Suppression of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation in mice by transduced Tat-Annexin protein

Models in vivo and in vitro for the study of acute and chronic inflammatory activity: A comprehensive review

Inflammatory conditions are among the principal causes of morbidity worldwide, and their treatment continues to be a challenge, given the restricted availability of effective and safe drugs. Thus, the identification of new compounds with biological activity that can be used for the treatment of inflammatory disorders is an essential field in medical and health research, in order to improve the health and quality of life of patients suffering from these diseases. Evaluation of the anti-inflammatory activity of drugs requires the implementation of models that accurately depict the biochemical and/or physiological responses that characterize human inflammation; for this reason, several in vitro and in vivo models have been developed, providing a platform for discovering novel or repurposed compounds. For this reason, in the present review we have selected twelve commonly used models for the evaluation of the anti-inflammatory effect, and extensively describes the difference between in vivo and in vitro models of inflammation, highlighting their advantages and limitations. On the other hand, the inflammatory mechanisms involved in them, the methods employed for their establishment, and the different parameters assessed to determine the anti-inflammatory activity of a given compound are extensively discussed. We expect to provide a comprehensive guide for the improved selection of a suitable model for the preclinical evaluation of plausible anti-inflammatory agents.

Cell-penetrating peptide-mediated delivery of therapeutic peptides/proteins to manage the diseases involving oxidative stress, inflammatory response and apoptosis

OBJECTIVES

Peptides and proteins represent great potential for modulating various cellular processes including oxidative stress, inflammatory response, apoptosis and consequently the treatment of related diseases. However, their therapeutic effects are limited by their inability to cross cellular barriers. Cell-penetrating peptides (CPPs), which can transport cargoes into the cell, could resolve this issue, as would be discussed in this review.

KEY FINDINGS

CPPs have been successfully exploited in vitro and in vivo for peptide/protein delivery to treat a wide range of diseases involving oxidative stress, inflammatory processes and apoptosis. Their in vivo applications are still limited due to some fundamental issues of CPPs, including nonspecificity, proteolytic instability, potential toxicity and immunogenicity.

SUMMARY

Totally, CPPs could potentially help to manage the diseases involving oxidative stress, inflammatory response and apoptosis by delivering peptides/proteins that could selectively reach proper intracellular targets. More studies to overcome related CPP limitations and confirm the efficacy and safety of this strategy are needed before their clinical usage.

Efficient In Vitro and In Vivo Anti-Inflammatory Activity of a Diamine-PEGylated Oleanolic Acid Derivative

Recent evidence has shown that inflammation can contribute to all tumorigenic states. We have investigated the anti-inflammatory effects of a diamine-PEGylated derivative of oleanolic acid (OADP), in vitro and in vivo with inflammation models. In addition, we have determined the sub-cytotoxic concentrations for anti-inflammatory assays of OADP in RAW 264.7 cells. The inflammatory process began with incubation with lipopolysaccharide (LPS). Nitric oxide production levels were also determined, exceeding 75% inhibition of NO for a concentration of 1 µg/mL of OADP. Cell-cycle analysis showed a reversal of the arrest in the G0/G1 phase in LPS-stimulated RAW 264.7 cells. Furthermore, through Western blot analysis, we have determined the probable molecular mechanism activated by OADP; the inhibition of the expression of cytokines such as TNF-α, IL-1β, iNOS, and COX-2; and the blocking of p-IκBα production in LPS-stimulated RAW 264.7 cells. Finally, we have analyzed the anti-inflammatory action of OADP in a mouse acute ear edema, in male BL/6J mice treated with OADP and tetradecanoyl phorbol acetate (TPA). Treatment with OADP induced greater suppression of edema and decreased the ear thickness 14% more than diclofenac. The development of new derivatives such as OADP with powerful anti-inflammatory effects could represent an effective therapeutic strategy against inflammation and tumorigenic processes.

