p-Coumaric Acid Attenuates IL-1β-Induced Inflammatory Responses and Cellular Senescence in Rat Chondrocytes

Poly(p-coumaric acid) nanoparticles alleviate temporomandibular joint osteoarthritis by inhibiting chondrocyte ferroptosis

Oxidative stress and inflammation are key drivers of osteoarthritis (OA) pathogenesis and disease progression. Herein we report the synthesis of poly(p-coumaric) nanoparticles (PCA NPs) from p-courmaic acid (p-CA), a naturally occurring phytophenolic acid, to be a multifunctional and drug-free therapeutic for temporomandibular joint osteoarthritis (TMJOA). Compared to hyaluronic acid (HA) that is clinically given as viscosupplementation, PCA NPs exhibited long-term efficacy, superior anti-oxidant and anti-inflammatory properties in alleviating TMJOA and repairing the TMJ cartilage and subchondral bone in a rat model of TMJOA. Notably, TMJ repair mediated by PCA NPs could be attributed to their anti-oxidant and anti-inflammatory properties in enhancing cell proliferation and matrix synthesis, while reducing inflammation, oxidative stress, matrix degradation, and chondrocyte ferroptosis. Overall, our study demonstrates a multifunctional nanoparticle, synthesized from natural p-coumaric acid, that is stable and possess potent antioxidant, anti-inflammatory properties and ferroptosis inhibition, beneficial for treatment of TMJOA.

Plant-derived and dietary phenolic cinnamic acid derivatives: Anti-inflammatory properties

Cinnamic acids are aromatic acids primarily found in plants and plant-derived food. Phenolic cinnamic acids, with one or more hydroxyl groups in the aromatic ring, often contribute to the biological activities attributed to these compounds. The presence of hydroxyl groups and a carboxyl group makes cinnamic acids very hydrophilic, preventing them from crossing biological membranes and exerting their biological activities. To alleviate this condition, a panel of synthetic modifications have been made leading to a diverse set of phenolic cinnamic structures. In this review, an overview of the natural phenolic cinnamic acid derivatives and their plant sources (more than 200) is described. The synthetic approaches to obtain the referred derivatives (more than 200) namely esters and amides are reviewed. Further, their anti-inflammatory activity (more than 70 compounds) is scrutinized. Finally, future directions will be indicated to translate the research on phenolic cinnamic derivatives into potentially effective anti-inflammatory drugs.

Effect of Selected Antioxidants on the In Vitro Aging of Human Fibroblasts

The modification of the replicative lifespan (RLS) of fibroblasts is of interest both from a knowledge point of view and for the attenuation of skin aging. The effect of six antioxidants at a concentration of 1 μM on the replicative lifespan of human dermal fibroblasts was studied. The nitroxide 4-hydroxy-TEMPO (TEMPOL), ergothioneine, and Trolox extended the replicative lifespan (RLS) (40 ± 1 population doublings (PD)) by 7 ± 2, 4 ± 1, and 3 ± 1 PD and lowered the expression of p21 at late passages. Coumaric acid, curcumin and resveratrol did not affect the RLS . The level of reactive oxygen species (ROS) was decreased or not affected by the antioxidants although TEMPOL and coumaric acid decreased the level of glutathione. Only ergothioneine and resveratrol decreased the level of protein carbonylation. The antioxidants that could prolong the RLS elevated the mitochondrial membrane potential. Protecting the activity of mitochondria seems to be important for maintaining the replicative capacity of fibroblasts.

ASIC1a-CMPK2-mediated M1 macrophage polarization exacerbates chondrocyte senescence in osteoarthritis through IL-18

PURPOSE

Identification of a role for, and the mechanism of action of, the acid-sensing ion channel 1a (ASIC1a) in M1 macrophage polarization, which results in osteoarthritis (OA)-associated chondrocyte senescence.

METHOD

ASIC1a expression in synovial M1 macrophages of OA patients was assessed by immunofluorescence. A role for ASIC1a in M1 macrophage and chondrocyte senescence was assessed in a mouse OA model.

RESULTS

ASIC1a expression was found to be upregulated in synovial M1 macrophages of OA patients. Extracellular acidification (pH 6.0) promoted M1 polarization of bone marrow derived macrophages (BMDMs), which was reversed by PcTx-1 or ASIC1a-siRNA. RNA-seq transcriptome results demonstrated a downregulation of M1 macrophage-associated genes in BMDMs after PcTx-1 treatment. Mechanistically, a role for the ASIC1a-cytidine/uridine monophosphate kinase 2 (CMPK2) axis in M1 macrophage polarization was demonstrated. The concentration of IL-18 was elevated in synovial fluid and supernatants of acid-activated BMDMs. In vitro, IL-18 stimulation or co-culture with acid-activated macrophages promoted chondrocyte senescence. In vivo, intra-articular administration of PcTx-1 reduced articular cartilage destruction and chondrocytes senescence in OA mice, which related to reduced numbers of M1 macrophages and IL-18 in affected joints.

