Antiinflammatory Drugs

NSAIDs between past and present; a long journey towards an ideal COX-2 inhibitor lead

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most abundantly used classes among therapeutic agents in medicine. NSAIDs inhibit the enzyme cyclooxygenase (COX), which is responsible for the conversion of arachidonic acid to prostaglandins. Meanwhile, non-selective NSAIDs are considered as a double-edged weapon since inhibition of COX-1 can lead to gastrointestinal side effects and kidney damage, whereas selective COX-2 inhibition provides anti-inflammatory effects without gastrointestinal toxicity. The detection of COX-2 role in inflammation process launched a new era in its management. Several trials have been established to proceed towards selectivity of well-defined anti-inflammatory members. COX-2 selective inhibitors are evidently safer on the gastrointestinal tract than non-selective NSAIDs. Nevertheless, their unexpected cardiovascular risks cannot be ignored. This review article highlights the latest trials aimed at developing new compounds with promising selective COX-2 activity.

IBPA a mutual prodrug of ibuprofen and acetaminophen alleviates inflammation, immune dysregulation and fibrosis in preclinical models of systemic sclerosis

Systemic sclerosis (SSc) is a devastating autoimmune illness with a wide range of clinical symptoms, including vascular abnormalities, inflammation, and persistent and progressive fibrosis. The disease's complicated pathophysiology makes it difficult to develop effective therapies, necessitating research into novel therapeutic options. Molecular hybridization is a strategy that can be used to develop new drugs that act on two or multiple targets and represents an interesting option to be explored for the treatment of complex diseases. We aimed to evaluate the effects of a hybrid mutual prodrug of ibuprofen and acetaminophen (IBPA) in peripheral blood mononuclear cells (PBMC) isolated from SSc patients, and in an in vivo model of SSc induced in BALB/c mice by intradermal injections of hypochlorous acid (HOCl) for 6 weeks. The mice were treated at the same time with daily intraperitoneal injections of IBPA (40 mg/kg). Pulmonary and skin fibrosis as well as immune responses were evaluated. IBPA significantly decreased the release of cytokines in PBMC culture supernatants from SSc patients after stimulation with phytohemagglutinin-M (IL-2, IL-4, IL-6, IL-10, IL-13, IL-17A, TNF and IFN-γ).In HOCl-induced SSc, IBPA treatment prevented dermal and pulmonary fibrosis, in addition to reducing CD4 + T and B cells activation and reversing the M2 polarization of macrophages in spleen cells, and inhibiting IFN-γ secretion in splenocyte cultures. These results show the anti-inflammatory and antifibrotic effects of IBPA in SSc and highlight the therapeutic potential of this mutual prodrug, providing support for future studies.

2024 ISFM and AAFP consensus guidelines on the long-term use of NSAIDs in cats

PRACTICAL RELEVANCE

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used and are effective for the management of pain in cats. These Guidelines will support veterinarians in decision-making around prescribing NSAIDs in situations of chronic pain, to minimise adverse effects and optimise pain management. Information is provided on mechanism of action, indications for use, screening prior to prescription, use in the presence of comorbidities, monitoring of efficacy, and avoidance and management of adverse effects.

CLINICAL CHALLENGES

The cat's unique metabolism should be considered when prescribing any medications, including NSAIDs. Chronic pain may be challenging to detect in this species and comorbidities, particularly chronic kidney disease, are common in senior cats. Management of chronic pain may be complicated by prescription of other drugs with the potential for interactions with NSAIDs.

EVIDENCE BASE

These Guidelines have been created by a panel of experts brought together by the International Society of Feline Medicine (ISFM) and American Association of Feline Practitioners (AAFP). Information is based on the available literature, expert opinion and the panel members' experience.

A blinded, randomized and controlled multicenter field study investigating the safety and efficacy of long-term use of enflicoxib in the treatment of naturally occurring osteoarthritis in client-owned dogs

Background

Enflicoxib is a COX-2 selective NSAID shown to be efficacious and safe in the treatment of pain and inflammation associated with canine osteoarthritis (OA) in clinical studies of 6 weeks duration.

Objective

This prospective, multisite, blinded, randomized, placebo-controlled, parallel-group field study aimed to confirm the safety and efficacy of enflicoxib in long-term canine OA treatments.

Animals

A total of 109 client owned dogs with clinical and radiographic signs of OA for at least 3 weeks were enrolled with 78 dogs completing all study visits.