Decursinol angelate ameliorates 12-O-tetradecanoyl phorbol-13-acetate (TPA) -induced NF-κB activation on mice ears by inhibiting exaggerated inflammatory cell infiltration, oxidative stress and pro-inflammatory cytokine production

Decursinol angelate (DA) is a pyranocoumarin purified from the roots of Angelica gigas. Here, we synthesized DA and determined its anti-inflammatory potential on TPA-induced mice ear inflammation. First, we evaluated the non-toxic behaviour of DA on HaCaT cells. Additionally, we observed the free radical scavenging potential of DA at 60 μM to be 50%. This finding was further supported by nitric oxide assay, malondialdehyde assay, H2DCFDA staining and western blotting analysis of antioxidant enzymes. DA also suppressed the activation and polarization of macrophage phagocytic activity on RAW 264.7 cells. We further evaluated the expression of ICAM-1, MCP-1, MIP-2 and MIP-1β on in-vivo model system. Consequently, DA significantly reduced the production of NF-κB and COX-2 induced proinflammatory cytokine levels on TPA induced ear edema. Inhibition of MAPK and transcriptional factor NF-κB was also validated by western blotting analysis of p-ERK, p-p38, IKKα, IKKγ, IκBα, NF-κB-p65. Immunohistochemistry and immunofluorescence staining of NFκB-p65, TNF-α and IL-1β were also performed to support the findings. Conclusively, these results suggest that topical administration of DA significantly inhibited the expression of pro-inflammatory cytokines by blocking the canonical NF-κB and MAPK pathway. Therefore, we suggest DA as a potent therapeutic compound against skin inflammation related diseases.

PEP-1-HO-1 prevents MPTP-induced degeneration of dopaminergic neurons in a Parkinson's disease mouse model

Heme oxygenase-1 (HO-1) degrades heme to carbon dioxide, biliverdin, and Fe2+, which play important roles in various biochemical processes. In this study, we examined the protective function of HO-1 against oxidative stress in SH-SY5Y cells and in a Parkinson's disease mouse model. Western blot and fluorescence microscopy analysis demonstrated that PEP-1-HO-1, fused with a PEP-1 peptide can cross the cellular membranes of human neuroblastoma SH-SY5Y cells. In addition, the transduced PEP-1-HO-1 inhibited generation of reactive oxygen species (ROS) and cell death caused by 1-methyl-4-phenylpyridinium ion (MPP+). In contrast, HO-1, which has no ability to transduce into SH-SY5Y cells, failed to reduce MPP+-induced cellular toxicity and ROS production. Furthermore, intraperitoneal injected PEP-1-HO-1 crossed the blood-brain barrier in mouse brains. In a PD mouse model, PEP-1-HO-1 significantly protected against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced toxicity and dopaminergic neuronal death. Therefore, PEP-1-HO-1 could be a useful agent in treating oxidative stress induced ailments including PD.

Chemopreventive efficacy of menthol on carcinogen-induced cutaneous carcinoma through inhibition of inflammation and oxidative stress in mice

Inflammation and oxidative stress have been implicated in various pathological processes including skin tumorigenesis. Skin cancer is the most common form of cancer responsible for considerable morbidity and mortality, the treatment progress of which remains slow though. Therefore, chemoprevention and other strategies are being considered. Menthol has shown high anticancer activity against various human cancers, but its effect on skin cancer has never been evaluated. We herein investigated the chemopreventive potential of menthol against 9,10-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, oxidative stress and skin carcinogenesis in female ICR mice. Pretreatment with menthol at various doses significantly suppressed tumor formation and growth, and markedly reduced tumor incidence and volume. Moreover, menthol inhibited TPA-induced skin hyperplasia and inflammation, and significantly suppressed the expression of cyclooxygenase-2 (COX-2). Furthermore, pretreatment with menthol inhibited the formation of reactive oxygen species and affected the activities of a battery of antioxidant enzymes in the skin. The expressions of NF-κB, Erk and p38 were down-regulated by menthol administration. Thus, inflammation and oxidative stress collectively played a crucial role in the chemopreventive efficacy of menthol on the murine skin tumorigenesis.

