Serotonergically dependent antihyperalgesic and antiallodynic effects of isoliquiritin in a mouse model of neuropathic pain

Injectable Regenerated Silk Fibroin Micro/Nanosphere with Enhanced Permeability and Stability for Osteoarthritis Therapy

In the therapy of early-stage osteoarthritis, to accomplish full infiltration of subchondral bone and cartilage, and to target osteoclast and chondrocyte simultaneously remain challenges in biomaterials design. Herein, a novel hierarchical drug delivery system is introduced, with micrometer-scale outer layer spheres composed of regenerated silk fibroin, characterized by connected porous structure through the n-butanol and regenerated silk fibroin combined emulsion route and freezing method. The design effectively resists clearance from the joint cavity, ensuring stable delivery and prolonged residence time within the joint space. Additionally, the system incorporates phenylboronic acid-enriched silk fibroin nanoparticles, stabilized through chemical cross-linking, which encapsulate isoliquiritin derived from Glycyrrhiza uralensis. These nanoparticles facilitate complete penetration of the cartilage extracellular matrix, exhibit pH-responsive behavior, neutralize reactive oxygen species, and enable controlled drug release, thereby enhancing therapeutic efficacy. The in vitro and in vivo experiments both demonstrate that the composite micro/nanospheres not only inhibit osteoclastogenesis with bone loss in subchondral bone and osteophyte formation, but also mitigate chondrocytes apoptosis, reduce oxidative stress associated with cartilage degeneration, and ameliorate neuropathic hyperalgesia, with the underlying mechanisms being elucidated. The study indicates that such an injectable strategy combining organic biomaterials with Chinese medicine holds substantial promise for the treatment of early osteoarthritis.

Pharmacological potential of 4-dimethylamino chalcone against acute and neuropathic pain in mice

OBJECTIVES

This work investigated the acute antinociceptive effect of a synthetic chalcone, 4-dimethylamino chalcone (DMAC), as well as its effects on vincristine-induced peripheral neuropathy (VIPN) in mice.

METHODS

The inhibitory activity of myeloperoxidase was assessed by measuring HOCl formation. Formalin and hot plate tests were used to study the acute antinociceptive effect of DMAC. VIPN was induced through the administration of vincristine sulphate (0.1 mg/kg, i.p., 14 days). Then, DMSO, DMAC (10 or 30 mg/kg; i.p.), or pregabalin (10 mg/kg, i.p.) were administered for 14 consecutive days. Thermal hyperalgesia and mechanical allodynia were evaluated before and after VIPN induction and on days 1, 3, 7, and 14 of treatment. Neurodegeneration and neuroinflammation were assessed through immunohistochemistry for NF200, iNOS, and arginase-1 within the sciatic nerve.

KEY FINDINGS

DMAC inhibited myeloperoxidase activity in vitro and presented an acute antinociceptive effect in both formalin and hot plate tests, with the involvement of muscarinic and opioid receptors. Treatment with 30 mg/kg of DMAC significantly attenuated thermal hyperalgesia and mechanical allodynia and prevented macrophage proinflammatory polarisation in VIPN mice.

CONCLUSIONS

Our results show that DMAC, acting through different mechanisms, effectively attenuates VIPN.

Significance of Chalcone Scaffolds in Medicinal Chemistry

Chalcone is a simple naturally occurring α,β-unsaturated ketone with biological importance, which can also be easily synthesized in laboratories by reaction between two aromatic scaffolds. In plants, chalcones occur as polyphenolic compounds of different frameworks which are bioactive molecules that have been in traditional medicinal practice for many years. Chalcone-based lead molecules have been developed, possessing varied potentials such as antimicrobial, antiviral, anti-inflammatory, anticancer, anti-oxidant, antidiabetic, antihyperurecemic, and anti-ulcer effects. Chalcones contribute considerable fragments to give important heterocyclic molecules with therapeutic utilities targeting various diseases. These characteristic features have made chalcone a topic of interest among researchers and have attracted investigations into this widely applicable structure. This review highlights the extensive exploration carried out on the synthesis, biotransformations, chemical reactions, hybridization, and pharmacological potentials of chalcones, and aims to provide an extensive, thorough, and critical review of their importance, with emphasis on their properties, chemistry, and biomedical applications to boost future investigations into this potential scaffold in medicinal chemistry.

