Design and synthesis of new disubstituted benzoxazolone derivatives that act as iNOS inhibitors with potent anti-inflammatory activity against LPS-induced acute lung injury (ALI).

Acute lung injury (ALI) is a pulmonary disease that acts as a severe acute inflammatory response with no specific drugs. iNOS, a catalyst of the excessive production of NO, has been demonstrated to participate in the inflammatory process, and targeting iNOS may be a promising therapeutic pathway to alleviate ALI. In our research, eighteen new disubstituted benzoxazolone derivatives were synthesized, characterized, and evaluated for activity against NO production in an LPS-induced RAW264.7 cell. The results showed that these compounds could obviously inhibit the over-generation of NO and disubstitution at the 4, N-position of the benzoxazolone ring, presenting better potency than substitution only at the 4-position. Among the analogues generated, compounds 2c, 2d, and 3d showed NO inhibitory activity with IC50 values of 16.43, 14.72, and 13.44 µM and iNOS inhibitory activity with IC50 values of 4.605, 3.342, and 9.733 µM, respectively. Meanwhile, compounds 2c, 2d, and 3d could also inhibit the release of IL-6, IL-1ß in vitro and suppress xylene-induced ear edema in vivo to realize anti-inflammatory activity. Furthermore, compound 2d could significantly protect the LPS-induced ALI, presenting as decreased inflammatory cytokines and obvious pathological changes. Immunohistochemistry and molecular modeling demonstrated that compound 2d significantly inhibited the expression of iNOS in vivo and interacted with iNOS through two hydrogen bindings with the MET368 and ILE195 residues of the iNOS protein. These results demonstrated that compound 2d could be a promising lead structure for iNOS inhibitors, with anti-inflammatory activity to treat LPS-induced acute lung injury.

4-Sulfonyloxy/alkoxy benzoxazolone derivatives with high anti-inflammatory activities: Synthesis, biological evaluation, and mechanims of action via p38/ERK-NF-κB/iNOS pathway.

In an effort to discover new agents with high anti-inflammatory activity, 22 new 4-sulfonyloxy/alkoxy benzoxazolone derivatives were synthesized, characterized, and evaluated for their anti-inflammatory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) production and TNF-α expression in RAW 264.7 cells in vitro. Most of these compounds displayed greater inhibitory ability against NO production than the lead compound 4-o-methyl-benzenesulfonyl benzoxazolone, and the most active compound 2h exhibited the strongest inhibitory activity against NO, IL-1ß, and IL-6 production with IC50 values 17.67, 20.07, and 8.61 µΜ, respectively. The effects of 2h were comparable or stronger than those of the positive control celecoxib. Compound 2h also displayed higher activity in vivo than celecoxib in a mouse model of xylene-induced ear edema, based on their inhibitory rates of 42.69% and 30.87%, respectively. Further molecular analysis revealed that compound 2h significantly reduced the iNOS levels in cell supernatant and suppressed the protein expression of iNOS, p-p38, p-ERK, and nuclear NF-κB. The results indicated that the anti-inflammatory effect of 2h might be realized through the regulation of ERK- and p38-mediated mitogen-activated protein kinase (MAPK)-NF-κB/iNOS signaling, thereby reducing the excessive release of NO, IL-1ß, and IL-6. Our findings demonstrated that compound 2h, a new benzoxazolone derivative, could inhibit activation of the MAPK-NF-κB/iNOS pathway, supporting its potential as a novel anti-inflammatory agent.

Anti-inflammatory effects of 4-o-methyl-benzenesulfonyl benzoxazolone (MBB) in vivo and in vitro as a novel NSAIDs lead compound.

BACKGROUND: Great attention has been paid to the development of novel anti-inflammatory drugs to overcome the adverse reactions of traditional drugs. Recently, a new compound 4-o-methyl-benzenesulfonyl benzoxazolone (MBB) we have prepared attracted our attention for its promising anti-inflammatory activity and low toxicity. The present study aimed to further investigate the anti-inflammatory effects of MBB both in vivo and in vitro in order to determine its potential as a novel NSAIDs lead compound. METHODS: The anti-inflammatory effects in vivo were evaluated using acetic acid-induced mice writhing, xylene-induced mice ear edema and collagen-induced rat arthritis. NO, TNF-α, IL-6, IL-1ß and iNOS productions by LPS-stimulated RAW264.7 cells were determined to investigate the basis of anti-inflammatory effects. Finally, the COX inhibition effect was tested in vitro using COX inhibitor screening assay kit. RESULTS: MBB could significantly decrease the writhing and ear swelling in a dose-dependent manner, and it also had a moderate anti-arthritic potential associated with an attenuation of arthritis index score, arthritis swelling, and inhibition of TNF-α and IL-1ß. MBB could inhibit the activity of NO, TNF-α, IL-6, IL-1ß and iNOS to perform its activity in vitro, but it had no effect against COX-1 and COX-2. The anti-inflammation effect may be mediated via the inhibition of iNOS to reduce the production of inflammatory mediators which should be further confirmed. CONCLUSIONS: The compound MBB displayed anti-inflammatory and anti-arthritic effect, and it could be considered as a new NSAIDs lead compound for the further structure modification to develop novel anti-inflammatory drugs.

Hepatotoxicity and proteomic mechanism of Di-n-butyl-di-(4-chlorobenzohydroxamato)tin(IV) (DBDCT) in vivo.

Di-n-butyl-di-(4-chlorobenzohydroxamato)tin(IV) (DBDCT) is an anti-tumour organotin(IV) compound with hepatotoxicity. To investigate the hepatotoxicity and mechanisms of DBDCT in vivo, proteomic technology 2D gel combined with MALDI-TOF-MS was used in our research. Results indicated that DBDCT increased AST, AKP and ACP activities and decreased ALT activity. Further, sporadic eosinophilic changes and nuclear pyknosis were visible in hepatic pathological observation. Proteomic analysis showed that twenty-two proteins involved in amino acid, nucleic acid, carbohydrate and lipid metabolism, stress response, multicellular organism development and cell apoptosis were differentially expressed and identified. Notably, a considerable amount of the altered proteins, such as OAT, HPPD, M2GD, GSTM2, Glud1, GSTa, HS90ß and PDIA3 participated in multi-metabolic pathways and oxidative stress reactions. Our findings indicated that the inhibition of enzyme activity and oxidative stress were the major mechanisms by which DBDCT induced hepatotoxicity, and the altered proteins could be potential drug targets for the further design of new type of organic tin with high activity and low toxicology.