Synthesis of Ottonia anisum Extract Mediated ZnO NPs and Their Local Anesthetic, Analgesic and HCl‑induced Acute Lung Injury Activities

In this study, we outlined the green synthesis of Zinc oxide nanoparticles (ZnO NPs) using the plant-mediated method. Employing the nitrate derivative of Zinc and the extract from the native medicinal plant, Ottonia anisum, the nanoparticles were effectively produced. After obtaining a yellow-colored paste, it was meticulously dried, gathered, and set aside for subsequent examination. The UV-visible spectrometry analysis indicated an absorption peak at 320 nm, which is indicative of ZnO NPs. Characterization techniques, such as XRD and HR-TEM, confirmed the existence of agglomerated ZnO NPs with an average diameter of 40 nm. Through EDS analysis, distinct energy signals for both Zinc and Oxygen were observed, confirming their composition. Furthermore, FT-IR spectroscopy highlighted an absorption peak for Zn-O bonding in the range of 400 to 600 cm -1 . Further, we employed three distinct pain models in mice to evaluate the influence of ZnO NPs on the nociceptive threshold. Our findings revealed that, when orally administered, ZnO NPs at concentrations ranging from 5-20 mg/kg exerted a dose-dependent analgesic effect in both the hot-plate and the acetic acid-induced writhing tests. Moreover, when ZnO NPs were administered at doses between 2.5-10 mg/kg, there was a notable reduction in pain responses during both the initial and subsequent phases of the formalin test, but no change in PGE 2 production within the mice's hind paw was found. On the other hand, acute lung injury studies revealed that the administration of ZnO NPs orally 90 minutes prior to HCl instillation decreased the neutrophil infiltration into the lungs in a doseresponsive manner. This reduction in pulmonary inflammation was paralleled by a significant decrease in lung edema, as evidenced by the reduced total protein content in the BALF. Additionally, the ZnO NPs appeared to recalibrate the lung's redox equilibrium following HCl exposure, which was determined through measurements of ROS, malondialdehyde, glutathione, and catalase activity. All these results further indicated the potential of biofabricated ZnO NPs for future applications in analgesics and acute lung injury treatments.

In vivo effects of a selected thiourea derivative 1-(2-chlorobenzoyl)-3-(2,3-dichlorophenyl) against nociception, inflammation and gastric ulcerogenicity: Biochemical, histopathological and in silico approaches

The current study was designed to investigate the potential of a synthetic therapeutic agent for better management of pain and inflammation, exhibiting minimal to non-existent ulcerogenic effects. The effect of 1-(2-chlorobenzoyl)-3-(2,3-dichlorophenyl) thiourea was assessed through model systems of nociception and anti-inflammatory activities in mice. In addition, the ulcerogenic potential was evaluated in rats using the NSAID-induced pyloric ligation model, followed by histopathological and biochemical analysis. The test was conducted on eight groups of albino rats, comprising of group I (normal saline), groups II and III (aspirin® at doses of 100 mg/kg and 150 mg/kg, respectively), groups IV and V (indomethacin at doses of 100 mg/kg and 150 mg/kg, respectively), and groups VI, VII, and VIII (lead-compound at 15 mg/kg, 30 mg/kg and 45 mg/kg doses, respectively). Furthermore, molecular docking analyses were performed to predict potential molecular target site interactions. The results showed that the lead-compound, administered at doses of 15, 30, and 45 mg/kg, yielded significant reductions in chemically and thermally induced nociceptive pain, aligning with the levels observed for aspirin® and tramadol. The compound also effectively suppressed inflammatory response in the carrageenan-induced paw edema model. As for the ulcerogenic effects, the compound groups displayed no considerable alterations compared to the aspirin® and indomethacin groups, which displayed substantial increases in ulcer scores, total acidity, free acidity, and gastric juice volume, and a decrease in gastric juice pH. In conclusion, these findings suggest that our test compound exhibits potent antinociceptive, anti-inflammatory properties and is devoid of ulcerogenic effects.

Electroacupuncture Alleviates Pain by Suppressing P2Y12R-Dependent Microglial Activation in Monoarthritic Rats

Electroacupuncture (EA) effectively improves arthritis-induced hyperalgesia and allodynia by repressing spinal microglial activation, which plays a crucial role in pain hypersensitivity following tissue inflammation. However, the mechanism by which EA suppresses spinal microglial activation in monoarthritis (MA) remains unclear. In the present study, a rat model of MA was established through unilateral ankle intra-articular injection of complete Freund's adjuvant (CFA). The relationship among P2Y12 receptor (P2Y12R) expression, spinal microglial activation, and EA analgesia was investigated using quantitative real-time PCR (qRT‒PCR), western blotting, immunofluorescence (IF), and behavioral testing. The results found that EA treatment at the ipsilateral "Huantiao" (GB30) and "Yanglingquan" (GB34) acupoints markedly attenuated pain and spinal microglia M1 polarization in MA rats. In particular, P2Y12R expression was significantly increased at the mRNA and protein levels in the spinal dorsal horn in MA rats, whereas EA treatment effectively repressed the MA-induced upregulation of P2Y12R. IF analysis further revealed that most P2Y12R was expressed in microglia in the spinal dorsal horn. Pharmacological inhibition of P2Y12R by its antagonist (AR-C69931MX) decreased MA-induced spinal microglial activation and subsequent proinflammatory cytokine production. Consequently, AR-C69931MX significantly intensified the anti-pain hypersensitive function of EA in MA rats. Taken together, these results demonstrate that EA alleviates MA-induced pain by suppressing P2Y12R-dependent microglial activation.

Strengthening Protocols for Rapid Response to Disruptions in Access to Prescription Opioids: Considerations for State and Territorial Health Agencies

Prescription opioid disruptions pose a danger and lead to adverse health outcomes for patients taking prescription opioids for pain or medication for opioid use disorder. State and territorial health agencies are uniquely positioned to respond to disruptions and potentially prevent risks associated with service disruptions. Responding to disruptions in access to prescription opioids necessitates a multifaceted, collaborative approach that prioritizes care continuity and patient well-being. State and territorial health agencies may benefit from developing and exercising a formal response protocol that outlines roles and activities during these types of events, strengthening capacity to rapidly respond and serve patient needs.

Chemical Investigation and Antinociceptive Activity Evaluation of Marrubium Vulgare L. Aqueous Extract

Marrubium vulgare L. (Lamiaceae) has a long history of use in traditional herbal medicine for the treatment of respiratory tract infections, inflammatory conditions, and pain. This study aimed to investigate the chemical composition, acute toxicity, and antinociceptive effects of the aqueous extract from M. vulgare leaves (AEMV). Antioxidant activity was evaluated using DPPH and reducing power assays. The chemical composition of AEMV was determined through LC-MS/MS, and the levels of total phenolics, flavonoids, and condensed tannins were quantified. Acute oral toxicity was assessed in male Swiss mice with a single oral dose of AEMV (1, 2, 5 g/kg). The analgesic impact was examined through writhing, hot plate, and formalin tests. Our findings not only confirmed the safety of the extract in animal models but also revealed significant antioxidant activity in AEMV. High-performance liquid chromatography (HPLC) analysis identified important bioactive compounds, with marrubiin being a major component. Furthermore, AEMV demonstrated robust antinociceptive properties in all conducted tests, highlighting its potential as a valuable natural source of bioactive compounds suitable for a wide range of therapeutic applications.

Safety profile of recombinant adjuvanted anti-herpes zoster vaccine (RZV) in high-risk groups: Data from active surveillance program. Puglia (Italy), 2021-23

BACKGROUND

Since 2021 a recombinant adjuvanted anti-Herpes Zoster vaccine(Recombinant Zoster Vaccine, RZV) is offered in Italy to high-risk patients. Few real-life data about RZV safety are available in target populations.

OBJECTIVES

This study investigates Adverse Events Following Immunization(AEFIs), baseline disease flare-ups, and Herpes Zoster (HZ) episodes occurring after RZV administration in a heterogeneous population of fragile patients to design its safety profile.

METHODS

This is a retrospective population-based study. RZV-vaccinated patients at Bari Policlinico General Hospital vaccination clinic from October 1st, 2021, to March 31st, 2023, were enrolled. Subjects were screened for reason of RZV eligibility and baseline chronic pathologies. AEFIs occurred in the first 7-days post-vaccination period were collected, and baseline disease flare-ups and post-vaccination HZ episodes were assessed via a 3-month follow-up.

RESULTS

Five-hundred-thirty-eight patients were included and total of 1,031 doses were administered. Most patients were vaccinated due to ongoing immunosuppressive therapy(54.65 %); onco-hematological and cardiovascular conditions were the most common chronic baseline pathologies. Out of 1,031 follow-ups, 441 AEFI cases were reported(42.7/100). The most common symptoms were injection site pain/itching(35.60/100), asthenia/malaise(11.44/100), and fever (10.09/100). Four serious AEFIs occurred(0.38/100). Older age, male sex, and history of cardiovascular diseases(OR:0.71; 95CI:0.52-0.98; p-value <0.05) were found to decrease AEFIs risk, while endocrine-metabolic illnesses(OR:1.61; 95CI:1.15-2.26; p-value <0.05) increased it. Twelve patients(2.23 %) reported a flare-up/worsening of their baseline chronic condition within the first three months after vaccination(mean interval 31.75 days, range 0-68 days). Patients with rheumatological illnesses had a higher risk of relapse(OR:16.56; 95CI:3.58-76.56; p-value <0.001), while male sex behaved as a protective factor. Twelve patients who completed the vaccination cycle(2.43%) had at least one HZ episode by the long-term follow-up.

CONCLUSIONS

The study demonstrates RZV safety in a significant number of high-risk patients. Hence, RZV should be actively offered as part of tailored vaccination programs to decrease the burden of HZ in fragile populations.

Experimental and pharmacoinformatic approaches unveil the neuropharmacological and analgesic potential of chloroform fraction of Roktoshirinchi (Achyranthes ferruginea Roxb.)

ETHNOPHARMACOLOGICAL RELEVANCE

Achyranthes ferruginea (A. ferruginea) Roxb. is a common plant used in traditional medicine in Asia and Africa. It has a variety of local names, including "Gulmanci" in Nigeria, "Dangar" in Pakistan, "Thola" in Ethiopia, and "Roktoshirinchi" in Bangladesh. It is edible and has several ethnomedical uses for a wide range of illnesses, including hysteria, dropsy, constipation, piles, boils, asthma, and shigellosis. However, the neuropharmacological and analgesic potential of A. ferruginea remains uninvestigated.

AIM OF THE STUDY

To assess the neuropharmacological and analgesic potential of A. ferruginea through a multifaceted approach encompassing both experimental and computational models.

