Non-steroidal anti-inflammatory drugs (NSAIDs), pain and aging: Adjusting prescription to patient features

A novel isoquinoline alkaloid HJ-69 isolated from Zanthoxylum bungeanum attenuates inflammatory pain by inhibiting voltage-gated sodium and potassium channels

ETHNOPHARMACOLOGY RELEVANCE

Zanthoxylum bungeanum Maxim. (Z. bungeanum), a member of the Rutaceae family, has a rich history of traditional use in Asia for treating arthritis and toothache conditions. As characteristic chemical components, numerous kinds of alkaloids have been extracted from plants and their diverse biological activities have been reported. However, research on the isoquinoline alkaloid, a specific type of alkaloids, in Z. bungeanum was scarce.

AIM OF THE STUDY

The study aimed to isolate a novel isoquinoline alkaloid from Z. bungeanum and explore its pharmacological activity in vitro and analgesic activity in vivo.

MATERIALS AND METHODS

Isoquinoline alkaloid isolation and identification from Z. bungeanum were conducted using chromatographic and spectroscopic methods. The whole-cell patch-clamp technique was applied to assess its impact on neuronal excitability, and endogenous voltage-gated potassium (Kv) and sodium (Nav) currents in acutely isolated mouse small-diameter dorsal root ganglion (DRG) neurons. Its inhibitory impacts on channels were further validated with HEK293 cells stably expressing Nav1.7 and Nav1.8, and Chinese hamster ovary (CHO) cells transiently expressing Kv2.1. The formalin inflammatory pain model was utilized to evaluate the potential analgesic activity in vivo.

RESULTS

A novel isoquinoline alkaloid named HJ-69 (N-13-(3-methoxyprop-1-yl)rutaecarpine) was isolated and identified from Z. bungeanum for the first time. HJ-69 significantly suppressed the firing frequency and amplitudes of action potentials in DRG neurons. Consistently, it state-dependently inhibited endogenous Nav currents of DRG neurons, with half maximal inhibitory concentration (IC50) values of 13.06 ± 2.06 μM and 30.19 ± 2.07 μM for the inactivated and resting states, respectively. HJ-69 significantly suppressed potassium currents in DRG neurons, which notably inhibited the delayed rectifier potassium (IK) currents (IC50 = 6.95 ± 1.29 μM) and slightly affected the transient outward potassium (IA) currents (IC50 = 523.50 ± 39.16 μM). Furtherly, HJ-69 exhibited similar potencies on heterologously expressed Nav1.7, Nav1.8, and Kv2.1 channels, which correspondingly represent the main components in neurons. Notably, intraperitoneal administration of 30 mg/kg and 100 mg/kg HJ-69 significantly alleviated pain behaviors in the mouse inflammatory pain model induced by formalin.

CONCLUSION

The study concluded that HJ-69 is a novel and active isoquinoline alkaloid, and the inhibition of Nav and Kv channels contributes to its analgesic activity. HJ-69 may be a promising prototype for future analgesic drug discovery based on the isoquinoline alkaloid.

Exploring the Pathophysiology of Long COVID: The Central Role of Low-Grade Inflammation and Multisystem Involvement

Long COVID (LC), also referred to as Post COVID-19 Condition, Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), and other terms, represents a complex multisystem disease persisting after the acute phase of COVID-19. Characterized by a myriad of symptoms across different organ systems, LC presents significant diagnostic and management challenges. Central to the disorder is the role of low-grade inflammation, a non-classical inflammatory response that contributes to the chronicity and diversity of symptoms observed. This review explores the pathophysiological underpinnings of LC, emphasizing the importance of low-grade inflammation as a core component. By delineating the pathogenetic relationships and clinical manifestations of LC, this article highlights the necessity for an integrated approach that employs both personalized medicine and standardized protocols aimed at mitigating long-term consequences. The insights gained not only enhance our understanding of LC but also inform the development of therapeutic strategies that could be applicable to other chronic conditions with similar pathophysiological features.

