• Journal of dental hygiene science
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• v.19 no.4
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• pp.254-260
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• 2019

Background: The primary aims of periodontal disease treatment is to remove dental plaque and calculus, the main causes of tooth loss, and restore periodontal tissue destroyed by inflammation. Periodontal disease treatment should also help maintain the alveolar bone, alleviate inflammation, and promote periodontal ligament cell proliferation, which is essential for tissue regeneration. Conventional antibiotics and anti-inflammatories have adverse side effects, especially during long-term use, so there is a need for adjunct treatment agents derived from natural products. The purpose of this study was to investigate whether the herbal flavone baicalein has the osteogenic activity under inflammatory conditions, and assess the involvement of osteoblast immediate early response 3 (IER3) expression. Methods: Human osteoblastic MG-63 cells were cultured with the pro-inflammatory cytokines tumor necrosis factor α and interleukin 1β in the presence and absence of baicalein. Proliferation was assessed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, and expression of IER3 mRNA was assessed using real-time polymerase chain reaction. The expression of IER3 protein levels and activation of associated signal transduction pathways were assessed using western blotting. Results: Baicalein increased IER3 mRNA and protein expression synergistically. In addition, baicalein reversed the suppression of cell proliferation, and the downregulation of osteogenic transcription factor runt-related transcription factor 2 and osterix induced by pro-inflammatory cytokines. Baicalein also upregulated the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK 1/2). The upregulation of IER3 by pro-inflammatory cytokines was blocked by pretreatment with inhibitors of AKT, p38, JNK, and ERK 1/2. Conclusion: Baicalein mitigates the deleterious responses of osteoblasts to pro-inflammatory cytokines. Further, IER3 enhanced the effect of baicalein via activation of AKT, p38, JNK, and ERK pathways.

• International Journal of Oral Biology
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• v.42 no.3
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• pp.91-97
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• 2017

Although anti-aging activities of melatonin, a hormone secreted by the pineal gland, have been reported in senescence-accelerated mouse models and several types of cells, its impact and mechanism on the senescence of human dental pulp cells (HDPCs) remains unknown. In this study, we examined the impact of melatonin on cellular premature senescence of HDPCs. Here, we found that melatonin markedly inhibited senescent characteristics of HDPCs after exposure to hydrogen peroxide ($H_2O_2$), including the increase in senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal)-positive HDPCs and the upregulation of p21 protein, an indicator for senescence. In addition, as melatonin attenuated $H_2O_2$-stimulated phosphorylation of c-Jun N-terminal kinase (JNK), while selective inhibition of JNK activity with SP600125 significantly attenuated $H_2O_2$-induced increase in SA-beta-gal activity. Results reveal that melatonin antagonizes premature senescence of HDPCs via JNK pathway. Thus, melatonin may have therapeutic potential to prevent stress-induced premature senescence, possibly correlated with development of dental pulp diseases, and to maintain oral health across the life span.

• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.316-322
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• 2012

Siegesbeckia Herba is known to have anti-oxidant, anti-inflammatory, anti-allergic and anti-tumor. The objective of this study is to explore the neuroprotective effect of Siegesbeckia Herba against glutamate-induced oxidative stress in mouse hippocampal HT22 cells. Siegesbeckia Herba 70% ethanol extract and solvent fractions have the potent neroprotective effects on glutamate-induced nerotoxicity by induced the expression of heme oxygenase (HO)-1 in the mouse hippocampal HT22 cells. Especially, ethyl acetate fraction showed higher protective effect. In HT22 cell, Siegesbeckia Herba ethyl acetate fraction makes the nuclear accumulation of Nrf2. Further, we found that treatment with c-JUN N-terminal kinase (JNK) inhibitor (SP600125) reduced Siegesbeckia Herba ethyl acetate fraction induced HO-1 expression and Siegesbeckia Herba ethyl acetate fraction also increased JNK phosphorylation. In conclusion, the ethyl acetate fraction of 70% ethanol extract of Siegesbeckia Herba significantly protect glutamate-induced oxidative damage by induction of HO-1 via Nrf2 and JNK pathway in mouse hippocampal HT22. Taken together these finding suggest that Siegesbeckia Herba ethyl acetate fraction good source for taking active compounds and may be a potential therapeutic for brain disorder by targeting the oxidative stress of neuronal cell.