CONCLUSION

These results demonstrate a novel pathogenic process that results in OA cartilage damage, in which M1 macrophage derived IL-18 induces articular chondrocytes senescence. Further, the ASIC1a-CMPK2 axis was shown to positively regulate M1 macrophage polarization. Hence, ASIC1a is a promising treatment target for M1 macrophage-mediated diseases, such as OA.

Modulation of the oxidative damage, inflammation, and apoptosis-related genes by dicinnamoyl-L-tartaric acid in liver cancer

Cancer cells can become resistant to existing treatments over time, so it is important to develop new treatments that target different pathways to stay ahead of this resistance. Many cancer treatments have severe side effects that can be debilitating and even life-threatening. Developing drugs that can effectively treat cancer while minimizing the risks of these side effects is essential for improving the quality of life of cancer patients. The study was designed to explore whether the combination of dicinnamoyl-L-tartaric (CLT) and sorafenib ((SOR), an anti-cancer drug)) could be used to treat hepatocellular carcinoma (HCC) in the animal model and to assess whether this combination would lead to changes in certain biomarkers associated with the tumour. In this study, 120 male mice were divided into 8 groups of 15 mice each. A number of biochemical parameters were measured, including liver functions, oxidative stress (malondialdehyde, (MDA); nitric oxide (NO)), and antioxidative activity (superoxide dismutase (SOD), and glutathione peroxidase (GPx)). Furthermore, the hepatic expressions of Bax, Beclin1, TNF-α, IL1β, and BCl-2 genes were evaluated by qRT-PCR. The combination of SOR and CLT was found to reduce the levels of liver enzymes, such as AST, ALT, ALP, and GGT, and reduce the pathological changes caused by DAB and PB. The upregulation of TNF-α, IL1β, and Bcl-2 genes suggests that the CLT was able to initiate an inflammatory response to combat the tumor, while the downregulation of the Bax and Beclin1 genes indicates that the CLT was able to reduce the risk of apoptosis in the liver. Furthermore, the combination therapy led to increased expression of cytokines, resulting in an enhanced anti-tumor effect.

CircTBX5 knockdown modulates the miR-558/MyD88 axis to alleviate IL-1β-induced inflammation, apoptosis and extracellular matrix degradation in chondrocytes via inactivating the NF-κB signaling

BACKGROUND

It has been widely shared that the dysregulation of circular RNA (circRNA) may contribute to the progression of osteoarthritis (OA). OA is characterized by persistent chondrocyte injury. We aimed to clarify the role of circTBX5 in IL-1β-induced chondrocyte injury.

METHODS

The expression of circTBX5, miR-558 and MyD88 mRNA was measured using quantitative real-time PCR (qPCR). Cell viability, proliferation and apoptosis were assessed by CCK-8, EdU or flow cytometry assay. The protein levels of extracellular matrix (ECM)-associated markers, MyD88, IkBα, p65 and phosphorylated IkBα were measured by western blot. The release of inflammatory factors was assessed by ELISA. The targets of circTBX5 were screened by RIP and pull-down assay. The putative binding between miR-558 and circTBX5 or MyD88 was validated by dual-luciferase reporter assay.

RESULTS

CircTBX5 and MyD88 were enhanced, while miR-558 was downregulated in OA cartilage tissues and IL-1β-treated C28/I2 cells. IL-1β induced C28/I2 cell injury by impairing cell viability and proliferation and promoting cell apoptosis, ECM degradation and inflammatory response, while circTBX5 knockdown alleviated IL-1β induced injury. CircTBX5 bound to miR-558 to regulate IL-1β induced cell injury. In addition, MyD88 was a target of miR-558, and circTBX5 targeted miR-558 to positively regulate MyD88 expression. MiR-558 enrichment attenuated IL-1β induced injury by sequestering MyD88 expression. Moreover, circTBX5 knockdown weakened the activity of NF-κB signaling, while miR-558 inhibition or MyD88 overexpression recovered the activity of NF-κB signaling.

