Effects Of Chlorogenic Acid Research Articles

Chlorogenic Acid Alleviates Inflammation and Fibrosis in a Murine Model of Bleomycin-Induced Systemic Sclerosis: A Histological Analysis

Background/Objectives: Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by cutaneous and visceral fibrosis, vascular alterations, and a persistent inflammatory response. Despite advances in understanding the pathogenic mechanisms underlying SSc, current therapeutic options remain limited. Chlorogenic acid (CGA) is a polyphenol widely distributed in plants and has shown antioxidant, anti-inflammatory, and antifibrotic properties. However, its therapeutic potential in SSc has not been investigated yet. Methods: A model of SSc was established by administering bleomycin (BLM) at 100 U/kg to CD1 mice via an osmotic minipump. After fourteen days of BLM administration, CGA (60 mg/kg) was intragastric administered on consecutive days until day 20. On day 21, all mice were sacrificed. The effect of CGA was histologically evaluated by hematoxylin and eosin and Masson’s trichrome staining. Results: CGA treatment significantly attenuated dermal fibrosis in the BLM-induced mice model of SSc by reducing histopathological damage, including increased dermal thickness, inflammation, collagen deposition, and SSc-associated pulmonary fibrosis. Conclusions: The evidence shows that CGA attenuates BLM-induced SSc in a mice model and strongly suggests that CGA may be a promising compound for the treatment of SSc.

Chlorogenic acid attenuates deoxynivalenol-induced apoptosis and pyroptosis in human keratinocytes via activating Nrf2/HO-1 and inhibiting MAPK/NF-κB/NLRP3 pathways

Deoxynivalenol (DON) is a common mycotoxic contaminant, frequently found in food and feed, causing a severe threat to human and animal health. Because of the widespread contamination of DON, humans involved in agricultural practices may be directly exposed to DON through the skin route. Chlorogenic acid (CGA) is a phenolic acid, which has anti-inflammatory and antioxidant properties. However, it is still unclear whether CGA can protect against DON-induced skin damage. Here, the effect of CGA on mitigating damage to human keratinocytes (HaCaT) triggered by DON, as well as its underlying mechanisms were investigated. Results demonstrated that DON exposure significantly decreased cell viability, and induced excessive mitochondrial reactive oxygen species (mtROS) generation, mitochondrial damage, oxidative stress, cell apoptosis and pyroptosis. However, CGA pretreatment for 2 h significantly increased cell viability and reversed DON-induced oxidative stress by improving antioxidant enzyme activities such as superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), reducing mtROS generation and enhancing mitochondrial function through activating Nrf2/HO-1 pathway. Moreover, CGA significantly increased the Bcl-2 protein expression, decreased the protein expressions of Bax and cleaved Caspase-3, and suppressed the phosphorylated of ERK, JNK, NF-κB. Further experiments revealed that CGA could also inhibit the pyroptosis-related protein expressions including NLRP3, cleaved Caspase-1, GSDMD-N, cleaved IL-1β and IL-18. In conclusion, our results suggest that CGA could attenuate DON-induced oxidative stress, inflammation, and apoptosis by activating the Nrf2/HO-1 pathway and inhibiting MAPK/NF-κB/NLRP3 pathway. CGA might be a novel promising therapeutic agent for alleviating the dermal damage triggered by DON.

Anti-inflammatory effects of chlorogenic acid from Taraxacum officinale on LTA-stimulated bovine mammary epithelial cells via the TLR2/NF-κB pathway.

Mastitis is an inflammatory disease caused by microbial infection. Chlorogenic acid (CGA), one of the major phenolic acids in Taraxacum officinale, has natural antioxidant and anti-inflammatory properties in various cell types; however, the effects of CGA on Lipoteichoic acid (LTA)-induced bovine mammary epithelial cells (BMECs) have not been investigated. In this study, the CGA content in T. officinale was determined by High-performance liquid chromatography (HPLC). BMECs were infected with LTA to induce the mastitis model. Different concentrations of CGA were administered after establishing the LTA infection. The results showed that the T. officinale contained CGA 1.36 mg/g. CGA significantly reduced the pro-inflammatory gene and protein expression of TNF-α, IL-6, and IL-1β. In addition, CGA downregulated the NO, TLR2, and NF-κB signaling pathways in LTA-infected bovine mammary epithelial cells. Our results indicate that CGA reduced the expression of TNF-α, IL-6, IL-1β, and TLR2 by inhibiting the phosphorylation of proteins in the NF-κB signaling pathways in a dose-dependent manner. This finding suggests that CGA may be a potential agent for the treatment of mastitis in dairy cows.

