Isolation and Identification of Antiarthritic Constituents from Glycine tabacina and Network Pharmacology-Based Prediction of Their Protective Mechanisms against Rheumatoid Arthritis

Dual regulation of phaseol on osteoclast formation and osteoblast differentiation by targeting TAK1 kinase for osteoporosis treatment

INTRODUCTION

Osteoporosis is an osteolytic disorder resulting from an inequilibrium between osteoblast-mediated osteogenesis and osteoclast-driven bone absorption. Safe and effective approaches for osteoporosis management are still highly demanded.

PURPOSE

This study aimed to examine the osteoprotective effect and the mechanisms of phaseol (PHA) in vitro and in vivo.

METHODS

Virtual screening identified the potential inhibitors of transforming growth factor-beta-activated kinase 1 (TAK1) from coumestans. The interaction between PHA and TAK1 was investigated by molecular simulation, pronase and thermal resistance assays. The maturation and function of osteoclasts were determined using tartrate-resistant acid phosphatase staining, bone absorption and F-actin ring formation assays. The differentiation and calcification of osteoblasts were assessed by alkaline phosphatase staining and Alizarin Red S staining. The activity of related targets and pathways were detected using immunoblotting, immunofluorescence and co-immunoprecipitation assays. The in vivo osteoprotective effect of PHA was evaluated using a lipopolysaccharide (LPS)-induced mouse osteoporosis model.

RESULTS

Firstly, we confirmed that TAK1 was essential in controlling bone remodeling by regulating osteogenesis and osteoclastogenesis. Moreover, PHA, a coumestan compound predominantly present in leguminous plants, was identified as a potent TAK1 inhibitor through virtual and real experiments. Subsequently, PHA was observed to enhance osteoblast differentiation and calcification, while suppress osteoclast maturation and bone resorptive function in vitro. Mechanistically, PHA remarkably inhibited the TRAF6-TAK1 complex formation, and inhibited the activation of TAK1, MAPK and NF-κB pathways by targeting TAK1. In the in vivo study, PHA strongly attenuated bone loss, inflammatory responses, and osteoclast over-activation in lipopolysaccharide-induced osteoporosis mice.

CONCLUSION

PHA had a dual-functional regulatory impact on osteogenesis and osteoclastogenesis by targeting TAK1, suppressing TRAF6-TAK1 complex generation, and modulating its associated signaling pathways, ultimately leading to mitigating osteoporosis. This study offered compelling evidence in favor of using PHA for preventing and managing osteoporosis as both a bone anabolic and anti-resorptive agent.

Isoflavone Derivatives as Potential Anticancer Agents: Synthesis and Bioactivity Studies

Isoflavones are phenolic natural compounds with a C6C3C6 framework. They possess a plethora of biological activities that are associated with putative benefits to human health. In particular, the cancer chemopreventive and chemotherapeutic potential of isoflavones has attracted the interest of researchers. Several isoflavone derivatives have been synthesised and probed for their anticancer activities. The isoflavone analogues are mainly synthesised by molecular hybridisation and other strategies that enable diversification through early or late-stage functionalisation of A-, B- and C-rings of the isoflavones. This has resulted in the discovery of isoflavone analogues with improved antiproliferative activities against several cancer cells and different mechanisms of action. In this review, the synthesis of isoflavone derivatives and their anticancer activity studies are discussed.

Coumarins as versatile therapeutic phytomolecules: A systematic review

BACKGROUND

Coumarins, abundantly distributed in a plethora of biologically active compounds, serve as a fundamental motif in numerous natural products, drugs, and therapeutic leads. Despite their small size, they exhibit a diverse range of biological activities, intriguing researchers with their immense pharmacological potential.

PURPOSE

This study consolidates the evidence regarding the essential role of coumarins in modern drug discovery, exploring their broad-spectrum pharmaceutical effects, structural versatility, and mechanisms of action across various domains.

