Pain Perception and Management: Where do We Stand?

Iranian Nurses' Knowledge, Attitude, and Practice of Complementary Therapies for Pain Management

INTRODUCTION

Complementary therapies (CTs) are being increasingly used by people with health issues and recommended by their health care providers. Although there are numerous studies available that address nurses' knowledge and attitudes regarding pain management, there are few that include the use of CTs by nurses in Iran. Therefore, this study was conducted in selected areas of Iran to assess nurses' knowledge, attitudes, and current practice regarding the use of CTs.

METHODS

A cross-sectional study was conducted on a random sample of 850 nurses from various regions of Iran between 2020 and 2022. A questionnaire was used that consisted of seven items addressing demographic characteristics, 15 items to assess knowledge, 25 items to address attitude and 22 items to address the practice of CTs in the area of pain relief. Descriptive and inferential statistics were used to analyze the data.

RESULTS

The participants' mean age was 33.26 ± 7.24 years. Most nurses (89.9%) had not received formal education on CTs. However, 78.6% of nurses reported personal use of CTs, and 62.3% reported using or recommending it to their patients at least once. Regarding the knowledge of CTs, nurses scored 5.81 on a 15 points scale indicating a considerable gap in their knowledge of CTs. Regarding attitudes toward the specific therapies, nurses believed that massage is highly (46.4%) or moderately (31.6%) effective in pain relief. Regarding effectiveness, nurses ranked the following as the top four CTs: music therapy, humor, hydrotherapy, and use of cold / heat.

CONCLUSION

The nurses in this study scored low on knowledge of CTs, meaning that they knew little about CTs. However, they showed a favorable attitude toward CTs and a majority of them had a history of personal use, and recommending some types of CTs to their patients for pain relief. Therefore, it is crucial for nurse managers to provide opportunities to acquire knowledge of CTs. Moreover, nurse educators should advocate for updating nursing curricula to include CTs as an essential component of pain management education.

Spinal antinociceptive effect of the PnTx4(5-5) peptide is possibly mediated by the NMDA autoreceptors

BACKGROUND

Medications currently used to treat pain are frequently associated with serious adverse effects and rapid development of tolerance. Thus, there is a need to develop more effective, and safer medicines for the population. Blocking NMDA receptors (NMDAR) has shown to be a promising target for the development of new drugs. That statement is due to NMDAR activation and glutamate release in the spinal cord which affects chronic pain modulation. Therefore, the aim of this study was to evaluate the possible spinal antinociceptive activity of PnTx4(5-5) toxin. The peptide is purified from the venom of the spider P. nigriventer and its affinity for NMDAR and sodium channels Nav1.2-1.6 has already been established.

METHODS

We compared its effect and safety with MK-801 (NMDAR antagonist) and evaluated its influence on glutamate and reactive oxygen species (ROS) levels in CSF. PnTx4(5-5) was administered intrathecally in the Formalin test and co-administered with NMDA in the Spontaneous pain test. After three minutes of observation, mice cerebrospinal fluid was collected to measure glutamate and ROS levels.

RESULTS

The spider peptide inhibited nociception as post-treatment in the inflammatory phase of the Formalin test. Furthermore, it inhibited spontaneous nociception induced by NMDA, being more potent and effective than MK-801 in both models tested. A glutamate rise level in the CSF of mice was significantly reduced by the toxin, but ROS increase was not affected. The animals' motor skills were not affected by the tested doses of NMDAR inhibitors.

CONCLUSION

In conclusion, the results suggest PnTx4(5-5) may mediate its antinociceptive effect in the spinal cord not only by inhibiting postsynaptic receptors but probably also by acting on autoreceptors. This effect does not affect the motricity of mice at the highest dose tested, which suggests that it has therapeutic potential and safety for use as a painkiller.

Nanotechnology in Pain Management

Chronic pain is a debilitating condition that affects millions of patients worldwide, contributing to a high disease burden and millions of dollars in lost wages, missed workdays, and healthcare costs. Opioids, NSAIDs, acetaminophen, gabapentinoids, muscle relaxants, anticonvulsants, and antidepressants are the most used medications for chronic pain and carry significant side effects, including gastric bleeding, hepatotoxicity, stroke, kidney damage, constipation, dizziness, and arrhythmias. Opioids in particular carry the risk of long-term dependence, drug tolerance, and overdose. In 2022, 81,806 people died from opioid overdose in the United States alone. Alternative treatments for chronic pain are critically needed, and nanotechnology has emerged as a promising means of achieving effective long-term analgesia while avoiding the adverse side effects associated with conventional pharmacological agents. Nanotechnology-based treatments include liposomes, Poly Lactic-co-Glycolic Acid (PLGA) and other polymeric nanoparticles, and carbon-based polymers, which can help mitigate those adverse side effects. These nanomaterials can serve as drug delivery systems that facilitate controlled release and drug stability via the encapsulation of free molecules and protein-based drugs, leading to longer-lasting analgesia and minimizing side effects. In this review, we examine the role of nanotechnology in addressing concerns associated with conventional chronic pain treatments and discuss the ongoing efforts to develop novel, nanotechnology-based treatments for chronic pain such as nanocapacitor patches, gene therapy, the use of both viral and non-viral vectors, CRISPR, and scavengers.