MATERIALS AND METHODS

Methanol was used to extract the leaves of A. ferruginea. It was then fractionated with low to high polar solvents (n-hexane, chloroform, ethyl acetate, and water) to get different fractions, including chloroform fraction (CLF). The study selected CLF at different doses and conducted advanced chemical element and proximate analyses, as well as phytochemical profiling using GC-MS. Toxicological studies were done at 300 μg per rat per day for 14 days. Cholinesterase inhibitory potential was checked using an in-vitro colorimetric assay. Acetic acid-induced writhing (AAWT) and formalin-induced licking tests (FILT) were used to assess anti-nociceptive effects. The forced swim test (FST), tail suspension test (TST), elevated plus maze (EPM), hole board test (HBT), and light and dark box test (LDB) were among the behavioral tests used to assess depression and anxiolytic activity. Network pharmacology-based analysis was performed on selected compounds using the search tool for interacting chemicals-5 (STITCH 5), Swiss target prediction tool, and search tool for the retrieval of interacting genes and proteins (STRING) database to link their role with genes involved in neurological disorders through gene ontology and reactome analysis.

RESULTS

Qualitative chemical element analysis revealed the presence of 15 elements, including Na, K, Ca, Mg, P, and Zn. The moisture content, ash value, and organic matter were found to be 11.12, 11.03, and 88.97%, respectively. GC-MS data revealed that the CLF possesses 25 phytoconstituents. Toxicological studies suggested the CLF has no effects on normal growth, hematological and biochemical parameters, or cellular organs after 14 days at 300 μg per rat. The CLF markedly reduced the activity of both acetylcholinesterase and butyrylcholinesterase (IC50: 56.22 and 13.22 μg/mL, respectively). Promising dose-dependent analgesic activity (p < 0.05) was observed in chemically-induced pain models. The TST and FST showed a dose-dependent substantial reduction in immobility time due to the CLF. Treatment with CLF notably increased the number of open arm entries and time spent in the EPM test at doses of 200 and 400 mg/kg b.w. The CLF showed significant anxiolytic activity at 200 mg/kg b.w. in the HBT test, whereas a similar activity was observed at 400 mg/kg b.w. in the EPM test. A notable increase in the amount of time spent in the light compartment was observed in the LDB test by mice treated with CLF, suggesting an anxiolytic effect. A network pharmacology study demonstrated the relationship between the phytochemicals and a number of targets, such as PPARA, PPARG, CHRM1, and HTR2, which are connected to the shown bioactivities.

CONCLUSIONS

This study demonstrated the safety of A. ferruginea and its efficacy in attenuating cholinesterase inhibitory activity, central and peripheral pain, anxiety, and depression, warranting further exploration of its therapeutic potential.

Scoping review of interventions to de-implement potentially harmful non-steroidal anti-inflammatory drugs (NSAIDs) in healthcare settings

OBJECTIVES

Potentially harmful non-steroidal anti-inflammatory drugs (NSAIDs) utilisation persists at undesirable rates worldwide. The purpose of this paper is to review the literature on interventions to de-implement potentially harmful NSAIDs in healthcare settings and to suggest directions for future research.

DESIGN

Scoping review.

DATA SOURCES

PubMed, CINAHL, Embase, Cochrane Central and Google Scholar (1 January 2000 to 31 May 2022).

STUDY SELECTION

Studies reporting on the effectiveness of interventions to systematically reduce potentially harmful NSAID utilisation in healthcare settings.

DATA EXTRACTION

Using Covidence systematic review software, we extracted study and intervention characteristics, including the effectiveness of interventions in reducing NSAID utilisation.

RESULTS

From 7818 articles initially identified, 68 were included in the review. Most studies took place in European countries (45.6%) or the USA (35.3%), with randomised controlled trial as the most common design (55.9%). Interventions were largely clinician-facing (76.2%) and delivered in primary care (60.2%) but were rarely (14.9%) guided by an implementation model, framework or theory. Academic detailing, clinical decision support or electronic medical record interventions, performance reports and pharmacist review were frequent approaches employed. NSAID use was most commonly classified as potentially harmful based on patients' age (55.8%), history of gastrointestinal disorders (47.1%), or history of kidney disease (38.2%). Only 7.4% of interventions focused on over-the-counter (OTC) NSAIDs in addition to prescription. The majority of studies (76.2%) reported a reduction in the utilisation of potentially harmful NSAIDs. Few studies (5.9%) evaluated pain or quality of life following NSAIDs discontinuation.

CONCLUSION

Many varied interventions to de-implement potentially harmful NSAIDs have been applied in healthcare settings worldwide. Based on these findings and identified knowledge gaps, further efforts to comprehensively evaluate the effectiveness of interventions and the combination of intervention characteristics associated with effective de-implementation are needed. In addition, future work should be guided by de-implementation theory, focus on OTC NSAIDs and incorporate patient-focused strategies and outcomes, including the evaluation of unintended consequences of the intervention.

Blocking the dopaminergic receptors within the hippocampal dentate gyrus reduced analgesic responses induced by restraint stress in the formalin test

Previous studies have shown that various receptors, including dopamine receptors, are expressed in the hippocampal dentate gyrus (DG). Besides, indicatively, dopamine receptors play an essential role in the modulation of pain perception. On the other hand, stressful experiences can produce analgesia, termed stress-induced analgesia (SIA). The current study examined the probable role of dopamine receptors within the DG in antinociception induced by restraint stress (RS). Ninety-seven male albino Wistar rats were unilaterally implanted with a cannula in the DG. Animals received intra-DG microinjections of SCH23390 or Sulpiride (0.25, 1, and 4 μg/rat) as D1-and D2-like dopamine receptor antagonists, respectively, five minutes before RS. Ten minutes after the end of the induction of RS for three hours, 50 μl 2.5% formalin was injected subcutaneously into the plantar surface of the hind paw to induce persistent inflammatory pain. Pain scores were evaluated at 5-minute intervals for 60 minutes. These findings showed that; exposure to RS for three hours produced SIA in both phases of the formalin test, while this RS-induced analgesia was attenuated in the early and late phases of the formalin test by intra-DG microinjection of SCH23390 and Sulpiride. The results of the present study suggested that both D1- and D2-like dopamine receptors in the DG have a considerable role in the induced analgesia by RS.

Electroacupuncture promotes macrophage/microglial M2 polarization and suppresses inflammatory pain through AMPK

Inflammatory pain, the most prevalent disease globally, remains challenging to manage. Electroacupuncture emerges as an effective therapy, yet its underlying mechanisms are not fully understood. This study investigates whether adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)-regulated silent information regulator 1 (SIRT1) contributes to electroacupuncture's antinociceptive effects by modulating macrophage/microglial polarization in the spinal dorsal horn of a mouse model of inflammatory pain. In this study, mice, introduced to inflammatory pain through subcutaneous injections of complete freund's adjuvant (CFA) in the plantar area, underwent electroacupuncture therapy every alternate day for 30-min sessions. The assessment of mechanical allodynia and thermal hyperalgesia in these subjects was carried out using paw withdrawal frequency and paw withdrawal latency measurements, respectively. Western blot analysis measured levels of AMPK, phosphorylation-adenosine 5'-monophosphate (AMP)-activated protein kinase, SIRT1, inducible nitric oxide synthase, cluster of differentiation 86, arginase 1, and interleukin 10. In contrast to the group treated solely with CFA, the cohort receiving both CFA and electroacupuncture demonstrated notable decreases in both thermal hyperalgesia and mechanical allodynia. This was accompanied by a marked enhancement in AMPK phosphorylation levels. AMPK knockdown reversed electroacupuncture's analgesic effects and reduced M2 macrophage/microglial polarization enhancement. Additionally, AMPK knockdown significantly weakened electroacupuncture-induced SIRT1 upregulation, and EX-527 injection attenuated electroacupuncture's facilitation of M2 macrophage/microglial polarization without affecting AMPK phosphorylation levels. Furthermore, combining electroacupuncture with SRT1720 enhanced the analgesic effect of SRT1720. Our findings suggest that AMPK regulation of SIRT1 plays a critical role in electroacupuncture's antinociceptive effect through the promotion of M2 macrophage/microglial polarization.

Cannabidiol (CBD) Products for Pain: Ineffective, Expensive, and With Potential Harms

Cannabidiol (CBD) attracts considerable attention for promoting good health and treating various conditions, predominantly pain, often in breach of advertising rules. Examination of available CBD products in North America and Europe demonstrates that CBD content can vary from none to much more than advertised and that potentially harmful other chemicals are often included. Serious harm is associated with chemicals found in CBD products and reported in children, adults, and the elderly. A 2021 International Association for the Study of Pain task force examined the evidence for cannabinoids and pain but found no trials of CBD. Sixteen CBD randomized trials using pharmaceutical-supplied CBD or making preparations from such a source and with pain as an outcome have been published subsequently. The trials were conducted in 12 different pain states, using 3 oral, topical, and buccal/sublingual administration, with CBD doses between 6 and 1,600 mg, and durations of treatment between a single dose and 12 weeks. Fifteen of the 16 showed no benefit of CBD over placebo. Small clinical trials using verified CBD suggest the drug to be largely benign; while large-scale evidence of safety is lacking, there is growing evidence linking CBD to increased rates of serious adverse events and hepatotoxicity. In January 2023, the Food and Drug Administration (FDA) announced that a new regulatory pathway for CBD was needed. Consumers and health care providers should rely on evidence-based sources of information on CBD, not just advertisements. Current evidence is that CBD for pain is expensive, ineffective, and possibly harmful. PERSPECTIVE: There is no good reason for thinking that CBD relieves pain, but there are good reasons for doubting the contents of CBD products in terms of CBD content and purity.

Evaluation of anti-inflammatory activity of kaurenol: Experimental evaluation and mechanistic insights

BACKGROUND

Kaurenol, a diterpene alcohol found in Copaifera langsdorffii Desf. (known as "copaiba"), is historically used in traditional medicine for inflammatory conditions.

OBJECTIVES

This study aims to comprehensively assess the potential anti-inflammatory and antinociceptive properties of kaurenol.

METHODS

To this end, the following experiments were conducted to evaluated toxicity: locomotor performance and acute toxicity; nociception: acetic acid-induced writhing and formalin-induced antinociception; and anti-inflammatory activity: carrageenan and dextran-induced paw edema at 10, 20, and 40 mg/kg, and measurement of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) in macrophages at 1, 3, and 9 μg/ml.

RESULTS

Kaurenol did not show significant locomotor changes, acute toxicity, and central analgesic activity in the first phase of formalin test at dosages tested. Kaurenol showed 53%, 64%, 64%, and 58% of inhibition in the acetic acid-induced writhing, second phase of formalin test, carrageenan and dextran-induced paw edema, respectively.

CONCLUSION

The anti-inflammatory activity was associated with the regulation of NO release and probably with the regulation of mediators, such as serotonin and prostaglandin in vascular permeability, as well as by being associated with the regulation of IL-6 and IL-10. Kaurenol display anti-inflammatory activity but has no analgesic activity.