METHODS

For literature search, we utilized PubMed, Google scholar, and SciFinder databases. Keyword and keyword combinations such as "coumarins", "natural coumarins", "specific natural coumarins for particular diseases", and "therapeutic effects" were employed to retrieve relevant studies. The search encompassed articles published between 2005 and 2023. Selection criteria included studies reporting on the pharmacological activities of natural coumarins against various diseases.

RESULTS

The results highlight the therapeutic potential of natural coumarins against various diseases, demonstrating anti-cancer, anti-oxidant, and anti-inflammatory activities. They also act as monoamine oxidase inhibitors and phosphodiesterase inhibitors, and as anti-thrombotic, anti-diabetic, and hepatoprotective agents. They also show efficacy against diabetic nephropathy, neurodegenerative diseases, microbial infections and many other diseases.

CONCLUSION

This review underscores the significant role of natural coumarins in medicinal chemistry and drug discovery. Their diverse biological activities and structural versatility make them promising therapeutic agents. This study serves as a catalyst for further research in the field, aiming to address emerging challenges and opportunities in drug development.

New Cytotoxic γ-Lactam Alkaloids from the Mangrove-Derived Fungus Talaromyces hainanensis sp. nov. Guided by Molecular Networking Strategy

The fungus Talaromyces hainanensis, isolated from the mangrove soil, was characterized as a novel species by morphology observation and phylogenetic analyses. Four new γ-lactam alkaloids talaroilactams A-D (1-4) and two reported compounds harzianic acid (5) and isoharzianic acid (6) were identified from the fungus T. hainanensis WHUF0341, assisted by OSMAC along with molecular networking approaches. Their structures were determined through ECD calculations and spectroscopic analyses. Moreover, the biosynthetic route of 1-4 was also proposed. Compound 1 displayed potent cytotoxicity against HepG2 cell lines, with an IC50 value of 10.75 ± 1.11 μM. In addition, network pharmacology was employed to dissect the probable mechanisms contributing to the antihepatocellular carcinoma effects of compound 1, revealing that cytotoxicity was mainly associated with proteolysis, negative regulation of autophagy, inflammatory response, and the renin-angiotensin system. These results not only expanded the chemical space of natural products from the mangrove associated fungi but also afforded promising lead compounds for developing the antihepatocellular carcinoma agents.

Advantages of Chinese herbal medicine in treating rheumatoid arthritis: a focus on its anti-inflammatory and anti-oxidative effects

Oxidative stress is a condition characterized by an imbalance between the oxidative and antioxidant processes within the human body. Rheumatoid arthritis (RA) is significantly influenced by the presence of oxidative stress, which acts as a pivotal factor in its pathogenesis. Elevated levels of mitochondrial reactive oxygen species (ROS) and inflammation have been found to be closely associated in the plasma of patients with RA. The clinical treatment strategies for this disease are mainly chemical drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), glucocorticoids (GCs) and biological agents, but it is difficult for patients to accept long-term drug treatment and its side effects. In the theory of traditional Chinese medicine (TCM), RA is thought to be caused by the attack of "wind, cold, damp humor," and herbs with the effect of removing wind and dampness are used to relieve pain. Chinese herbal medicine boasts a rich heritage in effectively attenuating the symptoms of RA, and its global recognition continues to ascend. In particular, RA-relevant anti-inflammatory/anti-oxidative effects of TCM herbs/herbal compounds. The main aim of this review is to make a valuable contribution to the expanding pool of evidence that advocates for the incorporation of Chinese herbal medicine in conventional treatment plans for RA.

Unprecedented spirodioxynaphthalenes from the endophytic fungus Phyllosticta ligustricola HDF-L-2 derived from the endangered conifer Pseudotsuga gaussenii

Four undescribed palmarumycin-type spirodioxynaphthalenes (phyligustricins A-D) and a known biogenetic precursor (palmarumycin BG1) were isolated from a solid fermentation of Phyllosticta ligustricola HDF-L-2, an endophyte associated with the endangered Chinese conifer Pseudotsuga gaussenii. The structures were elucidated by spectroscopic methods, single-crystal X-ray diffraction analyses, and electronic circular dichroism calculations. Both phyligustricins A and B have an unprecedented spirodioxynaphthalene-derived skeleton containing an extra 4H-furo [3,2-c]pyran-4-one moiety, while phyligustricins C and D are p-hydroxy-phenethyl substituted spirodioxynaphthalenes. The plausible biosynthetic relationships of the isolates were briefly proposed. Phyligustricins C and D and palmarumycin BG1 showed considerable antibacterial activity against Staphylococcus aureus, each with an MIC value of 16 μg/mL. Palmarumycin BG1 displayed significant inhibitory effects against ACL and ACC1, with IC₅₀ values of 1.60 and 8.00 μM, respectively.