Imrecoxib: Advances in Pharmacology and Therapeutics

Imrecoxib, a cyclooxygenase-2 (COX-2) selective non-steroidal anti-inflammatory drug (NSAID), was discovered via the balanced inhibition strategy of COX-1/COX-2. It is indicated for the relief of painful symptoms of osteoarthritis. There have been some pharmacological and therapeutic advances since the approval of imrecoxib in 2011. However, an update review in this aspect is not yet available. Relevant literature until January 2024 was identified by search of PubMed, Web of science, Embase and CNKI. From the perspective of efficacy, imrecoxib provides relief of osteoarthritis symptoms, and potential off-label use for treatment of idiopathic pulmonary fibrosis, perioperative pain, hand-foot syndrome, axial spondyloarthritis, COVID-19, cartilage injury, and malignancies such as lung and colon cancer. From a safety point of view, imrecoxib showed adverse effects common to NSAIDs; however, it has lower incidence of new-onset hypertension than other types of selective COX-2 inhibitors, less gastrointestinal toxicities than non-selective NSAIDs, weaker risk of drug interaction than celecoxib, and more suitable for elderly patients due to balanced inhibition of COX-1/COX-2. From a pharmacoeconomic perspective, imrecoxib is more cost-effective than celecoxib and diclofenac for osteoarthritis patients. With the deepening of the disease pathophysiology study of osteoarthritis, new therapeutic schemes and pharmacological mechanisms are constantly discovered. In the field of osteoarthritis treatment, mechanisms other than the analgesic and anti-inflammatory effects of COX-2 inhibitors are also being explored. Taken together, imrecoxib is a moderate selective COX-2 inhibitor with some advantages, and there would be more clinical applications and research opportunities in the future.

The Multifaceted Effects of Non-Steroidal and Non-Opioid Anti-Inflammatory and Analgesic Drugs on Platelets: Current Knowledge, Limitations, and Future Perspectives

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely utilized pharmaceuticals worldwide. Besides their recognized anti-inflammatory effects, these drugs exhibit various other pleiotropic effects in several cells, including platelets. Within this article, the multifaceted properties of NSAIDs on platelet functions, activation and viability, as well as their interaction(s) with established antiplatelet medications, by hindering several platelet agonists' pathways and receptors, are thoroughly reviewed. The efficacy and safety of NSAIDs as adjunctive therapies for conditions involving inflammation and platelet activation are also discussed. Emphasis is given to the antiplatelet potential of commonly administered NSAIDs medications, such as ibuprofen, diclofenac, naproxen and ketoprofen, alongside non-opioid analgesic and antipyretic medications like paracetamol. This article delves into their mechanisms of action against different pathways of platelet activation, aggregation and overall platelet functions, highlighting additional health-promoting properties of these anti-inflammatory and analgesic agents, without neglecting the induced by these drugs' side-effects on platelets' functionality and thrombocytopenia. Environmental issues emerging from the ever-increased subscription of these drugs are also discussed, along with the need for novel water treatment methodologies for their appropriate elimination from water and wastewater samples. Despite being efficiently eliminated during wastewater treatment processes on occasion, NSAIDs remain prevalent and are found at significant concentrations in water bodies that receive effluents from wastewater treatment plants (WWTPs), since there is no one-size-fits-all solution for removing all contaminants from wastewater, depending on the specific characteristics of the wastewater. Several novel methods have been studied, with adsorption being proposed as a cost-effective and environmentally friendly method for wastewater purification from such drugs. This article also presents limitations and future prospects regarding the observed antiplatelet effects of NSAIDs, as well as the potential of novel derivatives of these compounds, with benefits in other important platelet functions.

Development of engineered transferosomal gel containing meloxicam for the treatment of osteoarthritis

OBJECTIVE

.In this study, we investigated the potential of meloxicam (MLX) developed as transferosomal gel as a novel lipidic drug delivery system to address osteoarthritis (OTA), a degenerative joint disease that causes pain and stiffness. By incorporating meloxicam into a transferosomal gel, our aim was to provide a targeted and efficient delivery system capable of alleviating symptoms and slowing down the progression of OTA.

MATERIAL AND METHODS

Classical lipid film hydration technique was utilized to formulate different transferosomal formulations. Different transferosomal formulations were prepared by varying the molar ratio of phospholipon-90H (phosphodylcholine) to DSPE (50:50, 60:40, 70:30, 80:20, and 90:10) and per batch, 80mg of total lipid was used. The quality control parameters such as entrapment efficiency, particle size and morphology, polydispersity and surface electric charge, in vitro drug release, ex vivo permeation and stability were measured.