Caffeine Impaired Acupuncture Analgesia in Inflammatory Pain by Blocking Adenosine A1 Receptor

Caffeine consumption inhibits acupuncture analgesic effects by blocking adenosine signaling. However, existing evidence remains controversial. Hence, this study aimed to examine the adenosine A1 receptor (A1R) role in moderate-dose caffeine-induced abolishing effect on acupuncture analgesia using A1R knockout mice (A1R-/-). We assessed the role of A1R in physiological sensory perception and its interaction with caffeine by measuring mechanical and thermal pain thresholds and administering A1R and adenosine 2A receptor antagonists in wild-type (WT) and A1R-/- mice. Formalin- and complete Freund's adjuvant (CFA)-induced inflammatory pain models were recruited to explore moderate-dose caffeine effect on pain perception and acupuncture analgesia in WT and A1R-/- mice. Moreover, a C-fiber reflex electromyogram in the biceps femoris was conducted to validate the role of A1R in the caffeine-induced blockade of acupuncture analgesia. We found that A1R was dispensable for physiological sensory perception and formalin- and CFA-induced hypersensitivity. However, genetic deletion of A1R impaired the antinociceptive effect of acupuncture in A1R-/- mice under physiological or inflammatory pain conditions. Acute moderate-dose caffeine administration induced mechanical and thermal hyperalgesia under physiological conditions but not in formalin- and CFA-induced inflammatory pain. Moreover, caffeine significantly inhibited electroacupuncture (EA) analgesia in physiological and inflammatory pain in WT mice, comparable to that of A1R antagonists. Conversely, A1R deletion impaired the EA analgesic effect and decreased the caffeine-induced inhibitory effect on EA analgesia in physiological conditions and inflammatory pain. Moderate-dose caffeine administration diminished the EA-induced antinociceptive effect by blocking A1R. Overall, our study suggested that caffeine consumption should be avoided during acupuncture treatment. PERSPECTIVE: Moderate-dose caffeine injection attenuated EA-induced antinociceptive effect in formalin- and CFA-induced inflammatory pain mice models by blocking A1R. This highlights the importance of monitoring caffeine intake during acupuncture treatment.

Comparing Intracanalicular and Topical Steroid Use in Patients Undergoing Pterygium Surgery

OBJECTIVE

The study received funding from Ocular Therapeutix, Inc., Bedford, MA.We undertook this study to compare the efficacy of intracanalicular dexamethasone 0.4 mg with topical prednisolone acetate (PA) 1% in controlling postoperative pain and inflammation in patients undergoing pterygium surgery.

METHODS

This was an open-label, prospective, interventional, nonrandomized comparative trial. Thirty patients were assigned to one of the following groups: Group A [intracanalicular insert of 0.4 mg dexamethasone placed into upper and lower puncta during the procedure, followed by at postoperative month 1 visit institution of topical PA 1% twice daily × 2 weeks then once daily × 2 weeks] or Group B [nonintervention group with institution on postoperative day 1 topical PA 1% every 2 hours × 2 weeks then four times per day × 2 weeks then twice daily × 2 weeks then once daily × 2 weeks].

RESULTS

Fifteen cases and 15 controls were enrolled. There was no statistical difference in patient-reported pain or satisfaction between the case and control groups at 1 day; 1 week; and 1, 3, and 6 months postoperatively. There was no significant difference in time to an ocular hyperemia score of 0 between the two groups. There was no difference in the rate of corneal reepithelialization and recurrence rate (two controls). Nine eyes had transient ocular hypertension (seven cases and two controls).

CONCLUSION

Intracanalicular dexamethasone 0.4 mg may reduce the medication burden for patients who need prolonged postoperative steroid therapy as is routine in the setting of pterygium surgery. It is a safe and effective alternative to PA 1% drops alone for postoperative control of pain and inflammation in pterygium surgery.

Antinociceptive and anti-inflammatory potential, and chemical characterization of the dichloromethane fraction of Solanum lycocarpum (Solanaceae) ripe fruits by LC-DAD-MS

ETHNOPHARMACOLOGICAL RELEVANCE

Solanum lycocarpum A. St. Hil. (Solanaceae) is a species from the Brazilian Cerrado, exhibiting several medicinal properties, being used by the population in the treatment of ulcers, bronchitis, asthma and hepatitis, which involve inflammatory processes.

AIM OF THIS STUDY

This study aimed to chemically characterize the dichloromethane fraction (DCM), as well as verify its antinociceptive, anti-inflammatory and antioxidant potential.

MATERIALS AND METHODS

The DCM fraction was obtained by partitioning the ethanol extract. The chemical constituents of the DCM fraction were characterized by LC-DAD-MS. The DPPH and FRAP assays were used to evaluate the antioxidant potential. The carrageenan-induced paw edema model was used to assess the anti-inflammatory effects, and the inflammatory infiltrate was evaluated by qualitative and quantitative histological analyses. The antinociceptive action of the DCM fraction was evaluated by acetic acid-induced abdominal writhing test, formalin-induced nociception and hot-plate test.

RESULTS

Steroidal alkaloids solasonine, solasodine and solamargine, as well as the alkaloid peiminine/imperialine and caffeoylquinic acids, were annotated in DCM fraction by LC-DAD-MS. The DCM fraction showed antioxidative action in the in vitro DPPH and FRAP tests, as well as an anti-inflammatory effect for the three evaluated doses of 30, 100 and 300 mg/kg in the fourth and sixth hours after the administration of carrageenan. The histological analyses evidenced considerably reduction in leukocyte migration and the number of polymorphonuclear leukocytes. The study also demonstrated antinociceptive activity for the DCM fraction, which reduced abdominal writhing at three concentrations evaluated, as well as a decrease in paw licking in the formalin-induced nociception test both in the neurogenic phase and the inflammatory phase, with greater effectiveness compared to the anti-inflammatory indomethacin. The DCM fraction also increased the latency time of the animals in the hot plate test 60 min after treatment, although it did not seem to involve the opioidergic system.

CONCLUSION

This work evidenced that the dichloromethane fraction of S. lycocarpum fruit possesses antinociceptive and anti-inflammatory potential, which supports its use in folk medicine for management inflammatory conditions.

Antiedema and antinociceptive potential of the essential oil of Pectis elongata Kunt (Asteraceae) from the Brazilian Amazon

ETHNOPHARMACOLOGICAL RELEVANCE

Pectis elongata, a herbaceous species that is known in northern Brazil as "cominho" or "limãozinho", is traditionally used in the region for the treatment of fevers, colds, hypotension, genitourinary and gastric disorders, and pain.

AIM OF THE STUDY

Determine the chemical composition and acute oral toxicity and evaluate whether Pectis elongata essential oil (PeEO) has antiedema and antinociceptive activity.

MATERIALS AND METHODS

The chemical composition was determined using gas chromatography coupled to mass spectrometry (GC/MS) and the degree of toxicity determined by the LD50. The antiedema and antinociceptive potential was evaluated via the λ-carrageenan-induced paw edema test and formalin test, respectively.

RESULTS

Citral (geranial and neral) was characterized as a major component of the PeEO, representing 89% of the total identified compounds. According to OECD criteria (2002), the EO was considered non-toxic since it presented LD50 values over 2000 mg kg-1. Its antiedema potential was observed at doses of 200 and 400 mg kg-1 (p ≤ 0.05). At a dose of 400 mg kg-1, PeEO also showed antinociceptive potential (p ≤ 0.05), both in the neurogenic phase and in the inflammatory phase.

CONCLUSIONS

PeEO, which is rich in citral, did not induce any characteristic signs of acute oral toxicity and was also efficient in reducing carrageenan-induced paw edema, in addition to presenting antinociceptive potential and acting on both central and peripheral pain. It is thus a promising candidate for the development of a new herbal medicine with anti-inflammatory and analgesic action.

Oral treatment with Berberine reduces peripheral nociception: Possible interaction with different nociceptive pathways activated by different allogeneic substances

ETHNOPHARMACOLOGICAL RELEVANCE

Berberine was identified in extracts of Berberis ruscifolia Lam., a plant used in traditional medicine as an analgesic. Its presence may be involved in the reported pharmacological activity of this species. However, there is still a lack of scientific research concerning its analgesic activity in the peripheral nervous system.

AIM OF THE STUDY

To investigate Berb-induced antinociception in the formalin test and to evaluate several pathways related to its pharmacological antinociceptive effects in chemical models of nociception in mice.

MATERIALS AND METHODS

The antinociceptive activity of Berb was assessed by inducing the paw licking in mice with different allodynic agents. In the formalin test, the antiedematous and antithermal effect of Berb was evaluated simultaneously in the same experiment. Other nociceptive behavior produced by endogenous [prostaglandin E2 (PGE2), histamine (His), glutamate (Glu) or bradykinin (BK)] or exogenous [capsaicin (Caps) and cinnamaldehyde (Cin)] chemical stimuli, and activators as protein kinase A (PKA) and C (PKC), were also evaluated.The in vivo doses for p.o. were 3 and 30 mg/kg.

RESULTS

Berb, at 30 mg/kg p.o., showed a significant inhibition of the nociceptive action in formalin in both phases being stronger at the inflammatory phase (59 ± 9%) and more active than Asp (positive control) considering the doses evaluated. Moreover, Berb inhibited the edema (34 ± 10%), but not the temperature in the formalin test. Regarding the different nociceptive signaling pathways evaluated, the most relevant data were that the administration of p.o. of Berb, at 30 mg/kg, caused significant inhibition of nociception induced by endogenous [His (72 ± 11%), PGE2 (78 ± 4%), and BK (51 ± 7%)], exogenous [Cap (68 ± 4%) and Cinn (57 ± 5%)] compounds, and activators of the PKA [(FSK (86 ± 3%)] and PKC [(PMA(86 ± 6%)] signaling pathway. Berb did not inhibit the nociceptive effect produced by Glu.

CONCLUSION

The present study demonstrated, for the first time, the potential of Berb in several nociceptive tests, with the compound present in B. ruscifolia contributing to the analgesic effect reported for this species.

Opioid dose titration for cancer pain

BACKGROUND

Opioid dose titration is a fundamental process of opioid therapy in cancer pain.

AIMS

To assess data opioid dose titration.

METHODS

The principal opioid dose titration methods, outcomes, and modalities of administration regarding the different opioid preparations were examined in different clinical contexts.

RESULTS

Most studies suggested that opioid-naive patients should be started at doses of 15-30 mg/day of oral morphine equivalents. Opioid-tolerant patients may receive low or higher doses of oral morphine equivalents, depending on the level of opioid tolerance. Generally, dose increments of 30%-50% seem to be indicated to start dose titration. Some patients with severe excruciating cancer pain may present as an emergency requiring a rapid application of powerful analgesic strategies. The intravenous use of opioids may circumvent this problem providing a faster pain relief, due to the large availability and rapid achievement of effective plasma concentrations.

DISCUSSION

Opioid dose titration is a delicate passage in patients with cancer pain. This approach may be different according to different clinical conditions. Opioid dose titration requires expertise to optimize cancer pain management while minimizing the development of adverse effects.

CONCLUSION

While most approaches are meaningful and partially supported by existing literature, more studies are necessary to establish advantages and disadvantages in different clinical conditions. Optimization of opioid dose titration is of paramount importance.

SIGNIFICANCE

This review provides the most recent insights on the different modalities of opioid dose titration in cancer pain management.

