Anti-tumor effects of a nonsteroidal anti-inflammatory drug zaltoprofen on chondrosarcoma via activating peroxisome proliferator-activated receptor gamma and suppressing matrix metalloproteinase-2 expression

Emerging Treatments Targeting the Tumor Microenvironment for Advanced Chondrosarcoma

Chondrosarcoma (ChS), a malignant cartilage-producing tumor, is the second most frequently diagnosed osseous sarcoma after osteosarcoma. It represents a very heterogeneous group of malignant chemo- and radiation-resistant neoplasms, accounting for approximately 20% of all bone sarcomas. The majority of ChS patients have a good prognosis after a complete surgical resection, as these tumors grow slowly and rarely metastasize. Conversely, patients with inoperable disease, due to the tumor location, size, or metastases, represent a great clinical challenge. Despite several genetic and epigenetic alterations that have been described in distinct ChS subtypes, very few therapeutic options are currently available for ChS patients. Therefore, new prognostic factors for tumor progression as well as new treatment options have to be explored, especially for patients with unresectable or metastatic disease. Recent studies have shown that a correlation between immune infiltrate composition, tumor aggressiveness, and survival does exist in ChS patients. In addition, the intra-tumor microvessel density has been proven to be associated with aggressive clinical behavior and a high metastatic potential in ChS. This review will provide an insight into the ChS microenvironment, since immunotherapy and antiangiogenic agents are emerging as interesting therapeutic options for ChS patients.

New advances in the treatment of chondrosarcoma under the PD-1/PD-L1 pathway

ABSTRACT

Bone sarcomas encompass a group of spontaneous mesenchymal malignancies, among which osteosarcoma, Ewing sarcoma, chondrosarcoma, and chordoma are the most common subtypes. Chondrosarcoma, a relatively prevalent malignant bone tumor that originates from chondrocytes, is characterized by endogenous cartilage ossification within the tumor tissue. Despite the use of aggressive treatment approaches involving extensive surgical resection, chemotherapy, and radiotherapy for patients with osteosarcoma, chondrosarcoma, and chordoma, limited improvements in patient outcomes have been observed. Furthermore, resistance to chemotherapy and radiation therapy has been observed in chondrosarcoma and chordoma cases. Consequently, novel therapeutic approaches for bone sarcomas, including chondrosarcoma, need to be uncovered. Recently, the emergence of immunotherapy and immune checkpoint inhibitors has garnered attention given their clinical success in various diverse types of cancer, thereby prompting investigations into their potential for managing chondrosarcoma. Considering that circumvention of immune surveillance is considered a key factor in the malignant progression of tumors and that immune checkpoints play an important role in modulating antitumor immune effects, blockers or inhibitors targeting these immune checkpoints have become effective therapeutic tools for patients with tumors. One such checkpoint receptor implicated in this process is programmed cell death protein-1 (PD-1). The association between PD-1 and programmed cell death ligand-1 (PD-L1) and cancer progression in humans has been extensively studied, highlighting their remarkable potential as biomarkers for cancer treatment. This review comprehensively examines available studies on current chondrosarcoma treatments and advancements in anti-PD-1/PD-L1 blockade therapy for chondrosarcoma.

A nonsteroidal anti-inflammatory drug, zaltoprofen, inhibits the growth of extraskeletal chondrosarcoma cells by inducing PPARγ, p21, p27, and p53

Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor and master transcription factor of adipogenesis-related genes, and has been reported as an antitumor target for chondrosarcomas. Herein, we show that the nonsteroidal anti-inflammatory drug, zaltoprofen, induces the expression of PPARγ at the mRNA and protein levels, following the induction of PPARγ-activating factors, such as Krox20, C/EBPβ, and C/EBPα, in human extraskeletal chondrosarcoma H-EMC-SS cells. Upregulation of the cell cycle checkpoint proteins, p21, p27, and p53, was observed upon treatment of H-EMC-SS cells with zaltoprofen, which probably resulted in the inhibition of proliferation of these cells observed in vitro. Zaltoprofen treatment inhibited tumor growth, induced tumor cell apoptosis, and was well tolerated in a mouse model of extraskeletal myxoid chondrosarcoma. Our results provide mechanistic insights into the therapeutic effect of zaltoprofen that should promote further studies on the rational use of this drug for the effective treatment of sarcomas.

