The Anti-inflammatory Activity Of Natural Product Azabenzone In Vitro And In Vivo

Inflammation is a complex pathological process mainly based on defense responses that eliminates harmful stimuli such as viruses,bacteria and other biological factors.Main clinical symptoms of inflammation are redness,swelling,heat,pain and dysfunction,combined with peripheral blood leukocyte count changes and other systemic reactions.In generally speaking,inflammation is beneficial as an autoimmune response.Nevertheless,chronic inflammation is also adverse and has been identified as one of the causes of diverse diseases,such as arthritis,acute lung injury etc.Moreover,there is evidence that inflammation plays a significant role in tumor initiation,progression and invasion.Furthermore,Nuclear factor ?B(NF-?B)is widely known as a crucial transcription factor to transcribe all kinds of genes,that are involved in control of endogenous and exogenous immune inflammatory responses.And researches indicate that the NF-?B signaling pathway,a classic pathway of inflammation,is involved in regulating the release of several pro-inflammatory cytokines and chemokines — such as interleukin(IL)-1?,IL-6,and tumor necrosis factor-alpha(TNF-?).Moreover,with the growth of these cytokines can produce tissue damage and immune dysregulation,resulting in the onset or progression of diverse inflammatory diseases.Specially,NF-k B activates the nucleotide-binding oligomerization domain-like receptor pyrin-domain-containing protein 3(NLRP3)inflammasome by inducing pro-IL-1? and NLRP3 expression.Upon stimulation by LPS,the inflammasome assemble complexes with the adaptor protein ASC and pro-caspase-1,resulting in the maturation of the pro-inflammatory chemokines IL-1? and IL-18.Thus,proper restrain of NF-k Bactivation and NLRP3-inflammasome assemble is crucial to prevention excessive inflammation.A new azaphilone,isochromophilone was isolated from the culture broth of Penicillium multicolor FO-3216.However,we know little about anti-inflammatory effects of isochromophilone IV.In order to gain better understanding of the biological activity potency of isochromophilone IV,we reversely searched for the target and found its interaction with the COX-2 structure(PDB: 3MQE).The molecular docking result demonstrated that isochromophilone IV has the potential to exert anti-inflammatory activity.In our study,we use cell and animal models to explore the anti-inflammation of isochromophilone IV and underlying molecular mechanisms with NLRP3-inflammasome.We explore the anti-inflammatory effect of Isochromophilone IV in LPS-stimulated RAW264.7 cells.Isochromophilone IV can reduce the concentration of NO by down-regulating the level of iNOS.It also negatively regulate of COX-2,TNF-?,IL-6,IL-1?,IL-18 as well as ROS production.And the compounds inhibit the secretion of NLRP3 and caspase-1,which are the major protein of NLRP3-inflammasome.Further,the inhibitory effect of isochromophilone IV on the NF-?B pathway contributes to blocking the NLRP3-inflammasome activation.Our data suggest that this natural compound may be an excellent scaffold in drug design research.