ABSTRACT
This study investigated the effects of Lycium chinense Mill (LCM) extract on obesity and diabetes, using both in vitro and high-fat diet (HFD)-induced obesity mouse models. We found that LCM notably enhanced glucagon-like peptide-1 (GLP-1) secretion in NCI-h716 cells from 411.4 ± 10.75 pg/mL to 411.4 ± 10.75 pg/mL compared to NT (78.0 ± 0.67 pg/mL) without causing cytotoxicity, implying the involvement of Protein Kinase A C (PKA C) and AMP-activated protein kinase (AMPK) in its action mechanism. LCM also decreased lipid droplets and lowered the expression of adipogenic and lipogenic indicators, such as Fatty Acid Synthase (FAS), Fatty Acid-Binding Protein 4 (FABP4), and Sterol Regulatory Element-Binding Protein 1c (SREBP1c), indicating the suppression of adipocyte differentiation and lipid accumulation. LCM administration to HFD mice resulted in significant weight loss (41.5 ± 3.3 g) compared to the HFD group (45.1 ± 1.8 g). In addition, improved glucose tolerance and serum lipid profiles demonstrated the ability to counteract obesity-related metabolic issues. Additionally, LCM exhibited hepatoprotective properties by reducing hepatic lipid accumulation and diminishing white adipose tissue mass and adipocyte size, thereby demonstrating its effectiveness against hepatic steatosis and adipocyte hypertrophy. These findings show that LCM can be efficiently used as a natural material to treat obesity and diabetes, providing a new approach for remedial and therapeutic purposes.
Subject(s)
Anti-Obesity Agents , Diet, High-Fat , Hypoglycemic Agents , Lycium , Obesity , Plant Extracts , Animals , Mice , Lycium/chemistry , Obesity/drug therapy , Obesity/metabolism , Plant Extracts/pharmacology , Plant Extracts/chemistry , Diet, High-Fat/adverse effects , Anti-Obesity Agents/pharmacology , Anti-Obesity Agents/therapeutic use , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/therapeutic use , Male , Humans , Adipocytes/drug effects , Adipocytes/metabolism , Lipid Metabolism/drug effects , Glucagon-Like Peptide 1/metabolism , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolism , Mice, Inbred C57BL , Sterol Regulatory Element Binding Protein 1/metabolismABSTRACT
Obesity is a serious global health challenge, closely associated with numerous chronic conditions including type 2 diabetes. Anemarrhena asphodeloides Bunge (AA) known as Jimo has been used to address conditions associated with pathogenic heat such as wasting-thirst in Korean Medicine. Timosaponin A3 (TA3), a natural compound extracted from AA, has demonstrated potential therapeutic effects in various disease models. However, its effects on diabetes and obesity remain largely unexplored. We investigated the anti-obesity and anti-diabetic properties of TA3 using in vitro and in vivo models. TA3 treatment in NCI-H716 cells stimulated the secretion of glucagon-like peptide 1 (GLP-1) through the activation of phosphorylation of protein kinase A catalytic subunit (PKAc) and 5'-AMP-activated protein kinase (AMPK). In 3T3-L1 adipocytes, TA3 effectively inhibited lipid accumulation by regulating adipogenesis and lipogenesis. In a high-fat diet (HFD)-induced mice model, TA3 administration significantly reduced body weight gain and food intake. Furthermore, TA3 improved glucose tolerance, lipid profiles, and mitigated hepatic steatosis in HFD-fed mice. Histological analysis revealed that TA3 reduced the size of white adipocytes and inhibited adipose tissue generation. Notably, TA3 downregulated the expression of lipogenic factor, including fatty-acid synthase (FAS) and sterol regulatory element-binding protein 1c (SREBP1c), emphasizing its potential as an anti-obesity agent. These findings revealed that TA3 may be efficiently used as a natural compound for tackling obesity, diabetes, and associated metabolic disorders, providing a novel approach for therapeutic intervention.