CONCLUSION

CircTBX5 knockdown modulated the miR-558/MyD88 axis to alleviate IL-1β induced chondrocyte apoptosis, ECM degradation and inflammation via inactivating the NF-кB signaling pathway.

Autophagy and apoptosis: regulatory factors of chondrocyte phenotype transition in osteoarthritis

Osteoarthritis (OA) is the main pathogenic factor in diseases that cause joint deformities. As the main manifestation of the progress of OA, cartilage degradation has been closely associated with the degeneration of chondrocytes, which is induced by inflammatory factors and other trauma factors. Autophagy and apoptosis are the main mechanisms for cells to maintain homeostasis and play crucial roles in OA. Under the influence of external environmental factors (such as aging and injury), the metabolism of cells can be altered, which may affect the extent of autophagy and apoptosis. With the progression of OA, these changes can alter the cell phenotypes, and the cells of different phenotypes display distinct differences in morphology and function. In this review, we have summarized the alteration in cell metabolism, autophagy, and the extent of apoptosis during OA progression and its effects on the cell phenotypes to provide new ideas for further research on the mechanisms of phenotypic transition and therapeutic strategies so as to reverse the cell phenotypes.

Comparison of the effects of oxidative and inflammatory stresses on rat chondrocyte senescence

Osteoarthritis (OA) is an age-related degenerative joint disease that causes progressive cartilage loss. Chondrocyte senescence is a fundamental mechanism that contributes to the imbalance of matrix homeostasis in OA by inducing senescence-associated secretory phenotype (SASP). Although OA chondrocytes are mainly exposed to oxidative and inflammatory stresses, the role of these individual stresses in chondrocyte senescence remains unclear. In this study, we compared the effects of these stresses on the senescence of rat chondrocytes. Rat chondrocytes were treated with H₂O₂ and a combination of IL-1β and TNF-α (IL/TNF) to compare their in vitro effect on senescent phenotypes. For in vivo evaluation, H₂O₂ and IL/TNF were injected into rat knee joints for 4 weeks. The in vitro results showed that H₂O₂ treatment increased reactive oxygen species, γ-H2AX, and p21 levels, stopped cell proliferation, and decreased glycosaminoglycan (GAG)-producing ability. In contrast, IL/TNF increased the expression of p16 and SASP factors, resulting in increased GAG degradation. Intraarticular injections of H₂O₂ did not cause any changes in senescent markers; however, IL/TNF injections reduced safranin O staining and increased the proportion of p16- and SASP factor-positive chondrocytes. Our results indicate that oxidative and inflammatory stresses have significantly different effects on the senescence of rat chondrocytes.

A bio-polymeric scaffold incorporated with p-Coumaric acid enhances diabetic wound healing by modulating MMP-9 and TGF-β3 expression

Diabetic wounds lead to severe health complications as the tissue regeneration process fails predominantly due to prolonged inflammation, reactive oxygen species generation, and imbalance in collagen turnover. Modern wound dressings that can aid in wound management thus improving the public healthcare system, is the present need. This study aims to fabricate an effective wound dressing using plant polyphenol to treat chronic wounds as polyphenols possess excellent wound-healing ability. The collagen scaffold enriched with the polyphenol, p-Coumaric acid, was fabricated by freeze-drying method (Col-OxP3-Ca) and examined for its wound-healing ability by in vitro and in vivo analyses. Col-OxP3-Ca scaffold exhibited 85% antioxidant activity, biocompatibility in fibroblast cells, enhanced cell proliferation and migration rate. The diabetic excision wound treated with Col-OxP3-Ca scaffold healed within 21 days and a well-developed epidermis, blood vessels, hair follicle formation, fewer inflammatory cells and collagen deposition was observed in histological analysis. The immunohistochemical results depicted the enhanced expression of TGF-β3 and lessened expression of the MMP-9 in Col-OxP3-Ca scaffold treatment group. p-Coumaric acid shortened the inflammatory stage, enhanced angiogenesis, tissue regeneration and balanced collagen turnover during healing. From this, we can accomplish that the Col-OxP3-Ca wound dressing could be an outstanding alternative to treat chronic wounds.

