Identification of 3',4',5'-trihydroxyflavone as an mammalian target of rapamycin inhibitor and its suppressive effects on dextran sulfate sodium-induced ulcerative colitis

Efficient synthesis and evaluation of therapeutic potential of fluorine containing 2-arylchromen-4-ones

A large series of 2-arylchromen-4-ones containing from 1 to 3 fluorine atoms or a trifluoromethyl group in the structure was synthesized by condensation of fluorinated 2-hydroxyacetophenones with benzaldehydes in an alkaline medium and subsequent oxidative cyclization of the resulting 2'-hydroxychalcones by action of I2 in DMSO. The cytotoxicity of the obtained compounds was studied in glioblastoma cell line, SNB19, and in a monkey-derived normal kidney epithelium cell line, Vero. In addition, antiglycation activity of the obtained compounds was evaluated. The inhibitory activity of some fluorinated 2-arylchromen-4-ones against acetylcholinesterase, butyrylcholinesterase and carboxylesterase as well their primary antioxidant activity in ABTS and FRAP tests were investigated. Screening of the synthesized compounds for their inhibitory activity against influenza A virus A/Puerto Rico/8/34 (H1N1) in the MDCK cell culture revealed that fluorinated compounds 32, 31 and 39 showed manifest antiviral effects (with IS = 57, 38 and 25 correspondingly) that makes this series of new biologically attractive fluorinated heterocycles promising for further development and in-depth study.

Potential mitigating impact of a dipeptidyl peptidase-IV inhibitor, vildagliptin, on oxazolone-induced ulcerative colitis: Targeting the role of PI3K/AKT/mTOR and AMPK/Nrf2 signaling pathways

Growing evidence suggests that phosphoinositide 3-kinase (PI3K) and adenosine monophosphate-activated protein kinase (AMPK) signaling cascades are critical in ulcerative colitis (UC) pathophysiology by influencing gut mucosal inflammation. Recently, the coloprotective properties of dipeptidyl peptidase-IV (DPP-IV) inhibitors have emerged. Thus, this study assessed for the first time the potential mitigating impact of a DPP-IV inhibitor, vildagliptin (Vilda), on oxazolone (OXZ)-induced colitis in rats, targeting the role of PI3K/AKT/mTOR and AMPK/Nrf2 pathways. Thirty-two adult Albino rats were divided into four groups: control, Vilda (10 mg/kg/day orally), OXZ (300 µL of 5 % OXZ in 50 % aqueous ethanol solution introduced once into the colon via catheter), and Vilda+OXZ. Inflammatory cytokines (interleukin 13, tumor necrosis factor-α, interleukin 10), oxidative/endoplasmic reticulum stress markers (myeloperoxidase, reduced glutathione, catalase, CHOP), mitochondrial reactive oxygen species, adenosine triphosphate levels, and mitochondrial transmembrane potential were estimated. p-AMPK, p-AKT, beclin-1, and SQSTM1 levels were immunoassayed. Nrf2, PI3K, and mTOR expression levels were quantified using the real-time polymerase chain reaction. Furthermore, p-NF-ĸBp65 and LC3II immunoreactivity were evaluated. Vilda administration effectively ameliorated OXZ-induced colitis, as evidenced by the reduced Disease Activity Index, macroscopic colon damage score, colon weight/length ratio, ulcer index, and histopathological and electron microscopic changes in the colon tissues. Vilda treatment also counteracted OXZ-triggered inflammation, oxidative/endoplasmic reticulum stress, mitochondrial dysfunction, and enhanced autophagy in the colon. Vilda substantially suppressed PI3K/AKT/mTOR and activated the AMPK/Nrf2 pathway. Vilda has potent coloprotective and anti-ulcerogenic properties, primarily attributed to its antiinflammatory, antioxidant, and modulatory impact on mitochondrial dysfunction and autophagy activity. These effects were mostly mediated by suppressing PI3K/AKT/mTOR and activating AMPK/Nrf2 signaling cascades, suggesting a potential role of Vilda in UC therapy.