Chlorogenic Acid, the Main Antioxidant in Coffee, Reduces Radiation-Induced Apoptosis and DNA Damage via NF-E2-Related Factor 2 (Nrf2) Activation in Hepatocellular Carcinoma.

Radiotherapy produces excessive reactive oxygen species (ROS), which can lead to DNA damage and apoptosis in tumor cells, thereby killing malignant cells. Chlorogenic acid (CGA) is a well-known antioxidant in coffee due to its strong ability to remove ROS. However, the effect of CGA on radiotherapeutic efficacy remains unclear. In this study, we showed that CGA could hinder the therapeutic effect of radiotherapy by inhibiting radiation-induced apoptosis and DNA damage via scavenging excessive ROS and activating the NF-E2-related factor 2 (Nrf2) antioxidant system in hepatocellular carcinoma (HCC) cells and a murine model. The knockdown of Nrf2 reversed CGA-mediated radiation resistance in HCC cells. In conclusion, CGA might be a potential tumor-protective compound upon irradiation and reduce the efficacy of radiotherapy via ROS scavenging and Nrf2 activation.

Short-Term Intake of Chlorogenic Acids Improves Psychomotor Speed and Motor Speed in Adults: A Randomized Crossover Trial.

Chlorogenic acid (CGA), a polyphenolic compound found in various plants, has been reported to improve cognitive function. However, it remains unclear how long it takes for CGAs to exert their effects. Here, we evaluated the short-term effects of CGAs on cognitive function. We assessed the effects of 2-week CGA intake on cognitive function. The study was carried out as a randomized, double-blind, placebo-controlled, crossover trial. Twenty-six healthy Japanese participants (50–65 years of age) were randomly assigned to either the active beverage (CGAs: 270 mg) or the placebo beverage group daily for 2 weeks. After a 2-week washout period, the participants consumed the other beverages. We assessed cognitive function at baseline and following the first treatment period using the Japanese version of CNS Vital Signs. CGAs significantly improved the scores for psychomotor speed, motor speed, and right and left finger tapping compared to placebo. In addition, processing speed scores improved significantly from baseline only after CGA intake. In conclusion, CGAs were confirmed to improve cognitive function over a short period of two weeks.

Abstract 10928: Chlorogenic Acid Ameliorates Pressure Overload-Induced Cardiac Hypertrophy in Mouse Models

Introduction: Cardiac hypertrophy leading to heart failure is one of the critical causes of morbidity and mortality. Although social interest in treatment and prevention of cardiovascular disease is high, sufficient outcome has not been obtained yet. Chlorogenic acid (CGA) is one of the most abundant phenolics in plants, and is called caffeic acid. Recently, the cardioprotective effects of CGA which ameliorate isoproterenol-induced hypertrophy in vitro research have been reported. However, it has not been elucidated whether CGA affects cardiac hypertrophy in vivo models with TAC. Hypothesis: We assessed the hypothesis that the administration of CGA has protective effect on TAC-induced cardiac hypertrophy. Methods: We used mouse models of cardiac hypertrophy induced by TAC for four weeks. Mice were randomly assigned to sham, TAC, and TAC+CGA groups. CGA was administered at dose of 40mg/kg intraperitoneally once a day for four weeks after the TAC operation. cardioprotective effect was investigated by echocardiography and histological analysises. In addition, immunoblot and metabolome analysises and biomedical assays were conducted in excised hearts. Statistical analysis was performed by one-way ANOVA. All data are expressed as mean ± SD. Statistical significance was defined as P < 0.05. Results: We evaluated sham group (n=8), TAC group (n=7), TAC+CGA group (n=7) four weeks after TAC operation. TAC group showed an increase of heart weight, which was attenuated by CGA (120.3±9.3mg, 148.8±9.0mg, 126.6±6.2mg, p<0.05). Consistently, echocardiography revealed that the change of myocardial diastolic wall thickness (0.79±0.1mm, 1.13±0.1mm, 0.93±0.1mm, p<0.05). Histological analysis indicated that fibrosis induced by TAC was alleviated by CGA. According to immunoblot analysis, TAC group showed overexpression of TGF-β, IL-6, and TNF-α. In addition, the enhancements of glycolysis and TCA cycle were indicated in metabolome analysis. These changes were modulated by CGA administration. Conclusion: In conclusion, the present study revealed that CGA administration ameliorates pressure overload-induced cardiac hypertrophy in rodent model. As a key factor, expression of inflammatory cytokines and modulation of glucose metabolism were observed.