Diallyl trisulfide exerts anti-inflammatory effects in lipopolysaccharide-stimulated RAW 264.7 macrophages by suppressing the Toll-like receptor 4/nuclear factor-κB pathway

Diallyl trisulfide (DATS; di‑2‑propen‑1‑yl trisulfide) is an organic polysulfide compound found in garlic and other allium vegetables. Although certain studies have demonstrated that DATS possesses strong anti‑inflammatory activity, the underlying molecular mechanisms remain largely unresolved. In the present study, the anti‑inflammatory potential of DATS was investigated using the murine macrophage RAW 264.7 cell model. At non‑toxic concentrations, DATS inhibited the production of nitric oxide (NO) and prostaglandin E2 by inhibiting inducible NO synthase and cyclooxygenase‑2 expression at the transcriptional level in lipopolysaccharide (LPS)‑activated RAW 264.7 macrophages. DATS attenuated the release of the pro‑inflammatory cytokines, tumor necrosis factor‑α and interleukin‑1β, by inhibiting mRNA expression, respectively. DATS also suppressed LPS‑induced DNA‑binding activity of nuclear factor‑κB (NF‑κB), as well as the nuclear translocation of the NF‑κB p65, which correlated with the inhibitory effects of DATS on inhibitor κB (IκB) degradation. In addition, DATS was observed to significantly suppress LPS‑induced Toll‑like receptor 4 (TLR4) and myeloid differentiation factor 88 expression and the binding of LPS to macrophages, indicating the antagonistic effect of DATS against TLR4. Furthermore, blocking TLR4 signaling with the specific TLR4 signaling inhibitor, CLI‑095, increased the anti‑inflammatory potential of DATS in LPS‑stimulated RAW 264.7 macrophages. These data demonstrate that DATS may attenuate the initiation of LPS‑mediated intracellular signaling cascades by suppressing activation of NF‑κB and by inhibiting binding of LPS to TLR4 on macrophages.

Anti-inflammatory effects of cordycepin in lipopolysaccharide-stimulated RAW 264.7 macrophages through Toll-like receptor 4-mediated suppression of mitogen-activated protein kinases and NF-κB signaling pathways

Cordycepin is the main functional component of the Cordyceps species, which has been widely used in traditional Oriental medicine. This compound possesses many pharmacological properties, such as an ability to enhance immune function, as well as antioxidant, antiaging, and anticancer effects. In the present study, we investigated the anti-inflammatory effects of cordycepin using a murine macrophage RAW 264.7 cell model. Our data demonstrated that cordycepin suppressed production of proinflammatory mediators such as nitric oxide (NO) and prostaglandin E₂ by inhibiting inducible NO synthase and cyclooxygenase-2 gene expression. Cordycepin also inhibited the release of proinflammatory cytokines, including tumor necrosis factor-alpha and interleukin-1-beta, through downregulation of respective mRNA expression. In addition, pretreatment with cordycepin significantly inhibited lipopolysaccharide (LPS)-induced phosphorylation of mitogen-activating protein kinases and attenuated nuclear translocation of NF-κB by LPS, which was associated with abrogation of inhibitor kappa B-alpha degradation. Furthermore, cordycepin potently inhibited the binding of LPS to macrophages and LPS-induced Toll-like receptor 4 and myeloid differentiation factor 88 expression. Taken together, the results suggest that the inhibitory effects of cordycepin on LPS-stimulated inflammatory responses in RAW 264.7 macrophages are associated with suppression of mitogen-activating protein kinases and activation of NF-κB by inhibition of the Toll-like receptor 4 signaling pathway.

Chemopreventive effect of a novel, selective TACE inhibitor on DMBA- and TPA-induced skin carcinogenesis

Abstract Context: Tumor necrosis factor (TNF)-α, a potent proinflammatory cytokine, plays a major role in the pathogenesis of cancer. TNF-α converting enzyme (TACE) mediates processing and release of biologically active TNF-α.

OBJECTIVE

We aimed to investigate the effect of a novel, selective TACE inhibitor (compound 11p) on skin inflammation and associated tumorigenesis in mice.

METHODS

Skin edema was induced in mice by dermal application 12-O-tetradecanoylphorbol-13-acetate (TPA) solution in acetone on to the ear and the effect of post-treatment of compound 11p (topical application) was evaluated. Edema and inflammation was assessed by measuring ear thickness, weight of skin punch and cytokine levels. Skin cancer in mice was initiated by single topical application of 7,12-dimethylbenz[a]anthracene (DMBA) and promoted by repeated TPA application for 20 weeks. The effect of compound 11p on papilloma incidence and multiplicity was evaluated.