Subject(s)
Anti-Obesity Agents , Diabetes Mellitus, Type 2 , Saponins , Animals , Mice , Obesity/metabolism , Steroids/pharmacology , Anti-Obesity Agents/pharmacology , Adipogenesis , AMP-Activated Protein Kinases/metabolism , Lipids/pharmacology , 3T3-L1 Cells , Diet, High-Fat , Mice, Inbred C57BLABSTRACT
Bitter taste receptors (TAS2Rs) are G protein-coupled receptors localized in the taste buds of the tongue. They may also be present in non-lingual organs, including the brain, lung, kidney, and gastrointestinal (GI) tract. Recent studies on bitter taste receptor functions have suggested TAS2Rs as potential therapeutic targets. The human bitter taste receptor subtype hTAS2R50 responds to its agonist isosinensetin (ISS). Here, we demonstrated that, unlike other TAS2R agonists, isosinensetin activated hTAS2R50 as well as increased Glucagon-like peptide 1 (GLP-1) secretion through the Gßγ-mediated pathway in NCI-H716 cells. To confirm this mechanism, we showed that ISS increased intracellular Ca2+ and was suppressed by the IP3R inhibitor 2-APB as well as the PLC inhibitor U73122, suggesting that TAS2Rs alters the physiological state of enteroendocrine L cells in a PLC-dependent manner. Furthermore, we demonstrated that ISS upregulated proglucagon mRNA and stimulated GLP-1 secretion. ISS-mediated GLP-1 secretion was suppressed in response to small interfering RNA-mediated silencing of Gα-gust and hTAS2R50 as well as 2-APB and U73122. Our findings improved the understanding of how ISS modulates GLP-1 secretion and indicates the possibility of using ISS as a therapeutic agent in the treatment of diabetes mellitus.
Subject(s)
Glucagon-Like Peptide 1 , Receptors, G-Protein-Coupled , Signal Transduction , Humans , Enteroendocrine Cells/metabolism , Gastrointestinal Tract/metabolism , Glucagon-Like Peptide 1/drug effects , Glucagon-Like Peptide 1/metabolism , Receptors, G-Protein-Coupled/metabolismABSTRACT
Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide, and despite advances in treatment, survival rates are still low; therefore, the development of novel drugs is imperative. Acetylcorynoline (ACN) is derived from Corydalis ambigua Cham. et Schltdl tubers. The effect of ACN on colon cancer is still unknown. Therefore, we investigated its potential effects. Our data showed that ACN inhibited cell viability and proliferation. Moreover, ACN induced apoptosis and cell cycle arrest by inhibiting cell growth. In the present study, we hypothesized that ACN regulates c-Myc through CNOT2 or MID1IP1. ACN reduced the protein expression of oncogenic genes, decreased c-Myc half-life, and rapidly inhibited the serum stimulation response. Moreover, knockdown of CNOT2 and MID1IP1 with ACN increased apoptosis and further reduced the expression of oncogenes. In addition, ACN exhibited a synergistic effect with low-dose 5-fluorouracil (5-FU) and doxorubicin (Dox). Collectively, our data demonstrate that ACN inhibited c-Myc expression through CNOT2 and MID1IP1, and induced apoptosis. These findings indicate the potential of ACN as a therapeutic agent against colon cancer.
Subject(s)
Colonic Neoplasms , Signal Transduction , Humans , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Colonic Neoplasms/drug therapy , Colonic Neoplasms/metabolism , Cell Cycle Checkpoints , Apoptosis , Fluorouracil/pharmacology , Mitosis , Cell Proliferation , Cell Line, Tumor , Repressor Proteins/geneticsABSTRACT
In this study, we investigated the potential anticancer effects of Viscum album, a parasitic plant that grows on Malus domestica (VaM) on breast cancer cells, and explored the underlying mechanisms. VaM significantly inhibited cell viability and proliferation and induced apoptosis in a dose-dependent manner. VaM also regulated cell cycle progression and effectively inhibited activation of the STAT3 signaling pathway through SHP-1. Combining VaM with low-dose doxorubicin produced a synergistic effect, highlighting its potential as a promising therapeutic. In vivo, VaM administration inhibited tumor growth and modulated key molecular markers associated with breast cancer progression. Overall, our findings provide strong evidence for the therapeutic potential of VaM in breast cancer treatment and support further studies exploring clinical applications.
