Synthesis of novel andrographolide beckmann rearrangement derivatives and evaluation of their HK2-related anti-inflammatory activities

Cirsium japonicum leaf extract attenuated lipopolysaccharide-induced acute respiratory distress syndrome in mice via suppression of the NLRP3 and HIF1α pathways

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe inflammatory disorder characterized by acute respiratory failure, alveolar barrier dysfunction, edema, and dysregulated alveolar macrophage-mediated pulmonary inflammation. Despite advancements in treatment strategies, the mortality rate in patients with ARDS remains high, ranging from 40-60 %. Current approaches are limited to supportive care, necessitating the exploration of effective therapeutic options such as suppressing broad inflammatory responses. Although Cirsium japonicum leaves possess anti-inflammatory properties, their specific effects on ARDS have not yet been investigated.

METHODS

The anti-inflammatory activity of Cirsium japonicum extract (CJE) was investigated in a lipopolysaccharide (LPS)-induced ARDS model.

RESULTS

CJE significantly attenuated LPS-induced lung injury, including reduced alveolar wall thickness, inflammatory cell infiltration, proteinaceous debris, and hyaline membranes. Moreover, CJE repressed infiltration of inflammatory cells and pro-inflammatory gene expression in bronchoalveolar lavage fluid. Concordantly, CJE mitigated alveolar macrophage activation, which consequently reduced neutrophil chemoattractic infiltration. Additionally, CJE suppressed NLRP3 and HIF1α expression in the lungs of the ARDS mouse. Similarly, LPS-induced NLRP3 and HIF1α pathway-associated inflammatory and glycolytic gene expressions significantly diminished by CJE in murine alveolar macrophage cell line, MH-S cells, and bone marrow-derived macrophages.

CONCLUSION

CJE suppressed multiple inflammatory responses through the regulation of NLRP3 and HIF1α signaling-related gene expression in macrophages of LPS-induced ARDS mice. These results suggest that CJE has therapeutic potential for treating patients with ARDS via macrophage regulation.

Current Progress of Hederagenin and Its Derivatives for Disease Therapy (2017-Present)

Natural products have emerged as crucial sources of biologically active compounds, holding promise for applications in drug development. Among the extensively researched pentacyclic triterpenes, hederagenin (HG) stands out for its diverse biological activities and serves as a valuable scaffold for synthesizing novel derivatives. These derivatives hold significant promise for the development of novel therapeutic agents aimed at treating a wide range of diseases. Over the past years, a multitude of HG derivatives with varied bioactivities have been synthesized through chemical modifications. This review article consolidates the most recent findings (since 2017) on HG derivatives, emphasizing their biological effects and mechanisms of action in both in vitro and in vivo models. The objective of this compilation is to offer insights and direct future research endeavors in the realm of HG.

mTOR/HIF-1α pathway-mediated glucose reprogramming and macrophage polarization by Sini decoction plus ginseng soup in ALF

BACKGROUND

Acute liver failure (ALF) has a high mortality rate, and despite treatment advancements, long-term outcomes remain poor.

PURPOSE

This study explores the therapeutic targets and pathways of Sini Decoction plus Ginseng Soup (SNRS) in ALF using bioinformatics and network pharmacology, focusing on its impact on macrophage polarization through glucose metabolism reprogramming. The efficacy of SNRS was validated in an LPS/D-GalN-induced ALF model, and its optimal concentration was determined for in vitro macrophage intervention.

STUDY DESIGN AND METHODS

Differentially expressed genes (DEGs) in HBV-induced and acetaminophen-induced ALF were identified from GEO datasets. The correlation between target gene expression and immune cell infiltration in ALF liver tissue was analyzed. AST, ALT, TNF-α, HMGB1, IL-1β, IL-6, and IL-10 levels were measured, and liver histopathology was assessed. Macrophage polarization was analyzed via immunofluorescence, flow cytometry, and Western blot. Glycolysis-related enzymes and metabolites, including HK2, PFK-1, PKM2, and LDHA, were quantified. Cellular ultrastructure was examined by transmission electron microscopy.

