disk degeneration model and treated rats with SA. In vivo treatment effects were evaluated by hematoxylin and eosin (HE) and safranin O (SO) staining and magnetic resonance imaging (MRI) method.

Results

Our results showed that SA not only inhibited apoptosis but also suppressed inflammatory mediators including nitric oxide (NO), prostaglandin E2 (PGE2), cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS) interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in IL-1β-stimulated NP cells. As to extracellular matrix (ECM), SA could increase collagen II and aggrecan levels and reduce the expression of MMP13 and ADAMTS5 during the stimulation of IL-1β. Furthermore, SA could activate nuclear factor‐erythroid 2‐related factor‐2 (Nrf2) to inhibit nuclear factor κB (NF‐κB) induced by IL‐1β. Nrf2 knockdown partly reduced the protective effect of SA on NP cells. Correspondingly, SA ameliorated IDD by promoting Nrf2 expression. In vivo results also showed that SA could delay the progression of IDD.

Conclusion

In conclusion, we demonstrated that SA could protect the degeneration of NP cells and revealed the underlying mechanism of SA on Nrf2 activation in NP cells.

Aminoguanidine inhibits IL-1β-induced protein expression of iNOS and COX-2 by blocking the NF-κB signaling pathway in rat articular chondrocytes

Osteoarthritis is a chronic joint disease which has a serious impact on the health and quality of life of affected humans and animals. As an inhibitor of inducible nitric oxide synthase (iNOS), aminoguanidine (AG) displays anti-inflammatory effects. The purpose of the present study was to investigate the effect of AG on the expression of iNOS and cyclooxygenase-2 (COX-2), and the activity of the NF-κB signaling pathway in rat chondrocytes stimulated by interleukin-1β (IL-1β). The viability of chondrocytes treated with AG (0.3, 1 or 3 mM) alone was determined using a Cell Counting Kit-8 assay. Subsequently, the chondrocytes were treated with either 10 ng/ml IL-1β alone, or co-treated with increasing concentrations of AG (0.3, 1 or 3 mM) and 10 ng/ml IL-1β. The protein levels of COX-2, iNOS, phosphorylated (p)-p65, p65, p-NF-κβ inhibitor α (IκBα), IκBα, p-inhibitor of NF-κβ-β (IKKβ) and IKKβ were evaluated by western blotting. NF-κB translocation was determined by immunofluorescence analysis. Western blotting and reverse transcription-quantitative PCR were used to detect expression levels of relevant proteins/genes. The results suggested that the inhibitory effect of AG on the protein and gene expression levels of iNOS and COX-2 in IL-1β-treated chondrocytes was dose-dependent. In addition, AG decreased the level of phosphorylation of IKKβ, IκBα and NF-κB p65, the degradation of IKKβ, IκBα and p65, and the translocation of NF-κB in IL-1β-stimulated chondrocytes. The most significant inhibitory effect of AG was observed at a concentration of 1 mM. Therefore, the present study suggested that AG may serve as a potential agent to reduce the inflammatory response of chondrocytes stimulated by IL-1β.

Semen Brassicae reduces thoracic aortic remodeling, inflammation, and oxidative damage in spontaneously hypertensive rats

BACKGROUND

This study aimed to evaluate the role of Semen Brassicae, a common Traditional Chinese Medicine, in the treatment of hypertension.

METHODS

Spontaneously hypertensive rats (SHRs) were divided into five groups and were gavaged with either distilled water, water-decocted solution from Semen Brassicae (0.5, 1 or 2 g/kg), or nifedipine (2.7 mg/kg). Normal rats gavaged with distilled water were used as a control. Systolic (SBP) and diastolic blood pressure (DBP) were measured using a non-invasive method. After 8 weeks of administration, all animals were anesthetized. Abdominal aortic serum was collected to measure serum factors; the thoracic aorta was collected for hematoxylin and eosin staining and western blot analysis.