Subject(s)
Breast Neoplasms , Viscum album , Humans , Female , Viscum album/metabolism , Breast Neoplasms/metabolism , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Apoptosis , Signal Transduction , Cell Proliferation , Cell Line, Tumor , STAT3 Transcription Factor/metabolismABSTRACT
We hypothesized that Euonymus sachalinensis (ES) induces apoptosis by inhibiting the expression of c-Myc in colon cancer cells, and this study proved that the methanol extract of ES has anticancer effects in colon cancer cells. ES belongs to the Celastraceae family and is well known for its medicinal properties. Extracts of species belonging to this family have been used to treat diverse diseases, including rheumatoid arthritis, chronic nephritis, allergic conjunctivitis, rhinitis, and asthma. However, ES has been targeted because there are currently few studies on the efficacy of ES for various diseases, including cancer. ES lowers cell viability in colon cancer cells and reduces the expression of c-Myc protein. We confirm that the protein level of apoptotic factors such as PARP and Caspase 3 decrease when ES is treated with Western blot, and confirm that DNA fragments occur through TUNEL assay. In addition, it is confirmed that the protein level of oncogenes CNOT2 and MID1IP1 decrease when ES is treated. We have also found that ES enhances the chemo-sensitivity of 5-FU in 5-FU-resistant cells. Therefore, we confirm that ES has anticancer effects by inducing apoptotic cell death and regulating the oncogenes CNOT2 and MID1IP1, suggesting its potential for use in the treatment of colon cancer.
Subject(s)
Colonic Neoplasms , Euonymus , Humans , Colonic Neoplasms/metabolism , Apoptosis , Cell Line, Tumor , Fluorouracil/pharmacology , Cell Proliferation , Repressor ProteinsABSTRACT
Colorectal cancer cell (CRC) is the fourth most common cancer in the world. There are several chemotherapy drugs available for its treatment, though they have side effects. Cycloastragenol (CY) is a compound from Astragalus membranaceus (Fisch.) Bge known to be effective in aging, anti-inflammatory, anticancer, and anti-heart failure treatments. Although many studies have demonstrated the functions of CY in cancer cells, no studies have shown the effects of p53 in colon cancer cells. In this study, we found that CY reduces the viability of colon cancer cells in p53 wild-type cells compared to p53 null cells and HT29. Furthermore, CY induces apoptosis by p53 activation in a dose- and time-dependent manner. And it was confirmed that it affects the L5 gene related to p53. Additionally, CY enhanced p53 expression compared to when either doxorubicin or 5-FU was used alone. Altogether, our findings suggest that CY induces apoptosis via p53 activation and inhibits the proliferation of colon cancer cells. In addition, apoptosis occurs in colon cancer cells due to other factors. Moreover, CY is expected to have a combined effect when used together with existing treatments for colon cancer in the future.
Subject(s)
Colonic Neoplasms , Tumor Suppressor Protein p53 , Humans , Apoptosis , Colonic Neoplasms/drug therapy , Colonic Neoplasms/genetics , HCT116 Cells , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Antineoplastic Agents/pharmacologyABSTRACT
Timosaponin A3 (TA3), extracted from the rhizome of Anemarrhenaasphodeloides Bunge, has been reported to affect various diseases, such as cancer, Alzheimer's disease, and allergies. However, the underlying molecular mechanisms and impacts are largely unknown. In the present study, we hypothesized that TA3 induces apoptosis through the inhibition of c-Myc expression via CNOT2 or MID1IP1 in HCT116. An MTT assay and colony formation assay were used to measure cell viability and proliferation. The protein expression of apoptotic markers and oncogenes was measured using immunoblotting and immunofluorescence assays. The interaction between MID1IP1 and c-Myc was confirmed by performing an immunoprecipitation assay. TA3 markedly inhibited colon cancer cell proliferation. Consistently, TA3 regulated the apoptotic proteins pro-PARP and caspase 3. TA3 inhibited the half-life of c-Myc and suppressed its expression in response to serum stimulation. In addition, TA3 enhanced the apoptotic effects of doxorubicin and 5-FU in colon cancer cells. Altogether, our results reveal a mechanism by which TA3 induces apoptosis through inhibiting c-Myc expression via CNOT2 or MID1IP1 in HCT116, which may help in the development of new therapies for colon cancer based on TA3 in the future.
