Inhibition of 5-lipoxygenase and cyclooxygenase-2 pathways by pain-relieving plaster in macrophages

β-Citronellol: a potential anti-inflammatory and gastro-protective agent-mechanistic insights into its modulatory effects on COX-II, 5-LOX, eNOS, and ICAM-1 pathways through in vitro, in vivo, in silico, and network pharmacology studies

BACKGROUND

The current study aimed to evaluate the anti-inflammatory, anti-oxidant, and pronounced gastro-protective activities of β- Citronellol using in vitro, in vivo assays and in silico approaches.

METHODS

In vitro assays, denaturation of bovine serum albumin, egg protein, and human Red Blood Cells (RBCs) membrane stabilization were performed, using Piroxicam as standard. For in vivo assessment, Histamine (0.1 ml from 1% w/v) and Formaldehyde (0.1 ml from 2% v/v) were used to mediate inflammation. In silico molecular docking and network pharmacology were employed to probe the possible target genes mediating gastroprotective effect of β-Citronellol at 25, 50, and 100 mg/kg, using indomethacin-induced (25 mg/kg i.p) gastric ulcer in rats. Moreover, Gastric tissues were evaluated for morphological, histopathological, and bio-chemical analysis of PGE2, COX-I, COX-II, 5-LOX, eNOS, ICAM-1, oxygen-free radical scavengers (SOD, CAT), and oxidative stress marker (MDA).

RESULTS

β-Citronellol prevented denaturation of proteins and RBCs membrane stabilization with maximum effect observed at 6,400 µg/mL. Citronellol decreased rat's paw edema. Network pharmacology and docking studies revealed gastro-protective potential of Citronellol possibly mediated through arachidonic acid pathways by targeting COX-I, COX-II, PGE2, and 5-LOX. Citronellol reduced the ulcer indices, and histopathological changes. Further, β-Citronellol (50 and 100 mg/kg) increased gastric PGE2, COX-1, and eNOS; while suppressing COX-2, 5-LOX and ICAM-1. Citronellol markedly enhanced the oxidative balance in isolated rat stomach tissues.

CONCLUSIONS

The anti-inflammatory, anti-oxidant, and gastro-protective effects of β-Citronellol against indomethacin-induced gastric ulcer model in rats through mediating COX-I, COX-II, PGE2, 5-LOX, eNOS, and ICAM-1 inflammatory markers.

Topical Chinese patent medicines for chronic musculoskeletal pain: systematic review and trial sequential analysis

PURPOSE

Chronic musculoskeletal pain (CMP) is defined as persistent or recurrent pain that occurs in the joints, musculo-soft tissue, spine or bones for more than three months and is not completely curable. Although topical Chinese patent medicine (CPM) is the most extensively utilized medication in Asia and is widely used for pain management, its efficacy remains controversial. This article presents a systematic review of clinical studies on the therapeutic properties of topical CPM for CMP patients to better inform clinical decision-making and provide additional and safer treatment options for patients with CMP.

METHOD

We performed a comprehensive search on PubMed, Cochrane Library, web of science and Chinese databases (CNKI and WanFang data) from 2010 to 2022. In all the studies, knee osteoarthritis, cervical spondylosis, low back pain, and periarthritis of shoulder met the International Pain Association definition of chronic musculoskeletal pain. We included only randomized controlled trials (RCTs) using topical CPM primarily for chronic musculoskeletal pain in adults. To determine the effect of topical CPM on clinical symptoms, we extracted the Visual Analog Scale (VAS, range 0-10) and the Western Ontario and McMaster Universities Arthritis Index pain scores (WOMAC pain, range 0-20), in which the lower the score, the better the results. We also accepted the comprehensive outcome criteria developed by the Chinese National Institute of Rheumatology as an endpoint (total effectiveness rate, range 0-100%, higher score = better outcome), which assesses the overall pain, physical function and wellness. Finally, trial sequential analysis of VAS pain score and total effectiveness rate was performed using TSA software.