RESULTS

Treatment with compound 11p strongly suppressed TPA-induced elevation in skin thickness and weight. A dose-dependent suppression in TPA-mediated TNF-α, IL-6, IFN-γ, IL-17 and PGE2 levels which was associated with a decrease in infiltration of inflammatory cells was also observed with the treatment. Moreover, compound 11p treatment delayed the onset, markedly reduced the papilloma incidence and multiplicity persuaded by DMBA and TPA.

DISCUSSION AND CONCLUSION

These findings suggest that selective blockade of TACE suppresses TPA-induced epidermal hyperplasia, inflammatory cell infiltration and cytokine level. Inhibition of inflammatory events related to tumor growth might have led to the anti-tumor effect in mouse skin cancer model induced by DMBA and TPA.

Ethanol extract of Poria cocos reduces the production of inflammatory mediators by suppressing the NF-kappaB signaling pathway in lipopolysaccharide-stimulated RAW 264.7 macrophages

Background

Poria cocos Wolf, a medicinal fungus, is widely used in traditional medicines in East Asian countries owing to its various therapeutic potentials. Although several studies have demonstrated the anti-inflammatory activity of this fungus, its underlying mechanisms have not yet been clearly defined.

Methods

In the present study, we have demonstrated the anti-inflammatory effects of ethanol extract of P. cocos (EEPC) in lipopolysaccaride (LPS)-stimulated RAW 264.7 macrophages. As inflammatory parameters, the productions of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin (IL)-1β and tumor necrosis factor (TNF)-α were evaluated. We also examined the EEPC’s effect on the nuclear factor-kappaB (NF-κB) signaling pathway.

Results

Our results indicated that EEPC exhibits a potent inhibitory effect on NO production and inhibits PGE2 release in LPS-induced macrophages without affecting cell viability. EEPC also significantly attenuated LPS-induced secretion of inflammatory cytokines IL-1β and TNF-α. Additionally, LPS-induced expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2, IL-1β, and TNF-α was decreased by pre-treatment with EEPC at the transcriptional level. Moreover, EEPC clearly inhibited LPS-induced nuclear translocation of NF-κB p65 subunits, which correlated with EEPC’s inhibitory effects on inhibitor kappaB (IκB) degradation. Moreover, EEPC clearly suppressed the LPS-induced DNA-binding activity of NF-κB, as well as the nuclear translocation of the NF-κB p65, which correlated with EEPC’s inhibitory effects on inhibitor kappaB (IκB) degradation.

Conclusions

Taken together, our data indicates that EEPC targets the inflammatory response of macrophages via inhibition of iNOS, COX-2, IL-1β, and TNF-α through inactivation of the NF-κB signaling pathway, supporting the pharmacological basis of P. cocos as a traditional herbal medicine for treatment of inflammation and its associated disorders.

Curcumin ameliorates TNF-α-induced ICAM-1 expression and subsequent THP-1 adhesiveness via the induction of heme oxygenase-1 in the HaCaT cells

Adhesion molecules such as ICAM-1 are important in the infiltration of leukocytes into the site of inflammation. In this study, we investigated the inhibitory effects of curcumin on ICAM-1 expression and monocyte adhesiveness as well as its underlying action mechanism in the TNF-α-stimulated keratinocytes. Curcumin induced expression of heme oxygenase-1 (HO-1) in the human keratinocyte cell line HaCaT. In addition, curcumin induced Nrf2 activation in dose- and time-dependent manners in the HaCaT cells. Curcumin suppressed TNF-α- induced ICAM-1 expression and subsequent monocyte adhesion, which were reversed by the addition of tin protoporphyrin IX (SnPP), a specific inhibitor of HO-1, or HO-1 knockdown using siRNA. Furthermore, Nrf2 knockdown using siRNA reversed the inhibitory effect of curcumin on the TNF-α-induced ICAM-1 expression and adhesion of monocytes to keratinocytes. These results suggest that curcumin may exert its anti-inflammatory activity by suppressing the TNF-α-induced ICAM-1 expression and subsequent monocyte adhesion via expression of HO-1 in the keratinocytes. [BMB Reports 2013;46(8): 410-415]

Tat-fused recombinant human SAG prevents dopaminergic neurodegeneration in a MPTP-induced Parkinson's disease model