RESULTS

Both SBP and DBP were significantly decreased after Semen Brassicae treatment. Endothelin-1 and angiotensin II levels in abdominal aortic serum, as well as the levels of inflammatory factors interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha, were significantly decreased after Semen Brassicae treatment. The wall thickness of the thoracic aorta was significantly reduced after Semen Brassicae treatment. Nitric oxide level and the activity of superoxide dismutase and glutathione peroxidase were significantly increased, and malondialdehyde level was significantly decreased in the abdominal aortic serum after Semen Brassicae treatment. Semen Brassicae treatment increased the levels of peroxisome proliferator-activated receptor gamma and IκB-α and decreased the levels of intercellular adhesion molecule 1, monocyte chemoattractant protein-1, von Willebrand factor, p-IκB-α and p-p65 NF-κB.

CONCLUSIONS

In conclusion, water-decocted solution from Semen Brassicae can decrease blood pressure, improve vascular remodeling, and attenuate oxidative stress and inflammation in SHRs.

Sinapic Acid Promotes Browning of 3T3-L1 Adipocytes via p38 MAPK/CREB Pathway

Sinapic acid is a plant-derived phenolic compound, which acts as an antioxidant, anticancer, and anti-inflammatory agent. Although sinapic acid is valuable in a variety of therapeutic applications, its role in the improvement of obesity-related metabolic disease is relatively unexplored. Brown-like adipocytes (beige adipocytes) are characterized by a high concentration of mitochondria and high expression of uncoupling protein 1 (UCP1), which has specific functions in energy expenditure and thermogenesis. This study assessed the browning effects of sinapic acid in 3T3-L1 adipocytes. We investigated the expression of beige marker genes in 3T3-L1 adipocytes treated with sinapic acid. Sinapic acid increased the expression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and UCP1. Sinapic acid also promoted mitochondrial biogenesis by dose-dependently upregulating the oxygen consumption rate and enhancing the expression of representative subunits of oxidative phosphorylation complexes. In addition, treatment with p38 mitogen-activated protein kinase (MAPK) inhibitor and cAMP response element binding (CREB) inhibitor decreased the expressions of genes associated with thermogenesis, mitochondrial biogenesis, and oxidative phosphorylation. In summary, sinapic acid initiates browning 3T3-L1 adipocytes via the p38 MAPK/CREB signaling pathway. Thus, sinapic acid may have potential therapeutic implication in obesity.

Role of iNOS in osteoarthritis: Pathological and therapeutic aspects

Accumulating evidence suggests that inflammation has a key role in the pathogenesis of osteoarthritis (OA). Nitric oxide (NO) has been established as one of the major inflammatory mediators in OA and drives many pathological changes during the development and progression of OA. Excessive production of NO in chondrocytes promotes cartilage destruction and cellular injury. The synthesis of NO in chondrocytes is catalyzed by inducible NO synthase (iNOS), which is thereby an attractive therapeutic target for the treatment of OA. A number of direct and indirect iNOS inhibitors, bioactive compounds, and plant-derived small molecules have been shown to exhibit chondroprotective effects by suppressing the expression of iNOS. Many of these iNOS inhibitors hold promise for the development of new, disease-modifying therapies for OA; however, attempts to demonstrate their success in clinical trials are not yet successful. Many plant extracts and plant-derived small molecules have also shown promise in animal models of OA, though further studies are needed in human clinical trials to confirm their therapeutic potential. In this review, we discuss the role of iNOS in OA pathology and the effects of various iNOS inhibitors in OA.

An Evaluation of the DNA-Protective Effects of Extracts from Menyanthes trifoliata L. Plants Derived from In Vitro Culture Associated with Redox Balance and Other Biological Activities