Nalbuphine-6-glucuronide is a potent analgesic with superior safety profiles by altering binding affinity and selectivity for mu-/kappa-opioid receptors

Although nalbuphine, a semi-synthetic analgesic compound, is less potent than morphine in terms of alleviating severe pain, our recent findings have revealed that nalbuphine-6-glucuronide (N6G), one of the glucuronide metabolites of nalbuphine, promotes a significantly more robust analgesic effect than its parent drug. Nevertheless, despite these promising observations, the precise mechanisms underlying the analgesic effects of nalbuphine glucuronides have yet to be determined. In this study, we aim to elucidate the mechanisms associated with the analgesic effects of nalbuphine glucuronides. Pharmacokinetic and pharmacodynamic studies were conducted to investigate the relationship between the central and peripheral compartments of nalbuphine and its derivatives. The analgesic responses of these compounds were evaluated based on multiple behavioral tests involving thermal and mechanical stimuli. Radioligand binding assays were also performed to determine the binding affinity and selectivity of these compounds for different opioid receptors. The results of these tests consistently confirmed that the heightened analgesic effects of N6G are mediated through its enhanced binding affinity for both mu- and kappa-opioid receptors, even comparable to those of morphine. Notably, N6G exhibited fewer side effects and did not induce sudden death, thereby highlighting its superior safety profile. Additionally, pharmacokinetic studies indicated that N6G could cross the blood-brain barrier when administered peripherally, offering pain relief. Overall, N6G provides great analgesic efficacy and enhanced safety. These findings highlight the potential value of nalbuphine glucuronides, particularly N6G, as promising candidates for the development of novel analgesic drugs.

Buprenorphine Versus Diclofenac for Pain Relief in Acute Pancreatitis: A Double-Blinded Randomized Controlled Trial

BACKGROUND

Although both nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids are used for analgesia in acute pancreatitis (AP), the analgesic of choice is not known. We compared buprenorphine, an opioid, and diclofenac, an NSAID, for analgesia in AP.

METHODS

In a double-blind randomized controlled trial, AP patients were randomized to receive intravenous diclofenac or intravenous buprenorphine. Fentanyl was used as rescue analgesia, delivered through a patient-controlled analgesia pump. Primary outcome was the difference in the dose of rescue fentanyl required. Secondary outcomes were the number of effective and ineffective demands of rescue fentanyl, pain-free interval, reduction in visual analogue scale (VAS) score, adverse events, and organ failure development.

RESULTS

Twenty-four patients were randomized to diclofenac and 24 to buprenorphine. The 2 groups were matched at baseline. The total amount of rescue fentanyl required was significantly lower in the buprenorphine group:130 μg, interquartile range (IQR), 80-255 vs 520 μg, IQR, 380-1065 (P < .001). The number of total demands was 32 (IQR, 21-69) in the diclofenac arm vs 8 (IQR, 4-15) in the buprenorphine arm (P < .001). The buprenorphine group had more prolonged pain-free interval (20 vs 4 hours; P < .001), with greater reduction in the VAS score at 24, 48, and 72 hours compared with the diclofenac group. These findings were confirmed in the subgroup of moderately severe/severe pancreatitis. Adverse events profile was similar in the 2 groups.

CONCLUSIONS

Compared with diclofenac, buprenorphine appears to be more effective and equally safe for pain management in AP patients, even in the subcohort of moderately severe or severe pancreatitis (Trial Registration number: CTRI/2020/07/026914).

Chemical composition and potential antioxidant, anti-inflammatory, and analgesic efficacy of Cistus albidus L

This study aims to assess the chemical composition of the aqueous extract of Cistus albidus L. leaves, as well as the potential of aqueous and hydroethanol extracts of the leaves and seeds as analgesic, anti--inflammatory, and antioxidant agents. The contents of phenolics and inorganic constituents were determined in C. albidus seeds and leaves; antioxidant capacity was assessed by 3 complementary and diverse tests. The carrageenan-induced paw edema technique was used to investigate the anti-inflammatory effect in vivo, and albumin denaturation to evaluate the anti-inflammatory effect in vitro. The acetic acid-induced contortion test, the tail-flick test, and the plantar test were used to assess the analgesic effi cacy in vivo. Chemical analysis was performed by UPLC-MS/MS to quantify several phenolic compounds including catechin (1,627.6 mg kg-1), quercitrin (1,235.8 mg kg-1) and gallic acid (628. 2 mg kg-1). The ICP analysis revealed that potassium and calcium were the main inorganic components in the seeds and leaves of C. albidus. The hydroethanolic extract of the leaves showed the highest content of polyphenols/flavonoids, whereas the highest value of proantho cyanidins was detected in the aqueous extract of the seeds. All extracts showed potent antioxidant activity related to different phenolic compounds (quercetin, gallic acid, astragalin, catechin, and rutin). The aqueous extract of the leaves strongly inhibited paw edema (76.1 %) after 6 h of treatment and showed maximal inhibition of protein denaturation (191.0 µg mL-1 for 50 % inhibition) and analgesic activity in different nociceptive models. The presented data reveal that C. albidus extracts potentially show antioxidant, anti-inflammatory, and analgesic activities that could confirm the traditional use of this plant.

Transient Worsening of Pain After Administration of Immune Checkpoint Inhibitors - A Case Series

BACKGROUND/AIM

Transient pain enhancement or flare pain, is observed following the administration of immune checkpoint inhibitors (ICIs). However, the detailed mechanism of this phenomenon remains unclear. In this report, we present our experience of documenting the course of flare pain following ICI administration in six cases.

PATIENTS AND METHODS

Six patients with advanced solid tumors received ICI monotherapy between July 2017 and November 2019. Their pain increased within hours of ICI administration despite being stable before ICI administration. We evaluated the changes in the numerical rating scale (NRS) score over 72 h after ICI administration.

RESULTS

Four non-small cell lung cancer patients, one gastric cancer patient, and one renal cell cancer patient were included. Four patients experienced an increase in NRS, as evidenced by scores on two or more scales compared to the day before administration, whereas two patients showed an increase only on one scale. The NRS score decreased to almost the same level as that on the day before administration. Flare pain is observed in the same area as the primary site. Most of the pain was alleviated without the need for rescue analgesics, although one patient experienced a 4-point increase in the NRS scale.

CONCLUSION

Flare pain may occur following ICI administration. Healthcare providers should be aware of these events and provide patients with suitable information and coping techniques.

Baseline Characteristics of Fabry Disease "Amenable" Migalastat Patients in Argentinian Cohort

Fabry disease (FD) is a multisystem lysosomal storage disorder induced by genetic variants in the alpha-galactosidase A (αGalA) gene. Some FD patients have GLA variants with a reduction in overall αGalA enzymatic activity due to mutated proteins with reduced stability, caused by protein misfolding and premature degradation, but the αGalA catalytic activity remains conserved ("amenable" genetic variants). To correct this misfolding and to prevent premature degradation, migalastat, a small iminosugar molecule was developed. We report the clinical characteristics of FD "amenable" cohort patients from Argentina, prior to starting treatment with migalastat. Seventeen Fabry adult patients were recruited from 13 Argentinian Centers; 8 males (47.1%) and 9 females (52.9%) were included. All genotypes included were missense-type "amenables" mutations. Some classic FD typical early manifestations were more frequent in patients with "classic" versus "late-onset" FD phenotype (pain, p=0.002; cornea verticillata, p=0.019). There was a statistically significant difference in estimated glomerular filtration rate in the "classic" versus "late-onset" phenotype (p=0.026) but no difference between genders (p=0.695). Left ventricular mass was similar between genders (p=0.145) and phenotypes (p=0.303). Cardiovascular risk factors were present among "late-onset" females (obesity 50% and smoke 25%). In patients who started "de novo" migalastat, the main indications were (i) heart disease, (ii) kidney damage, and (iii) pain, while in "switched from prior enzyme replacement therapy" patients, the most frequent indication was "patient decision;" this coincides with publications by other authors.

Thiophenpiperazine amide derivatives as new dual MOR and σ1R ligands for the treatment of pain

A new series of thiophenpiperazine amide derivatives as potent dual ligands for the μ-opioid (MOR) and sigma-1 (σ1R) receptors are reported. Compound 23 exhibited good affinity to σ1R (Ki = 44.7 ± 7.05 nM) and high selectivity to σ2R. Furthermore, Compound 23 exerted MOR agonism and σ1R antagonism and potent analgesic activity in animal moldes (the abdominal constriction test (ED50 = 3.83 mg/kg) and carrageenan-induced inflammatory hyperalgesia model (ED50 = 5.23 mg/kg)). We obtained new dual ligands that might serve as starting points for preparing targeted tools. Furthermore, 23 may be a useful chemical probe for understanding more fully analgesic effects associated with MOR agonism and σ1R antagonism.

Toward reducing racialized pain care disparities: Approaching cannabis research and access through the lens of equity and inclusion

There is growing interest in cannabis use for cancer pain. This commentary aims to discuss the evidence surrounding cannabis use for cancer pain in the context of the long-racialized landscape of cannabis policies and the disparity in pain control among cancer patients holding minoritized racial identities. Much evidence surrounding both the benefits and harms of cannabis use in cancer patients, and all patients in general, is lacking. Although drawing on the research in cancer that is available, it is also important to illustrate the broader context about how cannabis' deep roots in medical, political, and social history impact patient use and health care policies. There are lessons we can learn from the racialized disparities in opioid risk mitigation strategies, so they are not replicated in the settings of cannabis for cancer symptom management. Additionally, the authors intentionally use the term "cannabis" here rather than "marijuana.: In the early 1900s, the lay press and government popularized the use of the word "marijuana" instead of the more common "cannabis" to tie the drug to anti-Mexican prejudice.

Differences in prescribed medicinal cannabis use by cannabinoid product composition: Findings from the cannabis as medicine survey 2020 (CAMS-20) Australia-wide study

INTRODUCTION

Prescribed medicinal cannabis (MC) is an increasingly common prescription in Australia for treating pain, anxiety, and sleep disorders. Prescribed MC products generally contain tetrahydrocannabinol (THC) and/or cannabidiol (CBD) in a variety of dose levels and forms. It is unclear whether THC and CBD products are used by patients with different characteristics and for different conditions.

OBJECTIVES

To examine consumer experiences of using THC- and CBD-containing prescribed MC products to better understand how they are being used within the Australian context.

METHODS

We utilised data collected from an online anonymous cross-sectional survey of individuals (CAMS-20 survey), consisting of Australian residents using cannabis for therapeutic reasons. We focused on a subgroup of participants (N = 546) receiving prescribed MC products. We utilised linear, logistic, and multinomial regression modelling to analyse responses to survey questions based on the cannabinoid profile of the prescribed product.

RESULTS

Participants prescribed THC-dominant MC products were statistically more likely to be younger, male, and to prefer inhaled routes of administration than participants using CBD-dominant products who were older, female, and preferred oral routes of administration. Pain and mental health were the most common reasons for all types of prescribed MC, but were more likely to be treated with THC than CBD despite the significantly higher risk of mild to severe drowsiness, dry mouth and eye irritation. Consumer reported effectiveness of prescribed MC was very positive, particularly for THC-containing products. Consumers on opioids and antipsychotics were statistically more likely to be prescribed THC-containing products than products containing CBD only, despite the greater risk of impairment.