RESULTS

Twenty-six randomized controlled trials (n = 3180 participants) compared topical CPM with oral Nonsteroidal Anti-inflammatory Drugs (NSAIDs) (n = 15), topical NSAIDs (n = 9), physiotherapy (n = 5), exercise therapy (n = 4), and intra-articular Sodium hyaluronate injection (n = 2). Sixteen studies found that topical CPM was statistically significant in improving CMP pain (measured by VAS pain and Womac pain scores)(p < 0.05), and 12 studies found topical CPMs to be more clinically effective (assessed by ≥ 30% reduction in symptom severity) in treating patients with CMP (p < 0.05). Trial sequential analysis indicates that the current available evidence is robust, and further studies cannot reverse this result. In most of the studies, randomisation, allocation concealment and blinding were not sufficiently described, and no placebo-controlled trials were identified.

CONCLUSION

Most studies showed superior analgesic effects of topical CPM over various control treatments, suggesting that topical CPM may be effective for CMP and is an additional, safe and reasonable treatment option. These reported benefits should be validated in higher-quality RCTs.

Tibetan Herbal Pain-Relieving Plaster for Chronic Musculoskeletal Pain Among Cancer Survivors: Study Protocol of a Randomized, Double-Blind, Placebo-Controlled Trial

Chronic pain is common and debilitating in cancer survivors. Tibetan herbal pain-relieving plaster is used as an external analgesic to treat musculoskeletal pain in China; however, its safety and efficacy have not been evaluated via clinical trials in cancer survivors. We designed this Phase II randomized, double-blind, placebo-controlled trial (ClinicalTrials.gov Identifier: NCT04916249) to assess the efficacy and safety of the pain-relieving plaster for temporary pain relief among cancer survivors with chronic musculoskeletal pain. Under ethical approval from the Institutional Review Board at the Memorial Sloan Kettering Cancer Center, we will enroll eligible cancer survivors who have a clinical diagnosis of moderate to severe chronic musculoskeletal pain in this study. We use a central randomization system to allocate the eligible participants to either the treatment or the control group in a 1:1 ratio, with stratification by baseline opioid use. We will instruct the participants to apply the herbal patch (Tibetree Pain-Relieving Plaster, Tibet Cheezheng Tibetan Medicine Co. Ltd., Tibet, China) or placebo patch daily at the focal area with worst pain for 14 consecutive days. Study physician, participant, outcome assessor, and biostatistician are blinded to the group allocation. The primary outcome is pain severity measured by the Brief Pain Inventory on Days 2–7. Secondary outcomes include changes in insomnia, anxiety, depression, fatigue, pressure pain threshold, pain medication use, and global impression of change. We will also monitor the adverse events throughout the study period. Statistical analysis will follow the intention-to-treat principle and linear mixed modeling will be used. With rigorous design and implementation, this randomized, placebo-controlled trial will provide the initial evidence on the efficacy and safety of the pain-relieving plaster for pain relief among cancer survivors with chronic musculoskeletal pain.

Boswellia serrata Extract Containing 30% 3-Acetyl-11-Keto-Boswellic Acid Attenuates Inflammatory Mediators and Preserves Extracellular Matrix in Collagen-Induced Arthritis