Subject(s)
Colonic Neoplasms , Colorectal Neoplasms , Apoptosis , Caspase 3/metabolism , Cell Line, Tumor , Cell Proliferation , Colonic Neoplasms/pathology , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Fluorouracil/pharmacology , Fluorouracil/therapeutic use , HCT116 Cells , Humans , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Repressor Proteins , Saponins , SteroidsABSTRACT
Obesity is a risk factor for metabolic diseases including type 2 diabetes, nonalcoholic steatohepatitis (NASH), heart diseases, and cancer. This study aimed to investigate the anti-obesity effect of Polygalin C (PC) isolated from Polygala japonica Houtt. in 3T3-L1 adipocytes. Based on Oil Red O assay results, PC significantly decreased lipid accumulation compared to the control. We found that PC suppressed adipogenesis transcription factors including peroxisome proliferator-activated receptor γ (PPAR γ) and CCAAT/enhancer-binding protein (C/EBP) α, and lipogenic factors such as sterol regulatory element-binding protein 1c (SREBP 1c) and fatty acid synthase (FAS), in 3T3-L1 adipocytes using Western blotting and real-time polymerase chain reaction (PCR). Moreover, PC inhibited the differentiation of 3T3-L1 cells by regulating the AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) and mitogen-activated protein kinase/protein kinase B (MAPK/Akt) signaling pathways. Additionally, we confirmed that PC inhibited early adipogenesis factors C/EBP ß and C/EBP δ. Therefore, PC inhibited adipogenesis and lipogenesis in vitro. Thus, PC appears to exert potential therapeutic effects on obesity by suppressing lipid metabolism.
Subject(s)
Adipogenesis/drug effects , Flavonols/pharmacology , Lipogenesis/drug effects , MAP Kinase Signaling System/drug effects , Obesity , Polygala/chemistry , 3T3-L1 Cells , Animals , Fatty Acid Synthase, Type I/biosynthesis , Flavonols/chemistry , Flavonols/isolation & purification , Mice , Obesity/drug therapy , Obesity/metabolism , Obesity/pathology , PPAR gamma/metabolism , Sterol Regulatory Element Binding Protein 1/metabolismABSTRACT
Atopic dermatitis (AD) can occur in both children and adults, and the symptoms include itching and eczema, which in turn cause patients to suffer. Ophiopogonin D (OP-D) is a steroidal glycoside from Radix Ophiopogon japonicus, which is well known as an effective anti-inflammatory herbal medicine in many Asian countries. In this study, we aimed to investigate the anti-inflammatory effects of OP-D, using an AD mouse model and inflamed HaCaT cells. Through a histopathological analysis, we were able to confirm the suppressive effects of OP-D on skin thickening and the mast cell activation in AD-like mouse back skin tissues stimulated by DNCB. In addition, we detected significant decreases in cytokine expression levels through multiplex assessment assays of the OP-D-treated mice blood. We observed the anti-inflammatory effect of OP-D in the spleen, causing weight loss in the spleen and in the mRNA expression levels related to diverse cytokines. In human keratinocytes inflamed by TNF-α, OP-D inhibited p38 and ERK protein activation and showed a reduction of NF-κB nuclear translocation. Furthermore, OP-D attenuated pro-inflammatory cytokine mRNA expressions in TNF-α-inflamed HaCaT cells. Accordingly, we came to the conclusion that OP-D is a potential natural drug which can be used in order to treat inflammatory skin diseases, such as AD.
Subject(s)
Dermatitis, Atopic/drug therapy , Keratinocytes/drug effects , Saponins/pharmacology , Spirostans/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Active Transport, Cell Nucleus , Animals , Cell Line , Cytokines/metabolism , Dermatitis, Atopic/chemically induced , Dinitrochlorobenzene/pharmacology , Female , Humans , Inflammation , Mice , Mice, Inbred BALB C , Skin/drug effects , Spleen/drug effectsABSTRACT
