Aminoguanidine inhibits IL-1β-induced protein expression of iNOS and COX-2 by blocking the NF-κB signaling pathway in rat articular chondrocytes

Acupuncture for radicular pain: a review of analgesic mechanism

Radicular pain, a common and complex form of neuropathic pain, presents significant challenges in treatment. Acupuncture, a therapy originating from ancient traditional Chinese medicine and widely utilized for various pain types, including radicular pain, has shown promising outcomes in the management of lumbar radicular pain, cervical radicular pain, and radicular pain due to spinal stenosis. Despite its efficacy, the exact mechanisms through which acupuncture achieves analgesia are not fully elucidated and are the subject of ongoing research. This review sheds light on the current understanding of the analgesic mechanisms of acupuncture for radicular pain, offering valuable perspectives for both clinical application and basic scientific research. Acupuncture is postulated to relieve radicular pain by several mechanisms: peripherally, it reduces muscle spasms, lessens mechanical pressure on nerve roots, and improves microcirculation; at the molecular level, it inhibits the HMGB1/RAGE and TLR4/NF-κB signaling pathways, thereby decreasing the release of pro-inflammatory cytokines; within the spinal cord, it influences synaptic plasticity; and centrally, it modulates brain function, particularly affecting the medial prefrontal cortex, anterior cingulate cortex, and thalamus within the default mode network. By acting across these diverse biological domains, acupuncture presents an effective treatment modality for radicular pain, and deepening our understanding of the underlying mechanisms regarding analgesia for radicular pain is crucial for enhancing its clinical efficacy and advancement in pain management.

Network Pharmacology-Based Strategy to Investigate the Mechanisms of Cibotium barometz in Treating Osteoarthritis

Cibotium barometz is a representative tonifying kidney drug and is widely used for osteoarthritis (OA) in traditional Chinese medicine. However, its regulatory mechanisms in treating OA remain to be sufficiently investigated. The main chemical components of Cibotium barometz were screened through the TCMID database and the corresponding targets were acquired through SwissTargetPrediction. The OA-related targets were obtained from the OMIM, Genecards, Genebank, TTD, and DisGeNET databases. The prediction of key targets and pathways of Cibotium barometz in the treatment of OA was achieved by constructing a compounds-targets network and performing KEGG enrichment analysis. The OA model rats were established by the Hulth method and used to explore the protective effect of Cibotium barometz via cartilage pathological assessment. In vitro models of OA were built by the proinflammatory factor interleukin-1β (IL-1β) induced SW1353 cells and used to validate the mechanisms predicted by network pharmacology. Network pharmacology results suggested that the therapeutic effects of Cibotium barometz were closely related to matrix metalloproteinase (MMP)-1, 3, 13 and inflammation-related gene COX2, which are regulated by the NFκB pathway. In vivo experiments revealed that Cibotium barometz could effectively restrain cartilage from degeneration and inhibit the mRNA expression of MMP-1, MMP-3, MMP-13, and COX2 in cartilage. In vitro experiments indicated that Cibotium barometz water extract (CBWE) could significantly inhibit the expression of MMP-1, MMP-3, MMP-13, and PGE₂ in IL-1β-induced SW1353 cells and markedly prevent the translocation of NFκB p65 from the cytoplasm to the nuclei and decrease its phosphorylation level. After small-interfering RNA (siRNA) was used to suppress the synthesis of NFκB p65 to block NFκB signaling pathway, the ability of CBWE to inhibit MMP-1, MMP-3, MMP-13, and PGE₂ was greatly reduced. Cibotium barometz has a chondroprotective effect on OA by inhibiting the response to inflammation and substrate degradation, and the related mechanism is associated with the inhibition of the NFκB pathway.

Emodin Attenuates the ECM Degradation and Oxidative Stress of Chondrocytes through the Nrf2/NQO1/HO-1 Pathway to Ameliorate Rat Osteoarthritis

Osteoarthritis (OA) substantially reduces the quality of life of the elderly. OA therapy remains a challenge since no treatment options for its causes are so far available. Over recent years, researchers have speculated that emodin may represent a potential treatment strategy for OA. However, it remains unclear whether the mechanism of action of emodin is associated with the inhibition of OA-induced oxidative stress. In the present study, the potential antioxidant mechanism of action of emodin and its protective properties against the development of OA were investigated both in vitro and in vivo. In vitro, emodin inhibited the production of reactive oxygen species (ROS) in chondrocytes induced by hydrogen peroxide (H2O2) and reduced the expression of matrix metalloproteinase (MMP)3 and MMP13 in a concentration-dependent manner. It was found that emodin upregulated the Nrf2/NQO1/HO-1 pathway, thereby attenuating the effects of oxidative stress caused by OA. In a rat model of posttraumatic OA induced by anterior cruciate ligament transection (ACLT), emodin reduced the extent of joint swelling. Emodin attenuated oxidative damage in the cartilage by upregulating superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) activity, reducing malondialdehyde (MDA) concentration and inhibiting the expression of the extracellular matrix (ECM) degradation biomarkers cartilage oligomeric matrix protein (COMP), and C-terminal telopeptide of type I collagen (CTX-I) and type II collagen (CTX-II), thereby reducing cartilage damage. In summary, the present study indicates that emodin reduces ECM degradation and oxidative stress in chondrocytes via the Nrf2/NQO1/HO-1 pathway, thereby ameliorating OA in rats.

Novel Aminoguanidine Hydrazone Analogues: From Potential Antimicrobial Agents to Potent Cholinesterase Inhibitors

A series of thirty-one hydrazones of aminoguanidine, nitroaminoguanidine, 1,3-diaminoguanidine, and (thio)semicarbazide were prepared from various aldehydes, mainly chlorobenzaldehydes, halogenated salicylaldehydes, 5-nitrofurfural, and isatin (yields of 50–99%). They were characterized by spectral methods. Primarily, they were designed and evaluated as potential broad-spectrum antimicrobial agents. The compounds were effective against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus with minimum inhibitory concentrations (MIC) from 7.8 µM, as well as Gram-negative strains with higher MIC. Antifungal evaluation against yeasts and Trichophyton mentagrophytes found MIC from 62.5 µM. We also evaluated inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The compounds inhibited both enzymes with IC₅₀ values of 17.95–54.93 µM for AChE and ≥1.69 µM for BuChE. Based on the substitution, it is possible to modify selectivity for a particular cholinesterase as we obtained selective inhibitors of either AChE or BuChE, as well as balanced inhibitors. The compounds act via mixed-type inhibition. Their interactions with enzymes were studied by molecular docking. Cytotoxicity was assessed in HepG2 cells. The hydrazones differ in their toxicity (IC₅₀ from 5.27 to >500 µM). Some of the derivatives represent promising hits for further development. Based on the substitution pattern, it is possible to modulate bioactivity to the desired one.