Anti-inflammatory and arthritic activity of zaltoprofen compared to piroxicam in murine models

Zaltoprofen, a unique propionic acid group of NSAIDs, works by blocking the enhancing effects of bradykinin along with the COX-2 enzyme. Therefore, it is of interest to evaluate the acute and chronic anti-inflammatory (arthritic) potential of zaltoprofen versus piroxicam in Murine models. A total of 48 Wister rats (200-250 g) of either sex (24 in each model) were used in the present study. The anti-inflammatory and arthritic potential of zaltoprofen was evaluated and compared by Carrageenan-induced acute inflammation and formalin-induced chronic inflammation. There was a significant inhibition of paw volume (P<0.001) on different time scales with two different doses of the test compound (Zaltoprofen 10 & 20 mg/kg) in the acute inflammation model compared to the negative control (NaCl 10 ml/kg). However, in the chronic inflammation model, zaltoprofen 10 mg/kg and 20 mg/kg doses of the test compound showed a significant reduction in chronic inflammation, comparable to the negative control (NaCl 10 ml/kg), although the potency was lower than the positive control (piroxicam 10 mg/kg) (P 0.05). Thus, zaltoprofen shows significant anti-inflammatory and arthritic effects in both acute and chronic models by inhibiting various inflammatory mediators.

Relationships of pain-causing substances with dry skin and effects of zaltoprofen on alleviation of symptoms in arthritis model mice

Skin dryness is a symptom of rheumatoid arthritis (RA). However, the mechanisms through which dry skin is induced in RA are unclear. Accordingly, in this study, we characterized substances related to pruritus and pain and then evaluated whether oral administration of zaltoprofen (ZLT) alleviated the symptom of dry skin induced by RA in model mice. DBA/1JJmsSlc collagen-induced arthritis model mice were treated with ZLT, and transepidermal water loss (TEWL), capacitance, and inflammation-, pruritus-, and pain-related markers were assessed. Our findings demonstrated that arthritis model mice treated with ZLT exhibited suppression of increases in TEWL and decreases in capacitance. Furthermore, ZLT also blocked the increase in mast cell numbers, substance P expression, and cyclo-oxygenase-2 expression in the skin and prevented enhancement of plasma levels of thymic stromal lymphopoietin, tumor necrosis factor-α, interleukin-6, histamine, and bradykinin. No changes in plasma levels of corticosterone or reactive oxygen species or skin levels of glucocorticoid receptor were observed in ZLT-treated arthritis model mice. Overall, these findings suggested that patients with RA may benefit from biopharmacy to alleviate joint symptoms and nonsteroidal anti-inflammatory drugs for pain relief and alleviation of skin symptoms.

Randomized placebo-controlled double-blind phase II study of zaltoprofen for patients with diffuse-type and unresectable localized tenosynovial giant cell tumors: The REALIZE study

Background

A tenosynovial giant cell tumor (TGCT) is a locally aggressive benign neoplasm arising from intra- or extra-articular tissue, categorized as localized (L-TGCT, solitary lesion) and diffuse (D-TGCT, multiple lesions) TGCT. Surgical excision is the mainstay of the treatment, and a high local recurrence rate of approximately 50% has been reported. We focused on zaltoprofen, a nonsteroidal anti-inflammatory drug that can activate peroxisome proliferator-activated receptor gamma (PPARγ) and inhibit the proliferation of TGCT stromal cells. Therefore, we conducted a randomized trial to evaluate the safety and effectiveness of zaltoprofen in patients with D-TGCTs or unresectable L-TGCTs.

Methods

This randomized, placebo-controlled, double-blind, multicenter trial evaluated the safety and efficacy of zaltoprofen. In the treatment group, zaltoprofen (480 mg/day) was administered for 48 weeks; the placebo group received similar dosages without zaltoprofen. The primary outcome was progression-free rate (PFR) 48 weeks after treatment administration. Disease progression was defined as the following conditions requiring surgical intervention: 1) repetitive joint swelling due to hemorrhage, 2) joint range of motion limitation, 3) invasion of the adjacent cartilage or bone, 4) severe joint space narrowing, and 5) increased tumor size (target lesion).