Corn Silk Flavonoids Ameliorate Hyperuricemia via PI3K/AKT/NF-κB Pathway

Hyperuricemia (HUA) is a widespread metabolic disease marked by an elevated level of uric acid, and is a risk factor for premature death. The protective effect of corn silk flavonoids (CSF) against HUA and its potential mechanisms were explored. Five important apoptosis and inflammation-related signaling pathways were identified by network pharmacological analysis. The CSF exhibited significant uric acid (UA)-lowering activity in vitro by decreasing xanthine oxidase (XOD) and increasing hypoxanthine-guanine phosphoribosyl transferase levels. In a potassium oxonate-induced HUA in vivo, CSF treatment effectively inhibited XOD activity and promoted UA excretion. Furthermore, it decreased the levels of TNF-α and IL-6 and restored pathological damage. In summary, CSF is a functional food component to improve HUA by reducing inflammation and apoptosis through the down-regulating PI3K/AKT/NF-κB pathway.

Sesquiterpenes from Kadsura coccinea attenuate rheumatoid arthritis-related inflammation by inhibiting the NF-κB and JAK2/STAT3 signal pathways

The roots of Kadsura coccinea is commonly used in Tujia ethnomedicine, named "heilaohu", having the effect of treating rheumatic arthritis (RA). Chemical investigation on the ethanol extract of heilaohu led to the isolation of one undescribed cuparane sesquiterpenoid, heilaohusesquiterpenoid A, one undescribed carotane sesquiterpenoids, heilaohusesquiterpenoid B, and eighteen sesquiterpene derivatives. Their structures were subsequently determined based on their 1D and 2D-NMR, HR-ESI-MS, and ECD spectroscopic data. Gaultheriadiolide was the most cytotoxic compound against the proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells with an IC₅₀ value of 9.37 μM. In the same line, nine compounds exhibited significant inhibition effects against TNF-α and IL-6 release in the LPS-induced RAW264.7 cells with IC₅₀ values ranging between 1.03 and 10.99 μM. The potential molecular mechanisms of the active compounds against RA were established through pharmacological network analysis based on the initial screening results. Experimental validation showed that gaultheriadiolide suppressed inflammation by inhibiting the NF-kB and JAK2/STAT3 pathways. This study enriches the structural diversity of sesquiterpenes in K. coccinea and lays a foundation for further anti-RA and anti-inflammatory studies.

Glytabastan B, a coumestan isolated from Glycine tabacina, alleviated synovial inflammation, osteoclastogenesis and collagen-induced arthritis through inhibiting MAPK and PI3K/AKT pathways

The roots of Glycine tabacina are used to treat rheumatoid arthritis (RA) and joint infection in folk medicine. Glytabastan B (GlyB), a newly reported coumestan isolated from this species, was found to significantly attenuate IL-1β-induced inflammation in SW982 human synovial cells at 3 and 6 μM, as evidenced by the decreased levels of pro-inflammatory mediators and matrix metalloproteinases (MMPs). GlyB also suppressed RANKL-induced osteoclastogenesis, decreased the expression of osteoclastogenic markers (NFATc1, CTSK, MMP-9) and osteoclast-mediated bone resorption. Further, GlyB administration (12.5 and 25 mg/kg) significantly inhibited inflammation, osteoclast formation and disease progression in collagen-induced arthritis (CIA) mice. Integration of network pharmacology, quantitative phosphoproteomic and experimental pharmacology results revealed that these beneficial actions were closely associated with the blockade of GlyB on the activation of MAPK, PI3K/AKT and their downstream signals including NF-κB and GSK3β/NFATc1. Drug affinity responsive target stability (DARTS) assay, cellular thermal shift (CETSA) assay and molecular docking analysis confirmed that there were direct interactions between GlyB and its target proteins ERK2, JNK1 and class Ⅰ PI3K catalytic subunit p110 (α, β, δ and γ), which significantly contributed to the inhibition of activation of MAPK and PI3K/AKT pathways. In conclusion, these results strongly suggest GlyB is a promising multiple-target candidate for the development of agents for the prevention and treatment of RA.