Methods

Dogs were randomized at a 3:1 ratio to receive enflicoxib (n = 83) or placebo (n = 26) once weekly during 6 months. Dogs underwent veterinary assessments from Day 0 to Day 189 using a clinical sum score (CSS). Efficacy was also assessed by the owners using the Canine Brief Pain Inventory (CBPI). Safety was assessed clinically and by repeated blood and urine sample analysis. The efficacy outcome measure was the treatment response according to the CSS and secondarily the treatment response according to the CBPI. The primary safety outcome was the incidence of adverse events (AEs) and secondarily the evolution of the clinical pathology parameters.

Results

Percentages of CSS responders for enflicoxib were 71.6; 74.6 and 71.6% on Days 44, 135 and 189 respectively, always showing statistically significant differences (p < 0.05) vs. placebo (41.7, 33.3, and 20.8% respectively). Treatment response according to owner assessments followed the same pattern, achieving significant differences compared to placebo after 2 weeks of treatment. The incidence and type of AEs were as described in previous enflicoxib studies of shorter duration and as for other NSAIDs, with no tendency to increase over time. No relevant changes in hematology, biochemistry or urine parameters were observed.

Conclusions and clinical relevance

Enflicoxib safety and efficacy profile is maintained after a long-term treatment, which together with its weekly administration, makes it a good alternative for the chronic treatment of dogs with naturally occurring OA.

Effect of acupuncture inclusion in the enhanced recovery after surgery protocol on tumor patient gastrointestinal function: a systematic review and meta-analysis of randomized controlled studies

Introduction

Acupuncture has been shown to be effective in restoring gastrointestinal function in tumor patients receiving the enhanced recovery after surgery (ERAS) protocol. The present systematic review and meta-analysis aimed to evaluate the rationality and efficacy of integrating acupuncture in the ERAS strategy to recuperate gastrointestinal function.

Methods

We searched eleven databases for relevant randomized clinical trials (RCTs) of acupuncture for the treatment of gastrointestinal dysfunction in tumor patients treated with the ERAS protocol. The quality of each article was assessed using the Cochrane Collaboration risk of bias criteria and the modified Jadad Scale. As individual symptoms, the primary outcomes were time to postoperative oral food intake, time to first flatus, time to first distension and peristaltic sound recovery time (PSRT). Pain control, adverse events, and acupoint names reported in the included studies were also investigated.

Results

Of the 211 reviewed abstracts, 9 studies (702 patients) met eligibility criteria and were included in the present systematic review and meta‑analysis. Compared to control groups, acupuncture groups showed a significant reduction in time to postoperative oral food intake [standardized mean difference (SMD) = -0.77, 95% confidence interval (CI) -1.18 to -0.35], time to first flatus (SMD=-0.81, 95% CI -1.13 to -0.48), time to first defecation (SMD=-0.91, 95% CI -1.41 to -0.41, PSRT (SMD=-0.92, 95% CI -1.93 to 0.08), and pain intensity (SMD=-0.60, 95% CI -0.83 to -0.37).The Zusanli (ST36) and Shangjuxu (ST37) acupoints were used in eight of the nine included studies. Adverse events related to acupuncture were observed in two studies, and only one case of bruising was reported.

Discussion

The present systematic review and meta‑analysis suggested that acupuncture significantly improves recovery of gastrointestinal function and pain control in tumor patients receiving the ERAS protocol compared to the control group. Moreover, ST36 and ST37 were the most frequently used acupoints. Although the safety of acupuncture was poorly described in the included studies, the available data suggested that acupuncture is a safe treatment with only mild side effects. These findings provide evidence-based recommendations for the inclusion of acupuncture in the ERAS protocol for tumor patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/ PROSPERO, identifier CRD42023430211.

Two Amnion-Derived Mesenchymal Stem-Cells Injections to Osteoarthritic Elbows in Dogs-Pilot Study