The Mechanism of Kelulut Honey in Reversing Metabolic Changes in Rats Fed with High-Carbohydrate High-Fat Diet

Metabolic syndrome (MetS) is composed of central obesity, hyperglycemia, dyslipidemia and hypertension that increase an individual's tendency to develop type 2 diabetes mellitus and cardiovascular diseases. Kelulut honey (KH) produced by stingless bee species has a rich phenolic profile. Recent studies have demonstrated that KH could suppress components of MetS, but its mechanisms of action are unknown. A total of 18 male Wistar rats were randomly divided into control rats (C group) (n = 6), MetS rats fed with a high carbohydrate high fat (HCHF) diet (HCHF group) (n = 6), and MetS rats fed with HCHF diet and treated with KH (HCHF + KH group) (n = 6). The HCHF + KH group received 1.0 g/kg/day KH via oral gavage from week 9 to 16 after HCHF diet initiation. Compared to the C group, the MetS group experienced a significant increase in body weight, body mass index, systolic (SBP) and diastolic blood pressure (DBP), serum triglyceride (TG) and leptin, as well as the area and perimeter of adipocyte cells at the end of the study. The MetS group also experienced a significant decrease in serum HDL levels versus the C group. KH supplementation reversed the changes in serum TG, HDL, leptin, adiponectin and corticosterone levels, SBP, DBP, as well as adipose tissue 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) level, area and perimeter at the end of the study. In addition, histological observations also showed that KH administration reduced fat deposition within hepatocytes, and prevented deterioration of pancreatic islet and renal glomerulus. In conclusion, KH is effective in preventing MetS by suppressing leptin, corticosterone and 11βHSD1 levels while elevating adiponectin levels.

Indole-3-propionic acid alleviates chondrocytes inflammation and osteoarthritis via the AhR/NF-κB axis

BACKGROUND

Osteoarthritis (OA) is a common chronic disease characterized by chronic inflammation and extracellular matrix degradation. Indole-3-propionic acid (IPA) is a tryptophan metabolite secreted by intestinal flora, which can exert anti-inflammatory effects in a variety of diseases. In this study, we further investigated the potential therapeutic role of IPA in OA and the underlying mechanism.

METHODS

IL-1β was utilized to induce chondrocyte inflammation. Then, the cytotoxicity of IPA on rat chondrocytes was assessed. Meanwhile, RT-qPCR, Griess reaction, ELISA, Western blot and immunofluorescence were performed to evaluate the expression of inflammatory factors and stromal proteins, and the NF-κB pathway in chondrocytes treated with IL-1β alone, with IPA or with aryl hydrocarbon receptor (AhR) knockdown. An OA rat model was established by anterior cruciate ligament transection, and hematoxylin-eosin staining, Safranin-O/Fast Green staining and immunochemistry were applied to estimate OA severity.

RESULTS

IPA did not affect cellular viability at concentrations up to 80 µM. IPA significantly inhibited the IL-1β-induced expression of inflammatory factors (Nitric oxide, PGE2, TNF-α, IL-6, iNOS and COX-2) and matrix-degrading enzymes (MMP-3, MMP-13 and ADAMTS-5), upregulated the expression of anabolic markers (aggrecan and collagen-II) and inactivated the NF-κB pathway. However, AhR knockdown could abolish the above protection capabilities and the suppression of the NF-κB pathway induced by IPA. Furthermore, IPA significantly reduced serum inflammatory cytokines expression, cartilage destruction and synovitis in vivo, demonstrating its protective role in OA progression.

CONCLUSION

IPA improved IL-1β-induced chondrocyte inflammation and extracellular matrix degradation through the AhR/NF-κB axis, which provides an innovative therapeutic strategy for OA.

Soluble and EV-Associated Diagnostic and Prognostic Biomarkers in Knee Osteoarthritis Pathology and Detection

Osteoarthritis (OA) is the most common degenerative disease of the connective tissue of the human musculoskeletal system. Despite its widespread prevalence, there are many limitations in its diagnosis and treatment. OA diagnosis currently relies on the presence of clinical symptoms, sometimes accompanied by changes in joint X-rays or MRIs. Biomarkers help not only to diagnose early disease progression but also to understand the process of OA in many ways. In this article, we briefly summarize information on articular joints and joint tissues, the pathogenesis of OA and review the literature about biomarkers in the field of OA, specifically inflammatory cytokines/chemokines, proteins, miRNA, and metabolic biomarkers found in the blood, synovial fluid and in extracellular vesicles.