RESULTS

The optimized transferosomal formulations revealed a small vesicle size (121±12nm) and greater MLX entrapment (68.98±2.3%). Transferosomes mediated gel formulation MLX34 displayed pH (6.3±0.2), viscosity (6236±12.3 cps), spreadability (13.77±1.77 gm.cm/sec) and also displayed sustained release pattern of drug release (81.76±7.87% MLX released from Carbopol-934 gel matrix in 24h). MLX34 revealed close to substantial anti-inflammatory response, with ∼81% inhibition of TNF-α in 48h. Physical stability analysis concluded that refrigerator temperature was the preferred temperature to store transferosomal gel.

CONCLUSION

MLX loaded transferosomes containing gel improved the skin penetration and therefore resulted into increased inhibition of TNF-α level.

A series of indole-derived γ-hydroxy propiolate esters as potent anti-inflammatory agents: Design, synthesis, in-vitro and in-vivo biological studies

A variety of novel indole-derived γ-hydroxy propiolate esters were designed, synthesized, and evaluated for their anti-inflammatory activity in-vitro and in-vivo. According to the nitric oxide (NO) inhibitory analysis, all compounds showed potent NO inhibitory ability in a dose-dependent manner, with no apparent cytotoxicity. The model compound, L-37, also exhibited significant potency in PGE2 inhibition. In addition, compounds L-37 and L-39 can downregulate the expression of COX-2 enzyme at 5 μM via ELISA experiment. Compound L-37 (1 μM) also inhibited the PGF1 production as well as the expression of COX-1, but displayed weak inhibition activity towards the Leukotrienes (LT) and Thromboxane-B2 (TXB-2) production. However, the expression of 5-LOX was significantly inhibited by compound L-39 at 5 μM. Xylene-induced ear edema model was explored for in-vivo anti-inflammatory evaluation, compound L-37 showed similar inhibitory activity compared with celecoxib, approximately 80% at 50 mg/kg dosage. Every outcome showed that the newly synthesized compounds can effectively inhibit inflammation.

Structural modification based on the diclofenac scaffold: Achieving reduced colitis side effects through COX-2/NLRP3 selective inhibition

COX-2/NLPR3-targeted therapy might be beneficial for the inflammation diseases. To discover novel anti-inflammatory compounds with favorable safety profiles, three new series of non-carboxylic diclofenac analogues bearing various ring systems, such as oxadiazoles 4a-4w, triazoles 6a-6m, and cyclic imides 7a and 7b, were synthesized. The synthesized analogues were evaluated for their inhibitory activity against COX-2 enzyme. Among them, compound 6k exhibited potent selective COX-2 inhibition (IC50 = 1.53 μM; selectivity ((IC50 (COX-1)/IC50(COX-2) = 17.19). Treatment with compound 6k effectively suppressed the NF-κB/NLRP3 signaling pathway, resulting in reduced expression of pro-inflammatory factors. The in vivo ulcerative colitis assay demonstrated that compound 6k significantly ameliorated histological damages and showed strong protection against DSS-induced acute colitis. The collected results indicated that compound 6k displays anti-inflammatory activity through COX-2/NLRP3 inhibition. Therefore, compound 6k represents a promising candidate for further development as a new lead compound with reduced colitis side effects.

Potential mechanism of tea for treating osteoporosis, osteoarthritis, and rheumatoid arthritis

Osteoporosis (OP), osteoarthritis (OA), and rheumatoid arthritis (RA) are common bone and joint diseases with a high incidence and long duration. Thus, these conditions can affect the lives of middle-aged and elderly people. Tea drinking is a traditional lifestyle in China, and the long-term intake of tea and its active ingredients is beneficial to human health. However, the mechanisms of action of tea and its active ingredients against OP, OA, and RA are not completely elucidated. This study aimed to assess the therapeutic role and related mechanisms of tea and its active ingredients in OP, OA, and RA. Moreover, it expanded the potential mechanisms of tea efficacy based on network pharmacology and molecular docking. Results showed that tea has potential anti-COX properties and hormone-like effects. Compared with a single component, different tea components synergize or antagonize each other, thereby resulting in a more evident dual effect. In conclusion, tea has great potential in the medical and healthcare fields. Nevertheless, further research on the composition, proportion, and synergistic mechanism of several tea components should be performed.

Investigation of Anti-inflammatory, Antipyretic and Analgesic Activities of Citrullus colocynthis in Albino Rats through in vivo and Pharmacoinformatics Studies

INTRODUCTION

Hyperpyrexia, algesia and inflammation are pathological disorders which are treated with synthetic as well as herbal medications.