RESULTS

Five key glycolysis-regulating genes (HK2, CDK1, SOD1, VEGFA, GOT1) were identified, with significant involvement in the HIF-1 signaling pathway. Immune infiltration was markedly higher in ALF liver tissue. SNRS improved survival, reduced ALT/AST levels, alleviated liver injury, and modulated macrophage polarization by decreasing CD86 and increasing CD163 expression. In vitro, SNRS inhibited LPS-induced inflammatory cytokine release, lactate production, p-mTOR/mTOR ratio, and HIF-1α expression.

CONCLUSION

SNRS modulates macrophage polarization and glucose metabolism reprogramming via the mTOR/HIF-1α pathway, showing promise as a treatment for ALF.

The role of the interplay between macrophage glycolytic reprogramming and NLRP3 inflammasome activation in acute lung injury/acute respiratory distress syndrome

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a severe respiratory condition associated with elevated morbidity and mortality. Understanding their complex pathophysiological mechanisms is crucial for developing new preventive and therapeutic strategies. Recent studies highlight the significant role of inflammation involved in ALI/ARDS, particularly the hyperactivation of the NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome in macrophages. This activation drives pulmonary inflammation by releasing inflammatory signalling molecules and is linked to metabolic reprogramming, marked by increased glycolysis and reduced oxidative phosphorylation. However, the relationship between NLRP3 inflammasome activation and macrophage glycolytic reprogramming in ALI/ARDS, as well as the molecular mechanisms regulating these processes, remain elusive. This review provides a detailed description of the interactions and potential mechanisms linking NLRP3 inflammasome activation with macrophage glycolytic reprogramming, proposing that glycolytic reprogramming may represent a promising therapeutic target for mitigating inflammatory responses in ALI/ARDS. KEY POINTS: NLRP3 inflammasome activation is pivotal in mediating the excessive inflammatory response in ALI/ARDS. Glycolytic reprogramming regulates NLRP3 inflammasome activation. Therapeutic potential of targeting glycolytic reprogramming to inhibit NLRP3 inflammasome activation in ALI/ARDS.

Synthesis and Pesticidal Activities of Ester Derivatives of the Labdane Diterpenoid Andrographolide at the C-3 Position Containing the Isoxazoline Fragment and Their Toxicology Study against Tetranychus cinnabarinus Boisduval

Due to the long-term overuse of chemical pesticides, serious resistance and negative problems on human health and the ecological environment have appeared. To develop plant-product-based pesticide candidates, a series of novel andrographolide ester derivatives containing the isoxazoline skeleton were prepared at the C-3 position. Their pesticidal activities were evaluated against three typical pests such as Mythimna separata Walker, Aphis citricola Van der Goot, and Tetranychus cinnabarinus Boisduval. Against M. separata, compounds Ik, IIf, IIg, and IIk showed 1.6-1.8 times insecticidal activity compared to that of andrographolide; against A. citricola, compounds 6, Ih, and IIh possessed 3.7-3.9-fold aphicidal activity compared to that of andrographolide; against T. cinnabarinus, compounds Ib, Ig, and IIk exhibited 7.4-9.1-fold promising acaricidal activity compared to that of andrographolide. It is worth mentioning that effects of IIk on morphological changes of the treated mite cuticle layer structures were observed by the scanning electron microscope imaging method. Compound IIk can be studied as a pesticidal lead for further structural modification.

Regiodivergent Ring-Expansion of Oxindoles to Quinolinones

The development of divergent methods to expedite structure-activity relationship studies is crucial to streamline discovery processes. We developed a rare example of regiodivergent ring expansion to access two regioisomers from a common starting material. To enable this regiodivergence, we identified two distinct reaction conditions for transforming oxindoles into quinolinone isomers. The presented methods proved to be compatible with a variety of functional groups, which enabled the late-stage diversification of bioactive oxindoles as well as facilitated the synthesis of quinolinone drugs and their derivatives.

Research progress of hexokinase 2 in inflammatory-related diseases and its inhibitors

Hexokinase 2 (HK2) is a crucial enzyme involved in glycolysis, which converts glucose into glucose-6-phosphate and plays a significant role in glucose metabolism. HK2 can mediate glycolysis, which is linked to the release of inflammatory factors. The over-expression of HK2 increases the production of pro-inflammatory cytokines, exacerbating the inflammatory reaction. Consequently, HK2 is closely linked to various inflammatory-related diseases affecting multiple systems, including the digestive, nervous, circulatory, respiratory, reproductive systems, as well as rheumatoid arthritis. HK2 is regarded as a novel therapeutic target for inflammatory-related diseases, and this article provides a comprehensive review of its roles in these conditions. Furthermore, the development of potent HK2 inhibitors has garnered significant attention in recent years. Therefore, this review also presents a summary of potential HK2 inhibitors, offering promising prospects for the treatment of inflammatory-related diseases in the future.