As a plant medicine, Oxalidaceae has been used to treat various diseases in Korea. However, there is little data on the anti-cancer efficacy of Oxalidaceae, particularly O. obtriangulata. This study aimed to investigate the anti-cancer effect of O. obtriangulata methanol extract (OOE) and its regulatory actions on pancreatic carcinoma. OOE showed anti-proliferative effects and induced cell death in the colony formation and cell viability assays, respectively. The Fluorescence-activated cell sorting (FACS) data confirmed that OOE significantly induced cell cycle accumulation at the G2/M phase and apoptotic effects. Additionally, OOE inhibited the activated ERK (extracellular-signal-regulated kinase)/Src (Proto-oncogene tyrosine-protein kinase Src)/STAT3 (signal transducers and activators of transcription 3) pathways including nuclear translocation of STAT3. Furthermore, suppression of Ki67, PARP(Poly ADP-ribose polymerase), caspase-3, P27(Cyclin-dependent kinase inhibitor 1B), and c-Myc as well as the STAT3 target genes CDK(cyclin-dependent kinase)1, CDK2, Cyclin B1, VEGF-1(vascular endothelial growth factor-1), MMP-9(Matrix metallopeptidase 9), and Survivin by OOE was observed in BxPC3. We speculate that these molecular actions might support an anti-cancer effect of OOE. In this study, we demonstrated that OOE may be a promising anti-cancer material and may serve as a natural therapy and alternative remedy for pancreatic cancer treatment.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Cell Cycle/drug effects , Gene Expression Regulation, Neoplastic , Magnoliopsida/chemistry , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/isolation & purification , Cell Cycle/genetics , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin B1/genetics , Cyclin B1/metabolism , Humans , Matrix Metalloproteinase 9/genetics , Matrix Metalloproteinase 9/metabolism , Mitogen-Activated Protein Kinase 1/genetics , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/genetics , Mitogen-Activated Protein Kinase 3/metabolism , Pancreas/metabolism , Pancreas/pathology , Plant Extracts/chemistry , Plants, Medicinal , Proto-Oncogene Mas , Proto-Oncogene Proteins pp60(c-src)/genetics , Proto-Oncogene Proteins pp60(c-src)/metabolism , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism , Signal Transduction , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolismABSTRACT
A correlation between gastrointestinal (GI) inflammation and gut hormones has reported that inflammatory stimuli including bacterial endotoxins, lipopolysaccharides (LPS), TNFα, IL-1ß, and IL-6 induces high levels of incretin hormone leading to glucose dysregulation. Although incretin hormones are immediately secreted in response to environmental stimuli, such as nutrients, cytokines, and LPS, but studies of glucose-induced incretin secretion in an inflamed state are limited. We hypothesized that GI inflammatory conditions induce over-stimulated incretin secretion via an increase of glucose-sensing receptors. To confirm our hypothesis, we observed the alteration of glucose-induced incretin secretion and glucose-sensing receptors in a GI inflammatory mouse model, and we treated a conditioned media (MÏ 30%) containing inflammatory cytokines in intestinal epithelium cells and enteroendocrine L-like NCI-H716 cells. In GI-inflamed mice, we observed that over-stimulated incretin secretion and insulin release in response to glucose and sodium glucose cotransporter (Sglt1) was increased. Incubation with MÏ 30% increases Sglt1 and induces glucose-induced GLP-1 secretion with increasing intracellular calcium influx. Phloridzin, an sglt1 inhibitor, inhibits glucose-induced GLP-1 secretion, ERK activation, and calcium influx. These findings suggest that the abnormalities of incretin secretion leading to metabolic disturbances in GI inflammatory disease by an increase of Sglt1.
Subject(s)
Gastroenteritis/immunology , Glucose/immunology , Insulin/immunology , Sodium-Glucose Transporter 1/immunology , Animals , Cell Line , Cells, Cultured , Female , Gastric Inhibitory Polypeptide/immunology , Gastroenteritis/pathology , Glucagon-Like Peptide 1/immunology , Incretins/immunology , Inflammation/immunology , Inflammation/pathology , Intestinal Mucosa/immunology , Intestinal Mucosa/pathology , Mice, Inbred C57BLABSTRACT