Benefits of p-coumaric acid in mice with rotenone-induced neurodegeneration

The paper examines the use of natural antioxidant and anti-inflammation substances as therapeutic candidates for brain disease. Para-coumaric acid (pCA), a phenolic compound with a variety of medicinal properties, was used against deterioration caused by various diseases. Recently, pCA has gained attention for use against cardiovascular disease but less so for neurodegenerative disease (i.e., Parkinson's disease). Therefore, the present study intended to investigate the effect of pCA against rotenone-induced Parkinson's disease-like pathology in mice. Thirty male institute of cancer research (ICR) mice were randomly divided into three experimental groups: Sham-veh, Rot-veh, and Rot-pCA100. Rotenone (Rot) 2.5 mg/kg was subcutaneously injected every 48 h in the rotenone groups. Alternately, a 100 mg/kg pCA dose was given every 48 h via intragastric gavage to the Rot-pCA100 group for 6 weeks. Motor ability was assessed at the second, fourth, and sixth week before brain collection for biochemical and histological analyses. Results indicated significant motor deficits appeared from the second to sixth week after rotenone injection. Brain analysis detected a significant effect of rotenone in the increase of malondialdehyde and tumor necrosis factor-alpha (TNF-α). This result was observed in accordance with a reduction of tyrosine hydroxylase (TH) and an increase of neuronal degeneration in the substantia nigra par compacta (SNc) and striatum. However, pCA was able to reverse all of the deterioration (i.e., reduced malondialdehyde and TNF-α) rotenone had caused, and it protected against TH and neuronal loss in the SNc and striatum. Therefore, the present study has depicted the neuroprotective effect of pCA against rotenone-induced Parkinson's disease-like pathology in mice. Benefits of pCA include anti-lipid peroxidation and anti-inflammatory effects, inhibition of neurodegeneration, and a nurturing effect on the TH level in the SNc and striatum, leading to mitigation of motor deficits.

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.

Potential metabolites of Arecaceae family for the natural anti-osteoarthritis medicine: A review

Osteoarthritis (OA) is a chronic inflammatory disorder of the joints caused by fluid and cartilage matrix component reduction. This disease results in symptoms of pain, deformity, and limitation of movement. In general, OA is treated with anti-inflammatory drugs and chondroprotection compounds, includes natural nutraceutical ingredients, which are expected to be effective and have minimal side effects. Arecaceae plants are widely spread worldwide, especially in tropical areas. The objective of this review is to collect information about the Arecaceae family as anti-OA agents, with the main study focusing on the primary and secondary metabolites of plants of the Arecaceae family, i.e., sugar palm (Arenga pinnata), nipa palm (Nypa fruticans), palmyra palm (Borassus flabellifer), date palm (Phoenix dactylifera), and betel nut (Areca catechu) have potential as anti-OA agents. The Arecaceae's metabolites that show anti-inflammatory and chondroprotective effects are galactomannan, fatty acids (linoleic and linolenic acids), flavonoids (quercetin, luteolin, isorhamnetin), phenolics (coumaric acid, ferulic acid), polyphenols (epicatechin), and steroids (stigmasterol, campesterol, spirostane). Based on the reports, the Arecaceae family plants become worthy of being explored and developed into natural anti-OA products, such as supplements or nutraceuticals.

Silencing of Angiopoietin-Like Protein 4 (Angptl4) Decreases Inflammation, Extracellular Matrix Degradation, and Apoptosis in Osteoarthritis via the Sirtuin 1/NF-κB Pathway

Osteoarthritis (OA) is a frequently observed condition in aged people. OA cartilage is characterized by chondrocyte apoptosis, chondrocyte inflammation, and hyperactive catabolism of extracellular matrix. However, the specific molecular mechanisms remain unclear. Recent data has shown that Angptl4, a multifunctional cytokine, is involved in the regulation of inflammatory and apoptosis responses in different tissues. This study is aimed at defining the role of Angptl4 in the development of OA. We employed X-ray analysis, safranin O-fast green (S-O) staining, and hematoxylin staining to evaluate histomorphological characteristics in the knee joint of mice. Real-time quantitative polymerase chain reaction, Western blot assays, immunofluorescence staining, and enzyme-linked immunosorbent assays (ELISA) were performed to analyze the changes in gene and protein expression. Mechanically, our data demonstrated that Angptl4 knockdown improved the degradation of extracellular matrix and reduced TNF-α-mediated chondrocyte inflammation and apoptosis by suppressing sirtuin 1/NF-κB signaling pathway. In addition, animal studies showed that the suppression of Angptl4 expression might alleviate OA development. In conclusion, our findings revealed the underlying mechanisms of Angptl4 regulation in chondrocytes and its potential value in the treatment of OA.

