1. Introduction
Lonicera japonica Thunb. (Lj) is a Chinese herbal plant (homology of medicine and food) in which the flower, seeds, and leaves have been used for medicine since ancient times. Many studies have been done to evaluate the activity of Lj extract and its various effects on human health have been established, including antioxidative, antibacterial, anti- inflammatory, antiviral, anticancer, and various other activities [
1]. The dried flower buds of Lj may be prepared as tea and is known for its detoxifying and soothing effects [
2].
Recent studies have provided evidence suggesting a progressive rise in gastric inflammation-related disorders, which may be attributed to a multitude of factors, such as an aging population, the prevalence of chronic pain, and the increased use of nonsteroidal anti-inflammatory drugs (NSAIDs) or diverse chemotherapeutic medications. These factors contribute to a rapid escalation of gastric inflammation-related disorders, which can worsen gradually over time [
3,
4].
Gastric inflammation-related disorders arise from the chronic erosion of gastric mucosal epithelial cells, which surpasses the regenerative capacity of these cells. This imbalance leads to the manifestation of gastric inflammation, fibrosis at the site of injury, and thinning of the gastric wall, and may result in complications, such as gastric bleeding, gastric perforation, or the development of gastric cancer (GC) [
5].
The etiology of gastric inflammation includes impaired or recurrent inflammation of the gastric mucosal epithelial tissue, which culminates in the activation of cytokines and chemokines. This subsequently results in the activation and infiltration of macrophages, neutrophils, monocytes, and other immune cells into the gastric tissue. The immune cells produce proinflammatory cytokines, such as tumor necrosis factor alpha (TNF-α), interleukins, such as IL-1, IL-6, IL-8, and IL-10 as well as chemokines, like circular dichroism 44 (CD44) and intercellular adhesion molecule-1 (ICAM-1). The aforementioned factors serve as triggers for the production of inflammatory proteins, including cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9), within the mucosal lining in GC. The pathophysiological features of gastric inflammation arise from stimulation by immune cells, such as neutrophils, monocytes, and macrophages, and their infiltration into the gastric tissue. This leads to the development of inflammatory responses in the gastric mucosal epithelial cells, subsequent damage to the gastric mucosa, and the degradation of gastric secretory glands, among others [
6,
7,
8].
TNF-α regulates diverse biological functions, including fever, inflammation, immune response, apoptosis induction, lipid metabolism, tumorigenesis, and viral replication [
9,
10]. Several studies indicate that increased expression of TNF-α or TNF-α polymorphisms has been associated with an augmented susceptibility to chronic atrophic gastritis, metastasis [
11], tumorigenesis [
12], and GC in patients [
13,
14]. Harris et al. [
15] and Fan et al. [
16] reported similar findings, supporting the concept that the pathogenesis of
H. pylori-associated gastroduodenal diseases involves the upregulation of inflammatory TNF-α production.
COX-2 is an enzyme that is involved in the biosynthesis of prostaglandin (PG)-endoperoxide. Potter et al. [
17] observed marked upregulation of COX-2 in neoplastic sites and GC with inflammation. Moreover,
Helicobacter pylori infection stimulates toll-like receptor (TLR)/MyD88 and COX-2/PGE
2 pathways, resulting in NF-κB activation with different inflammatory responses in tumor tissues [
18]. We demonstrated that
H. zeylanica-E2 inhibits TNF-α-induced activation of the inflammatory cytosolic phospholipase A2 (cPLA2)/COX-2/PGE
2 response in GC cells [
19]. Therefore, the COX-2/PGE
2 system likely serves as a central pathological mediator of gastric inflammation-related disorders.
MMP-9 contributes to the development of various human malignancies by facilitating wound healing, cell migration, angiogenesis, and tumor progression through collagen IV degradation in the basement membrane and extracellular matrix [
20]. The upregulation of MMP-9, mediated by the nuclear factor kappa B (NF-κB) signaling, may promote gastric inflammation and actively contribute to the progression of GC [
21]. Moreover, the findings in our previous study indicated that under normal conditions, quercetin exerts protective effects in GES-1 cells by inhibiting TNF-α-induced MMP-9 upregulation [
22].