Results

Forty-one patients were allocated to the zaltoprofen (n=21) or placebo (n=20) groups. The PFR was not significant between the zaltoprofen group and the placebo group at 48 weeks (84.0% and 90.0%, respectively; p=0.619). The mean Japanese Orthopedic Association knee score significantly improved from baseline to week 48 in the zaltoprofen group (85.38 versus 93.75, p=0.027). There was a significant difference between the values at 48 weeks of placebo and zaltoprofen group (p=0.014). One severe adverse event (grade 3 hypertension) was observed in the zaltoprofen group.

Discussion

This is the first study to evaluate the efficacy and safety of zaltoprofen in patients with TGCT. No significant differences in PFR were observed between the groups at 48 weeks. Physical function significantly improved after zaltoprofen treatment. The safety profile of zaltoprofen was acceptable. This less invasive and safer treatment with zaltoprofen, compared to surgical removal, could be justified as a novel approach to treating TGCT. Further analysis of long-term administration of zaltoprofen should be considered in future studies.

Clinical Trial Registration

University Hospital Medical Information Network Clinical Trials Registry, identifier (UMIN000025901).

Adipose-Derived Stem Cell Sheets Promote Meniscus Regeneration Regardless of Whether the Defect Involves the Inner Half or the Whole Width of the Anterior Half of the Medial Meniscus in a Rabbit Model

PURPOSE

To investigate the regenerative effect of adipose-derived stem cell (ADSC) sheets in two different rabbit models of meniscal defects.

METHODS

Forty-two rabbits were randomly divided into two groups: the whole (Group 1) or the inner half (Group 2) of anterior half of the medial meniscus was removed from both knees. The ADSC sheets were transplanted into one knee, whereas in the other knee the meniscal defect was left untreated (self-control). The histological score and expression of genes encoding collagen type I and II (COL1/2), SRY-box transcription factor 9 (SOX9), and aggrecan (ACAN) were compared between the ADSC sheet-treated and untreated menisci at 4 and 12 weeks. The ADSC sheet-treated menisci at 12 weeks were also analyzed immunohistochemically to assess the collagen component.

RESULTS

The histological score was significantly higher in the treated side than in the control side at 4 and 12 weeks in both groups (Group 1; P = .016 and .032; Group 2; P = .030 and .016, respectively). All genes evaluated showed significantly higher expression in the treated side than in the control side in both groups, except COL2 and SOX9 at 4 weeks and COL2 at 12 weeks in Group 1, and COL1 in Group 2 at 4 weeks. The ADSC sheet-treated meniscus in Group 1 contained mostly COL1, whereas the Group 2 had less COL1, but was rich in COL2.

CONCLUSIONS

ADSC sheets can promote meniscal regeneration regardless of whether the defect involves the inner half or whole width of the anterior half of the medial meniscus. However, the collagen component of the ADSC sheet-treated tissue differs depending on the defect site.

CLINICAL RELEVANCE

ADSCs may help meniscal regeneration due to meniscal defects after meniscectomy. This study suggests longer-term follow-up and mechanical analysis as next steps.

Therapeutic Targets and Emerging Treatments in Advanced Chondrosarcoma

Due to resistance to standard anticancer agents, it is difficult to control the disease progression in patients with metastatic or unresectable chondrosarcoma. Novel therapeutic approaches, such as molecule-targeting drugs and immunotherapy, are required to improve clinical outcomes in patients with advanced chondrosarcoma. Recent studies have suggested several promising biomarkers and therapeutic targets for chondrosarcoma, including IDH1/2 and COL2A1. Several molecule-targeting agents and immunotherapies have shown favorable antitumor activity in clinical studies in patients with advanced chondrosarcomas. This review summarizes recent basic studies on biomarkers and molecular targets and recent clinical studies on the treatment of chondrosarcomas.

The mir-423-5p/MMP-2 Axis Regulates the Nerve Growth Factor-Induced Promotion of Chondrosarcoma Metastasis

Simple Summary

A chondrosarcoma is a common tumor of the bone that has a high propensity to metastasize to distant organs. The effects of NGF in a chondrosarcoma are not confirmed although NGF is capable of promoting the progression and metastasis of several different types of tumors. Here, we found that NGF promotes the chondrosarcoma migration and metastasis in vitro and in vivo. The levels of NGF and MMP-2 in human chondrosarcoma tumor tissues correlated strongly with the tumor stage. We identified that NGF induces the MMP-2 synthesis and chondrosarcoma cell motility by inhibiting miR-423-5p expression through the FAK and c-Src pathways. We suggest that NGF is a worthwhile therapeutic target in the treatment of a metastatic chondrosarcoma.

