curcumin and Gingival-Overgrowth

Gingival overgrowth (GO) is a common side effect of some drugs such as anticonvulsants, immunosuppressant, and calcium channel blockers. Among them, the antiepileptic agent phenytoin is the most common agent related to this condition due to its high incidence. Transforming growth factor β (TGFβ) importantly contributes to the pathogenesis of GO. Connective tissue growth factor (CTGF or CCN2) is a key mediator of tissue fibrosis and is positively associated with the degree of fibrosis in GO. We previously showed that Src, c-jun N-terminal kinase, and Smad3 mediate TGFβ1-induced CCN2 protein expression in human gingival fibroblasts (HGFs). This study investigates whether phenytoin can induce CCN2 synthesis through activated latent TGFβ in HGFs and its mechanisms.. CCN2 synthesis, latent TGFβ1 activation, and cellular reactive oxygen species (ROS) generation in HGFs were studied using western blot analysis, a TGFβ1 Emax® ImmunoAssay System, and 2',7'-dichlorodihydrofluorescein diacetate (an oxidation-sensitive fluorescent probe), respectively.. Phenytoin significantly stimulated CCN2 synthesis, latent TGFβ1 activation, and ROS generation in HGFs. Addition of an TGFβ-neutralizing antibody, TGFβ receptor kinase inhibitor SB431542, and Smad3 inhibitor SIS3 completely inhibited phenytoin-induced CCN2 synthesis. General antioxidant N-acetylcysteine, NADPH oxidase (NOX) inhibitor diphenylene iodonium, and specific NOX4 inhibitor plumbagin almost completely suppressed phenytoin-induced total cellular ROS and latent TGFβ1 activation. Curcumin dose-dependently decreased phenytoin-induced TGFβ1 activation and CCN2 synthesis in HGFs.. Our findings indicated that NOX4-derived ROS play pivotal roles in phenytoin-induced latent TGFβ1 activation. Molecular targeting the phenytoin/NOX4/ROS/TGFβ1 pathway may provide promising strategies for the prevention and treatment of GO. Curcumin-inhibited phenytoin-induced CCN2 synthesis is caused by the suppression of latent TGFβ1 activation.

Topics: Cells, Cultured; Connective Tissue Growth Factor; Curcumin; Fibroblasts; Fibrosis; Gingiva; Gingival Overgrowth; Humans; NADPH Oxidase 4; Phenytoin; Reactive Oxygen Species; Transforming Growth Factor beta1

At the moment there is no clear evidence with clinico-histological and immunohistochemical studies in animals to show the curcumin effect on the gingival overgrowth following phenytoin consumption. The purpose of the present study was to identify this subject.. In this experimental study, 50 adult male Wistar rats were divided into three groups. The rats in groups I and II received 100 mg/kg of phenytoin per day. Group II also received 20 mg/kg intraperitoneal curcumin per day. The control group received the curcumin vehicle only. Gingival clinical dimensions were measured at the beginning and end of the study. The rats were then sacrificed, biopsy of gingiva was prepared, and the samples were stained with hematoxylin-eosin. Morphometry was performed to evaluate the degree of inflammation, epithelial thickness, number, and cross-sectional area of the blood vessels. Immunohistochemical staining was performed using Ki67 and α-SMA.. Compared to the control group, Phenytoin in group I increased gingival volume. There was significance difference in group II with group I and control after intervention in the clinical view (. In rats, curcumin seems to exerts its effects in preventing an increase in gingival volume caused by Phenytoin through decreasing the inflammatory infiltration, decreasing the number of blood vessels and increasing their cross-sectional area, decreasing the thickness of the epithelium, and decreasing the expression of Ki67 and α-SMA.. It is suggested that curcumin may be effective in treatment of gingival enlargement following Phenytoin consumption in future. Larger sample size and clinical trials study are recommended. How to cite this article: Eftekharian S, Seifi S, Satari FD,

Topics: Animals; Curcumin; Gingiva; Gingival Overgrowth; Male; Phenytoin; Rats; Rats, Wistar