AIMS

The basic aim of the present study is to evaluate the ethnopharmacological activities of phytoconstituents that are present in C. colocynthis (fruit extract) by using in vivo and in silico studies.

METHODS

Thirty-six albino rats were used in our studies with an average weight between 150-170 g. Anti-inflammatory activity was investigated using carrageenan (an extract from a red seaweed) that induced edema in albino rat paws. However, in antipyretic and analgesic activity studies, yeast and acetic acid were used to cause pyrexia or algesia, respectively. Different doses of acetone fruit extract were used to treat inflammation, pyrexia and algesia.

RESULTS

Our results showed that the maximum percentage inhibition of acetonic fruit extract in anti-inflammatory and analgesic activities was observed at 70% and 100%, respectively, with 400 mg/kg doses, and in pyretic activity the maximum inhibitory percentage was 86% with a 100 mg/kg dose. In in silico analysis, we have shown that bioactive compounds (α-spinasterol, ascorbic acid and chlorogenic acid) found in fruit extract have outstanding inhibition properties that involves proteins PTGS2, TLR2 and TRPV4. C. colocynthis fruit extract shows results that are statistically significant (p < 0.005) and comparable to a reference drug. Acetonic fruit extract of C. colocynthis can be used as a natural and safe remedy with no side effects.

CONCLUSION

Both in vivo and in silico studies on chlorogenic acid, ascorbic acid and α-spinasterol have shown that these are inhibitory compounds that can be used for boosting the immune response.

Risk factors prediction of 6-month mortality after noncardiac surgery of older patients in China: a multicentre retrospective cohort study

BACKGROUND

Identifying the risk factors associated with perioperative mortality is crucial, particularly in older patients. Predicting 6-month mortality risk in older patients based on large datasets can assist patients and surgeons in perioperative clinical decision-making. This study aimed to develop a risk prediction model of mortality within 6 months after noncardiac surgery using the clinical data from 11 894 older patients in China.

MATERIALS AND METHODS

A multicentre, retrospective cohort study was conducted in 20 tertiary hospitals. The authors retrospectively included 11 894 patients (aged ≥65 years) who underwent noncardiac surgery between April 2020 and April 2022. The least absolute shrinkage and selection operator model based on linear regression was used to analyse and select risk factors, and various machine learning methods were used to build predictive models of 6-month mortality.

RESULTS

The authors predicted 12 preoperative risk factors associated with 6-month mortality in older patients after noncardiac surgery. Including laboratory-associated risk factors such as mononuclear cell ratio and total blood cholesterol level, etc. Also including medical history associated risk factors such as stroke, history of chronic diseases, etc. By using a random forest model, the authors constructed a predictive model with a satisfactory accuracy (area under the receiver operating characteristic curve=0.97).

CONCLUSION

The authors identified 12 preoperative risk factors associated with 6-month mortality in noncardiac surgery older patients. These preoperative risk factors may provide evidence for a comprehensive preoperative anaesthesia assessment as well as necessary information for clinical decision-making by anaesthesiologists.

Long-range action of an HDAC inhibitor treats chronic pain in a spared nerve injury rat model

Histone deacetylase inhibitors (HDACi) that modulate epigenetic regulation and are approved for treating rare cancers have, in disease models, also been shown to mitigate neurological conditions, including chronic pain. They are of interest as non-opioid treatments, but achieving long-term efficacy with limited dosing has remained elusive. Here we utilize a triple combination formulation (TCF) comprised of a pan-HDACi vorinostat (Vo at its FDA-approved daily dose of 50mg/Kg), the caging agent 2-hydroxypropyl-β-cyclodextrin (HPBCD) and polyethylene glycol (PEG) known to boost plasma and brain exposure and efficacy of Vo in mice and rats, of various ages, spared nerve injury (SNI) model of chronic neuropathic pain. Administration of the TCF (but not HPBCD and PEG) decreased mechanical allodynia for 4 weeks without antagonizing weight, anxiety, or mobility. This was achieved at less than 1% of the total dose of Vo approved for 4 weeks of tumor treatment and associated with decreased levels of major inflammatory markers and microglia in ipsilateral (but not contralateral) spinal cord regions. A single TCF injection was sufficient for 3-4 weeks of efficacy: this was mirrored in repeat injections, specific for the injured paw and not seen on sham treatment. Pharmacodynamics in an SNI mouse model suggested pain relief was sustained for days to weeks after Vo elimination. Doubling Vo in a single TCF injection proved effectiveness was limited to male rats, where the response amplitude tripled and remained effective for > 2 months, an efficacy that outperforms all currently available chronic pain pharmacotherapies. Together, these data suggest that through pharmacological modulation of Vo, the TCF enables single-dose effectiveness with extended action, reduces long-term HDACi dosage, and presents excellent potential to develop as a non-opioid treatment option for chronic pain.