Chlorogenic Acid Relaxes Rat Ileal Smooth Muscles by Mechanisms Independent of Rho Kinase Mediated Effects on Myosin Light Chain Phosphorylation

Chlorogenic acid (CGA) is a polyphenolic compound found in fruits and vegetables and generally known to have antioxidant, anti-inflammatory and antithrombotic effects. Studies have shown that CGA induces nitric oxide-sGC-PKG pathway to cause relaxation of the vascular smooth muscles. But the effects of CGA on ileal smooth muscles are still unknown. In our previous experiments, we have shown that CGA increases basal tone with no effect on relaxation of rat ileal smooth muscles when they are depolarized by 140 mM potassium kreb's buffer. The present study is designed to evaluate if CGA acts through the rho-kinase mediated pathway in relaxing rat ileal smooth muscles when challenged with acetylcholine. Effects of CGA (10 μM) on basal tension and maximum contractile tension induced by acetylcholine (0.5μM) in isolated rat ileal rings (3mm) were determined using tissue bath apparatus. CGA effects on myosin light chain phosphorylation at maximum contractile tension in response to acetylcholine (0.5 μM) were also measured by freezing the ileal rings and extracting the protein and running Western blots. The role of rho-kinase in regulating smooth muscle relaxation is tested by incubating ileal rings with rho-kinase inhibitor Y-27632 (1 μM) and measuring the basal tension, maximum contractile tension and myosin light chain phosphorylation as described above. The results show that basal tension increases from 100% (control group) to 130.8 ± 19.0% and 121.7 ± 30.6 % when treated with CGA alone and the combination of CGA and Y-27632 respectively. The peak contractile tension in response acetylcholine changes from 100% (control group) to 50.4 ± 12.13 % and 55 ± 4.05 % when treated with CGA alone and the combination of CGA and Y-27632 respectively. The results from Western blots show that myosin light chain phosphorylation didn't change significantly between CGA (41.8 ± 5.5%) and the combination of CGA and Y-27632 (37.7 ± 3.7%) treatments. These results suggest that CGA alone and in combination with rho-kinase inhibitor is involved in increasing the basal tone of ileal smooth muscles when compared with the control group. In contrast, CGA significantly decreased the acetylcholine induced peak contractile tension both in presence and absence of rho-kinase inhibitor with out any corresponding changes in myosin light chain phosphorylation. Therefore, we conclude that CGA relaxes ileal smooth muscles by mechanisms independent of rho-kinase mediated effects on myosin light chain phosphorylation. Further studies on effects of CGA on activity of soluble guanylate cyclase and phosphodiesterase activity may provide some insights on mechanism of action of CGA on smooth muscles.

Chlorogenic acid inhibits proliferation in human hepatoma cells by suppressing noncanonical NF-κB signaling pathway and triggering mitochondrial apoptosis.

Chlorogenic acid (CGA), a phenylpropanoid derived from Eucommia ulmoides Oliver, has been shown to exhibit potent cytotoxic and anti-proliferative activities against several human cancers. However, the effects of CGA on hepatocellular carcinoma (HCC) and the underlying mechanisms have not been intensively studied. In this study, the CGA treatment effects on the viability of human hepatoma cells were investigated by MTT assay. Our data showed that CGA could dose-dependently inhibit the activity of human hepatoma cells Hep-G2 and Huh-7, but did not affect the activity and growth of normal human hepatocyte QSG-7701. The genes and pathways influenced by CGA treatment were explored by RNA sequencing and bioinformatics analysis, which identified 323 differentially expressed genes (DEGs) involved in multiple pharmacological signaling pathways such as MAPK, NF-κB, apoptosis and TGF-β signaling pathways. Further analyses by real-time quantitative PCR, Western blot and flow cytometry revealed that CGA effectually suppressed the noncanonical NF-κB signaling pathway, meanwhile it activated the mitochondrial apoptosis of HCC by upregulation of the BH3-only protein Bcl-2 binding component 3 (BBC3). Our findings demonstrated the potential of CGA in suppressing human hepatoma cells and provided a new insight into the anti-cancer mechanism of CGA.