The aim of the study was to investigate the potential of cell-based regenerative therapy for elbow joints affected by osteoarthritis. Interest was focused on two intra-articular applications of amnion-derived mesenchymal stem cells (A-MSCs) to a group of different breeds of dogs with elbow osteoarthritis (13 joints). Two injections were performed 14 days apart. We evaluated synovial fluid biomarkers, such as IFN-γ, IL-6, IL-15, IL-10, MCP-1, TNF-α, and GM-CSF, by multiplex fluorescent micro-bead immunoassay in the treated group of elbows (n = 13) (day 0, day 14, and day 28) and in the control group of elbows (n = 9). Kinematic gait analysis determined the joint range of motion (ROM) before and after each A-MSCs application. Kinematic gait analysis was performed on day 0, day 14, and day 28. Kinematic gait analysis pointed out improvement in the average range of motion of elbow joints from day 0 (38.45 ± 5.74°), day 14 (41.7 ± 6.04°), and day 28 (44.78 ± 4.69°) with statistical significance (p < 0.05) in nine elbows. Correlation analyses proved statistical significance (p < 0.05) in associations between ROM (day 0, day 14, and day 28) and IFN-γ, IL-6, IL-15, MCP-1, TNF-α, and GM-CSF concentrations (day 0, day 14, and day 28). IFN-γ, IL-6, IL-15, MCP-1, GM-CSF, and TNF- α showed negative correlation with ROM at day 0, day 14, and day 28, while IL-10 demonstrated positive correlation with ROM. As a consequence of A-MSC application to the elbow joint, we detected a statistically significant (p < 0.05) decrease in concentration levels between day 0 and day 28 for IFN-γ, IL-6, and TNF-α and statistically significant increase for IL-10. Statistical significance (p < 0.05) was detected in TNF-α, IFN-γ, and GM-CSF concentrations between day 14 and the control group as well as at day 28 and the control group. IL-6 concentrations showed statistical significance (p < 0.05) between day 14 and the control group.

Multimodal Approach to Pain Management in Veterinary Rehabilitation

Pain recognition, assessment, and management is a primary focus and an integral part of veterinary rehabilitation. Evidence-based pain mitigation protocols will use both pharmacologic tools and nonpharmacologic methods to create a customized, safe, and effective treatment plan. A multimodal, patient-centered approach will allow for the best outcomes for pain relief and improved quality of life.

Advances in the pharmaceutical treatment options for canine osteoarthritis

Canine osteoarthritis is a significant cause of pain in many dogs and can therefore compromise animal welfare. As the understanding of the biology and pain mechanisms underpinning osteoarthritis grows, so do the number of treatments available to manage it. Over the last decade, there have been a number of advances in the pharmaceutical treatment options available for dogs with osteoarthritis, as well as an increasing number of clinical trials investigating the efficacy of pre-existing treatments. This review aims to examine the current evidence behind pharmaceutical treatment options for canine osteoarthritis, including non-steroidal anti-inflammatory drugs, piprants, monoclonal antibodies, adjunctive analgesics, structure modifying osteoarthritis drugs and regenerative therapies.

Selective inhibition of cyclooxygenase-2 by enflicoxib, its enantiomers and its main metabolites in vitro in canine blood

Enflicoxib is approved for the treatment of pain and inflammation in canine osteoarthritis. The objective of this work was to assess the mechanistic basis of enflicoxib therapy investigating the COX inhibitory activity of enflicoxib (racemate), its enantiomers and its main metabolites using the canine whole blood assay. The (R)‐(+)‐Enflicoxib enantiomer and metabolite M8 (hydroxylated pyrazoline) did not induce significant COX inhibition. Enflicoxib and its (S)‐(‐)‐Enflicoxib enantiomer inhibited COX‐1 and COX‐2 with variable degree of preferential isoform inhibition, but no significant therapeutic effect is anticipated in vivo. The pyrazol metabolite showed the highest COX‐2 inhibition and was the most selective (IC₅₀ COX‐1/ COX‐2 ratio: 19.45). As the pyrazol metabolite shows saturable binding to red blood cells, its in vivo concentrations in plasma are lower than in whole blood. Accordingly, when applying the red blood cell partitioning, the respective IC₅₀ and IC₈₀ for COX‐2 inhibition decreased from 2.8 µM (1129 ng/ml) and 13.4 µM (5404 ng/ml) to 0.2 µM (80.7 ng/ml) and 1.2 µM (484 ng/ml) and the selectivity ratio increased to close to 55. The corrected pyrazol metabolite IC₅₀ and IC₈₀ are well within the plasma levels described in treated dogs.

The efficacy and safety of preoperative glucocorticoids in herniorrhaphy: a systematic review and meta-analysis

Postoperative pain is the main reason for delayed recovery after herniorrhaphy. Preoperative glucocorticoid administration may improve postoperative recovery. The present study assessed the efficacy of preoperative glucocorticoids in facilitating recovery after herniorrhaphy. Randomized controlled trials (RCTs) conducted up to January 2021 were searched in electronic databases and trial registries. Meta-analyses were performed using random effects models. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to assess the certainty of evidence. Seven RCTs (744 patients) were included in the meta-analysis. Preoperative glucocorticoid administration reduced patients' pain on postoperative day 0 (standard mean difference [SMD] = - 0.73, 95% confidence interval [CI] - 1.45 to - 0.01; I² = 94%). However, there was no marked difference in rescue analgesic use (risk ratio [RR] = - 0.06, 95% CI - 0.28 to - 0.16; I² = 0%) or vomiting (RR = 0.78, 95% CI 0.50-1.20; I² = 30%) between preoperative glucocorticoid administration and control. The certainty of evidence was moderate because of inconsistencies or imprecision. No serious adverse effects were observed. Preoperative glucocorticoid administration reduced pain in patients following herniorrhaphy without increasing the occurrence of adverse events. Further studies will be required to confirm the efficacy of preoperative glucocorticoids.