In gastric mucosal epithelium cells, Lj has been shown to exhibit gastroprotective properties following TNF-α-induced damage. However, the detailed underlying mechanisms are still unknown. Here, we elucidated the potential preventive properties of Lj on gastric mucosal epithelial cells in response to TNF-α-induced damage, with a specific focus on determining its effects on COX-2/PGE2 and MMP-9 signaling pathways. We used GES-1 cells under normal conditions to assess the molecular processes and immune-inflammatory reactions regulated by TNF-α.
4. Discussion
Lj belongs to the
Caprifoliaceae family, also known as
Jin Yin Hua, and is a commonly used traditional Chinese medicine, health supplements, cosmetics, and ornamental groundcover [
1]. Lj could be used for
dietary/nutritional/functional/
health supplements due to the intestinal benefits [
37]. In addition to Lj, general natural products are also widely used in promoting human health through various ways such as
Rhizoma polygonati extract [
38], Gentiana extract [
39], Camel milk [
40], safranal [
41], and so on. Numerous studies have identified over 140 component compounds, including essential oils, flavones, organic acids, iridoids, saponins, and inorganic elements. Lj and its constituents demonstrate diverse pharmacological effects including anti-inflammatory, antiviral, antibacterial (including against
Helicobacter pylori), antioxidant, hepatoprotective, anticancer, immune-boosting functions, insecticidal, acaricidal, anti-pregnancy, anti-hyperlipidemic, anti-thrombotic, and anti-lipase activities [
1,
2,
42]. In the present study, Lj-EtOH was examined based on its documented anti-inflammatory and gastroprotective properties. The induction of gastric inflammation has an important role in the development of gastric epithelial injury and the development of gastric inflammation-related disorders.
Chang et al. [
43] found that LJ Flos (LJF) has been traditionally consumed orally as a medicinal plant and health food in China for years. To elucidate the gastrointestinal metabolism of LJF, three distinct in vitro models were used, specifically, gastric juice, intestinal juice, and human intestinal bacteria. The identification of prototype compounds within the water extraction of LJF (LJF-WE) was accomplished through rigorous qualitative and quantitative analysis methodologies. They evaluated the stability of eight bioactive composites (sweroside, secoxyloganin, isochlorogenic acid B, neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, isochlorogenic acid A, and isochlorogenic acid C) in simulated gastric fluid, intestinal fluid, and human fecal bacteria. The results indicated that these compounds exhibited a higher degree of stability when subjected to exposed to gastric and intestinal fluids compared with the presence of fecal bacteria.
Bang et al. [
31] examined the gastroprotective properties of BST-104, which is a water-based extract derived from LJ. They sought to elucidate the underlying mechanisms through the use of murine gastritis models induced by HCl/ethanol and gastric ulcer induced by acetic acid. The test subjects were orally administered BST-104, chlorogenic acid, or rebamipide, the latter serving as a positive control. The results indicated that BST-104 and its primary compound, chlorogenic acid, exhibited gastroprotective properties through their antioxidant activities, which involved enhanced levels of catalase, SOD, and GSH, whereas MDA levels were reduced. In addition, BST-104 and chlorogenic acid suppressed the secretion of proinflammatory cytokines (PGE
2, TNF-α, IL-6, and IL-1β) by significantly downregulating the expression of NF-κB. Tang et al. [
37] observed that Lj exhibited inhibitory effects on multiple cytokines, such as TNF-α, IL-1β, IL-6, IFN-γ, IL-12, and IL-17, in a murine model of DSS-induced ulcerative colitis. Furthermore, in a mouse model of induced immunosuppression through cyclophosphamide exposure, polysaccharide extracts derived from Lj successfully restored IL-2, TNF-α, and IFN-γ levels in the serum. This suggests that Lj’s polysaccharide extracts hold promise as immunomodulatory agents. Previous studies primarily concentrated on determining the regulatory impact of Lj on the well-being of animal intestines through the use of in vivo models, namely mice and rats, along with in vitro models, including HMC-1 Cells and RAW 264. 7 cells, whereas limited research has been conducted on other species and cell lines.