Current Pharmacological Therapies for the Management of Spondyloarthritis: Special Considerations in Older Patients

Spondylarthritis (SpA) is generally observed in young male patients but can be diagnosed in older patients. These cases correspond to late-onset SpA (LoSpA) with two main clinical presentations, axial and peripheral SpA. Another increasingly common situation is that of older patients who have had SpA for many years. The therapeutic management of LoSpA is quite smilar to the management of patients with an early-onset disease, combining both non-pharmacological and pharmacological treatments. The treatments that can be used in LoSpA include non-steroidal anti-inflammatory drugs (NSAIDs) and biological agents targeting TNFα or IL-17A. Janus kinase inhibitors (JAKi) were recently introduced on the market for SpA. TNF inhibitors and IL-17inhibitors are very effective drugs in early-onset SpA. The effectiveness and safety of targeted therapies have not been specifically evaluated in LoSpA or older patients, and thus caution is required for these patients with comorbidities and/or polymedication. According to indirect data, biological agents seem to be less effective in LoSpA compared with early-onset disease. In parallel, a careful evaluation for the risk of infection, malignancy and cardiovascular events is recommended before initiating these drugs in this age category. JAKi may be used in LoSpA, but only in selected patients according to recent recommendations from the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA). When considering that the prevalence of such situations is expected to increase as ageing progresses, it is certainly time to consider this patient category as a distinct subgroup within the spectrum of SpA. Specific studies evaluating targeted agents in this age category are thus desirable.

Anti-inflammatory and analgesic properties of Polyphyllin VI revealed by network pharmacology and RNA sequencing

Inflammatory pain, sustained by a complex network of inflammatory mediators, is a severe and persistent illness affecting many of the general population. We explore possible anti-inflammatory pathways of Polyphyllin VI (PPVI) based on our prior study, which showed that PPVI reduces inflammation in mice to reduce pain. Network pharmacology and RNA-Seq identified the contribution of the MAPK signaling pathway to inflammatory pain. In the LPS/ATP-induced RAW264.7 cell model, pretreatment with PPVI for 1 h inhibited the release of IL-6 and IL-8, down-regulated expression of the P2X7 receptor(P2X7R), and decreased phosphorylation of p38 and ERK1/2 components of the MAPK pathway. Moreover, PPVI decreased expression of IL-6 and IL-8 was observed in the serum of the inflammatory pain mice model and reduced phosphorylation of p38 and ERK1/2 in the dorsal root ganglia while the reductions of expression of IL-6 and phosphorylation of ERK1/2 were not observed after the pre-treatment with A740003 (an antagonist of the P2X7R). These results suggest that PPVI may inhibit the release of IL-8 by regulating P2X7R to reduce the phosphorylation of p38. However, the modulation of PPVI on the release of IL-6 and phosphorylation of ERK1/2 may mediated by other P2X7R-independent signals.

Synthesis, cytotoxicity, antioxidant activity and molecular modeling of new NSAIDs-EBS derivatives

Two series of NSAIDs-EBS derivatives (5a-j and 9a-i) based on the hybridization of nonsteroidal anti-inflammatory drugs (NSAIDs) skeleton and Ebselen moiety were synthesized. Their cytotoxicity was evaluated against five types of human cancer cell lines, BGC-823 (human gastric cancer cell line), SW480 (human colon adenocarcinoma cells), MCF-7 (human breast adenocarcinoma cells), HeLa (human cervical cancer cells), A549 (human lung carcinoma cells). Moreover, the most active compound 5j showed IC50 values below 3 μM in all cancer cell lines and with remarkable anticancer activity against MCF-7 (1.5 μM) and HeLa (1.7 μM). The redox properties of the NSAIDs-EBS derivatives prepared herein were conducted by 2, 2-didiphenyl-1-picrylhydrazyl (DPPH), bleomycin dependent DNA damage and glutathione peroxidase (GPx)-like assays. Finally, TrxR1 inhibition activity assay and molecular docking study revealed NSAIDs-EBS derivatives could serve as potential TrxR1 inhibitor.