CONCLUSIONS

This Australia-wide study found clear differences in consumer-reported experiences of prescribed THC- and CBD-containing products. Current prescriptions of these products do not always align with relevant clinical guidance. Educating prescribers around cannabinoid products is essential to ensure optimal prescribing practices and to prevent avoidable drug side effects and interactions.

Nyctanthes arbor-tristis bioactive extract ameliorates LPS-induced inflammation through the inhibition of NF-κB signalling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Nyctanthes arbor-tristis L. is a mythical plant used in traditional Indian medicinal systems for the treatment of inflammation, rheumatoid arthritis, and pain-related responses. However, its bioactive compounds and underlying mechanism of action have not been fully elucidated.

AIM OF THE STUDY

This investigation aimed to study the anti-inflammatory and anti-nociceptive effects of the bioactive extract of N. arbor-tristis (NATE), both in vitro and in vivo, elucidate the possible mechanism of action, and determine its chemicals.

MATERIALS AND METHODS

We studied the anti-inflammatory and anti-nociceptive activities of NATE on lipopolysaccharide-stimulated RAW264.7 macrophages, paw-ear edema, and acetic acid-induced pain in rats and analysed its chemical components using Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC-ESI-MS).

RESULTS

NATE efficiently reduced the production of various inflammatory mediators and factors, such as free radicals, lipid peroxidation, nitrous oxide (NO), reactive oxygen species (ROS), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNFα), interleukin-6 (IL-6), interleukin-1beta (IL-1β), and IL-10, as well as their corresponding mRNA expression in LPS-induced RAW264.7 cells (p < 0.001). Furthermore, NATE inhibited the activation of a key signaling pathway, nuclear factor-kappa B (NF-kB), as it caused a decrease in the degradation of inhibitor of kB alpha (IkBa). Administration of NATE significantly inhibited carrageenan-induced paw edema (p < 0.001), TPA-induced ear edema, and the production of inflammatory factors (p < 0.01). NATE revealed anti-nociceptive impacts in acetic acid-induced writhing and tail immersion experiments (p < 0.001) as well as no toxicity signs. A total of six compounds, namely iridoid glycoside (6,7-di-O-benzonylnyctanthoside), arborsides A, arborsides C, betulinic acid, kaempferol 3-O-glucoside, and kaempferol 3-O-rutinoside, were characterized through the examination of their mass spectra in correlation with those documented in a database of mass spectra.

CONCLUSIONS

The present study furnishes scientific corroboration of the inhibitory potency of N. arbor-tristis as a promising herbal treatment for inflammation and pain responses without toxicity, offering a scientific basis for future drug development strategies aimed at ameliorating inflammatory diseases.

Intravesical Botulinum Toxin Injection Plus Hydrodistention Is More Effective in Patients with Bladder Pain-Predominant Interstitial Cystitis/Bladder Pain Syndrome

Intravesical botulinum toxin A (BoNT-A) injections are included in the interstitial cystitis/bladder pain syndrome (IC/BPS) treatment guidelines. However, the IC phenotype suitable for treatment with BoNT-A has not been clarified. Therefore, we identified the factors influencing treatment outcomes for intravesical BoNT-A injections in patients with non-Hunner IC/BPS (NHIC). This retrospective study included patients with NHIC who underwent 100 U BoNT-A intravesical injections over the past two decades. Six months after treatment, treatment outcomes were assessed using the Global Response Assessment (GRA). Outcome endpoints included GRA, clinical symptoms, urodynamic parameters, urine biomarkers, and the identification of factors contributing to satisfactory treatment outcomes. The study included 220 patients with NHIC (42 men, 178 women). The satisfactory group (n = 96, 44%) had significantly higher pain severity scores and IC symptoms index, larger maximum bladder capacity (MBC), and lower 8-isoprostane levels at baseline. Logistic regression revealed that larger MBC (≥760 mL) and bladder pain predominance were associated with satisfactory outcomes after BoNT-A injection. Subjective parameters and pain severity scores improved significantly in patients with bladder pain-predominant IC/BPS after BoNT-A injection. Thus, NHIC patients with bladder or pelvic pain are more likely to experience satisfactory outcomes following intravesical BoNT-A injections.

Qingchang suppositry induced remission in patients with mild-to-moderate ulcerative proctitis: a multicenter, prospective, randomized, parallel-controlled clinical trial

OBJECTIVE

To evaluate the efficacy and safety of Qingchang suppository (, QCS), a preparation of Chinese herbal medicine, in the induction of remission in patients with mild-to-moderate ulcerative proctitis (UP).

METHODS

We performed a multicenter, prospective, randomized, parallel-controlled trial to evaluate the efficacy of QCS induction therapy in 140 adult patients with mild-to-moderate UP and TCM syndrome of dampness-heat in large intestine. The patients were randomized to receive QCS (study group) or Salicylazosulfapyridine (SASP) suppository (control group) one piece each time, twice a day, per anum for 12 weeks. Mayo score and main symptoms score were evaluated at weeks 0, 2, 4, 8 and 12, rectosigmoidscopy was taken at weeks 0, 4, 8 and 12, Geboes score, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and safety indexes were assessed at weeks 0 and 12. The primary efficacy endpoint is clinical remission rate, the secondary efficacy endpoints are clinical response rate, mucosa healing rate, Geboes score, the remission rates of the main symptoms, the median day to the remission of the symptom, etc. RESULTS: There were no statistical difference in the clinical remission rates, the clinical response rates, the mucosa healing rates, Geboes score, ESR and CRP between the two groups. The remission rates of tenesmus and anal burning sensation of the study group were significantly higher than those of the control group (76.5% vs 25.0%, P = 0.009; 74.51% vs 29.63%, P = 0.003). The median day to the remission of purulent bloody stool of the study group was significantly less than that of control group [11 (1, 64) vs 19 (2, 67), P = 0.007]. The patients receiving QCS had a significantly higher mucosa healing rate at week 4 than the patients receiving SASP suppository (71.42% vs 52.85%, P = 0.023). No adverse event occurred in the study group while the adverse events incidence of the control group was 5.7% (P = 0.049).

CONCLUSIONS

QCS could induce the remission of UP as effectively and safely as SASP suppository, and was superior to SASP suppository in relieving the symptoms of tenesmus, anal burning sensation and purulent bloody stool and the time to reach mucosa healing.

Chronic restraint stress and social transfer of stress produce tactile allodynia mediated by the HMGB1/TNFα/TNFR1 pathway in female and male rats

Previous studies have shown the relevance of high mobility group box 1 protein (HMGB1) and tumor necrosis factor α (TNFα) in nerve or tissue injury-induced nociception. However, the role of these proteins in chronic stress and social transfer of stress (STS)-induced dysfunctional pain is not entirely known. The aim of this study was to determine the participation of the spinal HMGB1-TNFα signaling pathway and TNFα receptor 1 (TNFR1) in rats subjected to chronic restraint stress (CRS) and STS. Non-stressed female and male rats in contact with CRS rats increased sniffing behavior of the anogenital area, behavior related to STS. Rats subjected to CRS and STS reduced 50 % withdrawal threshold and reached the value of tactile allodynia after 21 days of stress. Rats return to the basal withdrawal threshold after 30 days without stress and return to allodynia values in only 5 days of stress sessions (priming). Female and male rats subjected to 28 days of CRS or STS were intrathecal injected with glycyrrhizin (inhibitor of HMGB1), thalidomide (inhibitor of the TNFα synthesis), and R7050 (TNFR1 antagonist), in all the cases, an antiallodynic effect was observed. Rats under CRS or STS enhanced HMGB1 and TNFR1 protein expression in DRG and dorsal spinal cord. Data suggest that the spinal HMGB1/TNFα/TNFR1 signaling pathway plays a relevant role in the maintenance of CRS and STS-induced nociceptive hypersensitivity in rats. These proteins could be helpful in developing pain treatments for fibromyalgia in humans.

Cold pressed Pinus halepensis Mill. seed oil for potential health applications: Analgesic, anti-inflammatory effects, and assessment of inflammatory mediators by RT-qPCR in skin wound healing

ETHNOPHARMACOLOGICAL RELEVANCE

Pinus halepensis Mill. seed (Pinaceae), commonly known as "Zgougou," is widely consumed in the Mediterranean region and has long been used to treat diseases including bronchitis, rheumatism, infection, and inflammation.

AIM OF THE STUDY

The present study was focused on the investigation of some pharmacological activities, such as analgesic, anti-inflammatory, and wound healing effects, of cold-pressed oil of Pinus halepensis Mill. seed (COPHS).

MATERIALS AND METHODS

The fixed oil of Pinus halepensis seed was extracted by a cold pressing process. The analgesic activity of COPHS was examined by acetic acid and formalin-induced contortion and pain tests. The anti-inflammatory effects were evaluated in carrageenan and formalin induced paw and ear edema models. Wound healing potential was assessed on an experimental skin wound, and the expression levels of inflammation mediators were determined by RT-qPCR in skin wound healing.

RESULTS

The results showed analgesic efficacy through significant inhibition of abdominal cramps (59.15%) and pain (75.91%). In addition, this oil exerted an anti-inflammatory effect by inhibiting ear (62.25%) and paw (70.00%) edema. The COPHS stimulated wound contraction in experimental skin wound healing with a contraction rate of 89.23% with notable reduction of TNF-α and NF-kB expression levels in the treated groups.

CONCLUSIONS

This study provided for the first time the pharmacological profile, particularly the analgesic, anti-inflammatory, and healing effects, of fixed oil extracted by cold pressing from the seed of Pinus halepensis Mill.

Exploring the therapeutic potential of Prinsepia utilis Royle seed oil: A comprehensive study on chemical composition, physicochemical properties, anti-inflammatory, and analgesic activities

ETHNOPHARMACOLOGICAL RELEVANCE

Prinsepiautilis (PU) Royle, native to the Himalayan region, is a deciduous thorny shrub with numerous traditional uses of its roots, leaves and seeds for treatment of conditions such as rheumatic pain, joint pain, arthritis, and inflammation.

AIM OF THE STUDY

Keeping in mind the growing demand of products of natural origin as alternate medicine, the present study was undertaken to scientifically validate for the first time the traditional claims of healing pain and inflammation by evaluating the fatty oil isolated from the seeds using established in vitro and in vivo models.

MATERIALS AND METHODS

PU Seeds were Soxhlet extracted using n-hexane and fatty oil was isolated. Chemical composition of the oil was established with the aid of Gas Chromatography-Flame Ionization Detection (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS). The oil was then subjected to in vitro anti-inflammatory activity by following the established protocols of trypsin inhibitory and bovine serum albumin denaturation assays. The acute toxicity of the oil was also studied using OECD guidelines 423. The anti-inflammatory property of the oil was further evaluated using carrageenan-induced and formalin-induced edema in the rat paw. Moreover, hot plate latency and tail immersion assay were employed to evaluate analgesic activity of the oil. To establish the quality of the oil, various physicochemical properties were also studied.