Effect of chlorogenic acid on controlling kiwifruit postharvest decay caused by Diaporthe sp.

Chlorogenic acid (CGA) is a phenolic compound derived from plants that has anti-microbial activity. Effect of CGA toward Diaporthe sp. infection in kiwifruit was evaluated in the present study. Results demonstrated that fungal spore germination, germ tube elongation, and mycelial growth were all significantly inhibited by CGA. Exposure of Diaporthe sp. to CGA induced a reactive oxygen species (ROS) burst, which was mediated by an influx of calcium, resulting in mitochondrial dysfunction and apoptosis. The response of fungal cells of Diaporthe sp. to CGA included the activation of the calcium/calmodulin signaling pathway. Postharvest application of CGA induced defense-related enzyme activity in kiwifruit and inhibited Diaporthe sp. infection in a concentration dependent manner. CGA also contributed to the maintenance of fruit quality during storage. Collectively, our results suggest that CGA effectively inhibits the growth of Diaporthe sp. by inducing mitochondrial oxidative stress, which is mediated by calcium influx and by inducing defense-related enzyme activity in kiwifruit. The result of this collective effect was a significant reduction on the postharvest decay in kiwifruit.

Chlorogenic Acid Protects Against Indomethacin-Induced Inflammation and Mucosa Damage by Decreasing Bacteroides-Derived LPS.

Background: Chlorogenic acid (CGA), a natural bioactive polyphenol, exerts anti-inflammatory, antioxidant, and antibacterial effects that support the maintenance of intestinal health. However, the influence of CGA on gut microbiota and their metabolites, as well as its potential effects and mechanism of action in inflammatory bowel disease, remain to be elucidated.Methods: First, an oral gavage was used to administer CGA to indomethacin-treated mice. Then, fecal microbiota transplantation was performed to explore the role of intestinal microbiota in indomethacin-induced inflammation.Results: CGA treatment protected against body weight loss, damage to intestinal morphology and integrity, inflammation, and alteration of microbiota composition in indomethacin-treated mice. Interestingly, CGA failed to inhibit inflammation or protect intestine integrity in mice treated with antibiotics. Notably, mice who had been colonized with intestinal microbiota from CGA-treated or CGA-and-indomethacin-treated mice, through the fecal microbiota transplantation program, were protected from indomethacin-induced inflammation, growth of Bacteroides, and the accumulation of Bacteroides-derived LPS, in congruence with those who had been treated with CGA.Conclusion: The results suggest that CGA may protect intestine integrity and alleviate inflammatory responses, primarily by inhibiting the growth of Bacteroides and the accumulation of Bacteroides-derived LPS, in indomethacin-induced colitis. This newly identified mechanism broadens our knowledge of how CGA exerts protective effects on intestinal inflammation and provides strategies for the prevention of gastrointestinal mucosal damage in patients treated with indomethacin.

CGA restrains the apoptosis of Aβ25-35-induced hippocampal neurons

Background: Chlorogenic acid (CGA) has anti-oxidant and anti-inflammatory effects, but the study on its role in Alzheimer’s disease (AD) models remains rare. Here, the effects of CGA on β-amyloid protein (Aβ)-induced cell models were investigated, aiming to provide a direction for Aβ-induced AD.Material and methods: Hippocampal neurons were separated from newborn Sprague-Dawley (SD) rats and identified by immumofluorescence method. Hippocampal neurons were processed with Aβ25-35 after pre-treatment CGA. MTT assay was used for detecting viability of treated cells. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA) and lactate dehydrogenase (LDH) of treated hippocampal neurons were determined by corresponding kits. Flow cytometry analysis assessed the apoptosis and mitochondrial membrane potential (MMP) in hippocampal neurons after treatment. The expressions of proteins related to apoptosis and endoplasmic reticulum stress (ERS) were measured by western blot (WB) analysis.Results: Immumofluorescence method showed that the Aβ25-35 induction models were successfully constructed. CGA increased the viability and decreased the apoptosis rate of Aβ25-35-induced hippocampal neurons. Decreasing activities of LDH and MDA, and raised contents of SOD and GSH-Px were appeared in Aβ25-35-induced cells that pre-treated with CGA. Moreover, CGA also enhanced MMP intensity of hippocampal neurons induced by Aβ25-35. In WB analysis, CGA reversed the promoting effect of Aβ25-35 on the expressions of proteins related to pro-ERS and pro-apoptosis.Conclusion: CGA restrained the apoptosis of Aβ25-35-induced hippocampal neurons via improving the anti-oxidant capacity, mitochondrial injury and ERS state of cells, which may provide a direction for AD.