Pathophysiology of Pain and Mechanisms of Neuromodulation: A Narrative Review (A Neuron Project)

Pain serves as a vital innate defense mechanism that can significantly impact an individual's quality of life. Understanding the physiological effects of pain well plays an important role in developing novel pain treatments. Nociceptor neurons play a key role in pain and inflammation. Interactions between nociceptors and the immune system occur both at the site of injury and within the central nervous system. Modulating chemical mediators and nociceptor activity offers promising new approaches to pain management. Essentially, the sensory nervous system is essential for modulating the body's protective response, making it critical to understand these interactions to discover new pain treatment strategies. New innovations in neuromodulation have led to alternatives to opioids individuals with chronic pain with consequent improvement in disease-based treatment and nerve targeting. New neural targets from cellular and structural perspectives have revolutionized the field of neuromodulation. This narrative review aims to elucidate the mechanisms of pain transmission and processing, examine the characteristics and properties of nociceptors, and explore how the immune system influences pain perception. It further provides an updated overview of the physiology of pain and neuromodulatory mechanisms essential for managing acute and chronic pain. We assess the current understanding of different pain types, focusing on key molecules involved in each type and their physiological effects. Additionally, we compare painful and painless neuropathies and discuss the neuroimmune interactions involved in pain manifestation.

Commonly encountered symptoms and their management in patients with cirrhosis

This exhaustive review, explored the multifaceted symptoms and their management in patients with cirrhosis. Patients frequently endure pain, muscle cramps, sleep disturbances, psychological distress, and gastrointestinal issues, significantly impairing their quality of life. Pain is prevalent, often requiring analgesics, while muscle cramps affect up to 68% of patients, treated with supplements like zinc and taurine despite limited evidence. Sleep disturbances, including insomnia and excessive daytime sleepiness, afflict up to 80% of patients, managed through lactulose, melatonin, and cognitive behavioral therapies. Gastrointestinal symptoms, affecting 80%, include abdominal pain and bloating, necessitating lifestyle and dietary adjustments. Mental health disorders, such as depression and anxiety, are common, managed with a combination of pharmacotherapy and psychotherapy. Sexual dysfunction, often overlooked, profoundly impacts both men and women, requiring holistic treatment approaches. Pruritus, another distressing symptom, is managed with moisturizers and antihistamines, though many treatments show limited success. Hair loss and skin changes add to the psychological burden, highlighting the need for a comprehensive, multidisciplinary approach. The review underscores the imperative for tailored, compassionate care to enhance patient outcomes and quality of life in cirrhosis.

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

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

Pharmacological and phytochemical review of Acmella oleracea: a comprehensive analysis of its therapeutic potential

Acmella oleraceaL. (Asteraceae), commonly known as the toothache plant, is a tropical herb with significant therapeutic potential. Traditionally, it has been used for its analgesic and sialagogue properties, and it is known for its distinctive yellow flower crest. This review addresses current gaps in the understanding of its pharmacological properties and aims to provide a comprehensive analysis of its therapeutic potential. A thorough literature review was conducted using databases such as Google Scholar, ScienceDirect, and PubMed/MedLine. The findings indicate that A. oleraceacontains a variety of phytochemicals, including spilanthol, which exhibit diverse pharmacological activities such as antioxidant, anti-inflammatory, immunomodulatory, antinociceptive, pronociceptive, antibacterial, antifungal, antidiabetic, diuretic, and vasorelaxant effects. The results highlight the significant medicinal potential ofA. oleraceawhile also identifying areas for further research, particularly regarding its toxicological impacts on humans and animals. This review aims to guide future studies on the health benefits and safety of this plant.

The Role of the Thalamus in Nociception: Important but Forgotten

Pain is a complex response to noxious stimuli. Upon detection of the nociceptive stimulus by first-order neurons or nociceptors, an action potential ascends to the spinal dorsal horn, a crucial site for synapsing with second-order neurons. These second-order neurons carry the nociceptive stimulus to supraspinal regions, notably the thalamus. Although extensive research has focused on spinal-level nociceptive mechanisms (e.g., neurotransmitters, receptors, and glial cells), the thalamus is still poorly elucidated. The role of the thalamus in relaying sensory and motor responses to the cortex is well known. However, a comprehensive understanding of the mechanisms in the synapse between the second-order and third-order neurons that transmit this impulse to the somatosensory cortex, where the response is processed and interpreted as pain, is still lacking. Thus, this review investigated the thalamus's role in transmitting nociceptive impulses. Current evidence indicates the involvement of the neurotransmitters glutamate and serotonin, along with NMDA, P2X4, TLR4, FGR, and NLRP3 receptors, as well as signaling pathways including ERK, P38, NF-κB, cytokines, and glial cells at nociceptive synapses within the thalamus.

