Sanguinarine is an agonist of TRPA1 channel

Sanguinarine-Chelerythrine from Coptis chinensis Offers Analgesic and Anti-Inflammatory Effects Without Gastrotoxicity

Background: Pain is a major clinical and socioeconomic problem worldwide. The available therapies are not always effective and are often associated with the multiple adverse effects that reduce their clinical application. Natural compounds are an important group of pharmaceuticals that may be used in pain management. We aimed to investigate the analgesic activity of the sanguinarine-chelerythrine from Coptis chinensis. Methods: The analgesic and anti-inflammatory activity of the sanguinarine-chelerythrine fraction of C. chinensis extract (SC 5 and 10 mg/kg), sanguinarine (SAN 1 and 2 mg/kg) and chelerythrine (CHEL 4 and 8 mg/kg) was assessed in tail flick and formalin tests. A microscopic and macroscopic examination of stomach mucosae was performed. TNFα and MMP-9 levels were measured with ELISA kits. Results: Morphine (MORF), CHEL and SC prolongated the tail withdrawal latency, with comparable analgesic activity between MORF and CHEL 8 mg/kg. MORF, CHEL 8 mg/kg, and SAN 2 mg/kg ameliorated the pain reaction in the neurogenic phase of the formalin test. In the inflammatory phase of the formalin test, all tested substances exerted analgesic activity. SAN, CHEL and SC additionally reduced TNFα and MMP-9 secretion. Conclusions: Our results confirmed analgesic effects of CHEL and SC with CHEL analgesic activity comparable to MORF. All investigated substances exerted significant anti-inflammatory activity without concomitant gastrotoxicity.

TRPM8 and TRPA1 ideal targets for treating cold-induced pain

TRP channels are essential for detecting variations in external temperature and are ubiquitously expressed in both the peripheral and central nervous systems as integral channel proteins. They primarily mediate a range of sensory responses, including thermal sensations, nociception, mechanosensation, vision, and gustation, thus playing a critical role in regulating various physiological functions. In colder climates, individuals often experience pain associated with low temperatures, leading to significant discomfort. Within the TRP channel family, TRPM8 and TRPA1 ion channels serve as the primary sensors for cold temperature fluctuations and are integral to both cold nociception and neuropathic pain pathways. Recent advancements in the biosynthesis of inhibitors targeting TRPM8 and TRPA1 have prompted the need for a comprehensive review of their structural characteristics, biological activities, biosynthetic pathways, and chemical synthesis. This paper aims to delineate the distinct roles of TRPM8 and TRPA1 in pain perception, elucidate their respective protein structures, and compile various combinations of TRPM8 and TRPA1 antagonists and agonists. The discussion encompasses their chemical structures, structure-activity relationships (SARs), biological activities, selectivity, and therapeutic potential, with a particular focus on the conformational relationships between antagonists and the channels. This review seeks to provide in-depth insights into pharmacological strategies for managing pain associated with TRPM8 and TRPA1 activation and will pave the way for future investigations into pharmacotherapeutic approaches for alleviating cold-induced pain.

Bioactivity and mechanism of action of sanguinarine and its derivatives in the past 10 years

Sanguinarine is a quaternary ammonium benzophenanthine alkaloid found in traditional herbs such as Chelidonium, Corydalis, Sanguinarum, and Borovula. It has been proven to possess broad-spectrum biological activities, such as antitumor, anti-inflammatory, antiosteoporosis, neuroprotective, and antipathogenic microorganism activities. In this paper, recent progress on the biological activity and mechanism of action of sanguinarine and its derivatives over the past ten years is reviewed. The results showed that the biological activities of hematarginine and its derivatives are related mainly to the JAK/STAT, PI3K/Akt/mTOR, NF-κB, TGF-β, MAPK and Wnt/β-catenin signaling pathways. The limitations of using sanguinarine in clinical application are also discussed, and the research prospects of this subject are outlined. In general, sanguinarine, a natural medicine, has many pharmacological effects, but its toxicity and safety in clinical application still need to be further studied. This review provides useful information for the development of sanguinarine-based bioactive agents.

From Plant to Chemistry: Sources of Antinociceptive Non-Opioid Active Principles for Medicinal Chemistry and Drug Design

Pain is associated with many health problems and a reduced quality of life and has been a common reason for seeking medical attention. Several therapeutics are available on the market, although side effects, physical dependence, and abuse limit their use. As the process of pain transmission and modulation is regulated by different peripheral and central mechanisms and neurotransmitters, medicinal chemistry continues to study novel ligands and innovative approaches. Among them, natural products are known to be a rich source of lead compounds for drug discovery due to their chemical structural variety and different analgesic mechanisms. Numerous studies suggested that some chemicals from medicinal plants could be alternative options for pain relief and management. Previously, we conducted a literature search aimed at identifying natural products interacting either directly or indirectly with opioid receptors. In this review, instead, we have made an excursus including active ingredients derived from plants whose mechanism of action appears from the literature to be other than the modulation of the opioid system. These substances could, either by themselves or through synthetic and/or semi-synthetic derivatives, be investigated in order to improve their pharmacokinetic characteristics and could represent a valid alternative to the opioid approach to pain therapy. They could also be the basis for the study of new mechanisms of action in the approach to this complex and disabling pathology.