Many fibrotic processes are associated with an increased level of transforming growth factor-β1 (TGF-β1). TGF-β1 can increase synthesis of matrix proteins and enhance secretion of protease inhibitors, resulting in matrix accumulation. Connective tissue growth factor (CTGF) is a downstream profibrotic effector of TGF-β1 and is associated with the fibrosis in several human organs. Curcumin has been applied to reduce matrix accumulation in fibrotic diseases. This study was aimed to evaluate whether curcumin could suppress TGF-β1-induced CTGF expression and its related signaling pathway involving in this inhibitory action in primary human gingival fibroblasts.. The differences in CTGF expression among three types of gingival overgrowth and normal gingival tissues were assessed by immunohistochemistry. Gingival fibroblast viability in cultured media with different concentrations of curcumin was studied by MTT assay. The effect of curcumin on TGF-β1-induced CTGF expression in primary human gingival fibroblasts was examined by immunoblotting. Moreover, the proteins involved in TGF-β1 signaling pathways including TGF-β1 receptors and Smad2 were also analyzed by immunoblotting.. CTGF was highly expressed in fibroblasts, epithelial cells and some of endothelial cells, smooth muscle cells, and inflammatory cells in phenytoin-induced gingival overgrowth tissues rather than in those of hereditary and inflammatory gingival overgrowth tissues. Moreover, CTGF expression in the epithelial and connective tissue layers was higher in phenytoin-induced gingival overgrowth tissues than in normal gingival tissues. Curcumin was nontoxic and could reduce TGF-β1-induced CTGF expression by attenuating the phosphorylation and nuclear translocation of Smad2.. Curcumin can suppress TGF-β1-induced CTGF expression through the interruption of Smad2 signaling.

Topics: Cells, Cultured; Connective Tissue Growth Factor; Curcumin; Epithelial Cells; Fibroblasts; Gingival Overgrowth; Humans; Phosphorylation; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta1

Transforming growth factor β (TGFβ) plays a central role in the pathogenesis of gingival overgrowth (GO). Connective tissue growth factor (CTGF; or CCN2) is induced by TGFβ in human gingival fibroblasts (HGFs) and is overexpressed in GO tissues. CCN2 creates an environment favorable for fibrogenesis and is required for the maximal profibrotic effects of TGFβ. We previously showed that Src, JNK, and Smad3 mediate TGFβ1-induced CCN2 protein expression in HGFs. Moreover, Src is an upstream signaling transducer of JNK and Smad3. Recent studies suggested that NADPH oxidase (NOX)-dependent redox mechanisms are involved in mediating the profibrotic effects of TGFβ. In this study, we demonstrated that TGFβ1 upregulated NOX4 protein expression and increased reactive oxygen species (ROS) production in HGFs. Genetic or pharmacologic targeting of NOX4 abrogated TGFβ1-induced ROS production; Src, JNK, and Smad3 activation; and CCN2 and type I collagen protein expression in HGFs. Our results indicated that NOX4-derived ROS play pivotal roles in activating Src kinase activity leading to the activation of canonical (Smad3) and noncanonical (JNK) cascades that cooperate to attain maximum CCN2 expression. Furthermore, we demonstrated that curcumin significantly inhibited the TGFβ1-induced NOX4 protein expression in HGFs. Curcumin potentially qualifies as an agent to control GO by suppressing TGFβ1-induced NOX4 expression in HGFs.