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.

Isoliquiritin Ameliorates Ulcerative Colitis in Rats through Caspase 3/HMGB1/TLR4 Dependent Signaling Pathway

BACKGROUND

Isoliquiritin belongs to flavanol glycosides and has a strong antiinflammatory activity. This study sought to investigate the anti-inflammatory effect of isoliquiritin and its underlying mechanism.

METHODS

The inflammatory (trinitro-benzene-sulfonic acid-TNBS-induced ulcerative colitis (UC)) model was established to ascertain the effect of isoliquiritin on the caspase-3/HMGB1/TLR4 pathway in rats. We also explored its protective effect on intestinal inflammation and its underlying mechanism using the LPS-induced inflammation model of Caco-2 cells. Besides, Deseq2 was used to analyze UCassociated protein levels.

RESULTS

Isoliquiritin treatment significantly attenuated shortened colon length (induced by TNBS), disease activity index (DAI) score, and body weight loss in rats. A decrease in the levels of inflammatory mediators (IL-1β, I IL-4, L-6, IL-10, PGE2, and TNF-α), coupled with malondialdehyde (MDA) and superoxide dismutase (SOD), was observed in colon tissue and serum of rats after they have received isoliquiritin. Results of techniques (like western blotting, real-time PCR, immunohistochemistry, and immunofluorescence-IF) demonstrated the potential of isoliquiritin to decrease expressions of key genes in the TLR4 downstream pathways, viz., MyD88, IRAK1, TRAF6, NF-κB, p38, and JNK at mRNA and protein levels as well as inhibit HMGB1 expression, which is the upstream ligand of TLR4. Bioinformational analysis showed enteritis to be associated with a high expression of HMGB1, TLR4, and caspase-3.

CONCLUSION

Isoliquiritin could reduce intestinal inflammation and mucosal damage of TNBS-induced colitis in rats with a certain anti-UC effect. Meanwhile, isoliquiritin treatment also inhibited the expression of HMGB1, TLR4, and MyD88 in LPS-induced Caco-2 cells. These results indicated that isoliquiritin could ameliorate UC through the caspase-3/HMGB1/TLR4-dependent signaling pathway.

Isoliquiritin treatment of osteoporosis by promoting osteogenic differentiation and autophagy of bone marrow mesenchymal stem cells

Osteoporosis is a chronic progressive bone disease characterized by the decreased osteogenic ability of osteoblasts coupled with increased osteoclast activity. Natural products showing promising therapeutic potential for postmenopausal osteoporosis remain underexplored. In this study, we aimed to analyze the therapeutic effects of isoliquiritin (ISL) on osteoporosis in mice and its possible mechanism of action. An ovariectomy-induced osteoporosis mouse model and bone marrow mesenchymal stem cells (BMSCs) were used to analyze the effects of ISL on bone regeneration in vivo and in vitro, respectively. Mitogen-activated protein kinase (MAPK) and autophagy inhibitors were used, to investigate whether the MAPK signaling pathway and autophagy affect the osteogenic differentiation of BMSCs. ISL significantly improved bone formation and reduced bone resorption in mouse femurs without inducing any detectable toxicity in critical organs such as the liver, kidney, brain, heart, and spleen. In vitro experiments showed that ISL enhanced the proliferation and osteogenic differentiation of BMSCs and that its osteogenic effect was attenuated by p38/extracellular regulated protein kinase (ERK) and autophagy inhibitors. Further studies showed that the inhibition of phosphorylated p38/ERK blocked ISL autophagy in BMSCs. ISL promoted the osteogenic differentiation of BMSCs through the p38/ERK-autophagy pathway and was therapeutically effective in treating osteoporosis in ovariectomized mice without any observed toxicity to vital organs. These results strongly suggest the promising potential of ISL as a safe and efficacious candidate drug for the treatment of osteoporosis.