OBJECTIVE: Allergic asthma is the most common type in asthma, which is defined as a chronic inflammatory disease of the lung. In this study, we investigated whether embelin (Emb), the major component of Ardisia japonica BL. (AJB), exhibits anti-inflammatory effects on allergic asthma via inhibition of NF-κB activity using A549 cells and asthmatic airway epithelial tissues. METHODS: Inflammation was induced in A549 cells, a human airway epithelial cell line, by IL-1ß (10 ng/ml) treatment for 4 h. The effects of Emb on NF-κB activity and COX-2 protein expression in inflamed airway epithelial cells and human asthmatic airway epithelial tissues were analyzed via western blot. The secretion levels of NF-κB-mediated cytokines/chemokines, including IL-4, 6, 9, 13, TNF-α and eotaxin, were measured by a multiplex assay. RESULTS: Emb significantly blocked NF-κB activity in IL-1ß-treated A549 cells and human asthmatic airway epithelial tissues. COX-2 expression was also reduced in both IL-1ß-treated A549 cells and asthmatic tissues Emb application. Emb significantly reduced the secretion of IL-4, IL-6 and eotaxin in human asthmatic airway epithelial tissues by inhibiting activity of NF-κB. CONCLUSIONS: The results of this study suggest that Emb may be used as an anti-inflammatory agent via inhibition of NF-κB and related cytokines.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Asthma/immunology , Benzoquinones/pharmacology , Cytokines/immunology , Respiratory Mucosa/immunology , A549 Cells , Asthma/drug therapy , Asthma/pathology , Cyclooxygenase 2/immunology , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Enzymologic/immunology , Humans , NF-kappa B/immunology , Respiratory Mucosa/pathologyABSTRACT
BACKGROUND: Liver steatosis was caused by lipid accumulation in the liver. Alisma orientale (AO) is recognized as a promising candidate with therapeutic efficacy for the treatment of nonalcoholic fatty liver disease (NAFLD). HepG2 hepatocyte cell line is commonly used for liver disease cell model. METHOD: The HepG2 cells were cultured with the NEFAs mixture (oleic and palmitic acids, 2:1 ratio) for 24 h to induce hepatic steatosis. Then different doses of Alisma orientale extract (AOE) was treated to HepG2 for 24 h. Incubated cells were used for further experiments. RESULTS: The AOE showed inhibitory effects on lipid accumulation in the Oil Red O staining and Nile red staining tests with no cytotoxicity at a concentration of 300 µg/mL. Fatty acid synthase (FASN) and acetyl-CoA carboxylase 1 (ACC1) mRNA and protein expression level were down-regulated after AOE treatment. Bcl-2 associated X protein (Bax) and c-Jun N-terminal kinase (JNK) mRNA expression level were decreased as well as p-JNK (activated form of JNK), Bax, cleaved caspase-9, caspase-3 protein expression level. Anti-apopototic B-cell lymphoma 2 (Bcl-2) protein level increased after AOE treatment. In addition, inflammatory protein expression including p-p65, p65, COX-2 and iNOS were inhibited by AOE treatment. CONCLUSION: The results suggest that AOE has anti-steatosis effects that involve lipogenesis, anti-lipoapoptosis, and anti-inflammation in the NEFA-induced NAFLD pathological cell model.
Subject(s)
Alisma/chemistry , Apoptosis/drug effects , Lipogenesis/drug effects , Non-alcoholic Fatty Liver Disease/metabolism , Plant Extracts/pharmacology , Cell Survival/drug effects , Fatty Acid Synthases/genetics , Fatty Acid Synthases/metabolism , Gene Expression/drug effects , Hep G2 Cells , Humans , Lipogenesis/genetics , Plant Extracts/chemistryABSTRACT
Glucagon-like peptide-1 (GLP-1) hormone is known to regulate blood glucose by an insulinotropic effect and increases proliferation as and also prevents apoptosis of pancreatic ß cells. We know that GLP-1 is secreted by nutrients such as fatty acids and sweet compounds but also bitter compounds via stimulation of G-protein coupled receptors (GPCRs) in the gut. Among these, bitter compounds are multiply-contained in phytochemicals or artificial materials and perceived as ligands of various bitter taste receptors. We hypothesized that GLP-1 hormone is secreted through stimulation of a single bitter taste receptor by 1,10-phenanthroline which is known agonist of taste receptor type 2 member 5 (T2R5). To prove this hypothesis, we used the representatively well-known 1,10-phenanthroline as ligand of single receptor and evaluated the existence of T2R5 by double-labeling immunofluorescence and then 1,10-phenanthroline is able to secrete GLP-1 hormone through stimulation of T2R5 in human enteroendocrine cells. Consequently, we verify that GLP-1 hormone is colocalized with T2R5 in the human duodenum and ileum tissue and is secreted by 1,10-phenanthroline via T2R5 signal transduction in differentiated human enteroendocrine L cells.