Propolis as a Potential Therapeutic Agent to Counteract Age-Related Changes in Cartilage: An In Vivo Study

Aging is intricately linked to chronic low-grade systemic inflammation, which plays a significant role in various age-related conditions, including osteoarthritis (OA). The aging process significantly influences the development of OA due to alterations in cartilage composition, reduced proteoglycan content, dysregulation of growth factor signaling, and heightened oxidative stress. Propolis, a natural product renowned for its potent antioxidant and anti-inflammatory properties, has the potential to mitigate age-induced changes in cartilage. The primary objective of this study was to rigorously assess the impact of in vivo propolis treatment on the histopathological characteristics of knee articular cartilage in senescent rats. This study involved a cohort of twenty male Sprague-Dawley rats, randomly allocated into four distinct groups for comparative analysis: YR (control group consisting of young rats), SR (senescent rats), SR-EEP (senescent rats treated with an ethanolic extract of propolis, EEP), and SR-V (senescent rats administered with a control vehicle). This study employed comprehensive histological and stereological analyses of knee articular cartilage. Propolis treatment exhibited a significant capacity to alleviate the severity of osteoarthritis, enhance the structural integrity of cartilage, and augment chondrocyte density. These promising findings underscore the potential of propolis as a compelling therapeutic agent to counteract age-related alterations in cartilage and, importantly, to potentially forestall the onset of osteoarthritis.

Anti-Hyperuricemic, Anti-Arthritic, Hemolytic Activity and Therapeutic Safety of Glycoconjugated Triazole-Phthalimides

Hyperuricemia, the metabolic alteration that leads to gout or gouty arthritis, is increasing worldwide. Glycoconjugated triazole-phthalimides show potent anti-inflammatory activity. The aim of this study was to evaluate the anti-hyperuricemia effect of glycoconjugated triazole-phthalimides. To develop hyperuricemia, groups of mice received orally potassium oxonate (250 mg/kg) for 7 days, and F2, F3 and F4 glycoconjugated triazole-phthalimides (20 mg/kg), allopurinol (300 mg/kg), and 1% carboxymethylcellulose; indomethacin (2 and 4 mg/kg) was the positive control for anti-arthritic effect. Genotoxic and mutagenic effects were evaluated by the comet and micronucleus assays, respectively. The hemolytic action of the compounds was evaluated. Phthalimides F2, F3 and F4 significantly reduced the levels of serum uric acid, creatinine and urea in hyperuricemic animals. In addition, the compounds were efficient in reducing protein denaturation in a dose-dependent manner. In an interesting way, the histopathological analysis of kidneys from groups treated with F2, F3 and F4 showed a glomerular architecture, with the Bowman's capsule and renal tubules having a normal appearance and without inflammatory changes. Also, F2 and F4 showed a small increase in micronuclei, indicating a low mutagenic effect, whilst by comet assay only, we could infer that F4 affected the frequency and damage index, thus indicating a very small genotoxic action. Similarly, the phthalimides showed a low degree of erythrocyte hemolysis (<3%). Our data demonstrate that the new glycoconjugate triazole-phthalimides have potential to treat hyperuricemia and its secondary complications, such as gouty arthritis, with a low to non-significant rate of erythrocytes hemolysis, genotoxicity and mutagenicity making these molecules strong candidates as pharmaceutical agents for treatment requiring uric-acid-lowering therapy.

IL-33/ST2 signaling in pain and itch: Cellular and molecular mechanisms and therapeutic potentials

Pain is a cardinal feature of many diseases. Chronic pain poses heavy burdens to the suffering patients, both physically and mentally. However, current mainstream medications for chronic pain, including opioids, antidepressants and non-steroid anti-inflammatory drugs are sometimes inefficient for chronic pain management and may cause side effects that limit long term usage. IL-33 belongs to IL-1 cytokine family and it exerts biological activities through binding to its specific receptor ST2. IL-33/ST2 signaling is very important in both innate and adaptive immunity. Emerging evidence indicates IL-33/ST2 signaling regulates pain in both immune and somatosensory systems through promoting neuro-immune or neuron-glia crosstalk, neuroinflammation and neuronal hyperexcitability. Some very latest studies indicate a vital part of IL-33/ST2 in mediating chronic itch. This work aims to overview the existing knowledge regarding the mechanisms of IL-33/ST2 involvement in pain and itch conditions, considering their potential similarities. We also summarized some key findings obtained from clinical studies. The targeting of IL-33/ST2 signaling holds promise for the development of novel therapeutic modalities in the management of pain and itch.

