Antinociceptive effects of new pyrazoles compounds mediated by the ASIC-1α channel, TRPV-1 and μMOR receptors

Heterocyclic Compounds: Pharmacology of Pyrazole Analogs From Rational Structural Considerations

Low quality of life and life-threatening conditions often demand pharmacological screening of lead compounds. A spectrum of pharmacological activities has been attributed to pyrazole analogs. The substitution, replacement, or removal of functional groups on a pyrazole ring appears consistent with diverse molecular interactions, efficacy, and potency of these analogs. This mini-review explores cytotoxic, cytoprotective, antinociceptive, anti-inflammatory, and antidepressant activities of some pyrazole analogs to advance structure-related pharmacological profiles and rational design of new analogs. Numerous interactions of these derivatives at their targets could impact future research considerations and prospects while offering opportunities for optimizing therapeutic activity with fewer adverse effects.

Design, synthesis and pharmacological assessment of new pyrazole compounds

AIMS

This study investigated the antinociceptive and anti-inflammatory effects of new pyrazole compounds LQFM011(5), LQFM043(6) and LQFM044(7) as well as the mechanisms of action and acute in vitro toxicity.

MAIN METHODS

The antinociceptive activity was evaluated using the acetic acid-induced abdominal writhing test, formalin-induced pain test and the Randall-Selitto test. The anti-inflammatory activity was evaluated using models of paw oedema and pleurisy induced by carrageenan; cell migration, the levels of tumour necrosis factor α (TNF-α) and myeloperoxidase (MPO) enzyme activity were evaluated. In addition, the ability to inhibit phospholipase A2 (PLA2) in vitro and docking in PLA2 were used. Acute oral systemic toxicity in mice was evaluated through the neutral red uptake assay.

KEY FINDINGS

The synthesised compounds (5-7), delivered via gavage (p.o.) at 70, 140 or 280 µmol/kg, decreased the number of writhings induced by acetic acid; the three compounds (280 µmol/kg p.o.) reduced the paw licking time in the first and second phase of the formalin test and decreased the nociceptive threshold variation in the Randall-Selitto test. Furthermore, this dose reduced oedema formation, leucocyte migration (specifically through reduction in polymorphonuclear cell movement) and increased mononuclear cells. MPO activity and the levels of pro-inflammatory cytokines TNF-α were decreased. Evaluation of PLA2 inhibition via the docking simulation revealed more interactions of LQFM043R(6) and LQFM044(7), data that corroborated the half-maximal inhibitory concentration (IC₅₀) of PLA2 inhibition in vitro. Therefore, LQFM011(5), LQFM043(6) and LQFM044(7) were classified with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) as category 4.

A study of nanometre aggregates formation mechanism and antipyretic effect in Bai-Hu-Tang, an ancient Chinese herbal decoction

BACKGROUND

Bai-Hu-Tang (BHT), a Chinese herbal decoction used as an antipyretic agent, results from the combination of Anemarrhena asphodeloides Bunge, Glycyrrhizae, Japonica rice, and Gypsum. In our previous study, we identified nanoaggregates in BHT. However, the present study aimed to analyze and elucidate the mechanism of nanoaggregate formation and to investigate its antipyretic effect.

METHODS

A BHT decoction extract was split into 15 groups, and in each group, the extract was further separated into two solutions: Nano-phase and Decoction. The physicochemical properties of these solutions, such as particle size, salinity, conductivity, and surface tension were investigated, and analyzed the 15 groups of by transmission electron microscopy (TEM) and fingerprint chromatography. Furthermore, the antipyretic effect of nanoaggregates was evaluated through enzyme-linked immunosorbent assays, HE staining, Western Blot, and Real-time PCR.

RESULTS

In the 15 groups, the salinity and conductivity results showed a promoting and stabilizing effect towards the Nano-phase formation. Analysis of the surface tension indicated good solubilization of Radix Glycyrrhizae. The TEM analysis of the BHT separated extracts revealed that only in the presence of Japonica rice the Nano-phase is formed. Sixteen common peaks were identified in the BHT fingerprint chromatogram, and the main chemical components were Neomangiferin, Mangiferin, Liquiritin, and Ammonium glycyrrhizinate. Furthermore, BHT and nanoaggregates from Bai-Hu-Tang (N-BHT) groups did not differ in the main chemical components. Additionally, the N-BHT group had the same antipyretic effect compared with the BHT group. However, the pathological analysis indicated that treatment with N-BHT could ameliorate the lung damage in the rat. At the same time, N-BHT group inhibited expression of several proteins, specifically IL-1β, TRPV4, NF-κB, and TNF-α, which agreed with the Real-time PCR results.

CONCLUSION

We identified the key factors that are involved in the nano-phase formation. Also, by Western blot and Real-time PCR methods, we investigated the N-BHT mechanism of antipyretic action. The discovery of the N-BHT formation would provide a new idea of studying traditional Chinese medicine decoction.

Acid-sensing ion channels: Linking extracellular acidification with atherosclerosis

Extracellular acidification in atherosclerosis-prone regions of arterial walls is considered pro-atherosclerotic by exerting detrimental effect on macrophages, endothelial cells (ECs) and vascular smooth muscle cells (VSMCs). Acid-sensing ion channels (ASICs), a family of extracellular H⁺ (proton)-gated cation channels, are present extensively in the nervous system and other tissues, implying physiologic as well as pathophysiologic importance. Aberrant activation of ASICs is thought to be associated in EC dysfunction, macrophage phenotypic switch, and VSMC migration and proliferation. Although in vitro evidence acknowledges the contribution of ASIC activation in atherosclerosis, no direct evidence confirms their pro-atherosclerotic roles in vivo. In this review, the effect of extracellular acidity on three major contributors, ECs, macrophages, and VSMCs, is discussed focusing on the potential roles of ASICs in atherosclerotic development and underlying pathology. A more comprehensive understanding of ASICs in these processes may provide promising new therapeutic targets for treatment and prevention of atherosclerotic diseases.