2022 ISFM Consensus Guidelines on the Management of Acute Pain in Cats

PRACTICAL RELEVANCE

Increases in cat ownership worldwide mean more cats are requiring veterinary care. Illness, trauma and surgery can result in acute pain, and effective management of pain is required for optimal feline welfare (ie, physical health and mental wellbeing). Validated pain assessment tools are available and pain management plans for the individual patient should incorporate pharmacological and non-pharmacological therapy. Preventive and multimodal analgesia, including local anaesthesia, are important principles of pain management, and the choice of analgesic drugs should take into account the type, severity and duration of pain, presence of comorbidities and avoidance of adverse effects. Nursing care, environmental modifications and cat friendly handling are likewise pivotal to the pain management plan, as is a team approach, involving the cat carer.

CLINICAL CHALLENGES

Pain has traditionally been under-recognised in cats. Pain assessment tools are not widely implemented, and signs of pain in this species may be subtle. The unique challenges of feline metabolism and comorbidities may lead to undertreatment of pain and the development of peripheral and central sensitisation. Lack of availability or experience with various analgesic drugs may compromise effective pain management.

EVIDENCE BASE

These Guidelines have been created by a panel of experts and the International Society of Feline Medicine (ISFM) based on the available literature and the authors' experience. They are aimed at general practitioners to assist in the assessment, prevention and management of acute pain in feline patients, and to provide a practical guide to selection and dosing of effective analgesic agents.

Long-term safety evaluation of Daxocox® tablets (enflicoxib) in dogs after weekly oral administrations for seven months

Background

Daxocox® [Ecuphar/Animalcare Group] contains the selective COX-2 inhibitor enflicoxib, approved in the EU for the treatment of pain and inflammation associated with osteoarthritis in dogs. The safety of Daxocox^® was evaluated in a target animal safety study: Groups of 4 dogs per sex each were treated once weekly with placebo or Daxocox tablets at 1-, 3- and 5-times (1X, 3X and 5X) the maximum recommended therapeutic dose of enflicoxib (0, 4, 12 or 20 mg/kg, respectively). After an initial loading dose, dogs in the placebo control, 1X and 3X groups were administered for 32 weeks, and those in the 5X group were administered for 13 weeks. Dogs were subjected to daily food consumption measurements and clinical and dose observations. Body weight measurements, physical examinations, clinical pathology, urinalysis, faecal occult blood (FOB) and electrocardiographic (ECG) and blood pressure measurements, buccal mucosal bleeding time (BMBT), ophthalmology and gastroduodenal endoscopy examinations were conducted throughout the study. At study completion, all dogs were subjected to gross necropsy. Histopathology was performed on selected tissues from all animals in all groups.

Results

No clinical signs were noted, and no toxicologically relevant dose-associated effects were observed.

Conclusions

Results show that Daxocox® is well-tolerated and has a broad safety margin when administered as directed in dogs.

Intersecting Mechanisms of Hypoxia and Prostaglandin E2-Mediated Inflammation in the Comparative Biology of Oral Squamous Cell Carcinoma

The importance of inflammation in the pathogenesis of cancer was first proposed by Rudolph Virchow over 150 years ago, and our understanding of its significance has grown over decades of biomedical research. The arachidonic acid pathway of inflammation, including cyclooxygenase (COX) enzymes, PGE2 synthase enzymes, prostaglandin E2 (PGE2) and PGE2 receptors has been extensively studied and has been associated with different diseases and different types of cancers, including oral squamous cell carcinoma (OSCC). In addition to inflammation in the tumour microenvironment, low oxygen levels (hypoxia) within tumours have also been shown to contribute to tumour progression. Understandably, most of our OSCC knowledge comes from study of this aggressive cancer in human patients and in experimental rodent models. However, domestic animals develop OSCC spontaneously and this is an important, and difficult to treat, form of cancer in veterinary medicine. The primary goal of this review article is to explore the available evidence regarding interaction between hypoxia and the arachidonic acid pathway of inflammation during malignant behaviour of OSCC. Overlapping mechanisms in hypoxia and inflammation can contribute to tumour growth, angiogenesis, and, importantly, resistance to therapy. The benefits and controversies of anti-inflammatory and anti-angiogenic therapies for human and animal OSCC patients will be discussed, including conventional pharmaceutical agents as well as natural products.