The Role of Antioxidants in the Interplay between Oxidative Stress and Senescence

Cellular senescence is an irreversible state of cell cycle arrest occurring in response to stressful stimuli, such as telomere attrition, DNA damage, reactive oxygen species, and oncogenic proteins. Although beneficial and protective in several physiological processes, an excessive senescent cell burden has been involved in various pathological conditions including aging, tissue dysfunction and chronic diseases. Oxidative stress (OS) can drive senescence due to a loss of balance between pro-oxidant stimuli and antioxidant defences. Therefore, the identification and characterization of antioxidant compounds capable of preventing or counteracting the senescent phenotype is of major interest. However, despite the considerable number of studies, a comprehensive overview of the main antioxidant molecules capable of counteracting OS-induced senescence is still lacking. Here, besides a brief description of the molecular mechanisms implicated in OS-mediated aging, we review and discuss the role of enzymes, mitochondria-targeting compounds, vitamins, carotenoids, organosulfur compounds, nitrogen non-protein molecules, minerals, flavonoids, and non-flavonoids as antioxidant compounds with an anti-aging potential, therefore offering insights into innovative lifespan-extending approaches.

Therapeutic effects and mechanisms of Zhen-Wu-Bu-Qi Decoction on dextran sulfate sodium-induced chronic colitis in mice assessed by multi-omics approaches

BACKGROUND

Zhen-Wu-Bu-Qi Decoction (ZWBQD), a traditional Chinese medicine formula comprising Poria, Radix Paeoniae Alba, Rhizoma Atractylodis Macrocephalae, Rhizoma Zingiberis Recens, Radix Codonopsis and Rhizoma Coptidis, is used for treating ulcerative colitis (UC). In a previous study, we have reported ZWBQD mitigates the severity of dextran sulfate sodium (DSS)-induced colitis in mice.

HYPOTHESIS

In this study, we aimed to understand the systemic actions and underlying mechanisms of ZWBQD on experimental colitis in mice.

METHODS

We used multi-omics techniques and immunoblotting approach to study the pharmacological actions and mechanisms of ZWBQD in DSS-induced chronic colitic mice.

RESULTS

We showed that ZWBQD exhibited potent anti-inflammatory properties and significantly protected DSS-induced colitic mice against colon injury by regulating the PI3K-AKT, MAPK signaling pathway and NF-κB signaling pathways. We also revealed that ZWBQD significantly ameliorated gut microbiota dysbiosis and abnormalities of tryptophan catabolites induced by DSS.

CONCLUSIONS

We demonstrated that the therapeutic effects of ZWBQD on experimental colitis are mediated by regulating multiple signaling pathways and modulation of gut microbiota. Our study employed an integrative strategy to elucidate novel mechanisms of ZWBQD, which provides new insights into the development of Chinese herbal medicine-based therapeutics for UC.

p‑Coumaric acid suppresses reactive oxygen species‑induced senescence in nucleus pulposus cells

p-Coumaric acid (PCA) is a phenolic acid that is widely present in numerous plants and human diets. Studies have demonstrated the antioxidant and anti-senescence effects of PCA in different cell types. However, the anti-senescence effects of PCA in nucleus pulposus (NP) cells have remained to be determined. In the present study, reverse transcription-quantitative PCR was used to measure the gene expression of Cyclooxygenase-2 (Cox-2), inducible nitric oxide synthase (iNOS), p53, p16, aggrecan and collagen-2 in NP cells. Immunofluorescence staining was used to evaluate the protein expression of p53, p16 and collagen-2 in NP cells. In addition, cell cycle of NP cells was measured by flow cytometry. β-galactosidase staining were used to investigate the senescence of NP cells. Preliminary results indicated that PCA suppressed ROS-induced senescence in NP cells via both the p16 and p53 pathways. NP cells were pretreated with PCA at a concentration of 10 or 50 µg/ml prior to stimulation with 200 µM hydrogen peroxide (H₂O₂). Pretreatment with PCA significantly inhibited H₂O₂-induced cell cycle arrest in a dose-dependent manner. PCA also reduced the gene expression of Cox-2, iNOS, p53 and p16 induced by H₂O₂. By contrast, aggrecan and collagen-2 expression in NP cells was upregulated after PCA treatment. Furthermore, PCA suppressed H₂O₂-induced changes in the protein expression of p16, p53 and collagen-2. H₂O₂ stimulation of NP cells increased senescence-associated β-galactosidase (SA-β-gal) activities, while PCA treatment markedly reversed these SA-β-gal activities. Collectively, the present results indicated that PCA attenuated H₂O₂-induced oxidative stress and cellular senescence, suggesting a potential therapeutic utility of PCA in intervertebral disc degeneration.