Menyanthes trifoliata L. is a valuable medical plant found in Europe, North America, and Asia, which grows on peat bogs and swamps. It has long been used in folk medicine as a remedy for various ailments. This is the first report to demonstrate the protective antioxidant and anti-inflammatory properties of aqueous methanolic extracts derived from the aerial parts (MtAPV) and roots (MtRV) of in vitro grown plants on human umbilical vein endothelial cells (HUVECs). It describes the influence of the tested extracts on the expression of antioxidant (HO-1, NQO1, NRF2, kEAP1, and GCLC) and inflammation-related genes (IL-1α, IL-1β, IL-6, TNF-α, and IFN-γ) in cells stimulated with H₂O₂ or LPS, respectively. In addition, M. trifoliata extracts were found to moderately affect the growth of certain bacterial and fungal pathogens, with the strongest antibacterial effect found against Pseudomonas aeruginosa and Enterococcus faecalis. M. trifoliata extracts demonstrated protective effects against mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) damage caused by ROS, decreasing the numbers of mtDNA lesions in the ND1 and ND2 genes and nDNA damage in the TP53 and HPRT1 genes and reducing cleavage in PARP1- and γ-H2A.X-positive cells. The root extract of in vitro M. trifoliata (MtRV) appears to have better anti-inflammatory, antioxidant, antimicrobial, and protective properties than the extract from the aerial part (MtAPV). These differences in biological properties may result from the higher content of selected phenolic compounds and betulinic acid in the MtRV than in the MtAPV extract.

Berberine inhibits the interleukin-1 beta-induced inflammatory response via MAPK downregulation in rat articular chondrocytes

Osteoarthritis (OA) is one of the most chronic degenerative arthritic diseases, which gradually results in chondrocyte changes, articular cartilage degeneration, subchondral bone sclerosis, joint pain, swelling, and dysfunction. Berberine (BBR) has various confirmed biological activities, such as anti-inflammatory and antioxidant activities. However, the effect of BBR on the production of inflammation-associated proteins, including inducible nitric oxide synthase (iNOS), cyclooxygenase (Cox)-2, metalloproteinases (MMPs), Collagen II, TNF-α, and IL-6 via the MAPK (mitogen-activated protein kinases) pathway in IL-1β-stimulated rat chondrocytes, has not yet been studied. Thus, the purpose of this study was to evaluate whether BBR would decrease the production of inflammation-associated proteins through the MAPK signal pathway. Rat chondrocytes were cultured and pretreated with BBR at different concentrations (0, 25, 50, and 100 μM) and then stimulated with or without IL-1β (10 ng/mL). The mRNA expression of iNOS, COX-2, MMP-3, MMP-13, TNF-α, and IL-6 was measured by real-time polymerase chain reaction (RT-PCR), and the protein expression of iNOS, COX-2, Collagen II, MMP-3,MMP-13, and MAPKs were measured by Western blotting. The results showed that the expression of iNOS, COX-2, MMP-3, MMP-13, TNF-α, and IL-6 increased in the IL-1β-treated group and BBR showed an ability to inhibit the elevated expression under the pretreatment. Furthermore, the IL-1β-induced downregulation of Collagen II could be ameliorated by BBR. Moreover, the expression of MAPKs was significantly decreased by BBR. These results demonstrated that BBR had the anti-catabolic and anti-inflammation abilities that were through the MAPKs in IL-1β-induced rat chondrocytes. These findings may provide a novel therapeutic choice for treatment of OA using BBR.

Peimine suppresses interleukin‑1β‑induced inflammation via MAPK downregulation in chondrocytes

Osteoarthritis (OA) is the most common type of degenerative joint disease and secreted inflammatory molecules serve a pivotal role in it. Peimine has been reported to have anti‑inflammatory activity. In order to investigate the potential therapeutic role of Peimine in OA, mouse articular chondrocytes were treated with IL‑1β and different doses of Peimine in vitro. The data revealed that Peimine not only suppressed IL‑1β‑induced production of nitric oxide (NO) and prostaglandin E2, but also reduced the protein levels of inducible NO synthase (iNOS) and cyclooxygenase‑2 (COX‑2). In addition, Peimine inhibited the IL‑1β‑induced mRNA expression of matrix metalloproteinase (MMP)‑1, MMP‑3, MMP‑9, MMP‑13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)‑4 and ADAMTS‑5. Furthermore, Peimine inhibited IL‑1β‑induced activation of the mitogen‑activated protein kinase (MAPK) pathway. The protective effect of Peimine on IL‑1β‑treated chondrocytes was attenuated following activation of the MAPK pathway, as demonstrated by the increased expression levels of MMP‑3, MMP‑13, ADAMTS‑5, iNOS and COX‑2 compared with the Peimine group. The in vivo data suggested that Peimine limited the development of OA in the mouse model. In general, the data indicate that Peimine suppresses IL‑1β‑induced inflammation in mouse chondrocytes by inhibiting the MAPK pathway, suggesting a promising therapeutic role for Peimine in the treatment of OA.