Dextran sodium sulfate (DSS)-induced colitis is alleviated in mice after administration of flavone-derived NRF2-activating molecules

Inflammatory Bowel Disease (IBD) is a chronic and relapsing inflammatory condition characterized by severe symptoms such as diarrhea, fatigue, and weight loss. Growing evidence underscores the direct involvement of the nuclear factor-erythroid 2-related factor 2 (NRF2) in the development and progression of IBD, along with its associated complications, including colorectal cancer. The NRF2 pathway plays a crucial role in cellular responses to oxidative stress, and dysregulation of this pathway has been implicated in IBD. Flavones, a significant subclass of flavonoids, have shown pharmacological impacts in various diseases including IBD, through the NRF2 signaling pathway. In this study, we conducted a screening of compounds with a flavone structure and identified NJK15003 as a promising NRF2 activator. NJK15003 demonstrated potent NRF2 activation, as evidenced by the upregulation of downstream proteins, promoter activation, and NRF2 nuclear translocation in IBD cellular models. Treatment with NJK15003 effectively restored the protein levels of tight junctions in cells treated with dextran sodium sulfate (DSS) and in DSS-treated mice, suggesting its potential to protect cells from barrier integrity disruption in IBD. In DSS-treated mice, the administration of NJK15003 resulted in the prevention of body weight loss, a reduction in colon length shortening, and a decrease in the disease activity index. Furthermore, NJK15003 treatment substantially alleviated inflammatory responses and apoptotic cell death in the colon of DSS-treated mice. Taken together, this study proposes the potential utility of NRF2-activating flavone compounds, exemplified by NJK15003, for the treatment of IBD.

Design, synthesis and biological evaluation of 1H-indazole derivatives as novel ASK1 inhibitors

Apoptosis signal-regulating kinase 1 (ASK1, MAP3K5), a member of the mitogen-activated protein kinase (MAPK) signaling pathway, is involved in cell survival, differentiation, stress response, and apoptosis. ASK1 kinase inhibition has emerged as a promising therapeutic strategy for inflammatory disease. A series of novel ASK1 inhibitors with 1H-indazole scaffold were designed, synthesized and evaluated for their ASK1 kinase activity and AP1-HEK293 cell inhibitory effect. Systematic structure-activity relationship (SAR) efforts led to the discovery of promising compound 15, which showed excellent in vitro ASK1 kinase activity and potent inhibitory effects on ASK1 in AP1-HEK293 cells. In a tumor necrosis factor-α (TNF-α)-induced HT-29 intestinal epithelial cell model, compound 15 exhibited a significantly protective effect on cell viability comparable to that of GS-4997; moreover, compound 15 exhibited no obvious cytotoxicity against HT-29 cells at concentrations up to 25 μM. Mechanistic research demonstrated that compound 15 suppresses phosphorylation in the ASK1-p38/JNK signaling pathway in HT-29 cells, and regulates the expression levels of apoptosis-related proteins. Altogether, these results show that compound 15 may serve as a potential candidate compound for the treatment of inflammatory bowel disease (IBD).

Structure-based discovery of 1H-indole-2-carboxamide derivatives as potent ASK1 inhibitors for potential treatment of ulcerative colitis

Apoptosis signal-regulating kinase 1 (ASK1), a member of the mitogen-activated protein kinase (MAPK) family, is implicated in many human diseases. Here, we describe the structural optimization of hit compound 7 and conduct further structure-activity relationship (SAR) studies that result in the development of compound 19 with a novel indole-2-carboxamide hinge scaffold. Compound 19 displays potent anti-ASK1 kinase activity and stronger inhibitory effect on ASK1 in AP1-HEK293 cells than previously described ASK1 inhibitor GS-4997. Besides improved in vitro activity, compound 19 also exhibits an appropriate in vivo PK profile. In a dextran sulfate sodium (DSS)-induced mouse model of ulcerative colitis (UC), compound 19 shows significant anti-UC efficacy and markedly attenuates DSS-induced body weight loss, colonic shortening, elevation in disease activity index (DAI) and inflammatory cell infiltration in colon tissues. Mechanistically, compound 19 represses the phosphorylation of ASK1-p38/JNK signaling pathways and suppresses the overexpression of inflammatory cytokines. Together, these findings suggest that ASK1 inhibitors can potentially be used as a therapeutic strategy for UC.