In vivo anti-inflammatory, anti-nociceptive, and in vitro antioxidant efficacy, and acute oral toxicity effects of the aqueous and methanolic stem bark extracts of Lonchocarpus eriocalyx (Harms.)

Oxidative stress causes and drives many agonising inflammatory conditions, which cause disability, financial burden, and emotional stress. The current anti-inflammatory, analgesic, and antioxidant agents are associated with adverse effects, inaccessibility, high costs, and low efficacies, thereby warranting the need for alternatives, especially from natural sources. Lonchocarpus eriocalyx plant is traditionally used in Kenyan communities to treat various inflammatory and oxidative stress-associated diseases; however, its pharmacologic efficacy and safety have not been empirically validated, hence this study. The in vivo antiinflamatory and antinociceptive efficacy of the aqueous and methanolic stem bark extracts of L. eriocalyx were determined using the xylene-induced ear oedema, and the acetic acid-induced writhing techniques, respectively, in experimental mice. Also, in vitro antioxidant activities of the studied plant extracts were investigated using the Thiobarbituric acid test for lipid peroxidation, 1, 1-diphenyl -2-picrylhydrazyl (DPPH), and Ferric reducing antioxidant power standard assay methods. Moreover, the studied extracts' acute oral toxicity effects were investigated according to the Organisation for Economic Corporation and Development (OECD) guidelines. The studied plant extracts showed significant dose-dependent inhibitions of oedema and writhing, depicting their anti-inflammatory and antinociceptive efficacy. Besides, the extracts revealed significant inhibitions of in vitro lipid peroxidation in varying degrees. Notably, the extracts demonstrated very strong DPPH radical scavenging and ferric-reducing antioxidant efficacies. Furthermore, the two studied plant extracts did not elicit acute oral toxicity, with LD50 values of >2000 mg/kg BW, hence were considered safe. The anti-inflammatory, antinociceptive, and in vitro antioxidant efficacies of these extracts were attributed to antioxidant phytocompounds with diverse pharmacologic effects, especially through the amelioration of oxidative stress. Further studies on the anti-inflammatory, antinociceptive and antioxidant mechanism(s) and isolation and characterisation of responsible compounds are encouraged to spur the development of affordable, accessible, safe, and efficacious drugs.

Celecoxib, a selective COX-2 inhibitor, markedly reduced the severity of tamoxifen-induced adenomyosis in a murine model

The aim of the present study was to evaluate the effects of the selective cyclooxygenase (COX)-2 inhibitor celecoxib on the development of uterine adenomyosis in mice. ICR neonatal mice were first exposed to tamoxifen to establish a mouse model of adenomyosis. Following 60 days of celecoxib treatment, pathological formation of adenomyosis lesions and the depth of myometrial infiltration were evaluated using hematoxylin and eosin staining. To examine thermal pain modulation in mice, a hotplate test was conducted every 15 days from postnatal day 30 onwards. Immunohistochemistry was performed to assess the expression of aromatase P450, N-cadherin, E-cadherin, COX-2 and cluster of differentiation 31, whereas the levels of estrogen were analyzed in uterine tissue homogenates using ELISA. Masson trichrome staining was performed to assess the extent of fibrosis in the uterus. Celecoxib treatment significantly inhibited the depth of infiltration into the myometrium, resulting in significantly reduced disease severity. Treatment with high doses of celecoxib significantly prolonged thermal response latency. Following celecoxib treatment, the expression of E-cadherin was significantly increased whereas the expression of N-cadherin was significantly decreased. Concomitantly, the extent of fibrosis was also reduced following celecoxib treatment. Uterine tissue homogenates isolated from mice treated with both high and low doses of celecoxib exhibited lower concentrations of estrogen and decreased expression of aromatase P450. These observations suggest that celecoxib reduces adenomyosis severity by suppressing estrogen production in the uterus, reversing epithelial-mesenchymal transition and relieving fibrosis. Taken together, the results of the present study support the potential use of celecoxib, a selective COX-2 inhibitor, for the treatment of adenomyosis.

Feline Chronic Pain and Osteoarthritis

This article reviews the current knowledge regarding osteoarthritis-related pain in cats as a structure in which to discuss the assessment of chronic pain in the research and clinical settings. The scientific evidence available for current and emerging drug therapies is described. The importance of environmental enrichment and positive emotions to reduce pain, stress, and anxiety as means to promote feline welfare and human-pet bond is discussed.