The Anti-inflammatory Effect And Mechanisms Of Gossypol

Gossypol is a yellow polyphenolic compound extracted from cotton andsunflower plants and tropical tongmian. The cottonseed also contains a lot of gossypol.Because gossypol has anti-fertility effect, it usually need to treatment fordetoxification in feed processing. In recent years, gossypol has also been reported tohave anti-tumor, anti-virus and anti-parasitic activities. In this study, LPS-inducedmouse model of acute lung injury and LPS-stimulated RAW264.7macrophages wereused to evaluate the anti-inflammatory effects of gossypol in vivo and in vitro.Meanwhile, to investigate the anti-inflammatory mechanism of gossypol, TLRsignaling pathway and activation of Nuclear factor-κB (NF-κB), p38, extracellularsignal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) were detected. Thisstudy was aimed at providing experimental data and information of theanti-inflammatory effects of gossypol.Mice were administrated intranasally with LPS to induce lung injury. Gossypolwas administrated intraperitoneally1h before LPS challenge.7h after LPSadministration, the myeloperoxidase in lung tissues, lung wet/dry weight ratio andinflammatory cells in the bronchoalveolar lavage fluid (BALF) were determined. Theeffects of veratric acid on pro-inflammatory cytokines and signal pathways wereanalyzed by enzyme-linked immunosorbent assay (ELISA) and Western blotting. Theresults showed that pretreatment with gossypol significantly decreased the W/D ratioof lungs and reduced the number of total cells, neutrophils and macrophages in theBALF at7h after LPS challenge. In addition, gossypol also suppressed the productionof inflammatory cytokines, such as TNF-α, IL-1β and IL-6in BALF. Futhermore,western blot analysis showed that gossypol inhibited the phosphorylation of IκB-α,p65NF-κB, ERK1/2, JNK, and p38induced by LPS.RAW264.7cells were stimulated with LPS in the presence or absence ofgossypol. The expression of pro-inflammartory cytokines TNF-α, IL-6and IL-1βwere determined by ELISA and qRT-PCR. NF-κB, IκBα, p38, ERK, and JNK weredetermined by Western blotting. The results showed that gossypol dose-dependentlyinhibited the expression of TNF-α, IL-6and IL-1β in LPS-stimulated RAW264.7cellsboth in mRNA and protein levels. Western blot analysis showed that gossypolsuppressed LPS-induced NF-κB activation, IκBa degradation, phosphorylation of ERK, JNK and P38in a dose dependent manner.This study showed that gossypol (10,20,40mg/kg) could attenuate pulmonaryedema and inflammatory cell infiltration in LPS-induced acute lung injury in mouse.The results suggested that gossypol had a protective effect on LPS-induced acute lunginjury. To investigate the anti-inflammatory mechanism of gossypol, the effects ofgossypol on TNF-α, IL-6and IL-1β expression and NF-κB, IκBα, p38, ERK, and JNKactivation were detected. Our results suggested that the anti-inflammatory mechanismof gossypol may be due to its ability to inhibit NF-κB and MAPKs signalingpathways.