Abstract

A chondrosarcoma is a common tumor of the soft tissue and bone that has a high propensity to metastasize to distant organs. Nerve growth factor (NGF) is capable of promoting the progression and metastasis of several different types of tumors although the effects of NGF in a chondrosarcoma are not confirmed. Here, we found that the levels of NGF and matrix metalloproteinase-2 (MMP-2) correlated with the tumor stage in patients with a chondrosarcoma. NGF facilitated the MMP-2-dependent cellular migration in human chondrosarcoma JJ012 cells while the overexpression of NGF enhanced the lung metastasis in a mouse model of a chondrosarcoma. NGF promoted the MMP-2 synthesis and cell migration by inhibiting miR-423-5p expression through the FAK and c-Src signaling cascades. NGF appears to be a worthwhile therapeutic target in the treatment of a metastatic chondrosarcoma.

Peroxisome proliferator-activated receptor-γ as a novel and promising target for treating cancer via regulation of inflammation: A brief review

Peroxisome proliferator activated receptors (PPARs) are group of nuclear receptors and the ligand-activated intracellular transcription factors that are known to play a key role in physiological processes such as cell metabolism, proliferation, differentiation, tissue remodeling, inflammation, and atherosclerosis. However, in the past two decades, many reports claim that PPARs also play an imperious role as a tumor suppressor. PPAR- gamma (PPARγ), one of the best-known from the family of PPARs, is known to express in colon, breast, bladder, lung, and prostate cancer cells. Its function in tumour cells includes the modulation of several pathways involved in multiplication and apoptosis. The ligands of PPARγ act by PPARγ dependent as well as independent pathways and are also found to regulate different inflammatory mediators and transcription factors in systemic inflammation and in tumor microenvironment. Both synthetic and natural ligands that are known to activate PPARγ, suppress the tumor cell growth and multiplication through the regulation of inflammatory pathways, as found out from different functional assays and animal studies. Cancer and inflammation are interconnected process that are now being targeted to achieve tumor suppression by decreasing the risks and burden posed by cancer cells. Therefore, PPARγ can serve as a promising target for development of clinical drug molecule attenuating the proliferation of cancer cells. In this perspective, this mini review highlights the PPARγ as a potential target for drug development aiming for anti-inflammatory and thereby suppressing tumors.

Celecoxib inhibits acute edema and inflammatory biomarkers through peroxisome proliferator-activated receptor-γ in rats

Objective(s):

Celecoxib (CLX), a selective cyclooxygenase-II (COX-2) inhibitor, has been used for management of several inflammatory disorders. The present study aimed to explore the role of peroxisome proliferator-activated receptor-gamma (PPARγ) in CLX induced anti-inflammatory response in rats.

Materials and Methods:

Carrageenan-induced paw edema was used as an acute inflammation model. Rats were treated with various intra-peritoneal (IP) doses of CLX (0.3–30 mg/kg) and pioglitazone (PGL; PPARγ agonist, 1–20 mg/kg) alone or in combination. Amounts of PPARγ, COX-2, and prostaglandin E2 (PGE2) in paw tissue, and extents of TNF-α and IL-10 in serum were measured. Moreover, levels of oxidative stress parameters as malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx) activity in the cortex, hippocampus, and paw tissues were also determined.

Results:

CLX and PGL dose-dependent administration (IP), alone or in combination reduced carrageenan-induced paw edema. Further, both agents, alone or in combination, reduced either the amounts of COX-2, PGE2, and MDA in the inflamed paw, and the levels of TNF-α in serum which were elevated by carrageenan. Both drugs also increased both levels of PPARγ, GSH, GPx activity in paws, and serum levels of IL-10 that were decreased by carrageenan. Intraplantar injection of GW-9662 (IPL), a selective PPARγ antagonist, inhibited all biochemical modifications caused by both single and combined drug treatments.

Conclusion:

CLX produced its anti-inflammatory effects probably through PPARγ receptor activation. Besides, increased anti-inflammatory effects of CLX with PGL suggest that their combination might be applied for the clinical management of inflammation especially in patients suffering from diabetes.