Synthesis and anti-inflammatory activity of novel firocoxib analogues with balanced COX inhibition

The adverse effects caused by nonselective and selective cyclooxygenase-2 (COX-2) inhibitors remain a challenge for current anti-inflammatory medications. A balanced inhibition of COX-1/-2 represents a promising strategy for the development of novel COX-2 inhibitors. In this study, we present the design and synthesis of a novel series of firocoxib analogues incorporating an amide bond to facilitate essential hydrogen bonding with amino residues in COX-2. The synthesized analogs were evaluated for their inhibitory activity against both COX-1 and COX-2 enzymes. Among them, compound 9d demonstrated potent and balanced inhibition. Inhibition of COX enzymes by 9d in lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophages resulted in the suppression of the NF-κB signaling pathway to reduced expression of pro-inflammatory factors such as inducible nitric oxide synthase (iNOS), COX-2, nitric oxide (NO), and reactive oxygen species (ROS). The remarkable in vitro anti-inflammatory activity exhibited by 9d positions it as a promising candidate for further development as a novel lead compound for inflammation treatment.

The immunometabolic reprogramming of microglia in Alzheimer's disease

Alzheimer's disease (AD) is an age-related neurodegenerative disorder (NDD). In the central nervous system (CNS), immune cells like microglia could reprogram intracellular metabolism to alter or exert cellular immune functions in response to environmental stimuli. In AD, microglia could be activated and differentiated into pro-inflammatory or anti-inflammatory phenotypes, and these differences in cellular phenotypes resulted in variance in cellular energy metabolism. Considering the enormous energy requirement of microglia for immune functions, the changes in mitochondria-centered energy metabolism and substrates of microglia are crucial for the cellular regulation of immune responses. Here we reviewed the mechanisms of microglial metabolic reprogramming by analyzing their flexible metabolic patterns and changes that occurred in their metabolism during the development of AD. Further, we summarized the role of drugs in modulating immunometabolic reprogramming to prevent neuroinflammation, which may shed light on a new research direction for AD treatment.

Cytotoxic and Anti-Inflammatory Activity of 3,19-Isopropylidene-/Arylidene-Andrographolide Analogs

A series of 3,19-isopropylidene-/or arylidene-andrographolide analogs were synthesized and their structures were confirmed by NMR spectroscopic methodology. Twenty-five analogs were evaluated for their in vitro cytotoxic activity against HT-29, HepG2 and LNCaP cancer cell lines based on the sulforhodamine B (SRB) assay. Analog 2 f exhibited the most potent cytotoxic activity, with IC50 values of 11.14 and 9.25 μM on HepG2 and LNCaP cancer cell lines, respectively. Esterification of hydroxy functional group at position C-14 in andrographolide analogs, 2 a and 2 b, showed somewhat higher cytotoxicity than the precursor. In addition, andrographolide analogs (2 a-2 d, 2 f, 3 a, 4 a and 4 h) were evaluated for the NO inhibitory activity in the LPS stimulated RAW264.7 macrophages. The most active analog 2 a significantly reduced nitric oxide (NO) production from LPS stimulated RAW264.7 cells, with IC50 values of 0.34±0.02 μM providing encouraging results for anti-inflammatory compound development.

Interactions between NLRP3 inflammasome and glycolysis in macrophages: New insights into chronic inflammation pathogenesis

NLRP3 inflammasome activation in macrophages fuels sterile inflammation, which has been tied with metabolic reprogramming characterized by high glycolysis and low oxidative phosphorylation. The key enzymes in glycolysis and glycolysis‐related products can regulate and activate NLRP3 inflammasome. In turn, NLRP3 inflammasome is considered to affect glycolysis, as well. However, the exact mechanism remains ambiguous. On the basis of these findings, the focus of this review is mainly on the developments in our understanding of interaction between NLRP3 inflammasome activation and glycolysis in macrophages, and small molecule compounds that influence the activation of NLRP3 inflammasomes by regulating glycolysis in macrophages. The application of this interaction in the treatment of diseases is also discussed. This paper may yield valuable clues for development of novel therapeutic agent for NLRP3 inflammasome‐related diseases.