Pineapple Leaf Phenols Attenuate DSS-Induced Colitis in Mice and Inhibit Inflammatory Damage by Targeting the NF-κB Pathway

Colitis is not fully curable, although currently, some treatment options are being adopted. In this study, we investigated the effects of pineapple leaf phenols (PLPs), natural phenol products from pineapple leaves, on DSS-induced colitis in mice. The results showed that PLPs dramatically decreased the inflammatory response by inhibiting NF-κB activation and the secretion of pro-inflammatory factors. Moreover, PLPs provided protection against DSS-induced acute colitis by maintaining epithelial integrity. Caffeic and P-coumaric acids had similar effects and could be the active components responsible for PLPs’ effect on colitis. These results indicate that the oral administration of PLPs might be considered as a therapeutic strategy in the treatment of patients with colitis. However, further research on clinical applications and the exact effect of PLPs on colitis is required.

Rhoifolin Alleviates Inflammation of Acute Inflammation Animal Models and LPS-Induced RAW264.7 Cells via IKKβ/NF-κB Signaling Pathway

Rhoifolin (ROF) is a main effective component in Citrus grandis 'Tomentosa'. ROF has a potential anti-inflammatory activity, but its specific effects and mechanisms have not been studied. This study investigated the anti-inflammatory activity of ROF and searched for its possible molecular mechanisms. A mouse model of acute inflammation was induced by lipopolysaccharide, and the effects of ROF on pathological damages of the lung and liver were observed. Carrageenan-induced paw edema rat model was used to evaluate the effect of ROF on the volume of swelling paw. In LPS-induced RAW264.7 macrophages, the expression levels of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α were measured using ELISA. Real-time PCR was used to measure the mRNA levels of iNOS and CCL2. Western blot was used to detect the activation of IκBα and IKKβ in NF-κB signaling pathways. The results showed that ROF accelerated the recoveries of liver and lung tissue damages in acute inflammation mice and inhibited carrageenan-induced paw edema in rats; in addition, ROF significantly suppressed the secretion of TNF-α, IL-1β, and IL-6 in the serum of rats and mouse model. In LPS-induced RAW264.7 cells, 100 μmol/L ROF enhanced cell viability and suppressed the production of TNF-α, IL-6, and IL-1β significantly. ROF also decreased the mRNA expression of iNOS and CCL2 and inhibited IκBα and IKKβ phosphorylation. In summary, ROF had a potential therapeutic value for inflammation. Our research provided experimental basis for the further development of ROF as an anti-inflammatory drug and for clarifying the anti-inflammatory substance basis of Citrus grandis 'Tomentosa'. Graphical Abstract.

Anagliptin prevented interleukin 1β (IL-1β)-induced cellular senescence in vascular smooth muscle cells through increasing the expression of sirtuin1 (SIRT1)

Vascular smooth muscle cell senescence plays a pivotal role in the pathogenesis of atherosclerosis. Anagliptin is a novel dipeptidyl peptidase-4 (DPP-4) inhibitor for the treatment of hyperglycemia. Recent progress indicates that DPP-4 inhibitors show a wide range of cardiovascular benefits. We hypothesize that Anagliptin plays a role in vascular smooth muscle cell senescence and this may imply its modulation of atherosclerosis. Here, the beneficial effect of Anagliptin against interleukin 1β (IL-1β)-induced cell senescence in vascular smooth muscle cells was studied to learn the promising therapeutic capacity of Anagliptin on atherosclerosis. Firstly, we found that Anagliptin treatment ameliorated the elevated secretions of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and macrophage chemoattractant protein-1 (MCP-1). Secondly, our findings indicate that exposure to IL-1β reduced telomerase activity from 26.7 IU/L to 15.8 IU/L, which was increased to 20.3 and 24.6 IU/L by 2.5 and 5 μM Anagliptin, respectively. In contrast, IL-1β stimulation increased senescence- associated β-galactosidase (SA-β-gal) staining to 3.1- fold compared to the control group, it was then reduced to 2.3- and 1.6- fold by Anagliptin dose-dependently. Thirdly, Anagliptin dramatically reversed the upregulated p16, p21, and downregulated sirtuin1 (SIRT1) in IL-1β-treated vascular smooth muscle cells. Lastly, the protective effect of Anagliptin against cellular senescence in vascular smooth muscle cells was abolished by silencing of SIRT1. In conclusion, Anagliptin protects vascular smooth muscle cells from cytokine-induced senescence, and the action of Anagliptin in vascular smooth muscle cells requires SIRT1 expression.