Dissection of the Functional Mechanism of Human Gut Bacterial Strain AD16 by Secondary Metabolites' Identification, Network Pharmacology, and Experimental Validation

Gut microbiota plays important roles in several metabolic processes, such as appetite and food intake and absorption of nutrients from the gut. It is also of great importance in the maintenance of the health of the host. However, much remains unknown about the functional mechanisms of human gut microbiota itself. Here, we report the identification of one anticancer gut bacterial strain AD16, which exhibited potent suppressive effects on a broad range of solid and blood malignancies. The secondary metabolites of the strain were isolated and characterized by a bioactivity-guided isolation strategy. Five new compounds, streptonaphthalenes A and B (1-2), pestaloficins F and G (3-4), and eudesmanetetraiol A (5), together with nine previously known compounds, were isolated from the effective fractions of AD16. Structures of the new compounds were established by 1D and 2D NMR and MS analysis, and the absolute configurations were determined by the CD method. The analysis of network pharmacology suggested that 3, 2, and 13 could be the key components for the anti-NSCLC activity of AD16. In addition to the PI3K–Akt signaling pathway, the proteoglycans in cancer pathway could be involved in the anti-NSCLC action of AD16.

Davidones F and G, Two Novel Flavonoids from Sophora davidii (Franch.) Skeels

An unprecedented novel flavanone davidone F (1) with a seven-membered ring side chain, and a novel flavanonol davidone G (2), along with 11 known flavonoids, were isolated from the ethyl acetate fraction of Sophora davidii (Franch.) Skeels. Their planar structures were established by UV, IR, HRESIMS, 1D and 2D NMR data. The relative configurations of 1 and 2 were determined by calculation of NMR chemical shift values, the absolute configuration of 1 and 2 were assigned by comparing their experimental and calculated electronic circular dichroism (ECD) spectra. Moreover, compounds 1–13 were screened for the translocation activity of glucose transporter 4 (GLUT-4), and the fluorescence intensity was increased to the range of 1.56 and 2.79 folds. Compounds 1 and 2 showed moderate GLUT-4 translocation activity with 1.64 and 1.79 folds enhancement, respectively, at a concentration of 20 μg/mL.

Naturally occurring coumestans from plants, their biological activities and therapeutic effects on human diseases

Naturally occurring coumestans are known as a collection of plant-derived polycyclic aromatic secondary metabolites which are characterized by the presence of an oxygen heterocyclic four-ring system comprising a coumarin moiety and a benzofuran moiety sharing a C˭C bond. Recently, there is an increasing attention in excavating the medicinal potential of coumestans, particularly coumestrol, wedelolactone, psoralidin and glycyrol, in a variety of diseases. This review is a comprehensive inventory of the chemical structures of coumestans isolated from various plant sources during the period of 1956-2020, together with their reported biological activities. 120 molecules were collected and further classified as coumestans containing core skeleton, dimethylpyranocoumestans, furanocoumestans, O-glycosylated coumestans and others, which showed a wide range of pharmacological activities including estrogenic, anti-cancer, anti-inflammatory, anti-osteoporotic, organ protective, neuroprotective, anti-diabetic and anti-obesity, antimicrobial, immunosuppressive, antioxidant and skin-protective activities. Furthermore, this review focuses on the counteraction of coumestans against bone diseases and organ damages, and the involved molecular mechanisms, which could provide important information to better understand the medicinal values of these compounds. This review is intended to be instructive for the rational design and development of less toxic and more effective drugs with a coumestan scaffold.