The precise mechanism by which Lj manifests its gastroprotective effectiveness against TNF-α-activated inflammation in gastric mucosal epithelial cells has yet to be elucidated. Gastric inflammation, which is caused by proinflammatory cytokines, such as TNF-α secreted by activated immune cells, is dependent on the activation of NF-κB and MMP-9 through the NF-κB signaling [
44]. Potter et al. [
17] observed that a marked upregulation of COX-2 occurs in neoplastic sites or GC with inflammation. Moreover,
Helicobacter pylori infection stimulates TLRs/MyD88 and COX-2/PGE
2 pathways, leading to the activation of NF-κB and subsequent induction of an inflammatory response in tumor tissues [
18]. The mechanism of TNF-α-induced MMP-9 occurs via the MAPK pathway in different cell lineages in response to inflammatory mediators [
45,
46,
47,
48]. Furthermore, our study revealed that
H. zeylanica-E
2 inhibits the TNF-α-induced activation of the proinflammatory cPLA
2/COX-2/PGE
2 pathway in GC cells [
19]. This suggests that the COX-2/PGE
2 system may serve as an important pathological mediator in gastric inflammation-related disorders. In addition, we demonstrated that quercetin exhibits anti-inflammatory effects by suppressing the expression of TNF-α-stimulated MMP-9 in normal GES-1 cells [
22]. In the study, we assessed the potential protective effect of Lj against damage induced by TNF-α on COX-2 and MMP-9 expression in normal GES-1 cells. The cells were stimulated by TNF-α, which caused a reduction in COX-2 and MMP-9 expression in GES-1 cells following treatment with Lj. The results indicate that Lj exhibits the capacity to uphold the structural soundness of the gastric mucosa and may represent a treatment for inflammation. Previous studies implicated the MAPK family, specifically MAPK (extracellular p38, JNK1/2, and ERK1/2), in the underlying pathogenic mechanisms of gastric inflammation and gastric ulcer [
49]. Our results are consistent with these observations. In the present study, we explored the metastatic and inflammatory effects of Lj in normal GES-1 cells. Lj-EtOH ameliorated COX-2/PGE
2 and MMP-9 damage activated by TNF-α in normal GES-1 cells, highlighting its potential role in immune modulation of TNF-α-mediated inflammation. To determine the interplay among TNFR, NF-κB, ERK1/2, c-Fos, COX-2, and MMP-9 upon the response provoked by TNF-α, we evaluated distinct inhibitors, which included a TNF-TNFR, NF-κB, ERK1/2, c-Fos, COX-2, and MMP-9 inhibitors.
The data from IF stain analysis revealed that stimulation of TNF-α resulted in the phosphorylation and translocation of NF-κB (p65) and the activities of NF-κB/p65-Luc and AP-1-Luc were mediated through pathways involving TNFR-ERK1/2-c-Fos and NF-κB. In addition, Lj caused a reduction in the expression of COX-2/PGE
2 and MMP-9 induced by TNF-α in GES-1 cells and modulated the ERK1/2-c-Fos and NF-κB signaling. There is a plausible hypothesis suggesting that Lj effectively inhibits the activity of upstream molecules, such as TNFR, leading to the downstream inhibition of key signaling components, including NF-κB, ERK1/2, and c-Fos. The transcription factor NF-κB has a significant role in the modulation of inflammatory responses, given its involvement in the activation of proinflammatory cytokines. Following stimulation with these cytokines, NF-κB activity is activated, resulting from the phosphorylation and subsequent degradation of IκB. This results in the translocation of active NF-κB to the nucleus and stimulates the transcription of proinflammatory genes, cytokines, chemokines, adhesive proteins, and proteinases [
50].