Topics: Acetylcysteine; Cell Culture Techniques; Cells, Cultured; Connective Tissue Growth Factor; Curcumin; Enzyme Inhibitors; Fibroblasts; Free Radical Scavengers; Gene Silencing; Gingiva; Gingival Overgrowth; Humans; MAP Kinase Signaling System; NADPH Oxidase 4; NADPH Oxidases; Naphthoquinones; Oxidation-Reduction; Reactive Oxygen Species; RNA, Small Interfering; Signal Transduction; Smad3 Protein; src-Family Kinases; Superoxides; Transforming Growth Factor beta1

Transforming growth factor β (TGFβ) is a key regulator associated with the pathogenesis of gingival overgrowth (GO). Connective tissue growth factor (CTGF/CCN2) is overexpressed in GO tissues. CCN2 promotes and sustains fibrosis initiated by TGFβ. Previous studies have shown that JNK and Smad3 activation is required for TGFβ-induced CCN2 expressions in human gingival fibroblasts (HGFs). In this study, we have found that Src is a major signaling mediator for TGFβ-induced CCN2 expressions in HGFs. Pre-treatment with 2 Src kinase inhibitors (PP2, Src inhibitor-1) significantly reduced TGFβ1-induced CCN2 synthesis and JNK and Smad3 activation in HGFs. These results suggest that Src is an upstream signaling transducer of JNK and Smad3 with respect to TGFβ1-stimulated CCN2 expression in HGFs. We further found that curcumin significantly abrogated the TGFβ1-induced CCN2 in HGFs by inhibiting the phosphorylations of Src, JNK, and Smad3. Furthermore, curcumin inhibited TGFβ1-induced HGF migration and α-SMA expression. Curcumin potentially qualifies as a useful agent for the control of GO.

Topics: Anthracenes; Anti-Inflammatory Agents, Non-Steroidal; Catechin; Cell Culture Techniques; Cell Movement; Cells, Cultured; Connective Tissue Growth Factor; Curcumin; Enzyme Inhibitors; Fibroblasts; Flavonoids; Gingiva; Gingival Overgrowth; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Imidazoles; Lovastatin; MAP Kinase Kinase 4; Phosphorylation; Protein Kinase Inhibitors; Pyridines; Pyrimidines; Signal Transduction; Smad3 Protein; src-Family Kinases; Transforming Growth Factor beta1

Connective tissue growth factor (CTGF/CCN2), associated with multiple human fibrotic diseases, is overexpressed in the tissue of gingival overgrowth. Although surgical excision is the current treatment modality for gingival overgrowth, the recurrent rate is high despite proper recall programs. Thrombin plays a key role in wound repair, remodeling, and fibrosis after injury and exerts profibrotic effects by activating protease-activated receptors (PARs). Curcumin [1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione] is a natural plant phenolic compound that possesses both anti-inflammatory and antioxidant properties. This study investigates the signaling pathway of thrombin-induced CCN2 expression and inhibition of CCN2 expression by curcumin.. The signaling pathway of thrombin-induced CCN2 expression in human gingival fibroblasts (HGFs) was studied using Western blot analysis. The CCN2 mRNA level was determined by quantitative reverse transcription-polymerase chain reaction.. Thrombin induced CCN2 expression in HGFs by activating PAR1. Pretreatment with antioxidant N-acetyl-l-cysteine, apoptosis signal-regulating kinase 1 (ASK1) inhibitor thioredoxin, and c-Jun NH2-terminal kinase (JNK) inhibitor SP600125 (anthra[1,9-cd]pyrazol-6(2H)-one) significantly reduced thrombin-induced CCN2 expression in HGFs. Curcumin dose dependently inhibited thrombin-induced CCN2 expression through JNK suppression in HGFs.. The results of this study suggest that thrombin-induced CCN2 expression may occur through PAR1, reactive oxygen species, ASK1, and JNK signaling in HGFs. Curcumin could effectively inhibit CCN2 expression through JNK suppression. These signaling events are important for wound healing and fibrosis. Additional research, including animal studies, is required to confirm the inhibiting role of curcumin in the development of gingival overgrowth.

Topics: Cells, Cultured; Connective Tissue Growth Factor; Curcumin; Enzyme Activation; Enzyme Inhibitors; Fibroblasts; Gingiva; Gingival Overgrowth; Humans; JNK Mitogen-Activated Protein Kinases; MAP Kinase Kinase Kinase 5; MAP Kinase Signaling System; Reactive Oxygen Species; Receptors, Proteinase-Activated; Thrombin