Plant-microbial interaction: The mechanism and the application of microbial elicitor induced secondary metabolites biosynthesis in medicinal plants

Plants and microbes interact with each other via different chemical signaling pathways. At the risophere level, the microbes can secrete molecules, called elicitors, which act on their receptors located in plant cells. The so-called elicitor molecules as well as their actions differ according to the mcirobes and induce different bilogical responses in plants such as the synthesis of secondary metabolites. Microbial compounds induced phenotype changes in plants are known as elicitors and signaling pathways which integrate elicitor's signals in plants are called elicitation. In this review, the impact of microbial elicitors on the synthesis and the secretion of secondary metabolites in plants was highlighted. Moreover, biological properties of these bioactive compounds were also highlighted and discussed. Indeed, several bacteria, fungi, and viruses release elicitors which bind to plant cell receptors and mediate signaling pathways involved in secondary metabolites synthesis. Different phytochemical classes such as terpenoids, phenolic acids and flavonoids were synthesized and/or increased in medicinal plants via the action of microbial elicitors. Moreover, these compounds compounds exhibit numerous biological activities and can therefore be explored in drugs discovery.

A pH-responsive mesoporous silica nanoparticles-based drug delivery system with controlled release of andrographolide for OA treatment

Andrographolide (AG) has favorable anti-inflammatory and antioxidative capacity. However, it has low bioavailability due to high lipophilicity and can be easily cleared by the synovial fluid after intra-articular injection, leading to low therapeutic efficiency in osteoarthritis (OA). Herein, we designed a nano-sized pH-responsive drug delivery system (DDS) for OA treatment by using modified mesoporous silica nanoparticles (MSNs) with pH-responsive polyacrylic acid (PAA) for loading of AG to form AG@MSNs-PAA nanoplatform. The nanoparticles have uniform size (∼120 nm), high drug loading efficiency (22.38 ± 0.71%) and pH-responsive properties, beneficial to sustained release in OA environment. Compared with AG, AG@MSNs-PAA showed enhanced antiarthritic efficacy and chondro-protective capacity based on IL-1β-stimulated chondrocytes and anterior cruciate ligament transection-induced rat OA model, as demonstrated by lower expression of inflammatory factors and better prevention of proteoglycan loss. Therefore, the AG@MSNs-PAA nanoplatform may be developed as a promising OA-specific and on-demand DDS.

Andrographolide and its derivatives: Current achievements and future perspectives

Natural product andrographolide isolated from the plant Andrographis paniculata shows a plethora of biological activities, including anti-tumor, anti-bacterial, anti-inflammation, anti-virus, anti-fibrosis, anti-obesity, immunomodulatory and hypoglycemic activities. Based on extensive chemical structural modifications, a series of andrographolide derivatives with improved bioavailability and druggability has been developed. Moreover, greater understanding of their mechanisms of action at the molecular and cellular level has been thoroughly investigated. In this review, we give an outlook for the therapeutical potential of andrographolide and its derivatives in diverse diseases and highlighted the drug design, pharmacokinetic and mechanistic studies for the past ten years, together with a brief overview of the pharmacological effects. Notably, we focused to provide a critical enlightenment of the area of andrographolide and its derivatives with the intent of indicating the future perspectives, challenges and limitations. We believe that this review paper will benefit drug discovery where andrographolide was used as a template, shed light on the identification of drug targets for andrographolide and its analogs, as well as increase our knowledge for using them for therapeutic application, including the treatment for various forms of cancers.