Subject(s)
Enteroendocrine Cells/drug effects , Glucagon-Like Peptide 1/metabolism , Phenanthrolines/pharmacology , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/metabolism , Cell Line , Duodenum/drug effects , Duodenum/metabolism , Enteroendocrine Cells/metabolism , Glucagon-Like Peptide 1/analysis , Humans , Ileum/drug effects , Ileum/metabolism , Receptors, G-Protein-Coupled/analysisABSTRACT
Facilitation of the wound healing process is important because a prolonged wound site increases pain and the risk of infection. In oriental medicine, an extract of Morus alba root (MA) has usually been prescribed as traditional treatment for accelerating wound healing, and it has been proven to be safe for centuries. To study the molecular mechanism of MA-mediated skin wound healing, we performed a primary cell culture and a skin explant culture and observed significant difference between the groups with and without MA extract. In the cellular system, a real-time cell analysis and real-time quantitative PCR were performed. It was found that MA extract enhanced proliferation in a dose-dependent manner on Kera-308 cell line, and up-regulated keratin expression including wound-induced Krt6a. In skin explant culture, the mRNA level derived from cell outgrowth displayed a tendency toward more up-regulated mRNA associated keratin filaments and toward a more up-regulated mRNA level of C-X-C motif chemokine 12 (CXCL12) and a chemokine receptor 4 (CXCR4) axis signaling pathway downstream. In this process, we concluded that MA extract had a scientific possibility of wound repair by increasing intracellular and extracellular supports and by inducing a CXCL12/CXCR4 signaling pathway.
Subject(s)
Chemokine CXCL12/metabolism , Keratins/metabolism , Morus/chemistry , Plant Extracts/pharmacology , Receptors, CXCR4/metabolism , Wound Healing/drug effects , Animals , Cell Line , Cell Proliferation/drug effects , In Vitro Techniques , Keratinocytes/drug effects , Keratinocytes/metabolism , Mice, Inbred ICR , Plant Roots/chemistry , Primary Cell Culture , RNA, Messenger/metabolism , Signal Transduction , Skin/cytology , Skin/drug effects , Transcriptome , Up-RegulationABSTRACT
Cinobufagin (CBG) is a cardiotoxic bufanolide steroid secreted by the skin and parotid venom glands of the Asiatic toad Bufo bufo gargarizans (called Chan-Su). Although CBG is known to exhibit anti-cancer activities, very little is known about its potential mechanism(s) of action. In this study, we investigated whether CBG mediates its effect through the modulation of the mitogen-activated protein kinases (MAPKs) signaling pathway in human multiple myeloma (MM) U266 cells. We found that CBG caused the significant activation of ERK, JNK and p38 MAPK in U266 cells. CBG showed much higher cytotoxicity against U266 cells as compared to peripheral blood mononuclear cells (PBMC). Induction of CBG increased reactive oxygen species (ROS) generation from mitochondria, which is associated with the induction of apoptosis as characterized by increased sub-G1 DNA contents of cell cycle, positive Annexin V binding, activation of caspase-3 and cleavage of PARP. Inhibition of ROS generation by N-acetyl-l-cysteine (NAC) significantly prevented CBG-induced ERK, JNK and p38 MAPK activation and apoptosis. CBG also down-regulated the expression of various downstream gene products that mediate cell proliferation, survival, angiogenesis and metastasis. Interestingly, ERK, JNK and p38MAPK pharmacological inhibitors blocked CBG-induced MAPKs activation and ERK inhibitor (PD98059) also prevented the CBG-induced caspase-3 activation and PARP cleavage in U266 cells. Taken together, these findings suggest that CBG can act as a potent anticancer agent against MM and possibly exerts its effects through the ROS-mediated activation of ERK, JNK and p38 MAPK leading to the activation of caspase-3 in U266 cells.
Subject(s)
Apoptosis/drug effects , Bufanolides/pharmacology , Cell Proliferation/drug effects , MAP Kinase Signaling System/drug effects , Mitochondria/immunology , Reactive Oxygen Species/immunology , Apoptosis/immunology , Cell Line , Humans , MAP Kinase Signaling System/immunology , Mitochondria/pathologyABSTRACT
AIMS/HYPOTHESIS: This study was designed to ascertain whether human enteroendocrine cells express bitter taste receptors, and whether activation of these receptors with bitter-tasting ligands induces secretion of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). METHODS: We used human enteroendocrine NCI-H716 cells, isolated duodenal segments from mice, and whole mice as our experimental systems for investigating stimuli and mechanisms underlying GLP-1- and PYY-stimulated release. We measured hormone levels by ELISA and determined bitter taste receptor expression by real-time quantitative PCR. We adopted a pharmacological approach using inhibitors and enhancers of downstream signalling pathways known to be involved in bitter taste transduction in taste bud cells to investigate these pathways in NCI-H716 cells. RESULTS: Using a pharmacological approach, we identified signalling pathways triggered by the denatonium benzoate (DB)-activated bitter receptors. This involved activation of α-gustducin (Gαgust)-the specific G-protein subunit that is also present in taste bud cells-reduction of intracellular cAMP levels and enhancement of phospholipase C (PLC) activity, which ultimately led to increased intracellular calcium concentrations and hormone release. Gavage of DB, followed by gavage of glucose, to db/db mice stimulated GLP-1 and subsequent insulin secretion, leading to lower blood glucose levels. CONCLUSIONS/INTERPRETATION: Our study demonstrates that activation of gut-expressed bitter taste receptors stimulates GLP-1 secretion in a PLC-dependent manner. In diabetic mice, DB (a ligand of bitter taste receptor cells), when given via gavage, lowers blood glucose levels in diabetic mice after oral glucose administration, through increased secretion of GLP-1.
