Synthesis of Lathyrol PROTACs and Evaluation of Their Anti-Inflammatory Activities

Thirty years of NRF2: advances and therapeutic challenges

Over the last 30 years, NRF2 has evolved from being recognized as a transcription factor primarily involved in redox balance and detoxification to a well-appreciated master regulator of cellular proteostasis, metabolism and iron homeostasis. NRF2 plays a pivotal role in diverse pathologies, including cancer, and metabolic, inflammatory and neurodegenerative disorders. It exhibits a Janus-faced duality, safeguarding cellular integrity in normal cells against environmental insults to prevent disease onset, whereas in certain cancers, constitutively elevated NRF2 levels provide a tumour survival advantage, promoting progression, therapy resistance and metastasis. Advances in understanding the mechanistic regulation of NRF2 and its roles in human pathology have propelled the investigation of NRF2-targeted therapeutic strategies. This Review dissects the mechanistic intricacies of NRF2 signalling, its cross-talk with biological processes and its far-reaching implications for health and disease, highlighting key discoveries that have shaped innovative therapeutic approaches targeting NRF2.

Harnessing Functional Food Sources: Deriving Anti-Inflammatory and Antibacterial Naphthalene Derivatives from the Edible Bulbs of Eleutherine bulbosa

The red bulbs of Eleutherine bulbosa, commonly used as a daily dietary ingredient in cooking, are well-known for their rich nutritional profile and potential medicinal properties. This study focused on identifying bioactive components from E. bulbosa by a bioactivity-guided approach combined with global natural products' social molecular networking, which led to the characterization of 12 new naphthalene derivatives, eleuthalenes A-L (1-12), and 22 known analogues. The structures of these compounds were determined through spectroscopic data, X-ray crystallography, and quantum chemical calculations. The anti-inflammatory and antibacterial activities of these compounds were evaluated, with some demonstrating significant anti-inflammatory and moderate antibacterial activities. Further studies revealed that the most potent compound 5 displayed an anti-inflammatory effect in LPS-induced RAW 264.7 cells by suppressing the NF-κB/MAPK and activating Nrf2/Keap1 signaling pathways. The results suggested that bioactive naphthalene derivatives are the major pharmacodynamic substances of E. bulbosa.

HDAC6 promotes inflammation in lupus nephritis mice by regulating transcription factors MAFF and KLF5 in renal fibrosis

AIM

This study explored the effect and mechanism of MAFF and HDAC6 on renal fibrosis and inflammation in lupus nephritis (LN).

METHODS

IL-33 treated renal epithelial cells and MRL/lpr mice were respectively used for in vitro and in vivo experiments. The expressions of HDAC6, MAFF, and KLF5 were measured in cells and renal tissues. Before and after cell transfection, the morphological changes in renal tissues were observed using Hematoxylin and eosin (H&E) and Masson staining. The proteinuria, serum creatinine (SCr), blood urea nitrogen (BUN), and double-stranded DNA (dsDNA) levels were detected by biochemical analysis. The expressions of fibrosis and inflammation related proteins (including α-SMA, Vimentin, IL-1β, IL-6, and TNF-α), p65, and iNOS were also detected. The relationship among MAFF, HDAC6, and KLF5 was determined by chromatin immunoprecipitation and dual luciferase reporter gene assay.

RESULTS

Renal tissues and cell models had elevated expressions of HDAC6 and KLF5, and decreased MAFF expression. HDAC6 suppression or MAFF overexpression led to suppression of proteinuria, SCr, BUN, and dsDNA levels, as well as attenuation of inflammatory infiltration and collagen deposition. HDAC6 can suppress MAFF expression via deacetylation to abolish its suppression of KLF5 expression, thus increasing KLF5 expression. In vivo and in vitro experiments showed the suppressive effect of HDAC6 suppression on renal fibrosis and inflammation can be abolished by KLF5 overexpression.

CONCLUSION

HDAC6 suppresses MAFF expression via deacetylation to elevate KLF5 expression, which consequently enhances fibrosis and inflammatory response in LN.

Characteristic roadmap of linker governs the rational design of PROTACs

Proteolysis targeting chimera (PROTAC) technology represents a groundbreaking development in drug discovery, leveraging the ubiquitin‒proteasome system to specifically degrade proteins responsible for the disease. PROTAC is characterized by its unique heterobifunctional structure, which comprises two functional domains connected by a linker. The linker plays a pivotal role in determining PROTAC's biodegradative efficacy. Advanced and rationally designed functional linkers for PROTAC are under development. Nonetheless, the correlation between linker characteristics and PROTAC efficacy remains under-investigated. Consequently, this study will present a multidisciplinary analysis of PROTAC linkers and their impact on efficacy, thereby guiding the rational design of linkers. We will primarily discuss the structural types and characteristics of PROTAC linkers, and the optimization strategies used for their rational design. Furthermore, we will discuss how factors like linker length, group type, flexibility, and linkage site affect the biodegradation efficiency of PROTACs. We believe that this work will contribute towards the advancement of rational linker design in the PROTAC research area.