RESULTS

GC-FID and GC-MS analysis of the oil revealed the presence of linoleic acid (59.06 ± 0.00%), oleic acid (28.11 ± 0.01%), palmitic acid (9.51 ± 0.01%) and stearic acid (3.32 ± 0.01%). In vitro trypsin inhibitory and bovine serum albumin denaturation assay revealed dose-dependent notable activity of the oil with IC50 value of 63.57 μg/mL and 518.14 μg/mL, respectively. The physico-chemical characterization demonstrated that the oil possesses a low acidity and a high oxidative stability index. The oil was found to be non-toxic and displayed effective anti-inflammatory activities with significant inhibition till 4 h in carrageenan-induced and formalin-induced rat paw edema at maximum tested dose of 200 mg/kg b.w. The oil also exhibited significant results in hot plate latency and tail immersion assay with positive effects showing up to 4 h after dose administration.

CONCLUSION

These findings, besides supporting the traditional claims, suggest that P. utilis seed oil has potential therapeutic applications as a natural anti-inflammatory and analgesic agent. Further studies are warranted to explore its mechanisms of action and potential use in pharmaceutical and nutraceutical industries.

The safety of remimazolam versus propofol in gastroscopic sedation: a meta-analysis

BACKGROUND

This meta-analysis was designed to compare the safety and efficiency of remimazolam with those of propofol in patients undergoing gastroscope sedation.

METHODS

We searched PubMed, Cochrane Library, Embase, Ovid, Wanfang Database, China National Knowledge Infrastructure, SINOMED, and ClinicalTrials.gov for studies that reported on remimazolam versus propofol for gastroscope sedation from establishment to February 25, 2023. The sedative efficiency and the incidence of adverse events were assessed as outcomes. Version 2 of the Cochrane risk-of-bias assessment tool was used to assess the risk of bias. Review Manager 5.4 and STATA 17 were used to perform all statistical analyses.

RESULTS

A total of 26 randomized controlled trials involving 3,641 patients were included in this meta-analysis. The results showed that remimazolam had a significantly lower incidence of respiratory depression (risk ratio [RR] = 0.40, 95% confidence interval [CI]: 0.28-0.57; p < 0.01, GRADE high), hypoxemia (RR = 0.34, 95% CI: 0.23-0.49; p < 0.01, GRADE high), bradycardia (RR = 0.34, 95% CI: 0.23-0.51; p < 0.01, GRADE high), dizziness (RR = 0.45, 95% CI: 0.31-0.65; p < 0.01, GRADE high), injection site pain (RR = 0.06, 95% CI: 0.03-0.13; p < 0.01, GRADE high), nausea or vomiting (RR = 0.79, 95% CI: 0.62-1.00; p = 0.05, GRADE moderate), and hypotension (RR = 0.36, 95% CI: 0.26-0.48; p < 0.01, GRADE low).

CONCLUSIONS

Remimazolam can be used safely in gastroscopic sedation and reduces the incidence of respiratory depression, hypoxemia, bradycardia, injection site pain, and dizziness compared with propofol, and doesn't increase the incidence of nausea and vomiting.

Spinal interleukin-16 mediates inflammatory pain via promoting glial activation

Proinflammatory cytokines are crucial contributors to neuroinflammation in the development of chronic pain. Here, we identified il16, which encodes interleukin-16 (IL-16), as a differentially expressed gene in spinal dorsal horn of a complete Freund's Adjuvant (CFA) inflammatory pain model in mice by RNA sequencing. We further investigated whether and how IL-16 regulates pain transmission in the spinal cord and contributes to the development of inflammatory pain hypersensitivity. RNA sequencing and bioinformatics analysis revealed elevated IL-16 transcript levels in the spinal dorsal horn after CFA injection. This increase was further confirmed by qPCR, immunofluorescence, and western blotting. Knockdown of IL-16 by intrathecal injection of IL-16 siRNA not only attenuated CFA-induced mechanical and thermal pain hypersensitivity, but also inhibited enhanced c-fos expression and glial activation in the spinal dorsal horn in male mice injected with CFA. Moreover, exogenous IL-16 induced nociceptive responses and increased c-fos expression and glial activation in spinal dorsal horn. This effect was largely impaired when CD4, the binding receptor for IL-16, was inhibited. In addition, CD4 expression was upregulated in the spinal dorsal horn after CFA injection and CD4 was present in microglia and in contact with astrocytes and activated spinal neurons. Taken together, these results suggest that enhanced IL-16-CD4 signaling triggers pain and activates microglia and astrocytes in the spinal dorsal horn, thus contributing to inflammatory pain. IL-16 may serve as a promising target for the treatment of inflammatory pain.

Essential oil from leaves of Croton blanchetianus Baill does not present acute oral toxicity, has antigenotoxic action and reduces neurogenic and inflammatory nociception in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Croton blanchetianus Baill., popularly known as "marmeleiro preto", is an endemic plant from Brazil, being found mainly in the Northeast region. In traditional medicine, the use of medicines based on the leaves of this plant has been reported for the treatment of inflammatory processes, pain, urethral pain, gastrointestinal disorders, rheumatism and headache.

AIM OF THE STUDY

The present work describes the chemical characterization, as well as toxicological evaluation and antinociceptive activity of an essential oil of C. blanchetianus leaves (EOCb).

MATERIALS AND METHODS

The chemical constituents of the oil were identified by gas chromatography coupled to mass spectrometry (GC-MS). In vitro hemolytic activity was tested using mouse blood. Acute toxicity in mice was assessed by the oral or intraperitoneal administration of a single dose of 2000 mg/kg b.w. EOCb (1000 and 2000 mg/kg) was also evaluated for genotoxicity and antigenotoxicity in vivo using the micronucleus test. The antinociceptive activity of EOCb (25, 50 and 100 mg/kg) was evaluated through the abdominal writhing, formalin and tail flick tests.

RESULTS

The chemical characterization indicated as major components α-pinene (21.23%), β-phelandrene (13.92%), terpinolene (13.01%) and germacrene D (10.89%). EOCb did not cause hemolysis and was also neither toxic nor genotoxic, while protected the animals' bone marrow cells from damage caused by cyclophosphamide in oral treatment. However, all animals died after 15 min of intraperitoneal treatment. There was a reduction in the number of abdominal contortions (69.43-89.41%) as well as in licks in the first (38.77-84.47%) and second (59.75-90.74%) phases of the formalin test. In the latter case, the effects were reduced by naloxone and glibenclamide, indicating action via the opioid system and blockage of K+ channels. The latency time in the tail flick test also increased significantly.

CONCLUSION

In conclusion, ingestion of EOCb proved to be safe when administered orally; however, it was lethal intraperitoneally. Additionally, EOCb protected mouse blood cell DNA against the action of cyclophosphamide and showed an antinociceptive effect via the opioid system and dependent on K+ channels.

Curcuma latifolia Roscoe extract reverses inflammatory pain in mice and offers a favorable CNS safety profile

ETHNOPHARMACOLOGICAL RELEVANCE

Curcuma latifolia Roscoe, a plant in the Curcuma genus, has been used as a food additive and folk medicine in Thailand to treat pelvic pain and improve premenstrual syndrome. Although it has been used for centuries, no scientific studies have proved its potential effects on inflammatory pain and central nervous system (CNS) safety profiles.

AIM OF THE STUDY

This study aimed to evaluate the potential effects of the ethanolic extract of C. latifolia rhizome on inflammatory pain in mice, together with its CNS safety profiles.

MATERIALS AND METHODS

First, network pharmacology was employed to identify the role of bioactive constituents in C. latifolia on inflammatory pain. In addition, in vitro pharmacology was also evaluated to confirm the anti-inflammatory activity of C. latifolia extract at cellular levels in activated macrophages and microglia. Furthermore, the efficacy of the plant extract in attenuating formalin-induced pain-like behaviors in mice was evaluated. Mice were orally administered the extract (125, 250, 500 mg/kg) followed by the measurement of formalin-induced pain-like behaviors. The LABORAS automated behavioral analysis and rotarod test were used to assess potential CNS side effects of C. latifolia extract (500 mg/kg) in mice.

RESULTS

The results demonstrated that major bioactive constituents present in C. latifolia have the ability to regulate multiple targets, biological processes and pathways associated with inflammatory pain as assessed by network pharmacology. C. latifolia modulated peripheral and central immune cells via reducing proinflammatory mediators (NO, TNF-α, and IL-6). C. latifolia extract improved formalin-induced pain-like behaviors in a dose-dependent manner during phase II of the formalin test. The efficacy of the plant extract at doses of 250 and 500 mg/kg was comparable to that of the positive control (indomethacin 10 mg/kg). Furthermore, the highest therapeutic dose of the extract did not affect motor coordination, exploratory behaviors, general behaviors, and overall well-being of mice, indicating no development of potential CNS adverse effects after administration of the extract.

CONCLUSION

These findings provide novel perspectives on using C. latifolia extract for pain management, considering its therapeutic efficacy and CNS safety.

Arabinan-rich pectic polysaccharide fraction from Malpighia emarginata fruits alleviates inflammatory pain in mice

Malpighia emarginata (Malpighiaceae), popularly known as "acerola", is a tropical and subtropical fruit native to the Americas. Despite its high vitamin C content, which gives it a high antioxidant property, soluble dietary fibers, such as polysaccharides, are also abundant constituents of acerola (10% of the dried fruit). The acerola cold-water soluble (ACWS) fraction presented anti-fatigue and antioxidant effects in vivo and in vitro. To infer further systemic effects of ACWS, this study aimed to investigate the antinociceptive, anti-inflammatory, and antioxidant effects of ACWS in murine models of pain. In formalin-induced nociception, ACWS (0.1, 1, and 10 mg/kg) reduced only the inflammatory phase, and also (10 and 30 mg/kg) attenuated the acetic acid-induced writhing and leukocyte migration in the peritoneal cavity. The mechanical allodynia and paw edema induced by intraplantar injection of carrageenan were greatly reduced by ACWS (10 mg/kg). At the inflammatory pick induced by carrageenan (4 h), ACWS significantly reduced myeloperoxidase activity, TNF-α, IL-1β, and PGE2 levels, and restored IL-10 levels. ACWS also exhibited antioxidant properties by decreasing lipid hydroperoxides content, increasing GSH levels, and restoring superoxide dismutase and catalase activities in the carrageenan model and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay. Collectively, these results support the antinociceptive, anti-inflammatory, and antioxidant effects of ACWS and reveal a promising candidate for the treatment of inflammatory pain conditions.

The Opioid Analgesic Reduction Study (OARS) Pilot: A Double-Blind Randomized Multicenter Trial

BACKGROUND

With addiction rates and opioid deaths increasing, health care providers are obligated to help stem the opioid crisis. As limited studies examine the comparative effectiveness of fixed-dose combination nonopioid analgesia to opioid-containing analgesia, a comparative effectiveness study was planned and refined by conducting a pilot study.