• Nutrition Research and Practice
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• v.11 no.2
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• pp.90-96
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• 2017

BACKGROUND/OBJECTIVES: Although the antioxidative effects of lycopene are generally known, the molecular mechanisms underlying the anti-inflammatory properties of lycopene are not fully elucidated. This study aimed to examine the role and mechanism of lycopene as an inhibitor of inflammation. METHODS/MATERIALS: Lipopolysaccharide (LPS)-stimulated SW 480 human colorectal cancer cells were treated with 0, 10, 20, and $30{\mu}M$ lycopene. The MTT assay was performed to determine the effects of lycopene on cell proliferation. Western blotting was performed to observe the expression of inflammation-related proteins, including nuclear factor-kappa B ($NF-{\kappa}B$), inhibitor kappa B ($I{\kappa}B$), mitogen-activated protein kinase (MAPK), extracellular signal-related kinase (ERK), c-jun NH2-terminal kinase (JNK), and p38 (p38 MAP kinase). Real-time polymerase chain reaction was performed to investigate the mRNA expression of tumor necrosis factor ${\alpha}$ ($TNF-{\alpha}$), interleukin-1 beta ($IL-1{\beta}$), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Concentrations of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) were determined via enzyme-linked immunosorbent assays. RESULTS: In cells treated with lycopene and LPS, the mRNA expression of $TNF-{\alpha}$, $IL-1{\beta}$, IL-6, iNOS, and COX-2 were decreased significantly in a dose-dependent manner (P < 0.05). The concentrations of $PGE_2$ and NO decreased according to the lycopene concentration (P < 0.05). The protein expressions of $NF-{\kappa}B$ and JNK were decreased significantly according to lycopene concertation (P < 0.05). CONCLUSIONS: Lycopene restrains $NF-{\kappa}B$ and JNK activation, which causes inflammation, and suppresses the expression of $TNF-{\alpha}$, $IL-1{\beta}$, IL-6, COX-2, and iNOS in SW480 human colorectal cancer cells.

• Archives of Pharmacal Research
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• v.26 no.12
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• pp.1055-1060
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• 2003

Lysophosphatidic acid (LPA) is a well-known mitogen in various cell types. However, we found that LPA inhibits melanocyte proliferation. Thus, we further investigated the possible signaling pathways involved in melanocyte growth inhibition. We first examined the regulation of the three major subfamilies of mitogen-activated protein (MAP) kinases and of the Akt pathway by LPA. The activations of extracellular signal-regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK) were observed in concert with the inhibition of melanocyte proliferation by LPA, whereas p38 MAP kinase and Akt were not influenced by LPA. However, the specific inhibition of the ERK or JNK pathways by PD98059 or D-JNKI1, respectively, did not restore the antiproliferative effect. We next examined changes in the expression of cell cycle related proteins. LPA decreased cyclin $D_1 and cyclin D_2$ levels but increased $p21^{WAF1/CIP1}$ (p21) and $p27^{KIP1}$ (p27) levels, which are known inhibitors of cyclin-dependent kinase. Flow cytometric analysis showed the inhibition of DNA synthesis by a reduction in the S phase and an increase in the $G_0/G_1$ phase of the cell cycle. Our results suggest that LPA induces cell cycle arrest by regulating the expressions of cell cycle related proteins.