PPARγ Agonist Pioglitazone in Combination With Cisplatinum Arrests a Chemotherapy-resistant Osteosarcoma PDOX Model

BACKGROUND/AIM

Cisplatinum (CDDP) is a first-line drug in osteosarcoma treatment and the acquisition of resistance to CDDP is associated with a poor prognosis. Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear hormone receptor that plays important roles in cell proliferation, differentiation, development, metabolism and cell death. Recently, PPARγ was reported to enhance the efficacy, overcome resistance, and decrease the toxicity of CDDP in various human cancers. In this study we tested whether pioglitazone (PIO), a PPARγ agonist, could overcome CDDP resistance in osteosarcoma.

MATERIALS AND METHODS

In this study, we used a human osteosarcoma cell line and a patient-derived orthotopic xenograft (PDOX) models of osteosarcoma. We measured cell viability of 143B human osteosarcoma cells when treated with CDDP and PIO. We randomized PDOX models of osteosarcoma into four treatment groups: Group 1, Untreated control; Group 2, PIO alone; Group 3, CDDP alone; Group 4, a combination of CDDP and PIO. Each group comprised six mice. Mice were treated for 14 days and tumor size and body weight were measured.

RESULTS

Cell viability of 143B human osteosarcoma cells was significantly reduced when PIO (50 μmol/l) was combined with CDDP compared to CDDP alone. PDOX osteosarcoma tumors treated with the CDDP-PIO combination showed the strongest tumor growth inhibition compared to other treatment groups. PDOX osteosarcoma tumors treated with the CDDP-PIO combination had the least cancer cells and the most necrosis in histological section.

CONCLUSION

These results suggest that combining PIO along with CDDP could be an effective treatment strategy for osteosarcoma and has important clinical potential for patients.

Potential of Matrix Metalloproteinase Inhibitors for the Treatment of Local Tissue Damage Induced by a Type P-I Snake Venom Metalloproteinase

Snake bite envenoming is a public health problem that was recently included in the list of neglected tropical diseases of the World Health Organization. In the search of new therapies for the treatment of local tissue damage induced by snake venom metalloproteinases (SVMPs), we tested the inhibitory activity of peptidomimetic compounds designed as inhibitors of matrix metalloproteinases on the activities of the SVMP Batx-I, from Bothrops atrox venom. The evaluated compounds show great potential for the inhibition of Batx-I proteolytic, hemorrhagic and edema-forming activities, especially the compound CP471474, a peptidomimetic including a hydroxamate zinc binding group. Molecular dynamics simulations suggest that binding of this compound to the enzyme is mediated by the electrostatic interaction between the hydroxamate group and the zinc cofactor, as well as contacts, mainly hydrophobic, between the side chain of the compound and amino acids located in the substrate binding subsites S1 and S1′. These results show that CP471474 constitutes a promising compound for the development of co-adjuvants to neutralize local tissue damage induced by snake venom metalloproteinases.

An update on current and future treatment options for chondrosarcoma

Introduction: Human chondrosarcomas (CS; a malignant cartilage-forming bone tumor) respond poorly to chemotherapy and radiation treatment, resulting in high morbidity and mortality rates. Expanded treatment options are urgently needed. Areas covered: This article updates our 2014 review, in which we evaluated the CS treatments available at that time and potential treatment options under investigation. Since then, advances in research findings, particularly from Chinese herbal medicines, may be bringing us closer to more effective therapies for CS. In particular, promising findings have been reported from research targeting platelet-derived growth factor receptor. Expert opinion: Few treatment options exist for CS; chemotherapy is not even an option for unresectable disease, in which 5-year survival rates are just 2%. New information about the multitude of genes and signaling pathways that encourage CS growth, invasion and metastasis are clarifying how certain signaling pathways and plant-derived active compounds, especially molecularly-targeted therapies that inhibit the PDGF receptor, interfering with these biological processes. This review summarizes discoveries from the last 5 years and discusses how these findings are fueling ongoing work into effectively dealing with the disease process and improving the treatment of CS.