Transient receptor potential ankyrin 1 (TRPA1) modulators: Recent update and future perspective

The transient receptor potential ankyrin 1 (TRPA1) channel is a non-selective cation channel that senses irritant chemicals. Its activation is closely associated with pain, inflammation, and pruritus. TRPA1 antagonists are promising treatments for these diseases, and there has been a recent upsurge in their application to new areas such as cancer, asthma, and Alzheimer's disease. However, due to the generally disappointing performance of TRPA1 antagonists in clinical studies, scientists must pursue the development of antagonists with higher selectivity, metabolic stability, and solubility. Moreover, TRPA1 agonists provide a deeper understanding of activation mechanisms and aid in antagonist screening. Therefore, we summarize the TRPA1 antagonists and agonists developed in recent years, with a particular focus on structure-activity relationships (SARs) and pharmacological activity. In this perspective, we endeavor to keep abreast of cutting-edge ideas and provide inspiration for the development of more effective TRPA1-modulating drugs.

Insights into the potential of Sanguinarine as a promising therapeutic option for breast cancer

Breast cancer (BC) is one of the leading causes of cancer-related deaths in women worldwide. The tumor microenvironment (TME) plays a crucial role in the progression and metastasis of BC. A significant proportion of BC is characterized by a hypoxic TME, which contributes to the development of drug resistance and cancer recurrence. Sanguinarine (SAN), an isoquinoline alkaloid found in Papaver plants, has shown promise as an anticancer agent. The present review focuses on exploring the molecular mechanisms of hypoxic TME in BC and the potential of SAN as a therapeutic option. The review presents the current understanding of the hypoxic TME, its signaling pathways, and its impact on the progression of BC. Additionally, the review elaborates on the mechanisms of action of SAN in BC, including its effects on vital cellular processes such as proliferation, migration, drug resistance, and tumor-induced immune suppression. The review highlights the importance of addressing hypoxic TME in treating BC and the potential of SAN as a promising therapeutic option.

Regulation of transient receptor potential channels by traditional Chinese medicines and their active ingredients

In recent years, activation of thermal transient receptor potential (TRP) ion channels at a range of temperatures has received widespread attention as a target for traditional Chinese medicine (TCM) to regulate body temperature and relieve pain. Discovery of transient receptor potential vanilloid 1 (TRPV1) was awarded a Nobel Prize, reflecting the importance of these channels. Here, the regulatory effects of TCMs and their active ingredients on TRP ion channels are reviewed, and future directions for research on the cold, hot, warm, cool, and neutral natures of TCMs are considered. In herbs with cold, hot, warm, cool, and neutral natures, we found 29 TCMs with regulatory effects on TRP ion channels, including Cinnamomi Cortex, Capsici Fructus, Rhei Radix et Rhizoma, Macleayae cordatae Herba, Menthae Haplocalycis Herba, and Rhodiolae Crenulatae Radix et Rhizoma. Although some progress has been made in understanding the regulation of TRP ion channels by TCMs and their ingredients, the molecular mechanism by which TCMs have this effect remains to be further studied. We hope this review will provide a reference for further research on the cold, hot, warm, cool, and neutral natures of TCMs.

Molecular Activation of the Kv11.1 Channel Reprograms EMT in Colon Cancer by Inhibiting TGFβ Signaling via Activation of Calcineurin

Control of ionic gradients is critical to maintain cellular homeostasis in both physiological and pathological conditions, but the role of ion channels in cancer cells has not been studied thoroughly. In this work we demonstrated that activity of the Kv11.1 potassium channel plays a vital role in controlling the migration of colon cancer cells by reversing the epithelial-to-mesenchymal transition (EMT) into the mesenchymal-to-epithelial transition (MET). We discovered that pharmacological stimulation of the Kv11.1 channel with the activator molecule NS1643 produces a strong inhibition of colon cancer cell motility. In agreement with the reversal of EMT, NS1643 treatment leads to a depletion of mesenchymal markers such as SNAIL1, SLUG, TWIST, ZEB, N-cadherin, and c-Myc, while the epithelial marker E-cadherin was strongly upregulated. Investigating the mechanism linking Kv11.1 activity to reversal of EMT into MET revealed that stimulation of Kv11.1 produced a strong and fast inhibition of the TGFβ signaling. Application of NS1643 resulted in de-phosphorylation of the TGFβ downstream effectors R-SMADs by activation of the serine/threonine phosphatase PP2B (calcineurin). Consistent with the role of TGFβ in controlling cancer stemness, NS1643 also produced a strong inhibition of NANOG, SOX2, and OCT4 while arresting the cell cycle in G0/G1. Our data demonstrate that activation of the Kv11.1 channel reprograms EMT into MET by inhibiting TGFβ signaling, which results in inhibition of motility in colon cancer cells.