• Journal of Acupuncture Research
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• v.37 no.1
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• pp.42-48
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• 2020

Background: Atopic dermatitis (AD) is a chronic inflammatory condition which can be studied using phthalic anhydride (PA) to induce AD. Anti-inflammatory properties of bee venom (BV) wereinvestigated to determine whether it may be a useful treatment for AD. Methods: AD was induced by applying to pical PA to 8-week-old HR-1 mice (N = 50), then treating with (0.1, 0.25, and 0.5 ㎍) or without topical BV. Body weight, ear thickness histology, enzyme-linked immune sorbent assay (serum IgE concentrations), Western blot analysis [inducible nitric oxide synthase, cyclooxygenase-2, IκB-α, phospho-IκB-α, c-Jun N-terminal kinase (JNK), phospho-JNK, p38, phospho-p38, extra cellular signal-regulated kinase (ERK), and phospho-ERK], and the pull down assay for immunoblotting (p50), were used to measure inflammatory mediators. Results: PA + BV (0.1, 0.25, and 0.5 ㎍) significantly decreased ear thickness without altering body weight. IgE concentrations decreased in the PA + BV (0.5 ㎍)-treated groups compared with PAtreatment. Tumor necrosis factor-α, interleukin-1β, inducible nitric oxide synthase, cyclooxygenase-2, phospho-IκB-α, phospho-JNK, p38, phospho-p38, and phospho-ERK, all decreased following treatment with PA + BV compared with the PA-treatment alone. p50 was upregulated in the PA + BV-treated groups compared with the PA-treated group. Furthermore, the number of mast cells decreased in the PA + BV-treated groups compared with the PA-treated group. Epidermal thickness was significantly lower in the PA + BV-treated group compared with PA treatment alone. Conclusion: BV maybe a useful anti-inflammatory treatment for AD.

• Korean Journal of Pharmacognosy
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• v.46 no.2
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• pp.116-122
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• 2015

Keratinocytes are first barrier against outer challenges on skin. However, it is still largely unknown about effective protectors against ultraviolet B (UVB), and oxidative stress in human keratinocyte, HaCaT cells. Inducible heme oxygenase (HO)-1 acts against oxidants that are thought to play a role in the pathogenesis of skin disorders. Therefore, the purpose of this study was to evaluate the effect of Portulaca oleracea 70% EtOH extracts against hydrogen peroxide (H₂O₂)-induced oxidative stress in human keratinocytes, HaCaT cells. P. oleracea 70% EtOH extracts showed the potent protective effects on H₂O₂-induced toxicity by induced the expression of HO-1 in human keratinocyte, HaCaT cells. Furthermore, P. oleracea 70 % EtOH extracts caused the nuclear accumulation of nuclear factor E2-related factor 2 (Nrf2) in human keratinocytes, HaCaT cells. In addition, we found that treatment with c-Jun N-terminal kinase (JNK) inhibitor (SP600125) reduced P. oleracea 70% EtOH extracts-induced HO-1 expression, and JNK inhibitor (SP600125) also inhibited protective effects by P. oleracea 70% EtOH extracts. Therefore, these results suggest that P. oleracea 70 % EtOH extracts increases cellular resistance to H₂O₂-induced oxidative injury in human keratinocyte, HaCaT cells, presumably through JNK pathway-Nrf2-dependent HO-1 expression.

• Biomolecules & Therapeutics
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• v.28 no.5
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• pp.423-430
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• 2020

Telmisartan is an angiotensin-II receptor blocker and acts as a selective modulator of peroxisome proliferator-activated receptor gamma (PPARγ). Several studies have demonstrated that telmisartan ameliorates depression and memory dysfunction and reduces brain inflammation. We hypothesized that the beneficial effects of telmisartan on brain could be due to modulation of the blood-brain barrier (BBB) function. Here, we examined the effect of telmisartan on tumor necrosis factor alpha (TNF-α)-induced expression of intercellular adhesion molecule 1 (ICAM-1) which plays an important role in leukocyte transcytosis through the BBB. Telmisartan blocked TNF-α-induced ICAM-1 expression and leukocyte adhesion in U87MG human glioma cells but showed no effect on human brain microvascular endothelial cells. In U87MG cells, a PPAR antagonist, GW9662 did not block the effect of telmisartan on ICAM1 expression but rather potentiated. Moreover, GW9662 caused no change in TNF-α-induced ICAM-1 expression, suggesting no implication of PPARγ in the telmisartan effect. Further studies showed that telmisartan blocked TNF-α-induced activation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and nuclear factorkappa B (NF-κB). In contrast, inhibitors of JNK, ERK1/2 and NF-κB but not p38, blocked ICAM-1 expression induced by TNF-α. Thus, our findings suggest that the beneficial effect of telmisartan is likely due to the reduction of astrocytic ICAM1 expression and leukocytes adhesion to astrocytes, and that this response was mediated by the inhibition of JNK/ERK1/2/NF-κB activation and in the PPAR-independent manner. In conclusion, this study enhances our understanding of the mechanism by which telmisartan exerts the beneficial brain function.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.739-746
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• 2003