Subject(s)
Glucagon-Like Peptide 1/metabolism , Quaternary Ammonium Compounds/pharmacology , Receptors, G-Protein-Coupled/metabolism , Animals , Cell Line , Cyclic AMP/metabolism , Humans , Mice , Peptide YY/metabolism , Real-Time Polymerase Chain Reaction , Signal Transduction/drug effects , Signal Transduction/genetics , Type C Phospholipases/metabolismABSTRACT
We have recently reported that ß-caryophyllene oxide (CPO) can induce apoptosis, suppress tumor growth, and inhibit metastasis through the suppression of signal transducer and activator of transcription 3, PI3K/AKT/mTOR/S6K1 signaling cascades and ROS-mediated MAPKs activation. In the present study, we found that CPO potentiated the apoptosis induced by tumor necrosis factor α (TNFα) and chemotherapeutic agents, suppressed TNFα-induced tumor cell invasion, all of which are known to require NF-κB activation. We found that TNFα stimulated the expression of gene products involved in anti-apoptosis (IAP1, IAP2, Bcl-2, Bcl-xL, and survivin), proliferation (COX-2, cyclin D1, and c-Myc), invasion (MMP 9 and ICAM-1), and angiogenesis (VEGF) and that CPO treatment suppressed their expression. Because these gene products are also regulated by proinflammatory transcription factor NF-κB, we postulated that CPO may mediate its effects by modulating the NF-κB pathway. We found that CPO blocked both inducible and constitutive NF-κB activation in a wide variety of tumor cells. CPO was also found to inhibit the TNFα-induced degradation of IκBα through the inhibition of activation of IκBα kinase and p65 nuclear translocation and phosphorylation. Interestingly, CPO failed to potentiate the apoptotic effect induced by TNFα in p65 (-/-) cells as compared to the wild-type. Thus, overall, our results indicate that the inhibition of NF-κB is one of major mechanisms by which CPO enhances TNFα-induced apoptosis and suppresses invasion.
Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , NF-kappa B/metabolism , Sesquiterpenes/pharmacology , Tumor Necrosis Factor-alpha/metabolism , Apoptosis/genetics , Cell Line, Tumor , Cell Proliferation/genetics , Humans , NF-kappa B/genetics , Neoplasm Invasiveness/genetics , Neovascularization, Pathologic/genetics , Polycyclic Sesquiterpenes , Signal Transduction , Tumor Necrosis Factor-alpha/pharmacologyABSTRACT
BACKGROUND: ß-sitosterol is a cholesterol-like phytosterol, which widely distributed in the plant kingdom. Here, anti-fibrotic effect of the ß-sitosterol was studied using the activated human hepatic stellate cell (HSC) model and dimethylnitrosamine (DMN)-induced mouse hepatic fibrosis model. METHOD: HSCs were activated by transforming growth factor-ß (TGF-ß) and the collagen-1 and α-smooth muscle actin (α-SMA) expressions were measured at the mRNA and protein level. We also studied the effect ß-sitosterol using DMN-induced mouse hepatic fibrosis model. We then measured the collagen-1 and α-SMA expression levels in vivo to investigate anti-hepatofibrotic effect of ß-sitosterol, at both of the mRNA and protein level. RESULTS: ß-sitosterol down regulated the mRNA and protein expression levels of collagen-1 and α-SMA in activated HSC. Oral administration of the ß-sitosterol successfully alleviated the DMN-induced mouse liver damage and prevented collagen accumulation. The mRNA and protein expression levels of collagen-1 and α-SMA were also down regulated in ß-sitosterol treated mouse group. CONCLUSIONS: This study shows the effect of ß-sitosterol on the TGF-ß -or DMN-induced hepatofibrosis. Hence, we demonstrate the ß-sitosterol as a potential therapeutic agent for the hepatofibrosis.