METHODS

The Opioid Analgesic Reduction Study (OARS) pilot, a stratified, randomized, multisite, double-blind clinical trial, was designed to test technology and procedures to be used in the full OARS trial. Participants engaged in the full protocol, enabling the collection of OARS outcome data. Eligible participants reporting to 1 of 5 sites for partial or full bony impacted mandibular third molar extraction were stratified by biologic sex and randomized to 1 of 2 treatment groups, OPIOID or NONOPIOID. OPIOID participants were provided 20 doses of hydrocodone 5 mg/acetaminophen 300 mg. NONOPIOID participants were provided 20 doses of ibuprofen 400 mg/acetaminophen 500 mg. OARS outcomes data, including pain experience, adverse effects, sleep quality, pain interference, overall satisfaction, and remaining opioid tablets available for diversion, were collected via surveys, electronic medication bottles, eDiary, and activity/sleep monitor.

RESULTS

Fifty-three participants were randomized with 50 completing the OARS pilot protocol. Across all outcome pain domains, in all but 1 time period, NONOPIOID was better in managing pain than OPIOID (P < 0.05 level). Other outcomes suggest less pain interference, less adverse events, better sleep quality, better overall satisfaction, and fewer opioid-containing tablets available for diversion.

DISCUSSION

Results suggest patients requiring impacted mandibular third molar extraction would benefit from fixed-dose combination nonopioid analgesia.

KNOWLEDGE TRANSFER STATEMENT

Study results suggest fixed-dose nonopioid combination ibuprofen 400 mg/acetaminophen 500 mg is superior to opioid-containing analgesic (hydrocodone 5 mg/acetaminophen 500 mg). This knowledge should inform surgeons and patients in the selection of postsurgical analgesia.

Is it possible to predict which patients are most likely to benefit from intra-articular corticosteroid injections? A systematic review

AIM

Intra-articular corticosteroid injections (IACIs) can reduce osteoarthritis-related pain, with differing levels of response across patient groups. This systematic review investigates what is known about the positive and negative predictors of outcomes in patients with osteoarthritis who undergo IACIs.

METHODS

We systematically searched the Medline, Embase, and Cochrane databases to May 2023 for studies that evaluated patients undergoing IACIs for osteoarthritis and reported on predictors of outcomes in these patients.

RESULTS

Eight studies were included. Two were placebo-controlled trials, six were observational studies. Due to the heterogeneity of outcomes and variables between the studies, it was not possible to pool the results for formal meta-analysis. Higher baseline pain, older age, higher BMI, lower range of movement, higher Kellgren-Lawrence radiographic score, joint effusion, and aspiration were shown to be predictors of a positive response to IACIs in some of the included studies. However, other studies showed no difference in response with these variables, or a negative correlation with response. Sex, smoking, mental health status, hypertension/ischaemic heart disease, diabetes mellitus, duration of symptoms, and socioeconomic status did not demonstrate any correlation with the prediction of positive or negative outcomes after IACIs.

CONCLUSION

Several patient features have been identified as positive predictors of outcomes following IACIs. However, this systematic review has identified inconsistent and variable findings across the existing literature. Further research with standardization of IACI administration and outcome measures is required to facilitate further analysis of the reliability and significance of predictive factors for response to IACIs.

Peptide toxins that target vertebrate voltage-gated sodium channels underly the painful stings of harvester ants

Harvester ants (genus Pogonomyrmex) are renowned for their stings which cause intense, long-lasting pain, and other neurotoxic symptoms in vertebrates. Here, we show that harvester ant venoms are relatively simple and composed largely of peptide toxins. One class of peptides is primarily responsible for the long-lasting local pain of envenomation via activation of peripheral sensory neurons. These hydrophobic, cysteine-free peptides potently modulate mammalian voltage-gated sodium (NaV) channels, reducing the voltage threshold for activation and inhibiting channel inactivation. These toxins appear to have evolved specifically to deter vertebrates.

Efficacy and Safety of Rimegepant for Migraine Patients: A Meta-analysis of Randomized Controlled Studies

OBJECTIVES

Rimegepant may have some potential in treating migraine, and this meta-analysis aims to study the efficacy and safety of rimegepant for migraine patients.

METHODS

We have searched several databases including PubMed, Embase, Web of Science, EBSCO, and Cochrane Library databases and selected the randomized controlled trials comparing the efficacy of rimegepant versus placebo for migraine patients. This meta-analysis was conducted using the random- or fixed-effect model based on the heterogeneity.

RESULTS

Three randomized controlled trials were included in this meta-analysis. Compared with placebo in migraine patients, rimegepant treatment was associated with substantially improved freedom from pain at 2 hours (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.69-2.59; P < 0.00001), pain relief at 2 hours (OR, 1.93; 95% CI, 1.65 to 2.25; P < 0.00001), freedom from the most bothersome symptom at 2 hours (OR, 1.61; 95% CI, 1.35-1.91; P < 0.00001), ability to function normally at 2 hours (OR, 1.69; 95% CI, 1.42-2.01; P < 0.00001), sustained freedom from pain at 24 hours (OR, 2.88; 95% CI, 1.74-4.78; P < 0.0001), sustained pain relief at 24 hours (OR, 2.31; 95% CI, 1.96-2.72; P < 0.00001), and no rescue medication (OR, 2.42; 95% CI, 2.02-2.90; P < 0.00001) but showed no obvious impact on adverse events (OR, 1.27; 95% CI, 1.01-1.60; P = 0.04).

CONCLUSIONS

Rimegepant may be effective and safe for the treatment of migraine patients.

Needle-Free Jet Injector-Assisted Triamcinolone Treatment of Keloids and Hypertrophic Scars is Effective and Well Tolerated in Children

BACKGROUND

Keloids and hypertrophic scars can cause severe pain, pruritus, and psychological distress. Conventional intralesional corticosteroid treatment with needle injections remains challenging, especially in children with needle phobia.

OBJECTIVE

We aimed to evaluate the effectiveness, tolerability, and patient satisfaction of intralesional treatment with triamcinolone acetonide using a needle-free electronic pneumatic jet injector in children with keloids and hypertrophic scars.

METHODS

A retrospective study was performed in children with keloids and hypertrophic scars who received intralesional triamcinolone acetonide treatments using an electronic pneumatic jet injector. Effectiveness was evaluated using the Patient and Observer Scar Assessment Scale and Global Aesthetic Improvement Score at follow-up versus baseline. Tolerability was assessed with reported adverse effects and injection-related pain using a visual analog scale. Satisfaction questionnaires were used to evaluate treatment-related patient satisfaction.

RESULTS

Six female patients and five male patients aged 5-17 years, with a total of >118 keloids or hypertrophic scars were included. Electronic pneumatic jet injector treatment led to a significant reduction in the total Patient and Observer Scar Assessment Scale observer and patient scores compared with baseline, with a median reduction of 28.9% and 23.8%, respectively (p = 0.005; p = 0.009). Median visual analog scale pain scores for electronic pneumatic jet injector treatment were significantly lower compared with needle injections, 3.0 versus 7.0, respectively (p = 0.027). No severe adverse effects were reported. Overall, 6 patients were 'satisfied' and five patients were 'very satisfied' with the treatment.

CONCLUSIONS

Electronic pneumatic jet injector-assisted intralesional triamcinolone acetonide is an effective and well-tolerated treatment for keloids and hypertrophic scars in children. It should be considered as an alternative non-traumatic delivery method, especially in children with needle phobia or severe pain during previous needle injections.

Effects of inhibition of Nav1.3, Nav1.7, and Nav1.8 channels on pain-related behavior in Speke's hinge-back tortoise (Kinixys spekii)

Comparative studies using reptiles as experimental animals in pain research could expand our knowledge on the evolution and adaptation of pain mechanisms. Currently, there are no data reported on the involvement of voltage-gated sodium ion channels on nociception in reptiles. The aim of this study was to investigate the involvement of Nav1.3, Nav1.7, and Nav1.8 ion channels in nociception in Speke's hinge-back tortoise. ICA 121341 (selective blocker for Nav1.1/Nav1.3), NAV 26 (selective blocker for Nav1.7), and A803467 (selective blocker for Nav1.8) were used to investigate the involvement of Nav1.3, Nav1.7, and Nav1.8, respectively. The chemicals were administered intracoelomically thirty minutes before the start of nociceptive tests. ICA 121341 did not cause a significant decrease in the time spent in pain-related behavior in all the nociceptive tests. NAV 26 and A8034667 caused a statistically significant decrease in the mean time spent in pain-related behavior in the formalin and capsaicin tests. Only A803467 caused a statistically significant increase in the mean latency to pain-related behavior in the hot plate test. NAV 26 and A803467 had no observable side effects. In conclusion, Nav1.7 and Nav1.8 are involved in the processing of chemically induced inflammatory pain in Speke's hinge back tortoise. In addition, Nav1.8 are also significantly involved in the development of thermal-induced pain-related behavior in this species of reptile. However, our results do not support the involvement of Nav1.3 on the development of chemical or thermal induced pain-related behavior in the Speke's hinge back tortoise.

Effectiveness and tolerance of electrochemotherapy as palliative therapy for patients with head and neck cancer and malignant melanoma and its relation to early skin reaction

OBJECTIVES

To evaluate the efficacy and tolerance after the electrochemotherapy treatment for local therapy of cutaneous and subcutaneous metastases of head-and-neck tumors and malignant melanoma refractory to standard therapies, mainly in neck metastasis of squamous cell carcinoma. And, to evaluate the relation of this response according to the skin reaction (healing with ulcer or dry crust).

METHODS

prospective pase II, observational clinical study of 56 patients with metastases of head-and-neck squamous cell carcinoma (n=13), papillary thyroid carcinoma (n=4), adenoid cystic carcinoma of parotid gland (n=1) or malignant melanoma (n=37, 5 in head). Patients were treated by electrochemotherapy (application of electrical pulses into the tumor) after the administration of a single intravenous dose of bleomycin. Kaplan-Meier curves were performed. The statistical significance was evaluated using log-rank test; p-value of less than 0.05 was considered as significant.

RESULTS

Overall clinical response was observed in 47 patients (84%). Local side effects were mild in all the patients. Ten patients (76.9%) with neck metastasis of squamous cell carcinoma had some degree of response, but only in one was complete. Patients even with only partial response had a higher overall survival than patients without response (p= 0.02). Most of the patients with squamous cell carcinoma had diminution of pain and anxiety. Response rate and overall survival was higher in MM patients (86.5%) than in squamous cell cancer patients (76.9%) (p= 0.043). The healing process (dry crust/ulcer) was not associated with the overall survival (p= 0.86).

CONCLUSIONS

Electrochemotherapy is associated a higher overall survival and diminution of pain and anxiety. Therefore, it is an option as palliative treatment for patients with neck metastasis of squamous cell carcinoma refractory to other therapies or even as a concomitant treatment with newer immunotherapies. The type of healing of the surgical wound could not be associated with a higher rate of response or survival.

LEVEL OF EVIDENCE

III.