In the present study, we observed that pretreatment with BAY 11-7082 (NF-κB inhibitor) and TSIIA (c-Fos inhibitor) resulted in a reduction of TNF-α-induced COX-2/PGE
2 and MMP-9 expression in GES-1 cells. COX-2/PGE
2 and MMP-9 have emerged as promising targets for various therapies, which are the subject of many current studies [
51,
52]. Understanding the role of inflammatory mediators will be valuable for designing therapeutic strategies to treat gastric inflammatory diseases. There is the potential for mitigating gastric damage through the suppression of COX-2/PGE
2 and MMP-9 production. Because of the widespread use of nonsteroidal anti-inflammatory drugs (NSAIDs), there is a need to discover substitute compounds to manage inflammation. Lj and its extracts may represent a promising alternative as dietary supplements for ameliorating the initial perturbations associated with gastric inflammation.
From the data of cell viability assay (
Figure 2B, C), there existed a minimal effect on the viability of GES-1 cells upon the treatment of Lj at concentrations ≤10 mM for 24 h. However, it is important to note that the safety and efficacy of Lj have not been definitively established as indicated by previous studies [
53]. The optimal dosage of Lj may differ based on an individual’s age, state of health, and additional factors. Although adverse effects resulting from Lj supplementation are infrequent, current data have not suggested an optimal dose range for Lj. The safety of natural products cannot always be assured and determining a safe and effective dose is necessary [
54,
55]. However, an intravenous formulation containing Lj along with two other herbs has been safely administered to children for up to 7 days. When taken orally, Lj flower extracts are potentially safe for a duration of up to 8 weeks. Skin contact with Lj may cause allergic individuals to develop a rash [
56]. Lj may exert anticoagulant properties and could interact with medications that also have anticoagulant effects, such as aspirin, plavix, cataflam, heparin, and coumadin, thus increasing the risk of bruising and bleeding. There is limited information regarding the use of Lj during pregnancy and breastfeeding, so it is advisable to avoid its use during these periods. Lj may have anti-inflammatory properties, although further studies are necessary to fully understand its mechanisms of action [
57].
Figure 1.
Induction of COX-2 and MMP-9 expression by TNF-α through the TNF-α receptor in normal GES-1 cells. Normal GES-1 cells were stimulated with TNF-α at a concentration of 30 ng/ml for 0, 16, or 24 h. The transcripts of (A) COX-2 and (B) MMP-9 were measured by qRT-PCR. In addition, (C) GES-1 cells were stimulated with TNF-α at a concentration of 30 ng/ml for 0, 2, 4, 6, 16, or 24 h and the expression of COX-2 was examined by western blot analysis, (D) whereas the enzymatic activity of MMP-9 was assessed by gelatin zymography. The TNF-α antagonist effectively suppressed TNF-α-induced expression of (E) COX-2 and (F) MMP-9 in GES-1 cells. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 vs. TNF-α-stimulated cells).
Figure 1.
Induction of COX-2 and MMP-9 expression by TNF-α through the TNF-α receptor in normal GES-1 cells. Normal GES-1 cells were stimulated with TNF-α at a concentration of 30 ng/ml for 0, 16, or 24 h. The transcripts of (A) COX-2 and (B) MMP-9 were measured by qRT-PCR. In addition, (C) GES-1 cells were stimulated with TNF-α at a concentration of 30 ng/ml for 0, 2, 4, 6, 16, or 24 h and the expression of COX-2 was examined by western blot analysis, (D) whereas the enzymatic activity of MMP-9 was assessed by gelatin zymography. The TNF-α antagonist effectively suppressed TNF-α-induced expression of (E) COX-2 and (F) MMP-9 in GES-1 cells. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 vs. TNF-α-stimulated cells).
Figure 2.