Boswellia serrata extracts have been traditionally employed for the treatment of inflammatory diseases. In the present study, we have evaluated the mechanism of activity of Boswellin Super® FJ (BSE), a standardized extract of B. serrata containing not less than 30% 3-acetyl-11-keto-β-boswellic acid along with other β-boswellic acids. The in vitro anti-inflammatory activities were carried out in RAW 264.7 macrophages or human peripheral blood mononuclear cells stimulated with bacterial lipopolysaccharides (LPS) and treated with 1.25-5μg/ml BSE. The anti-arthritic activity of the extract was evaluated in a rat model of collagen-induced arthritis. BSE at 40 and 80mg/kg and celecoxib 10mg/kg were orally dosed for 21days. BSE showed significant (p<0.05) inhibition of inflammation (TNF-α, IL-6, nitric oxide, and COX-2 secretion) and downregulates the mRNA levels of TNF-α, IL-6, IL1-β, and inducible nitric oxide synthase in macrophages. BSE treatment reduced the levels of phosphorylated-NF-κB (P65), suggesting an anti-inflammatory activity mediated by blocking this key signal transduction pathway. In addition, BSE showed inhibition (p<0.05) of collagenase, elastase, hyaluronidase enzymes, and a reduction in reactive oxygen species and matrix-degrading proteins in RAW 264.7 macrophages stimulated with LPS. BSE treatment significantly (p<0.05) reduced the arthritic index, paw volume, and joint inflammation comparable to celecoxib in collagen-induced arthritis (CIA) in rats. The circulating anti-collagen antibodies were reduced in BSE and celecoxib-treated animals as compared to the CIA. In confirmation with in vitro data, BSE showed a significant (p<0.05) dose-dependent effect on C-reactive protein, prostaglandin E2, and erythrocyte sedimentation rate, which is widely used as a blood marker of inflammation. Further, BSE treatment suppressed the cartilage oligomeric matrix protein and significantly enhanced the hyaluronan levels in synovial fluid. As observed by collagen staining in joints, the loss of matrix proteins was lower in BSE-treated animals, suggesting that BSE could preserve the extracellular matrix in RA. The extract showed inhibition of collagenase enzyme activity in vitro, further strengthening this hypothesis. BSE treatment was found to be safe, and rats displayed no abnormal behavior or activities. The results suggest that Boswellin Super® mediates its activity by preserving matrix proteins, reducing pro-inflammatory mediators, and oxidative stress.

A Systematic Review of CheeZheng Pain Relieving Plaster for Musculoskeletal Pain: Implications for Oncology Research and Practice

BACKGROUND

Musculoskeletal pain is a common and debilitating condition for cancer patients. Existing therapies for these pain conditions have substantial limitations. To identify an integrative approach to pain management, we conducted a systematic review to evaluate the safety and efficacy of a Tibetan herbal-based topical agent, CheeZheng Pain Relieving Plaster (PRP), for the treatment of osteoarthritis (OA) pain.

METHODS

We extracted citations from PubMed and Chinese databases (CNKI, WanFang Data, and CQVIP). We included randomized clinical trials evaluating the effectiveness and safety of CheeZheng PRP compared to conventional OA pain treatments.

RESULTS

Twenty-two randomized clinical trials (n = 2556 participants) compared CheeZheng PRP against nonsteroidal anti-inflammatory drugs (11), glucosamine (2), intraarticular corticosteroid (2), hyaluronic acid injections (6), and acetaminophen (1). Ten studies found a statistically greater effectiveness (assessed by ≥30% reduction in symptom severity) of CheeZheng PRP in improving OA pain (measured by the Visual Analogue Scale), stiffness, and function compared to control. Ten studies reported that 4.8% of participants experienced application site skin irritation that resolved after discontinuing the plaster. Randomization was not sufficiently described in most studies, and no placebo-controlled trials were identified.

CONCLUSIONS

There is promising evidence for the safety and clinical effectiveness of CheeZheng PRP to treat OA; however, lack of placebo control and unclear descriptions of randomization increase the potential risk for bias. Future randomized, placebo-controlled trials are needed to establish the safety and efficacy of CheeZheng PRP for pain management in oncology settings.

Tibetan herbal pain-relieving plaster for low back pain: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Tibetan traditional medicine CheeZheng Pain-Relieving Plaster (CZPRP) is frequently used as an over-the-counter external analgesic for musculoskeletal pain; however, its evidence for low back pain (LBP) has not been evaluated.

AIM OF THE STUDY

This study aims to assess the efficacy and safety of CZPRP for both acute, subacute and chronic LBP through a systematic review and meta-analysis of clinical trials.