Pioglitazone, an agonist of PPARγ, reverses doxorubicin-resistance in an osteosarcoma patient-derived orthotopic xenograft model by downregulating P-glycoprotein expression

Multidrug resistance (MDR) which results in chemoresistance is a major problem in osteosarcoma. P-glycoprotein (P-gp) plays a critical role in MDR by pumping out chemotherapy agents. Peroxisome proliferator activated receptor gamma (PPARγ) is a nuclear receptor involved in cellular differentiation and proliferation. Recently, a correlation between the expression and activity of PPARγ and the expression of P-gp-associated with MDR, has been reported in several human cancers. The present study determined if pioglitazone (PIO), a PPARγ agonist, could modulate P-gp and overcome doxorubicin (DOX)-resistance in a patient-derived orthotopic xenograft (PDOX) model of osteosarcoma. P-gp mRNA expression was quantified in 143B human osteosarcoma cells treated with DOX with/without PIO. The osteosarcoma PDOX models were randomized into four treatment groups of six mice: Control; PIO alone; DOX alone; DOX and PIO combination. Tumor size and body weight were measured during the 14 days of treatment. DOX significantly induced P-gp mRNA in a dose-dependent manner in 143B cells. PIO inhibited the increase of P-gp mRNA induced by DOX treatment when co-administrated with DOX. Tumor growth was inhibited the most by the DOX-PIO combination. Tumors treated with the DOX-PIO combination also had the most tumor necrosis. This study suggests that the DOX-PIO combination could be used in the clinic for osteosarcoma patients who develop DOX-resistance.

A comparative experimental study of analgesic activity of a novel non-steroidal anti-inflammatory molecule - zaltoprofen, and a standard drug - piroxicam, using murine models

Purpose

Pain is an unpleasant sensation, but a protective mechanism of our body. It is the most common medical complaint requiring a visit to a physician. The new non-steroidal anti-inflammatory drug (NSAID) - zaltoprofen, is a preferential COX-2 inhibitor. It also inhibits bradykinin-induced nociceptive responses by blocking the B2 receptor-mediated pathway in the primary sensory neurons. The present study was conducted to evaluate and compare the anti-nociceptive activity of zaltoprofen with a conventional NSAID - piroxicam, in a mouse model of acute pain using hot plate and tail flick tests.

Materials and methods

Twenty-four adult Swiss albino mice (20-25 g) of either sex were used in this study. Oral zaltoprofen and piroxicam were used as test and standard drugs respectively. Anti-nociceptive activity was evaluated and compared using hot plate and tail flick tests.

Results

In comparison to the control group (vehicle), zaltoprofen showed a significant increase in reaction time at various time periods in the hot plate and tail flick tests. In the hot plate method, zaltoprofen groups (15 and 20 mg/kg) showed a significant elevation in pain threshold in comparison to control group (vehicle) (p<0.001). In the tail flick model also, zaltoprofen groups (15 and 20 mg/kg) showed a significant increase in the reaction time in comparison to control group (vehicle). In both the analgesiometer assays, zaltoprofen was found to be non-inferior compared to a standard drug - piroxicam (positive control).

Conclusion

Our study concludes that zaltoprofen is an effective analgesic agent in various pain models. Our results support that zaltoprofen has therapeutic potential for treating pain disorders and is non-inferior to a standard drug - piroxicam.

Self-regulation of the inflammatory response by peroxisome proliferator-activated receptors

The peroxisome proliferator-activated receptor (PPAR) family includes three transcription factors: PPARα, PPARβ/δ, and PPARγ. PPAR are nuclear receptors activated by oxidised and nitrated fatty acid derivatives as well as by cyclopentenone prostaglandins (PGA₂ and 15d-PGJ₂) during the inflammatory response. This results in the modulation of the pro-inflammatory response, preventing it from being excessively activated. Other activators of these receptors are nonsteroidal anti-inflammatory drug (NSAID) and fatty acids, especially polyunsaturated fatty acid (PUFA) (arachidonic acid, ALA, EPA, and DHA). The main function of PPAR during the inflammatory reaction is to promote the inactivation of NF-κB. Possible mechanisms of inactivation include direct binding and thus inactivation of p65 NF-κB or ubiquitination leading to proteolytic degradation of p65 NF-κB. PPAR also exert indirect effects on NF-κB. They promote the expression of antioxidant enzymes, such as catalase, superoxide dismutase, or heme oxygenase-1, resulting in a reduction in the concentration of reactive oxygen species (ROS), i.e., secondary transmitters in inflammatory reactions. PPAR also cause an increase in the expression of IκBα, SIRT1, and PTEN, which interferes with the activation and function of NF-κB in inflammatory reactions.