Lonicera japonica Thunb. ethanol extract exerts a suppressive effect on TNF-α-induced expression of PGE2, COX-2, and MMP-9 in normal GES-1 cells. (A) Lonicera japonica Thunb. extracts were prepared. (B) The effect of a water extract (Lj-H2O) and ethanol extract (Lj-EtOH) on the viability of normal GES-1 cells was evaluated. (C) GES-1 cells were treated with various concentrations of Lonicera japonica Thunb. extracts (0, 0.1, 0.5, 1, 5, or 10 μg/ml) for 24 h and cell viability was measured by CCK-8 assay. (D) The cells were divided into two groups: one for control and the other for treatment with Lj-H2O (1 μg/ml) or Lj-EtOH (1 μg/ml) for 1 h. TNF-α (30 ng/mL) was then added to both groups of cells. COX-2 was measured by western blot analysis. (E) Quantitation of PGE2 protein was done using an enzyme-linked immunosorbent assay (ELISA) at 0, 2, 4, 8, and 16 h of treatment. (F) Cells were treated with Lj-H2O (1 μg/ml), Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μg/ml), or NS-398 (5 μM; COX-2 inhibitor). The conditioned medium was collected and PGE2 levels were measured by ELISA after 4 h. (G) The MMP-9 activity of GES-1 cells was measured by gelatin zymography after 24 h. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 as compared to TNF-α-treated cells).
Figure 2.
Lonicera japonica Thunb. ethanol extract exerts a suppressive effect on TNF-α-induced expression of PGE2, COX-2, and MMP-9 in normal GES-1 cells. (A) Lonicera japonica Thunb. extracts were prepared. (B) The effect of a water extract (Lj-H2O) and ethanol extract (Lj-EtOH) on the viability of normal GES-1 cells was evaluated. (C) GES-1 cells were treated with various concentrations of Lonicera japonica Thunb. extracts (0, 0.1, 0.5, 1, 5, or 10 μg/ml) for 24 h and cell viability was measured by CCK-8 assay. (D) The cells were divided into two groups: one for control and the other for treatment with Lj-H2O (1 μg/ml) or Lj-EtOH (1 μg/ml) for 1 h. TNF-α (30 ng/mL) was then added to both groups of cells. COX-2 was measured by western blot analysis. (E) Quantitation of PGE2 protein was done using an enzyme-linked immunosorbent assay (ELISA) at 0, 2, 4, 8, and 16 h of treatment. (F) Cells were treated with Lj-H2O (1 μg/ml), Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μg/ml), or NS-398 (5 μM; COX-2 inhibitor). The conditioned medium was collected and PGE2 levels were measured by ELISA after 4 h. (G) The MMP-9 activity of GES-1 cells was measured by gelatin zymography after 24 h. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 as compared to TNF-α-treated cells).
Figure 3.
Lonicera japonica Thunb. ethanol extract exerts an inhibitory effect on TNF-α-induced COX-2 and MMP-9 expression in normal GES-1 cells by blocking the TNFR/ERK1/2/c-Fos pathway. (A,B) GES-1 cells were treated with TNF-α (30 ng/ml) for 24 h with a significant increase of COX-2 and MMP-9 expression. In drug pretreatment conditions, GES-1 cells were treated with Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μM), U0126 (1 μM), TSIIA (10 μM), BAY 11-7082 (10 μM), and NS-398 (5 μM) or MMP9i (5 μM) for a duration of 1 h before the introduction of TNF-α; Subsequently, the cells were incubated with TNF-α for a period of 24 h. The level of COX-2 protein expression was determined by western blot analysis (A), and the enzymatic activity of MMP-9 was determined by gelatin zymography (B). (C) GES-1 cells were treated with Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μM), or U0126 (1 μM) for 1 h before the addition of TNF-α (30 ng/ml) for 0, 15, or 30 min. The phosphorylation of ERK1/2 (p-ERK 1/2) was measured by western blot analysis. (D) GES-1 cells were treated with Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μM), U0126 (1 μM), BAY 11-7082 (10 μM), or TSIIA (10 μM) for 1 h before the addition of TNF-α (30 ng/ml) for 0 or 30 min. The phosphorylation of c-Fos (p-c-Fos) was measured by western blot analysis. (E) The GES-1 cell line was transfected with human AP-1–Luc response element reporter plasmids. The cells were then pretreated with Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μM), U0126 (1 μM), TSIIA (10 μM), or BAY 11-7082 (10 μM) for 1 h. Following pretreatment, the cells were exposed to TNF-α for 1 h. Luciferase activity was measured to determine the activity of AP-1 and normalized to that of Renilla luciferase activity. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 as compared to TNF-α-treated cells).