MATERIALS AND METHODS

PubMed, CENTRAL, CNKI, CQVIP, and Wanfang databases were searched through April 20, 2020 for randomized controlled trials of CZPRP for LBP. Eligible comparators were placebo, active treatment, or usual care. Clinical outcomes included pain severity, lower back function score, pain-free rate, and adverse events (AEs). Qualitative evaluations were conducted using the Cochrane risk of bias assessment tools. Quantitative analyses were conducted using a random-effects model.

RESULTS

This study includes 1674 LBP patients from nine clinical studies. Pooled analyses among subjects with acute LBP show 1) significant pain reductions (mean difference -0.84, 95% confidence interval[CI] -1.31, -0.37) in CZPRP plus diclofenac versus diclofenac, 2) significant improvements in lower back function (standard mean difference -1.50, 95% CI -2.16, -0.85) in CZPRP versus diclofenac, and 3) a higher pain-free rate in CZPRP alone (risk ratio 1.48, 95% CI 1.16, 1.89; I² = 61%) or CZPRP plus nonsteroidal anti-inflammatory drugs (NSAIDs) (risk ratio 1.66, 95% CI 1.14, 2.40; I² = 0%) versus NSAIDs. However, in a heterogeneous population with mixed LBP subtypes, there was no significant difference in pain outcomes between CZPRP and diclofenac. Additionally, CZPRP use did not increase AEs compared with no CZPRP (p = 0.40). All nine studies are associated with moderate to high risk of bias.

CONCLUSIONS

The use of CZPRP is associated with improved acute LBP outcomes compared to diclofenac. However, due to the moderate to high risk of bias of the studies, future rigorous randomized controlled trials are needed to evaluate the effects of CZPRP for acute and chronic LBP.

Skin Biophysical Parameters and Patch Test Results in People Predisposing to Xiaotong Tiegao Induced Irritant Contact Dermatitis

Background

Xiaotong Tiegao (XTT) is an ancient topical Tibetan medicine plaster which is widely used in China. Irritant contact dermatitis (ICD) caused by XTT is very common. It is still unclear why some people are more prone to develop ICD. The aim of this study is to study the baseline skin biophysical parameters and patch test results in individuals predisposing to XTT induced ICD.

Methods

During a four-month period, 149 healthy volunteers with ICD and 50 volunteers without ICD after applying XTT were recruited. The skin biophysical parameters were measured, and contact allergy to 20 common allergens was patch tested, at two weeks after the ICD was recovered.

Results

There were no significant differences in age and sex between ICD and control groups. It was found that skin median melanin value (176.50 vs 189.50, P < 0.05, Mann-Whitney U-test) and erythema value (319.90 ± 70.49 vs 347.93 ± 84.55, P < 0.05, Independent-Samples T test) were much lower in ICD than control group. Overall patch test results were not different, but the positivity rate of nickel sulfate (15.44% vs 4.00%, P < 0.05, Fisher's exact test) was significantly higher in ICD group.

Conclusions

In conclusion, people with nickel allergy, lower values of skin melanin, and erythema are predisposing to develop ICD.

Nonsteroidal Anti-Inflammatory Therapy: A Journey Toward Safety

The efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) against inflammation, pain, and fever has been supporting their worldwide use in the treatment of painful conditions and chronic inflammatory diseases until today. However, the long-term therapy with NSAIDs was soon associated with high incidences of adverse events in the gastrointestinal tract. Therefore, the search for novel drugs with improved safety has begun with COX-2 selective inhibitors (coxibs) being straightaway developed and commercialized. Nevertheless, the excitement has fast turned to disappointment when diverse coxibs were withdrawn from the market due to cardiovascular toxicity. Such events have once again triggered the emergence of different strategies to overcome NSAIDs toxicity. Here, an integrative review is provided to address the breakthroughs of two main approaches: (i) the association of NSAIDs with protective mediators and (ii) the design of novel compounds to target downstream and/or multiple enzymes of the arachidonic acid cascade. To date, just one phosphatidylcholine-associated NSAID has already been approved for commercialization. Nevertheless, the preclinical and clinical data obtained so far indicate that both strategies may improve the safety of nonsteroidal anti-inflammatory therapy.