Direct inhibition of microglial activation by a μ receptor selective agonist alleviates inflammatory-induced pain hypersensitivity

Opioids are widely used in the treatment of moderate and severe pain. Nociceptive stimulation has been reported to potentially promote microglial activation and neuroinflammation, which also causes chronic pain sensitization. The aim of this study was to demonstrate whether the novel μ receptor agonist MEL-0614 could inhibit activated microglia directly and the associated signaling pathway. Mice were administered lipopolysaccharide and formalin to induce allodynia. Von Frey test was used to detect the anti-allodynia effect of MEL-0614 before and after LPS and formalin injection. In the spinal cord, the levels of proinflammatory cytokines and microglial activation were determined after MEL-0614 administration. BV2 and primary microglia were cultured to further explore the effect of MEL-0614 on LPS-induced microglial activation and key signaling pathways involved. MEL-0614 partially prevented and reversed allodynia induced by LPS and formalin in vivo, which was not inhibited by the μ receptor antagonist CTAP. Minocycline was effective in reversing the established allodynia. MEL-0614 also downregulated the activation of microglia and related proinflammatory cytokines in the spinal cord. Additionally, in BV2 and primary microglia, MEL-0614 inhibited the LPS-induced upregulation of proinflammatory factors, which was unaffected by CTAP. The NLR family pyrin domain containing 3 (NLRP3) related signaling pathway may be involved in the interaction between MEL-0614 and microglia. The opioid agonist MEL-0614 inhibited the activation of microglia and the subsequent upregulation of proinflammatory factors both in vivo and in vitro. Notably, this effect is partially mediated by the μ receptor.

A Novel Bifunctional μOR Agonist and σ1R Antagonist with Potent Analgesic Responses and Reduced Adverse Effects

Bifunctional ligands possessing both μOR agonism and σ1R antagonism have shown promise in producing strong analgesic effects with reduced opioid-related side effects. However, the μOR agonism activity of most dual ligands diminishes compared with classical opioids, raising concern about their effectiveness in managing nociceptive pain. In this study, a new class of dual μOR agonist/σ1R antagonist was reported. Through structure-activity relationship analyses, we identified the optimal compound, 4x, which displayed picomolar μOR agonism activity (EC50: 0.6 ± 0.2 nM) and good σ1R inhibitory activity (Ki: 363.7 ± 5.6 nM) with excellent selectivity. Compound 4x exhibited robust analgesic effects in various pain models, with significantly reduced side effects. Importantly, compound 4x also possessed good safety profiles and no abnormalities were observed in biological parameters even under a high dosage. Our findings suggest that 4x may be a promising lead compound for developing safer opioids and warrants further in-depth studies.

A Randomized Placebo-Controlled Trial of the Anti-Nerve Growth Factor Antibody Tanezumab in Subjects With Cancer Pain Due to Bone Metastasis

BACKGROUND

This phase III, randomized, double-blind, placebo-controlled, parallel-group study assessed the efficacy and safety of tanezumab in subjects with cancer pain predominantly due to bone metastasis receiving background opioid therapy.

METHODS

Subjects were randomized (stratified by (1) tumor aggressiveness and (2) presence/absence of concomitant anticancer treatment) to placebo or tanezumab 20 mg. Treatment was administered by subcutaneous injection every 8 weeks for 24 weeks (3 doses) followed by a 24-week safety follow-up period. The primary outcome was change in daily average pain in the index bone metastasis cancer pain site (from 0 = no pain to 10 = worst possible pain) from baseline to week 8.

RESULTS

LS mean (SE) change in pain at week 8 was -1.25 (0.35) for placebo (n = 73) and -2.03 (0.35) for tanezumab 20 mg (n = 72). LS mean (SE) [95% CI] difference from placebo was -0.78 (0.37) [-1.52, -0.04]; P = .0381 with α = 0.0478. The number of subjects with a treatment-emergent adverse event during the treatment period was 50 (68.5%) for placebo and 53 (73.6%) for tanezumab 20 mg. The number of subjects with a prespecified joint safety event was 0 for placebo and 2 (2.8%) for tanezumab 20 mg (pathologic fracture; n = 2).

CONCLUSION

Tanezumab 20 mg met the primary efficacy endpoint at week 8. Conclusions on longer-term efficacy are limited since the study was not designed to evaluate the durability of the effect beyond 8 weeks. Safety findings were consistent with adverse events expected in subjects with cancer pain due to bone metastasis and the known safety profile of tanezumab. Clinicaltrials.gov identifier: NCT02609828.

Alpha 2 agonists for sedation to produce better outcomes from critical illness (A2B Trial): protocol for a multicentre phase 3 pragmatic clinical and cost-effectiveness randomised trial in the UK

INTRODUCTION

Almost all patients receiving mechanical ventilation (MV) in intensive care units (ICUs) require analgesia and sedation. The most widely used sedative drug is propofol, but there is uncertainty whether alpha2-agonists are superior. The alpha 2 agonists for sedation to produce better outcomes from critical illness (A2B) trial aims to determine whether clonidine or dexmedetomidine (or both) are clinically and cost-effective in MV ICU patients compared with usual care.

METHODS AND ANALYSIS

Adult ICU patients within 48 hours of starting MV, expected to require at least 24 hours further MV, are randomised in an open-label three arm trial to receive propofol (usual care) or clonidine or dexmedetomidine as primary sedative, plus analgesia according to local practice. Exclusions include patients with primary brain injury; postcardiac arrest; other neurological conditions; or bradycardia. Unless clinically contraindicated, sedation is titrated using weight-based dosing guidance to achieve a Richmond-Agitation-Sedation score of -2 or greater as early as considered safe by clinicians. The primary outcome is time to successful extubation. Secondary ICU outcomes include delirium and coma incidence/duration, sedation quality, predefined adverse events, mortality and ICU length of stay. Post-ICU outcomes include mortality, anxiety and depression, post-traumatic stress, cognitive function and health-related quality of life at 6-month follow-up. A process evaluation and health economic evaluation are embedded in the trial.The analytic framework uses a hierarchical approach to maximise efficiency and control type I error. Stage 1 tests whether each alpha2-agonist is superior to propofol. If either/both interventions are superior, stages 2 and 3 testing explores which alpha2-agonist is more effective. To detect a mean difference of 2 days in MV duration, we aim to recruit 1437 patients (479 per group) in 40-50 UK ICUs.

ETHICS AND DISSEMINATION

The Scotland A REC approved the trial (18/SS/0085). We use a surrogate decision-maker or deferred consent model consistent with UK law. Dissemination will be via publications, presentations and updated guidelines.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT03653832.

Spinal apolipoprotein E is involved in inflammatory pain via regulating lipid metabolism and glial activation in the spinal dorsal horn

INTRODUCTION

Inflammation and nerve injury promote astrocyte activation, which regulates the development and resolution of pain, in the spinal dorsal horn. APOE regulates lipid metabolism and is predominantly expressed in the astrocytes. However, the effect of astrocytic APOE and lipid metabolism on spinal cellular function is unclear. This study aimed to investigate the effect of spinal Apoe on spinal cellular functions using the complete Freund's adjuvant (CFA)-induced inflammatory pain mouse model.

METHODS

After intraplantar injection of CFA, we assessed pain behaviors in C57BL6 and Apoe knockout (Apoe-/-) mice using von Frey and Hargreaves' tests and analyzed dorsal horn samples (L4-5) using western blotting, immunofluorescence, quantitative real-time polymerase chain reaction, and RNA sequencing.

RESULTS

The Apoe levels were markedly upregulated at 2 h and on days 1 and 3 post-CFA treatment. Apoe was exclusively expressed in the astrocytes. Apoe-/- mice exhibited decreased pain on day 1, but not at 2 h, post-CFA treatment. Apoe-/- mice also showed decreased spinal neuron excitability and paw edema on day 1 post-CFA treatment. Global transcriptomic analysis of the dorsal horn on day 1 post-CFA treatment revealed that the differentially expressed mRNAs in Apoe-/- mice were associated with lipid metabolism and the immune system. Astrocyte activation was impaired in Apoe-/- mice on day 1 post-CFA treatment. The intrathecal injection of Apoe antisense oligonucleotide mitigated CFA-induced pain hypersensitivity.

CONCLUSIONS

Apoe deficiency altered lipid metabolism in astrocytes, exerting regulatory effects on immune response, astrocyte activation, and neuronal activity and consequently disrupting the maintenance of inflammatory pain after peripheral inflammation. Targeting APOE is a potential anti-nociception and anti-inflammatory strategy.

Chemical composition, antinociceptive and anti-inflammatory activities of the curzerene type essential oil of Eugenia uniflora from Brazil

ETHNOPHARMACOLOGICAL RELEVANCE

The Eugenia uniflora leaf infusion is widely used in folk medicine to treat gastroenteritis, fever, hypertension, inflammatory and diuretic diseases.

AIM OF THE STUDY

This work evaluated the acute oral toxic, antinociceptive, and anti-inflammatory activities of the curzerene chemotype of Eugenia uniflora essential oil (EuEO).

MATERIAL AND METHODS

EuEO was obtained by hydrodistillation and analyzed by GC and GC-MS. The antinociceptive action in mice was evaluated for the peripheral and central analgesic activity using abdominal contortion and hot plate tests (50, 100, and 200 mg/kg); xylene-induced ear swelling was carried out for the nociception test, and carrageenan-induced cell migration test. Spontaneous locomotor activity was assessed in the open field test to rule out any nonspecific sedative or muscle relaxant effects of EuEO.

RESULTS

The EuEO displayed a yield of 2.6 ± 0.7%. The major compounds classes were oxygenated sesquiterpenoids (57.3 ± 0.2%), followed by sesquiterpene hydrocarbons (16.4 ± 2.6). The chemical constituents with the highest concentrations were curzerene (33.4 ± 8.5%), caryophyllene oxide (7.6 ± 2.8%), β-elemene (6.5 ± 1.8%), and E-caryophyllene (4.1 ± 0.3%). Oral treatment with EuEO, at doses of 50, 300, and 2000 mg/kg, did not change the behavior patterns or mortality of the animals. EuEO (300 mg/kg) did not cause a reduction in the number of crossings in the open field compared to the vehicle group. The aspartate aminotransferase (AST) level was higher in EuEO-treated groups (50 and 2000 mg/kg) when compared to the control group (p < 0.05). EuEO, at doses of 50, 100, and 200 mg/kg, reduced the number of abdominal writhings by 61.66%, 38.33%, and 33.33%. EuEO did not show increased hot plate test time latency in any of the intervals analyzed. At 200 mg/kg, EuEO decreased paw licking time, with inhibition of 63.43%. In formalin-induced acute pain, EuEO decreased paw licking time at doses of 50, 100, and 200 mg/kg in the first phase, with inhibition of 30.54%, 55.02%, and 80.87%. The groups treated with EuEO at doses of 50, 100, and 200 mg/kg showed ear edema reduction of 50.26%, 55.17%, and 51.31%, respectively. Moreover, EuEO inhibited leukocyte recruitment only at a dose of 200 mg/kg. The inhibitory values of leukocyte recruitment after 4 h of carrageenan application were 4.86%, 4.93%, and 47.25% for 50, 100, and 200 mg/kg of essential oil, respectively.

CONCLUSION

The EuEO, curzerene chemotype, has significant antinociceptive and anti-inflammatory activities and low acute oral toxicity. This work confirms the antinociceptive and anti-inflammatory of this species as the traditional use.