Oleoresin Capsicum (OC) Spray: An Assessment of Respiratory Health and its Management Following Accidental and Deliberate Exposures

Introduced into law enforcement in 1976, the oleoresin capsicum (OC) spray has been labeled as one of the most significant and radical developments in law enforcement. However, epidemiological research on OC health effects is deficient, receiving little public support. The major responses to acute exposure to OC spray can be found in the pulmonary system. The molecular mechanism(s) involved in the action of capsaicinoids, the active constituents in OC, are complex cascades of reactions which end up in necrosis or apoptosis. OC may also damage and deplete biological redox systems in the epithelial lining fluids and within cells and mitochondria, modifying structural proteins and nucleic acids and leading to enzyme inactivation. Since there are no characteristic laboratory tests available for identification or confirmation of OC exposure, and on the basis of prevailing data, reassessment of the health risks of OC exposures in vulnerable populations and in-depth study of the molecular mechanics of receptors is the need of the hour for the development of effective countermeasures. This review aims to consider evidence for adverse effects of OC spray used in ways comparable to their application by law enforcement personnel and civilians, with possible treatment recommendations that are precedent for improved management.

Peripheral Neuroinflammation and Pain: How Acute Pain Becomes Chronic

The number of individuals suffering from severe chronic pain and its social and financial impact is staggering. Without significant advances in our understanding of how acute pain becomes chronic, effective treatments will remain out of reach. This mini review will briefly summarize how critical signaling pathways initiated during the early phases of peripheral nervous system inflammation/ neuroinflammation establish long-term modifications of sensory neuronal function. Together with the recruitment of non-neuronal cellular elements, nociceptive transduction is transformed into a pathophysiologic state sustaining chronic peripheral sensitization and pain. Inflammatory mediators, such as nerve growth factor (NGF), can lower activation thresholds of sensory neurons through posttranslational modification of the pain-transducing ion channels transient-receptor potential TRPV1 and TRPA1. Performing a dual role, NGF also drives increased expression of TRPV1 in sensory neurons through the recruitment of transcription factor Sp4. More broadly, Sp4 appears to modulate a nociceptive transcriptome including TRPA1 and other genes encoding components of pain transduction. Together, these findings suggest a model where acute pain evoked by peripheral injury-induced inflammation becomes persistent through repeated cycles of TRP channel modification, Sp4-dependent overexpression of TRP channels and ongoing production of inflammatory mediators.

GCSB-5 regulates inflammatory arthritis and pain by modulating the mitogen-activated protein kinase signaling pathway in a murine model of rheumatoid arthritis

Objectives

This study aimed to determine whether GCSB-5 has anti-inflammatory and antinociceptive effects in mice with collagen-induced arthritis (CIA), an animal model of rheumatoid arthritis (RA), and investigate the influence of GCSB-5 on the mitogen-activated protein kinase (MAPK) pathway.

Materials and methods

The experimental animal study was designed to include five groups: CIA mice treated with GCSB-5 (300 mg/kg), GCSB-5 (600 mg/kg), celecoxib (60 mg/kg), or saline for four weeks, and nontreated control mice. The clinical severity of arthritis was scored. Nociceptive thresholds were measured by using a von Frey dynamic plantar analgesimeter. The MAPK pathway was evaluated in mouse synovium. The expression of channels associated with pain signaling was assessed by western blot and immunohistochemical staining.

Results

GCSB-5 treatment diminished the severity of clinical arthritis and increased the nociceptive threshold in mice with CIA. Celecoxib, a positive control drug, also showed comparable changes. Clinical arthritis scores were inversely related to mechanical thresholds. GCSB-5 administration decreased the levels of anti-type II collagen antibody and inflammatory cytokines in the sera of mice with CIA. Furthermore, ERK, p38 MAPK, and JNK phosphorylation were downregulated and TRPV1 and ASIC3 expression were decreased in the synovium of GCSB-5-treated mice compared to salinetreated mice. Interleukin-6-induced TRPV1 and ASIC3 upregulation were also inhibited by GCSB-5 in human RA fibroblast-like synoviocytes in vitro.

Conclusion

GCSB-5 decreased inflammatory arthritis and pain in a murine model of RA. The results present evidence that GCSB-5 may be beneficial for relieving pain as well as decreasing inflammation in autoimmune arthritis, such as RA.

Natural Products: A Potential New Hope to Defeat Post-acute Sequelae of COVID-19

The COVID-19 pandemic was the most significant public healthcare crisis worldwide. It was estimated that 80% of infected patients with COVID-19 have not fully recovered and developed one or more long-term symptoms, referred to as post-acute sequelae of COVID-19 (PASC). Seeking a treatment strategy for PASC has become a concerning topic since the sequelae can cause irreversible multiple organ damage and can severely compromise quality of life. It is indicated that PASC may be closely related to lung injury-induced hypoxia, excessive immune response, cytokine storm, gut bacteria imbalance, and endothelial dysfunction. Also, more and more research has indicated that angiotensin-converting enzyme 2 (ACE2) receptor, transient receptor potential ankyrin 1 and vanillin 1 (TRPA1/V1), and nuclear factor erythroid 2-related factor 2 (Nrf2) can be considered as the targets to treat PASC. There is currently still no proven medication for PASC due to its complexity. Many clinical practices and studies have shown that natural products have great potential in preventing and treating PASC. Therefore, we intended to provide a comprehensive review of the current literature on PASC and the role of natural ingredients in PASC management. Meanwhile, this review provided meaningful insight for further study of natural ingredients to improve PASC and its clinical application.