Mechanistic inhibition of gastric cancer-associated bacteria Helicobacter pylori by selected phytocompounds: A new cutting-edge computational approach

Background

Helicobacter pylori (H. pylori) is a persistent bacterial inhabitant in the stomachs of approximately half the global populace. This bacterium is directly linked to chronic gastritis, leading to a heightened risk of duodenal and gastric ulcer diseases, and is the predominant risk factor for gastric cancer - the second most common cause of cancer-related deaths globally. The increasing prevalence of antibiotic resistance necessitates the exploration of innovative treatment alternatives to mitigate the H. pylori menace.

Methods

Initiating our study, we curated a list of thirty phytochemicals based on previous literature and subjected them to molecular docking studies. Subsequently, eight phytocompounds-Glabridin, Isoliquiritin, Sanguinarine, Liquiritin, Glycyrrhetic acid, Beta-carotin, Diosgenin, and Sarsasapogenin-were meticulously chosen based on superior binding scores. These were further subjected to an extensive computational analysis encompassing ADMET profiling, drug-likeness evaluation, principal component analysis (PCA), and molecular dynamic simulations (MDs) in comparison with the conventional drug, Mitomycin.

Results

The natural compounds investigated demonstrated superior docking affinities to H. pylori targets compared to the standard Mitomycin. Notably, the phytocompounds Diosgenin and Sarsasapogenin stood out due to their exceptional binding affinities and pharmacokinetic properties, including favorable ADMET profiles.

Conclusion

Our comprehensive and technologically-advanced approach showcases the potential of identified phytocompounds as pioneering therapeutic agents against H. pylori-induced gastric malignancies. In light of our promising in silico results, we recommend these natural compounds as potential candidates for advancing H. pylori-targeted drug development. Given their potential, we strongly advocate for subsequent in vitro and in vivo studies to validate their therapeutic efficacy against this formidable gastrointestinal bacterium.

Isoliquiritin modulates ferroptosis via NF-κB signaling inhibition and alleviates doxorubicin resistance in breast cancer

CONTEXT

Breast cancer (BC) is the most prevalent diagnosed tumor and the major reason for tumor-related death in females around the world. Isoliquiritin, a type of plant extract, has exhibited a probable inhibitory effect in a variety of cancers. However, the anti-tumor effect on BC is still unclear.

OBJECTIVE

To reveal the effect and potential mechanism of Isoliquiritin on BC.

MATERIALS AND METHODS

The cell viabilities were detected by CCK-8 assay. The levels of indicators of ferroptosis, oxidative stress, glycolysis, and inflammation were evaluated by commercial kits, flow cytometry, western blot, spectrophotometry, and ELISA assays. Mechanically, the expressions expression of the NF-κB pathway was determined by western blot. In vivo assay was also yielded on the BALB/c nude mice.

RESULTS

Iso induced a concentration and time-dependent decrease of viability in both MDA-MB-231 and MCF-7 cells. Iso treatment significantly increased the levels of Fe²⁺, ROS, and MDA, and decreased the GSH level, and the relative protein expressions of GPX4 and xCT. Furthermore, Iso modulated oxidative stress, glycolysis, and inflammation through ferroptosis. In addition, Iso induced a concentration-dependent decrease in cell viability and a concentration-dependent increase in apoptosis rate in both MDA-MB-231/Dox and MCF-7/Dox cells. Iso notably counteracted the LPS-induced relative protein levels of p-p50/p50, p-p65/p65, and IκB, and the levels of ferroptosis, oxidative stress, glycolysis, and inflammation. The same results were also verified in vivo.

CONCLUSION

Iso inhibited the NF-κB signaling to regulate ferroptosis and improved Dox-resistance in breast cancer.