Figure 3.
Lonicera japonica Thunb. ethanol extract exerts an inhibitory effect on TNF-α-induced COX-2 and MMP-9 expression in normal GES-1 cells by blocking the TNFR/ERK1/2/c-Fos pathway. (A,B) GES-1 cells were treated with TNF-α (30 ng/ml) for 24 h with a significant increase of COX-2 and MMP-9 expression. In drug pretreatment conditions, GES-1 cells were treated with Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μM), U0126 (1 μM), TSIIA (10 μM), BAY 11-7082 (10 μM), and NS-398 (5 μM) or MMP9i (5 μM) for a duration of 1 h before the introduction of TNF-α; Subsequently, the cells were incubated with TNF-α for a period of 24 h. The level of COX-2 protein expression was determined by western blot analysis (A), and the enzymatic activity of MMP-9 was determined by gelatin zymography (B). (C) GES-1 cells were treated with Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μM), or U0126 (1 μM) for 1 h before the addition of TNF-α (30 ng/ml) for 0, 15, or 30 min. The phosphorylation of ERK1/2 (p-ERK 1/2) was measured by western blot analysis. (D) GES-1 cells were treated with Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μM), U0126 (1 μM), BAY 11-7082 (10 μM), or TSIIA (10 μM) for 1 h before the addition of TNF-α (30 ng/ml) for 0 or 30 min. The phosphorylation of c-Fos (p-c-Fos) was measured by western blot analysis. (E) The GES-1 cell line was transfected with human AP-1–Luc response element reporter plasmids. The cells were then pretreated with Lj-EtOH (1 μg/ml), TNF-α antagonist (1 μM), U0126 (1 μM), TSIIA (10 μM), or BAY 11-7082 (10 μM) for 1 h. Following pretreatment, the cells were exposed to TNF-α for 1 h. Luciferase activity was measured to determine the activity of AP-1 and normalized to that of Renilla luciferase activity. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 as compared to TNF-α-treated cells).
Figure 4.
Activation of NF-κB (p65) upon TNF-α stimulation is inhibited by Lonicera japonica Thunb. ethanol extract in normal GES-1 cells (A) The cells were pretreated with 1 μg/ml Lj-EtOH, 1 μM TNF-α antagonist, 1 μM U0126, 10 μM TSIIA, or 10 μM BAY 11-7082 for 1 h followed by 30 ng/ml TNF-α for either 0 or 30 min. The phosphorylation of NF-κB was determined by western blot analysis. (B) After treating with 30 ng/ml TNF-α for 0, 5, 10, 15, 30, and 60 min, NF-κB phosphorylation in GES-1 cells was determined by immunofluorescence analysis. (C) The cells were treated with 1 μg/ml Lj-EtOH, 1 μM TNF-α antagonist, 1 μM U0126, 10 μM TSIIA, or 10 μM BAY 11-7082 for 1 h. Afterward, 30 ng/ml TNF-α was added for 30 min. The phosphorylation of NF-κB was determined by immunofluorescence analysis. (D) GES-1 cells were first transfected with human NF-κB response element reporter plasmids and then treated with 1 μg/ml Lj-EtOH, 1 μM TNF-α antagonist, 1 μM U0126, 10 μM TSIIA, or 10 μM BAY 11-7082 for 1 h. Afterward, 30 ng/ml TNF-α was added for 1 h, and luciferase activity was measured, using Renilla luciferase activity as normalization. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 compared to TNF-α-stimulated cells).
Figure 4.