Alleviation of Cartilage Destruction by Sinapic Acid in Experimental Osteoarthritis

Sinapic acid (SA) modulates the nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway in chondrocytes. In order to test the hypothesis that SA is protective against the development of osteoarthritis (OA), primary mouse chondrocytes were treated in vitro with SA and the promoter transactivation activity of heme oxygenase 1 (HO-1), nuclear translocation of Nrf2, and protein expression of HO-1 were assayed. To test the hypothesis in vivo, a destabilization of the medial meniscus (DMM) model was used to induce OA in the knees of mice and SA was delivered orally to the experimental group. The chondrocytes were harvested for further analysis. The expression of HO-1 was similarly upregulated in cartilage from both the experimental mice and human chondrocytes from osteoarthritic knees. SA was found to enhance the promoter transactivation activity of heme oxygenase 1 (HO-1) and increase the expression of Nrf2 and HO-1 in primary chondrocytes. Histopathologic scores showed that the damage induced by the DMM model was significantly lower in the SA treatment group. The addition of a HO-1 inhibitor with SA did not show additional benefit over SA alone in terms of cartilage degradation or histopathologic scores. The expression of TNF-α, IL-1β, IL-6, MMP-1, MMP-3, MMP-13, ADAMTS4, and ADAMTS5 was significantly reduced both in vitro and in vivo by the presence of SA. Protein expressions of HO-1 and Nrf2 were substantially increased in knee cartilage of mice that received oral SA. Our results suggest that SA should be further explored as a preventative treatment for OA.

Initial effects of inflammation-related cytokines and signaling pathways on the pathogenesis of post-traumatic osteoarthritis

The main pathological change in post-traumatic osteoarthritis (PTOA) is cartilage degeneration, which is closely related to inflammation and oxidative stress. Inflammation can cause degeneration of articular cartilage. Cartilage degeneration can also stimulate the progression of inflammation. It has been found that inflammatory cytokines can participate in the pathological process of cartilage degeneration through multiple signaling pathways, mainly mitogen-activated protein kinase, nuclear transcription factor kappa B, and Wnt–β-catenin signal transduction pathways. This review aimed at exploring the relationship between PTOA and inflammation-related cytokines by introducing the role of proinflammatory cytokines in chondrocyte destruction and extracellular matrix degradation.

Inducible nitric oxide synthase as a target for osteoarthritis treatment

INTRODUCTION

Inducible nitric oxide synthase (iNOS) is the enzyme responsible for the production of nitric oxide (NO), a major proinflammatory and destructive mediator in osteoarthritis (OA). Areas covered: This is a comprehensive review of the recent literature on the involvement of iNOS in osteoarthritis and its potential to be used as a target for OA treatment. Evidence from in vitro, in vivo and human studies was systematically collected using medical search engines. Preclinical studies have focused on the effect of direct and indirect iNOS inhibitors in both animal and human tissues. Apart from direct inhibitors, common pharmacological agents, herbal and dietary medicines as well as hyperbaric oxygen, low level laser and low intensity pulsed ultrasound have been shown to exhibit a chondroprotective effect by inhibiting the expression of iNOS. Expert opinion: Data support the further investigation of iNOS inhibitors for the treatment of OA in human studies and clinical trials. Indirect iNOS inhibitors such as interleukin 1 inhibitors also need to be studied in greater detail. Finally, human studies need to be conducted on the herbal and dietary medicines and on the non-invasive, non-pharmacological treatments.