Next generation behavioral sequencing for advancing pain quantification

With symptoms such as spontaneous pain and pathologically heightened sensitivity to stimuli, chronic pain accounts for about 20% of physician visits and up to 2/3 of patients are dissatisfied with current treatments. Much of our knowledge on pain processing and analgesics has emerged from behavioral studies performed on animals presenting the same symptoms under pathological conditions. While humans can verbally describe their pain, studies on rodents have relied on behavioral assays providing non-exhaustive characterization or altering animals' original sensitivity through repetitive stimulations. The emergence of what we term "next-generation behavioral sequencing" is now permitting us to quantitatively describe behavioral features on millisecond to minutes long timescales that lie beyond easy detection with the unaided eye. Here, we summarize emerging videography and computational based behavioral approaches that have the potential to significantly improve pain research.

Targeting autophagy and neuroinflammation pathways with plant-derived natural compounds as potential antidepressant agents

Major depressive disorder (MDD) is a life-threatening disease that presents several characteristics. The pathogenesis of depression still remains poorly understood. Moreover, the mechanistic interactions of natural components in treating depression to target autophagy and neuroinflammation are yet to be evaluated. This study overviewed the effects of plant-derived natural components in regulating critical pathways, particularly neuroinflammation and autophagy, associated with depression. A list of natural components, including luteolin, apigenin, hyperforin, resveratrol, salvianolic acid b, isoliquiritin, nobiletin, andrographolide, and oridonin, have been investigated. All peer-reviewed journal articles were searched by Scopus, MEDLINE, PubMed, Web of Science, and Google Scholar using the appropriated keywords, including depression, neuroinflammation, autophagy, plant, natural components, etc. The neuroinflammation and autophagy dysfunction are critically associated with the pathophysiology of depression. Natural components with higher efficiency and lower complications can be used for targeting neuroinflammation and autophagy. These components with different doses showed the beneficial antidepressant properties in rodents. These can modulate autophagy markers, mainly AMPK, LC3II/LC3I ratio, Beclin-1. Moreover, they can regulate the NLRP3 inflammasome, resulting in the suppression of proinflammatory cytokines (e.g., IL-1β and IL-18). Future in vitro and in vivo studies are required to develop novel therapeutic approaches based on plant-derived active components to treat MDD.

Senso-Immunologic Prospects for Complex Regional Pain Syndrome Treatment

Complex regional pain syndrome (CRPS) is a chronic pain syndrome that occurs in tissue injuries as the result of surgery, trauma, or ischemia. The clinical features of this severely painful condition include redness and swelling of the affected skin. Intriguingly, it was recently suggested that transient receptor potential ankyrin 1 (TRPA1) is involved in chronic post-ischemia pain, a CRPS model. TRPA1 is a non-selective cation channel expressed in calcitonin gene-related peptide (CGRP)-positive primary nociceptors that becomes highly activated in ischemic conditions, leading to the generation of pain. In this review, we summarize the history of TRPA1 and its involvement in pain sensation, inflammation, and CRPS. Furthermore, bone atrophy is also thought to be a characteristic clinical sign of CRPS. The altered bone microstructure of CRPS patients is thought to be caused by aggravated bone resorption via enhanced osteoclast differentiation and activation. Although TRPA1 could be a target for pain treatment in CRPS patients, we also discuss the paradoxical situation in this review. Nociceptor activation decreases the risk of bone destruction via CGRP secretion from free nerve endings. Thus, TRPA1 inhibition could cause severe bone atrophy. However, the suitable therapeutic strategy is controversial because the pathologic mechanisms of bone atrophy in CRPS are unclear. Therefore, we propose focusing on the remission of abnormal bone turnover observed in CRPS using a recently developed concept: senso-immunology.