Excessive reactive oxygen species (ROS) generated from abnormal cellular process lead to various human diseases such as inflammation, ischemia, and Parkinson's disease (PD). Sensitive to apoptosis gene (SAG), a RING-FINGER protein, has anti-apoptotic activity and anti-oxidant activity. In this study, we investigate whether Tat-SAG, fused with a Tat domain, could protect SH-SY5Y neuroblastoma cells against 1-methyl-4-phenylpyridinium (MPP(+)) and dopaminergic (DA) neurons in the substantia nigra (SN) against 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine (MPTP) toxicity. Western blot and immunohistochemical analysis showed that, unlike SAG, Tat-SAG transduced efficiently into SH-SY5Y cells and into the brain, respectively. Tat-SAG remarkably suppressed ROS generation, DNA damage, and the progression of apoptosis, caused by MPP(+) in SH-SY5Y cells. Also, immunohistochemical data using a tyrosine hydroxylase antibody and cresyl violet staining demonstrated that Tat-SAG obviously protected DA neurons in the SN against MPTP toxicity in a PD mouse model. Tat-SAG-treated mice showed significant enhanced motor activities, compared to SAG- or Tat-treated mice. Therefore, our results suggest that Tat-SAG has potential as a therapeutic agent against ROS-related diseases such as PD.

7,8-Dihydroxyflavone attenuates the release of pro-inflammatory mediators and cytokines in lipopolysaccharide-stimulated BV2 microglial cells through the suppression of the NF-κB and MAPK signaling pathways

7,8-Dihydroxyflavone (7,8-DHF), a member of the flavonoid family, has received considerable attention as a selective tyrosine kinase receptor B agonist. However, the pharmacological mechanisms responsible for its anti-inflammatory activities in microglial cells have yet to be elucidated. In this study, we evaluated the anti-inflammatory effects of this compound on the production of inflammatory mediators and cytokines in lipopolysaccharide (LPS)-stimulated murine BV2 microglial cells. At non-toxic concentrations, 7,8-DHF attenuated the production of nitric oxide (NO) and prostaglandin E2 (PGE2), by inhibiting inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, respectively. Furthermore, the release and expression of inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), were inhibited by 7,8-DHF. In addition, 7,8-DHF suppressed nuclear factor-κB (NF-κB) translocation and its transcriptional activity by blocking IκB (IκB)-α degradation; in addition, it exerted suppressive effects on the phosphorylation of mitogen-activated protein kinases (MAPKs). These results indicate that 7,8-DHF possesses therapeutic potential against neurodegenerative diseases that involve microglial activation.

Anti-inflammatory effects of genistein via suppression of the toll-like receptor 4-mediated signaling pathway in lipopolysaccharide-stimulated BV2 microglia

Genistein, a principal soy isoflavone, has received considerable attention as a protein kinase inhibitor. Although some studies have demonstrated that genistein possesses anti-inflammatory effects, the molecular mechanisms of genistein-mediated anti-inflammatory potential are unclear in microglial cells. In this study, we determined whether genistein attenuates pro-inflammatory responses in lipopolysaccharide (LPS)-stimulated BV2 microglia and attempted to establish the possible mechanisms. Our results indicated that genistein inhibited the production of nitric oxide (NO) and prostaglandin E2 at non-toxic concentrations by inhibiting inducible NO synthase and cyclooxygenase-2 expression. The increased release and expression of inflammatory cytokines, including interleukin-1β, tumor necrosis factor-α, by LPS, were markedly reduced by genistein. Genistein also attenuated LPS-induced reactive oxygen species generation and LPS-mediated nuclear translocation of nuclear factor-kappa B (NF-κB), associated with blocking degradation of the inhibitor of NF-κB-α. Furthermore, genistein potently suppressed binding of LPS to the microglial cell surface, indicating the antagonistic effect of genistein against toll like receptor 4 (TLR4), and inhibited LPS-induced TLR4 and myeloid differentiation factor 88 expression. In addition, blocking TLR4 signaling using the specific TLR4 signaling inhibitor CLI-095 increased the anti-inflammatory potential of genistein in BV2 microglia. Our data indicate that genistein may attenuate the initiation of intracellular signaling cascades by LPS through inhibiting NF-κB activation by inhibiting the binding of LPS to TLR-4 on microglial cells.