Feprazone Mitigates IL-1β-Induced Cellular Senescence in Chondrocytes

The proinflammatory cytokine interleukin-1 β (IL-1β)-mediated cellular senescence in chondrocytes is involved in the development and pathological progression of osteoarthritis (OA). Feprazone, a nonsteroidal anti-inflammatory drug (NSAID) and a cyclooxygenase (COX) inhibitor, is widely used in clinics. This study aims to investigate whether Feprazone has a protective effect against IL-1β-induced cellular senescence in human chondrocytes. In this study, C-28/I2 chondrocytes were stimulated with IL-1β (10 ng/mL) in the presence or absence of Feprazone (10 and 20 μM). Cellular senescence was assessed using senescence-associated β-galactosidase (SA-β-Gal) staining. The cell cycle was examined using flow cytometry. Gene and protein expressions were determined with real-time polymerase chain reaction (PCR) and western blot analysis. We found that treatment with Feprazone ameliorated IL-1β-induced increase in cellular senescence. Feprazone increased telomerase activity and prevented cell cycle arrest in the G0/G1 phase. We also found that Feprazone reduced the expressions of plasminogen activator inhibitor-1 (PAI-1) and p21, two important regulators of cellular senescence. Additionally, treatment with Feprazone reduced the expressions of matrix metalloprotein (MMP-13) and a disintegrin-like and metalloproteinase with thrombospondin type-1 motif-5 (ADAMTS-5). Interestingly, Feprazone prevented the activation of nuclear factor kappa-B (NF-κB) by preventing nuclear translocation of NF-κB p65 and the luciferase activity of the NF-κB promoter. The results also show that Feprazone increased nuclear levels of nuclear factor erythroid 2-related factor-2 (Nrf2) and reduced the production of reactive oxygen species (ROS). Importantly, silencing of Nrf2 abolished the protective effects of Feprazone against IL-1β-induced NF-κB activation and cellular senescence. These findings shed light on the potential use of Feprazone in the treatment of OA based on a novel mechanism.

Natural Sources, Pharmacokinetics, Biological Activities and Health Benefits of Hydroxycinnamic Acids and Their Metabolites

Hydroxycinnamic acids (HCAs) are important natural phenolic compounds present in high concentrations in fruits, vegetables, cereals, coffee, tea and wine. Many health beneficial effects have been acknowledged in food products rich in HCAs; however, food processing, dietary intake, bioaccessibility and pharmacokinetics have a high impact on HCAs to reach the target tissue in order to exert their biological activities. In particular, metabolism is of high importance since HCAs' metabolites could either lose the activity or be even more potent compared to the parent compounds. In this review, natural sources and pharmacokinetic properties of HCAs and their esters are presented and discussed. The main focus is on their metabolism along with biological activities and health benefits. Special emphasis is given on specific effects of HCAs' metabolites in comparison with their parent compounds.

Anti-Inflammatory Activity of Miodesin™: Modulation of Inflammatory Markers and Epigenetic Evidence

PURPOSE

To investigate the effects of a combined herbal medicine Miodesin™ on the inflammatory response of key cells involved in the acute and chronic inflammatory processes as well as the possible epigenetic involvement.

METHODS

After the establishment of the IC50 dose, the chondrocyte, keratinocyte, and macrophage cell lines were pretreated for 2 hours with Miodesin™ (200 μg/mL) and stimulated with LPS (1 μg/mL) for 24 hours. The supernatant was used to measure the levels of cytokines (IL-1β, IL-6, IL-8, and TNF-α) and chemokines (CCL2, CCL3, and CCL5), and the cells were used to extract the mRNA for the transcription factor (NF-κβ), inflammatory enzymes (COX-1, COX-2, PLA2, and iNOS), and chemokines (CCL2, CCL3, and CCL5).

RESULTS

Miodesin™ inhibited the release of LPS-induced cytokines (IL-1β, IL-6, IL-8, and TNF-α; p < 0.01) and chemokines (CCL2, CCL3, and CCL5; p < 0.01) and the expression of the transcription factor (NF-κβ; p < 0.01), inflammatory enzymes (COX-1, COX-2, PLA2, iNOS; p < 0.01), and chemokines (CCL2, CCL3, and CCL5; p < 0.01). In addition, the evaluation of epigenetic mechanism revealed that Miodesin™ did not induce changes in DNA methylation, assuring the genetic safeness of the compound in terms of the inflammatory response.

CONCLUSIONS

Miodesin™ presents anti-inflammatory properties, inhibiting hyperactivation of chondrocytes, keratinocytes, and macrophages, involving epigenetics in such effects.