Activation of NF-κB (p65) upon TNF-α stimulation is inhibited by Lonicera japonica Thunb. ethanol extract in normal GES-1 cells (A) The cells were pretreated with 1 μg/ml Lj-EtOH, 1 μM TNF-α antagonist, 1 μM U0126, 10 μM TSIIA, or 10 μM BAY 11-7082 for 1 h followed by 30 ng/ml TNF-α for either 0 or 30 min. The phosphorylation of NF-κB was determined by western blot analysis. (B) After treating with 30 ng/ml TNF-α for 0, 5, 10, 15, 30, and 60 min, NF-κB phosphorylation in GES-1 cells was determined by immunofluorescence analysis. (C) The cells were treated with 1 μg/ml Lj-EtOH, 1 μM TNF-α antagonist, 1 μM U0126, 10 μM TSIIA, or 10 μM BAY 11-7082 for 1 h. Afterward, 30 ng/ml TNF-α was added for 30 min. The phosphorylation of NF-κB was determined by immunofluorescence analysis. (D) GES-1 cells were first transfected with human NF-κB response element reporter plasmids and then treated with 1 μg/ml Lj-EtOH, 1 μM TNF-α antagonist, 1 μM U0126, 10 μM TSIIA, or 10 μM BAY 11-7082 for 1 h. Afterward, 30 ng/ml TNF-α was added for 1 h, and luciferase activity was measured, using Renilla luciferase activity as normalization. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 compared to TNF-α-stimulated cells).
Figure 5.
Lonicera japonica Thunb. ethanol extract exerts antimetastatic activities in vitro. (A) After reaching confluence and serum starvation for 24 h, GES-1 cells were pretreated with 1 μg/ml Lj-EtOH, 1 μM TNF-α antagonist, 1 μM U0126, 10 μM TSIIA, 10 μM BAY 11-7082 for 1 h, 5 μM MMP9i, or NS-398 for 1 h. To evaluate cellular migration, the cell monolayer was scratched using a blue pipette tip, followed by incubation with 30 ng/ml TNF-α for 24 h. Phase contrast images of the cells were acquired at 24 h. (B)The number of migrating cells was counted. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 compared to TNF-α-stimulated cells).
Figure 5.
Lonicera japonica Thunb. ethanol extract exerts antimetastatic activities in vitro. (A) After reaching confluence and serum starvation for 24 h, GES-1 cells were pretreated with 1 μg/ml Lj-EtOH, 1 μM TNF-α antagonist, 1 μM U0126, 10 μM TSIIA, 10 μM BAY 11-7082 for 1 h, 5 μM MMP9i, or NS-398 for 1 h. To evaluate cellular migration, the cell monolayer was scratched using a blue pipette tip, followed by incubation with 30 ng/ml TNF-α for 24 h. Phase contrast images of the cells were acquired at 24 h. (B)The number of migrating cells was counted. The data are presented as the mean ± SEM of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001 vs. control cells at 0 h; #P < 0.05, ##P < 0.01, ###P < 0.001 compared to TNF-α-stimulated cells).
Figure 6.
Diagram illustrating the effect of Lonicera japonica Thunb. ethanol extract on TNF-α-induced COX-2-derived PGE2 production and MMP-9 as well as the migration of normal GES-1 cells. Schematic diagram of the signaling pathways associated with the activity of Lj-EtOH extracts, which attenuated TNF-α-induced inflammation by downregulating COX-2, PGE2, and MMP-9 expression in normal GES-1 cells. Lonicera japonica Thunb. ethanol extract attenuates TNF-α-induced COX-2 and MMP-9 expressions in normal GES-1 cells through TNFR/ERK1/2/c-Fos and NF-κB pathways.
Figure 6.
Diagram illustrating the effect of Lonicera japonica Thunb. ethanol extract on TNF-α-induced COX-2-derived PGE2 production and MMP-9 as well as the migration of normal GES-1 cells. Schematic diagram of the signaling pathways associated with the activity of Lj-EtOH extracts, which attenuated TNF-α-induced inflammation by downregulating COX-2, PGE2, and MMP-9 expression in normal GES-1 cells. Lonicera japonica Thunb. ethanol extract attenuates TNF-α-induced COX-2 and MMP-9 expressions in normal GES-1 cells through TNFR/ERK1/2/c-Fos and NF-κB pathways.