Quality Assessment of Licorice Based on Quantitative Analysis of Multicomponents by Single Marker Combined with HPLC Fingerprint

Licorice is a commonly used traditional Chinese medicine and natural sweetening agent, rich in numerous bioactive compounds. Moreover, it is one of the oldest and most frequently employed folk medicines in both eastern and western countries. It is prescribed for the treatment of asthma, fever, and cough. However, with the increasing demand of licorice, its quality and safety become the important issue. The content in licorice varies significantly in materials from different geographical origins. In this study, a reasonable and feasible evaluation method for the quality assessment of licorice was developed based on the analysis of high-performance liquid chromatography (HPLC) fingerprint, combined with the quantitative analysis of multicomponents by single marker (QAMS) method. Glycyrrhizic acid was selected as the internal reference substance, and ten components were simultaneously determined based on relative correction factors. The contents of eleven components in 21 batches of licorice were determined by the QAMS and the ESM (external standard method); there was no significant difference by comparison of the quantitative results between the QAMS and the ESM method; the cosine value (Cir > 0.9999) confirmed the consistency of the two methods. According to the outcomes of 21 batches of licorice samples, the contents of the eleven components were used for further chemometric analysis. All of the samples of licorice from various geographical origins were divided into five categories based on hierarchical cluster analysis, which indicated the crucial influence of geographical origins on licorice. This study showed that QAMS combined with HPLC fingerprint and chemometrics methods could effectively control the quality of licorice. Hence, QAMS is a feasible and promising method for promoting the quality control standardization process of herbal medicines.

Liquorice for pain?

Liquorice has a long history of use in traditional Chinese, Ayurvedic and herbal medicine. The liquorice plant contains numerous bioactive compounds, including triterpenes, flavonoids and secondary metabolites, with glycyrrhizin being the main active compound. Liquorice constituents have been found to have anti-inflammatory, antioxidant, antiviral, anticancer, hepatoprotective and neuroprotective properties. In addition, they appear to have antidepressant actions and effects on morphine tolerance. Glycyrrhizin, its metabolite glycyrrhetic (glycyrrhetinic) acid and other liquorice-derived compounds such as isoflavonoids and trans-chalcones, exert potent anti-inflammatory effects via a wide range of mechanisms including high mobility group box 1 protein (HMGB1) inhibition, gap junction blockade and α_2A-adrenoceptor antagonism. These properties, together with an increasing body of preclinical studies and a long history of use in herbal medicine, suggest that liquorice constituents may be useful for pain management. Glycyrrhizin is used widely in the confectionary, food and tobacco industries, but has documented adverse effects that may limit clinical use. Whether liquorice plant-derived compounds represent a novel class of analgesics is yet to be established. Having a host of bioactive compounds with a broad range of mechanisms of effect, liquorice is a plant that, in the future, may give rise to new therapies for pain.

An Investigation of the Molecular Mechanisms Underlying the Analgesic Effect of Jakyak-Gamcho Decoction: A Network Pharmacology Study

Herbal drugs have drawn substantial interest as effective analgesic agents; however, their therapeutic mechanisms remain to be fully understood. To address this question, we performed a network pharmacology study to explore the system-level mechanisms that underlie the analgesic activity of Jakyak-Gamcho decoction (JGd; Shaoyao-Gancao-Tang in Chinese and Shakuyaku-Kanzo-To in Japanese), an herbal prescription consisting of Paeonia lactiflora Pallas and Glycyrrhiza uralensis Fischer. Based on comprehensive information regarding the pharmacological and chemical properties of the herbal constituents of JGd, we identified 57 active chemical compounds and their 70 pain-associated targets. The JGd targets were determined to be involved in the regulation of diverse biological activities as follows: calcium- and cytokine-mediated signalings, calcium ion concentration and homeostasis, cellular behaviors of muscle and neuronal cells, inflammatory response, and response to chemical, cytokine, drug, and oxidative stress. The targets were further enriched in various pain-associated signalings, including the PI3K-Akt, estrogen, ErbB, neurotrophin, neuroactive ligand-receptor interaction, HIF-1, serotonergic synapse, JAK-STAT, and cAMP pathways. Thus, these data provide a systematic basis to understand the molecular mechanisms underlying the analgesic activity of herbal drugs.