Investigation of small molecules disrupting dengue virus assembly by inhibiting capsid protein and blocking RNA encapsulation

Dengue fever is a significant global public health concern, causing substantial morbidity and mortality worldwide. The disease can manifest in various forms, from mild fever to potentially life-threatening complications. Developing effective treatments remains a critical challenge to healthcare systems. Despite extensive research, no antiviral drugs have been approved for either the prevention or treatment of dengue. Targeting the virus during its early phase of attachment is essential to inhibit viral replication. The capsid protein plays a crucial role in the virus's structural integrity, assembly, and viral genome release. In the present study, we employed a computational approach focused on the capsid protein to identify possible potent inhibitors against the dengue virus from a library of FDA-approved drugs. We employed high-throughput virtual screening on FDA-approved drugs to identify drug molecules that could potentially combat the disease and save both cost and time. The screening process identified four drug molecules (Nordihydroguaiaretic acid, Ifenprodil tartrate, Lathyrol, and Safinamide Mesylate) based on their highest binding affinity and MM/GBSA scores. Among these, Nordihydroguaiaretic acid showed higher binding affinity than the reference molecule with - 11.66 kcal/mol. In contrast, Ifenprodil tartrate and Lathyrol showed similar results to the reference molecule, with binding energies of - 9.42 kcal/mol and - 9.29 kcal/mol, respectively. Following the screening, molecular dynamic simulations were performed to explore the molecular stability and conformational possibilities. The drug molecules were further supported by post-molecular simulation analysis. Furthermore, binding energies were also computed using the MM/GBSA approach, and the free energy landscape was used to calculate the different transition states, revealing that the drugs exhibited significant transition states. Specifically, Nordihydroguaiaretic acid and Ifenprodil tartrate displayed higher flexibility, while Lathyrol and Safinamide Mesylate showed more predictable and consistent protein folding. This significant breakthrough offers new hope against dengue, highlighting the power of computational drug discovery in identifying potent inhibitors and paving the way for novel treatment approaches.

Anti-Inflammatory and Cytotoxic Compounds Isolated from Plants of Euphorbia Genus

Euphorbia is a large genus of the Euphorbiaceae family. Around 250 species of the Euphorbia genus have been studied chemically and pharmacologically; different compounds have been isolated from these species, especially diterpenes and triterpenes. Several reports show that several species have anti-inflammatory activity, which can be attributed to the presence of diterpenes, such as abietanes, ingenanes, and lathyranes. In addition, it was found that some diterpenes isolated from different Euphorbia species have anti-cancer activity. In this review, we included compounds isolated from species of the Euphorbia genus with anti-inflammatory or cytotoxic effects published from 2018 to September 2023. The databases used for this review were Science Direct, Scopus, PubMed, Springer, and Google Scholar, using the keywords Euphorbia with anti-inflammatory or cytotoxic activity. In this review, 68 studies were collected and analyzed regarding the anti-inflammatory and anti-cancer activities of 264 compounds obtained from 36 species of the Euphorbia genus. The compounds included in this review are terpenes (95%), of which 68% are diterpenes, especially of the types ingenanes, abietanes, and triterpenes (approximately 15%).

Evaluation of anti-inflammatory potential and GC-MS profiling of leaf extracts from Clerodendrum infortunatum L

ETHNOPHARMACOLOGICAL RELEVANCE

Clerodendrum infortunatum L. is commonly distributed in tropical and subtropical countries and is widely used in the indigenous systems of medicine including Ayurveda, Unani, and Homeopathy. The plant has important uses in the treatment of various inflammatory disorders which includes asthma, cough, chest complaints, pain, rheumatism, osteoarthritis, gastric ulcer, cancer, diabetes, skin diseases etc. AIM OF THE STUDY: Regarding the extensive healing properties of C. infortunatum in folk medicine, we aimed to explore the anti-inflammatory activity of the plant and analyze its bioactive components.

MATERIALS AND METHODS

Sequential extracts were prepared from C. infortunatum leaves using n-hexane, dichloromethane, ethyl acetate, methanol, ethanol and water. In vitro anti-inflammatory activity of these extracts were evaluated using membrane stabilization and protein anti-denaturation assays. Toxicity of the extracts was tested using brine shrimp lethality assay. GC-MS analysis has been carried out to analyze and characterize various bioactive constituents present in the plant.

RESULTS

Each of the tested extracts showed significant (p < 0.05) in vitro anti-inflammatory activity. Sequential ethyl acetate extract demonstrated the strongest membrane stabilization and protein anti-denaturation activities with IC50 values of 331.3, 308.3 and 279.2 μg/mL for heat and hypotonicity induced membrane stabilization and protein anti-denaturation assays, respectively. Sequential methanol extract also exhibited strong activity in heat and hypotonicity induced membrane stabilization and protein anti-denaturation assays with IC50 values of 371.5, 331.6 and 284.6 μg/mL, respectively. The extracts demonstrated a range of toxicity in the brine shrimp lethality assay with LC50 values of 51.4, 59.7, 47.3, 37.1, 68.1 and 77.3 μg/mL for n-hexane, dichloromethane, ethyl acetate, methanol, ethanol and water extracts respectively. The GC-MS analysis of direct n-hexane, ethyl acetate and methanol extracts detected 32 different compounds. The major compounds (> 5%) were phenol, 3,5-bis(1,1-dimethylethyl)-, hexadecanoic acid methyl ester, estragole, methyl stearate, lanosterol, 9-methoxybicyclo[6.1.0]nona-2,4,6-triene, benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl) 4 hydroxy methyl ester, 22,23-dibromostigmasterol acetate, 3-methyl-4-(phenylthio)-2-prop-2-enyl-2,5-dihydrothiophene 1,1-dioxide, benzenemethanol, α-methyl-α-propyl- and 9-octadecenoic acid (Z)- methyl ester.

CONCLUSIONS

The findings of our study revealed that C. infortunatum is rich with diverse bioactive phytoconstituents and the scientific evidences support the anti-inflammatory potential of the plant.