M2 macrophage polarization: a potential target in pain relief

Pain imposes a significant urden on patients, affecting them physically, psychologically, and economically. Despite numerous studies on the pathogenesis of pain, its clinical management remains suboptimal, leading to the under-treatment of many pain patients. Recently, research on the role of macrophages in pain processes has been increasing, offering potential for novel therapeutic approaches. Macrophages, being indispensable immune cells in the innate immune system, exhibit remarkable diversity and plasticity. However, the majority of research has primarily focused on the contributions of M1 macrophages in promoting pain. During the late stage of tissue damage or inflammatory invasion, M1 macrophages typically transition into M2 macrophages. In recent years, growing evidence has highlighted the role of M2 macrophages in pain relief. In this review, we summarize the mechanisms involved in M2 macrophage polarization and discuss their emerging roles in pain relief. Notably, M2 macrophages appear to be key players in multiple endogenous pathways that promote pain relief. We further analyze potential pathways through which M2 macrophages may alleviate pain.

Protective impacts of Withania somnifera leaf extract from Taif area against diclofenac induced hepato-renal toxicity: role of antioxidants, inflammation, apoptosis, and anti-oxidative stress biomarkers

Current study examined the boosting impacts of Withania somnifera leaf extract from Taif area (high-altitude area) against hepatic and renal toxicity induced by diclofenac in experimental rats. Withania is highly grown on Taif area as environmental herb with multiple functions. Diclofenac is non-steroidal medication used for treatment of pain but over dose has severe side effects. Thirty-two adult Wistar rats of male type were subdivided into 4 groups. The control rats (group 1) received saline. Second group received diclofenac (50 mg/kg BW intraperitoneally) at days 4 and 5. Third group received W. somnifera leaf extract (250 mg /kg body weight) for 6 days. The fourth protective group, received W. somnifera leaf extract plus diclofenac for 6 days as shown in groups 2 and 3. Diclofenac significantly increased serum AST, ALT, and decreased albumin and total proteins levels. It also increased serum concentrations of uric acid and creatinine. In addition, it increased lipid peroxidation, and decreased reduced glutathione and superoxide dismutase levels. Diclofenac increased inflammatory cytokines secretion and up-regulated hepatic oxidative stress genes (HO-1; hemoxygenase-1 and Nrf2nuclear factor erythroid 2-related factor 2 (Nrf2) and renal inflammatory transcriptional markers (TGF-β1; transforming growth factor-beta1 and COX-2; cycloxygenas-2). In parallel, hepatic caspase-3 expression was up-regulated as an apoptotic marker, while Bcl2; (B-cell lymphoma 2) mRNA expression was down regulated as anti-apoptotic marker. W. somnifera pre-administration in the protective group ameliorated the altered parameters induced by diclofenac. In conclusion, W. somnifera leaf extract has the potential to antagonize side effects of diclofenac by regulating the pathways of oxidative stress, inflammation, and apoptosis/antiapoptosis.

Spectrum-Effect Relationship between HPLC Fingerprint and Anti-Inflammatory and Analgesic Activities of Chloranthus fortunei (A. Gray) Solms-Laub

The predominant objective of the research is to establish the anti-inflammatory and analgesic spectrum-effect relationship of Chloranthus fortunei (A. Gray) Solms-Laub (CF), to reveal the pharmacodynamic basis of the anti-inflammatory and analgesic effects of CF. The fingerprints of ten batches of CF from various origins were established by high-performance liquid chromatography (HPLC) and evaluated for similarity, hierarchical cluster analysis (HCA), and principal component analysis (PCA). The anti-inflammatory and analgesic effects of CF were evaluated with the xylene-induced ear swelling in mice and the acetic acid torsion test, while the anti-inflammatory and analgesic spectrum-effect relationship of CF was evaluated by gray relational analysis (GRA) and partial least squares regression analysis (PLSR) to effectively elucidate the anti-inflammatory and analgesic substance basis of CF. The ten batches of CF HPLC fingerprints established in this work successfully identified a total of 13 common peaks that refer to 4 components, with peak 1 being neochlorogenic acid, peak 3 being chlorogenic acid, peak 5 being cryptochlorogenic acid, and peak 10 being rosmarinic acid. The HCA results presented that the ten batches of CF samples were clustered into 3 categories, which was consistent with the PCA results. Simultaneously, the results of the spectrum-effect relationship also indicated that neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, and rosmarinic acid were the possible anti-inflammatory and analgesic substances of CF. In order to better understand the anti-inflammatory and analgesic substance basis of CF, this experiment established the anti-inflammatory and analgesic spectrum-effect relationship of CF, which can provide a scientific foundation for the quality evaluation and further research as well as the usage of CF herbs.