PolyphyllinVI alleviates the spared nerve injury-induced neuropathic pain based on P2X3 receptor-mediated the release of inflammatory mediators

ETHNOPHARMACOLOGICAL RELEVANCE

PolyphyllinVI (PPⅥ) is the main bioactive component of Chonglou which is a traditional Chinese herbal with various effects, including antitumor, anti-inflammatory, and analgesia.

AIM OF THE STUDY

This study aimed to investigate the properties and mechanisms of the analgesia of PPⅥ by using neuropathic pain (NPP) mice.

MATERIALS AND METHODS

The potential targets and mechanisms of PPⅥ in alleviating NPP were excavated based on the network pharmacology. Subsequently, the construction of a spared nerve injury (SNI) mice model was used to evaluate the effect of PPⅥ on NPP and the expression of the P2X3 receptor. We identified the signaling pathways of PPⅥ analgesia by RNA sequencing.

RESULTS

The results of network pharmacology showed that BCL2, CASP3, JUN, STAT3, and TNF were the key targets of the analgesic effect of PPⅥ. PPⅥ increased the MWT and TWL of SNI mice and decreased the level of P2X3 receptors in the dorsal root ganglion (DRG) and spinal cord (SC). Additionally, PPⅥ reduced the release of pro-inflammatory mediators (TNF-α, IL-1β, and IL-6) in the DRG, SC, and serum. Based on the KEGG enrichment of differentially expressed genes (DEGs) identified by RNA-Seq, PPVI may relieve NPP by regulating the AMPK/NF-κB signaling pathway. Western blotting results showed that the AMPK signaling pathway was activated, followed by inhibition of the NF-κB signaling pathway.

CONCLUSION

PPⅥ increased the MWT and TWL of SNI mice maybe by inhibiting the expression of the P2X3 receptor and the release of inflammatory mediators. The properties of the analgesia of PPⅥ may be based on the AMPK/NF-κB pathway.

Unraveling the Potential of Electroanalgesia: A Literature Review of Current Therapeutics

Neuropathic pain (NP), arising from dysfunction in the neurological system, poses a significant challenge in pain management due to its intricate origin and unpredictable response to conventional treatments. Electroanalgesia, a collection of techniques such as transcutaneous electric nerve stimulation (TENS), peripheral electrical nerve stimulation (PENS), spinal cord stimulation (SCS), deep brain stimulation (DBS), and electroacupuncture (EA), presents a potential alternative or complementary approach. This review brings together evidence from 56 studies to evaluate the effectiveness and safety of electroanalgesia in chronic NP. It discusses the mechanisms underlying NP, the indications for electroanalgesia, and the techniques utilized, emphasizing the diverse applications and potential benefits. However, despite its potential uses, electroanalgesia has its limitations, including variable effectiveness and potential adverse effects. Furthermore, the review recognizes the limitations of the methodology and the need for further research to refine treatment protocols and enhance the understanding of electroanalgesia's role in comprehensive pain management strategies.

Sodium Leak Channel in Glutamatergic Neurons of the Lateral Parabrachial Nucleus Modulates Inflammatory Pain in Mice

Elevated excitability of glutamatergic neurons in the lateral parabrachial nucleus (PBL) is associated with the pathogenesis of inflammatory pain, but the underlying molecular mechanisms are not fully understood. Sodium leak channel (NALCN) is widely expressed in the central nervous system and regulates neuronal excitability. In this study, chemogenetic manipulation was used to explore the association between the activity of PBL glutamatergic neurons and pain thresholds. Complete Freund's adjuvant (CFA) was used to construct an inflammatory pain model in mice. Pain behaviour was tested using von Frey filaments and Hargreaves tests. Local field potential (LFP) was used to record the activity of PBL glutamatergic neurons. Gene knockdown techniques were used to investigate the role of NALCN in inflammatory pain. We further explored the downstream projections of PBL using cis-trans-synaptic tracer virus. The results showed that chemogenetic inhibition of PBL glutamatergic neurons increased pain thresholds in mice, whereas chemogenetic activation produced the opposite results. CFA plantar modelling increased the number of C-Fos protein and NALCN expression in PBL glutamatergic neurons. Knockdown of NALCN in PBL glutamatergic neurons alleviated CFA-induced pain. CFA injection induced C-Fos protein expression in central nucleus amygdala (CeA) neurons, which was suppressed by NALCN knockdown in PBL glutamatergic neurons. Therefore, elevated expression of NALCN in PBL glutamatergic neurons contributes to the development of inflammatory pain via PBL-CeA projections.