Purpurogallin exerts anti‑inflammatory effects in lipopolysaccharide‑stimulated BV2 microglial cells through the inactivation of the NF‑κB and MAPK signaling pathways

In this study, we investigated the inhibitory effects of purpurogallin, a naturally occurring phenol, on the production of lipopolysaccharide (LPS)-induced pro-inflammatory mediators and cytokines in BV2 microglia cells. The cells were pre-treated or not with various concentrations of purpurogallin and then stimulated with 0.5 µg/ml LPS. Cell viability was measured by MTT assay. We also measured the production of nictric oxice (NO) and prostaglandin E2 (PGE2). Our data indicated that treatment with purpurogallin significantly inhibited the excessive production of NO and PGE2 in LPS-stimulated BV2 microglial cells. These inhibitory effects were associated with the downregulation of key enzymes for NO and PGE2, inducible NO synthase (iNOS) and cyclooxygenase-2 (COX2) expression, respectively. Purpurogallin also attenuated the production of pro-inflammatory cytokines, including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) by suppressing their mRNA and protein expression. The molecular mechanisms underlying the purpurogallin-mediated attenuation of inflammation in BV2 cells closely correlated with the suppression of the translocation of the nuclear factor-κB (NF-κB) p65 subunit into the nucleus and the degradation of the inhibitor of NF-κB (IκB). Moreover, purpurogallin exhibited anti-inflammatory properties by suppressing the phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinase signaling pathways. These findings suggest that purpurogallin exerts neuroprotective effects through the suppression of pro-inflammatory pathways in activated microglia.

Transduced PEP-1-FK506BP ameliorates corneal injury in Botulinum toxin A-induced dry eye mouse model

FK506 binding protein 12 (FK506BP) belongs to a family of immunophilins, and is involved in multiple biological processes. However, the function of FK506BP in corneal disease remains unclear. In this study, we examined the protective effects on dry eye disease in a Botulinum toxin A (BTX-A) induced mouse model, using a cell-permeable PEP-1-FK506BP protein. PEP-1-FK506BP efficiently transduced into human corneal epithelial cells in a time- and dose-dependent manner, and remained stable in the cells for 48 h. In addition, we demonstrated that topical application of PEP-1-FK506BP was transduced into mouse cornea and conjunctiva by immunohistochemistry. Furthermore, topical application of PEP-1-FK506BP to BTX-A-induced mouse model markedly inhibited expression levels of pro-inflammatory cytokines such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and macrophage inhibitory factor (MIF) in corneal and conjunctival epithelium. These results suggest PEP-1-FK506BP as a potential therapeutic agent for dry eye diseases. [BMB Reports 2013; 46(2): 124-129]

Molecular mechanism of the inhibition effect of Lipoxin A4 on corneal dissolving pathology process

AIM

Excessive dissolve of corneal tissue induced by MMPs which were activated by cytokins and chemokines will lead to corneal ulcer. The molecular mechanism of Lipoxin A4 (LXA4) on corneal collagen degradation in three dimensions was investigated.

METHODS

Rabbit corneal fibroblasts were harvested and suspended in serum-free MEM. Type I collagen, DMEM, collagen reconstitution buffer and corneal fibroblast suspension were mixed on ice. The resultant mixture solidified in an incubator, after which test reagents and plasminogen was overlaid and the cultures were returned to the incubator. The supernatants from collagen gel incubations were collected and the amount of hydroxyproline in the hydrolysate was measured. Immunoblot analysis of MMP-1, -3 and TMMP-1,-2 was performed. MMP-2,-9 was detected by the method of Gelatin zymography. Cytotoxicity assay was measured.

RESULTS

LXA4 inhibited corneal collagen degradation in a dose and time manner. LXA4 inhibited the IL-1β induced increases in the pro-MMP-1, -2, -3, -9 and active MMP-1, -2, -3, -9 in a concentration dependent manner. LXA4 could also inhibit the IL-1β induced increases in TIMP-1, -2.

CONCLUSION

As a potent anti-inflammation reagent, LXA4 can inhibit corneal collagen degradation induced by IL-1β in corneal fibroblasts thus inhibiting corneal dissolving pathology process.