Current Trends on Repurposing and Pharmacological Enhancement of Andrographolide

Andrographolide, the main bioactive component separated from Andrographis paniculata in 1951, has been scrutinized with a modern drug discovery approach for anti-inflammatory properties since 1984. Identification of new uses of existing drugs can be facilitated by searching for evidence linking them to known or yet undiscovered drug targets and human disease states to develop new therapeutic indications.Furthermore, a wide spectrum of biological properties of andrographolide such as anticancer, antibacterial, antiviral, hepatoprotective, antioxidant, anti-malarial, anti-atherosclerosis are also reported. However, poor water solubility and instability limit its clinical application. It becomes crucial to enhance its pharmacological function and find a new treatment option for more diseases. Therefore, this article reviews the major recent developments in andrographolide, including repurposing applications in different diseases and underlying mechanisms, particularly focusing on pharmacological enhancement of andrographolide such as derivatives, chemical modifications with potent biological activity and drug delivery. The repurposing and pharmacological enhancement of andrographolide would not only have exciting therapeutic potential to different diseases to facilitate drug marketing, but also decrease the economic burden on healthcare worldwide.

Andrographolide, an Anti-Inflammatory Multitarget Drug: All Roads Lead to Cellular Metabolism

Andrographolide is a labdane diterpene and the main active ingredient isolated from the herb Andrographis paniculata. Andrographolide possesses diverse biological effects including anti-inflammatory, antioxidant, and antineoplastic properties. Clinical studies have demonstrated that andrographolide could be useful in therapy for a wide range of diseases such as osteoarthritis, upper respiratory diseases, and multiple sclerosis. Several targets are described for andrographolide, including the interference of transcription factors NF-κB, AP-1, and HIF-1 and signaling pathways such as PI3K/Akt, MAPK, and JAK/STAT. In addition, an increase in the Nrf2 (nuclear factor erythroid 2–related factor 2) signaling pathway also supports its antioxidant and anti-inflammatory properties. However, this scenario could be more complex since recent evidence suggests that andrographolide targets can modulate glucose metabolism. The metabolic effect of andrographolide might be the key to explaining the diverse therapeutic effects described in preclinical and clinical studies. This review discusses some of the most recent evidence about the anti-inflammatory and metabolic effects of andrographolide.

Semisynthesis and Pesticidal Activities of Derivatives of the Diterpenoid Andrographolide and Investigation on the Stress Response of Aphis citricola Van der Goot (Homoptera: Aphididae)

To discover natural-product-based pesticides, 7β-oxycarbonylandrographolide derivatives were stereoselectively constructed from a labdane diterpenoid andrographolide. Among them, 2'-(n)Pr-1',3'-dioxin-7β-oxy(m-Cl)benzoylandrographolide (IIc), 2'-(n)Pr-1',3'-dioxin-7β-oxyacetylandrographolide (IIf), 2'-(p-Me)Ph-1',3'-dioxin-7β-oxy(o-Cl)benzoylandrographolide (Vb), and 2'-(p-Me)Ph-1',3'-dioxin-7β-oxy(m-Cl)benzoylandrographolide (Vc) against Mythimna separata displayed the most promising growth inhibitory activity; 2'-(n)Pr-1',3'-dioxin-7β-oxy(o-Cl)benzoylandrographolide (IIb: LC₅₀ = 0.406 mg/mL) and IIc (LC₅₀ = 0.415 mg/mL) exhibited the most pronounced acaricidal activity (andrographolide; LC₅₀: 5.106 mg/mL) and good control effects against Tetranychus cinnabarinus; compounds Ic, IIe, and Va-c (LD₅₀ = 0.035-0.039 μg/nymph) showed potent aphicidal activity (andrographolide: LD₅₀ = 0.178 μg/nymph), and compounds IIe and Vb showed good control effects against Aphis citricola. Moreover, it was found that Hsp70 of A. citricola was an important gene involved in stress response to andrographolide and its derivatives.

Synthesis of New Lathyrane Diterpenoid Derivatives from Euphorbia lathyris and Evaluation of Their Anti-Inflammatory Activities

Euphorbia factor L₃ , a lathyrane diterpenoid extracted from Euphorbia lathyris, was found to display good anti-inflammatory activity with very low cytotoxicity. To find more potent anti-inflammatory drugs, two series of Euphorbia factor L₃ derivatives with fatty and aromatic acids were designed and synthesized. Among them, lathyrane derivative 5n exhibited most potent inhibition on LPS-induced NO production in RAW264.7 cells with no obvious cytotoxicity. To determine the key characteristics of Euphorbia factor L₃ derivatives that contribute to anti-inflammatory activity, we conducted a structure-activity relationship study of these compounds.