Inflammation and histone modification in chronic pain

Increasing evidence suggests that epigenetic mechanisms have great potential in the field of pain. The changes and roles of epigenetics of the spinal cord and dorsal root ganglia in the chronic pain process may provide broad insights for future pain management. Pro-inflammatory cytokines and chemokines released by microglia and astrocytes, as well as blood-derived macrophages, play critical roles in inducing and maintaining chronic pain, while histone modifications may play an important role in inflammatory metabolism. This review provides an overview of neuroinflammation and chronic pain, and we systematically discuss the regulation of neuroinflammation and histone modifications in the context of chronic pain. Specifically, we analyzed the role of epigenetics in alleviating or exacerbating chronic pain by modulating microglia, astrocytes, and the proinflammatory mediators they release. This review aimed to contribute to the discovery of new therapeutic targets for chronic pain.

Diclofenac removal by the microalgae species Chlorella vulgaris, Nannochloropsis oculata, Scenedesmus acutus, and Scenedesmus obliquus

In this work, we evaluated the removal efficiency of diclofenac by Chlorella vulgaris OW-01, Nannochloropsis oculata CCAP 849/7, Scenedesmus acutus UTEX 72, and Scenedesmus obliquus CCAP 276/2. Each microalga was grown in media with different concentrations (50 and 100% of the original formulation) of carbon, nitrogen, and phosphorus, to evaluate their effect on the removal of diclofenac. We also evaluated the photodegradation of diclofenac under the same conditions. The diclofenac removed from the media ranged from 59 to 92%, obtaining the highest removal with S. obliquus. The diclofenac adsorbed on the cell walls ranged from 12.2 to 26.5%, obtaining the highest adsorption with S. obliquus. The diclofenac degraded by light ranged from 15 to 28%. The nutrient deficit showed no influence on the removal of diclofenac in any of the microalgae under study. These results indicate that S. obliquus is the best alternative for the bioremediation of diclofenac.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03268-2.

DNA methylation changes and inflammaging in aging-associated diseases

Aging as an inevitable phenomenon is associated with pervasive changes in physiological functions. There is a relationship between aging and the increase of several chronic diseases. Most age-related disorders are accompanied by an underlying chronic inflammatory state, as demonstrated by local infiltration of inflammatory cells and greater levels of proinflammatory cytokines in the bloodstream. Within inflammaging, many epigenetic events, especially DNA methylation, change. During the aging process, due to aberrations of DNA methylation, biological processes are disrupted, leading to the emergence or progression of a variety of human diseases, including cancer, neurodegenerative disorders, cardiovascular disease and diabetes. The focus of this review is on DNA methylation, which is involved in inflammaging-related activities, and how its dysregulation leads to human disorders.

Pain Management in Older Adults with Chronic Wounds

Older people often suffer from different types of ulcers, with the most prevalent being chronic leg ulcers (CLUs) and diabetic foot ulcers. There are major issues in the current medical approach because these ulcers are hard to heal, and, in the case of CLUs, very painful and with a high frequency of relapse. Older people complain of pain more frequently than young people, frequently due to a combination of painful chronic wounds with other comorbidities (e.g. arthritis, peripheral arterial disease, vertebrogenic pain syndrome). However, chronic pain appears to be managed better by older people because the pain sensitivity is downregulated and the pain threshold is higher in older people. Pain management of chronic wounds is often insufficient, especially in older individuals. It is highly important to use non-traumatic wound dressings and pay attention to patients' feelings and fears because pain in chronic ulcers can impair wound healing. Key factors include good preparation for dressing change and adequate analgesia, ideally a combination of topical and oral agents.