Ultraviolet B (UVB) is known to induce apoptosis in human melanocytes. Here we show the cytoprotective effect of sphingosine-1-phosphate (S1P) against UVB-induced apoptosis. We also show that UVB-induced apoptosis of melanocytes is mediated by caspase-3 activation and poly(ADP-ribose) polymerase (PARP) cleavage, and that S1P prevents apoptosis by inhibiting this apoptotic pathway. We further investigated three major mitogen-activated protein (MAP) kinases after UVB irradiation. UVB gradually activated c-Jun N-terminal kinase (JNK) and p38 MAP kinase, while extracellular signal-regulated protein kinase (ERK) was inactivated transiently. Blocking of the p38 MAP kinase pathway using SB203580 promoted cell survival and inhibited the activation of caspase-3 and PARP cleavage. These results suggest that p38 MAP kinase activation may play an important role in the UVB-induced apoptosis of human melanocytes. To explain this cytoprotective effect, we next examined whether S1P could inhibit UVB-induced JNK and p38 MAP kinase activation. However, S1P was not found to have any influence on UVB-induced JNK or p38 MAP kinase activation. In contrast, S1P clearly stimulated the phosphorylation of ERK, and the specific inhibition of the ERK pathway using PD98059 abolished the cytoprotective effect of S1P. Based on these results, we conclude that the activation of p38 MAP kinase plays an important role in UVB-induced apoptosis, and that S1P may show its cytoprotective effect through ERK activation in human melanocytes.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.5
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• pp.425-437
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• 2021

Although the contributions of sitagliptin to endothelial dysfunction in diabetes mellitus were previously reported, the mechanisms still undefined. Autophagy plays an important role in the development of diabetes mellitus, but its role in diabetic macrovascular complications is unclear. This study aims to observe the effect of sitagliptin on macrovascular endothelium in diabetes and explore the role of autophagy in this process. Diabetic rats were induced through administration of high-fat diet and intraperitoneal injection of streptozotocin. Then diabetic rats were treated with or without sitagliptin for 12 weeks. Endothelial damage and autophagy were measured. Human umbilical vein endothelial cells were cultured either in normal glucose or in high glucose medium and intervened with different concentrations of sitagliptin. Rapamycin was used to induce autophagy. Cell viability, apoptosis and autophagy were detected. The expressions of proteins in c-Jun N-terminal kinase (JNK)-Bcl-2-Beclin-1 pathway were measured. Sitagliptin attenuated injuries of endothelium in vivo and in vitro. The expression of microtubuleassociated protein 1 light chain 3 II (LC3II) and beclin-1 were increased in aortas of diabetic rats and cells cultured with high-glucose, while sitagliptin inhibited the over-expression of LC3II and beclin-1. In vitro pre-treatment with sitagliptin decreased rapamycin-induced autophagy. However, after pretreatment with rapamycin, the protective effect of sitagliptin on endothelial cells was abolished. Further studies revealed sitagliptin increased the expression of Bcl-2, while inhibited the expression of JNK in vivo. Sitagliptin attenuates injuries of vascular endothelial cells caused by high glucose through inhibiting over-activated autophagy. JNK-Bcl-2-Beclin-1 pathway may be involved in this process.