Chlorogenic Acid Attenuates Kidney Ischemic/Reperfusion Injury via Reducing Inflammation, Tubular Injury, and Myofibroblast Formation.

Kidney ischemic/reperfusion (I/R) injury is the main cause of acute kidney injury (AKI) involving renal function deterioration, renal architecture damage, and inflammation. This condition may lead to kidney fibrosis with epithelial to mesenchymal transition (EMT) and myofibroblast formation. Inhibition of chronic effects of kidney I/R injury may provide effective strategies for treating AKI and chronic kidney diseases (CKDs). Chlorogenic acid (CGA) is recognized as a powerful antioxidant, with anti-inflammatory and antifibrotic properties in many conditions. However, the effect of CGA on kidney I/R injury has not been elucidated yet. Kidney I/R injury was performed on male Swiss background mice (I/R group, n = 5, 3-4 months, 30–40 g) which underwent bilateral renal pedicles clamping for 30 minutes and then were euthanized on day three after operation. Three groups of I/R were treated with 3 different doses of CGA intraperitoneally for 2 days: 3.5 (I/R + CGA1 group), 7 (I/R + CGA2 group), and 14 (I/R + CGA3 group) mg/kg of body weight. Tubular injury was quantified based on Periodic Acid-Schiff staining, while reverse transcriptase PCR (RT-PCR) was performed to quantify mRNA expression of TGF-β1, vimentin, SOD-1, TLR-4, TNF-α, NF-κB and MCP-1. Immunohistochemical staining was done to quantify proliferating cell nuclear antigen (PCNA), myofibroblast (α-SMA), SOD-1 and macrophage (CD68) number. Kidney I/R demonstrated tubular injury and increased inflammatory mediator expression, macrophage number, and myofibroblast expansion. Meanwhile, histological analysis showed lower tubular injury with higher epithelial cell proliferation in CGA-treated groups compared to the I/R group. RT-PCR also revealed significantly lower TGF-β1 and vimentin mRNA expressions with higher SOD-1 mRNA expression. CGA-treated groups also demonstrated a significantly lower macrophage and myofibroblast number compared to the I/R group. These findings associated with lower mRNA expression of TLR-4, TNF-α, NF-κB, and MCP-1 as inflammatory mediators in CGA groups. I/R + CGA3 represented the highest amelioration effect among other CGA-treated groups. CGA treatment attenuates kidney I/R injury through reducing inflammation, decreasing myofibroblast expansion, and inducing epithelial cells proliferation.

Chlorogenic acid ameliorates memory loss and hippocampal cell death after transient global ischemia.

Chlorogenic acid (CGA) is known to have antioxidant potentials, yet the effect of CGA on brain ischemia has not been sufficiently understood. Brain ischemia such as transient global ischemia disrupts many areas of the brain of rats, including the hippocampus. Male Wistar rats were randomly assigned into five groups, that is, sham-operated (SO), bilateral common carotid occlusion (BCCO), and BCCO+ 15, 30, and 60mg/kg bw CGA groups (CGA15, CGA30, and CGA60, respectively). Brain ischemia was induced in Wistar rats with BCCO for 20min followed by intraperitoneal injection of CGA. The rats were examined for the spatial memory in a Morris water maze test on the 3rd day and were euthanized on the 10th day after BCCO. The total number of pyramidal cells was estimated, and the mRNA expressions of Bcl2, Bax, caspase-3, SOD2, SOD1, GPx, ET-1, eNOS, CD31, and VEGF-A were measured. The BCCO group spent less time and distance in the target quadrant than any other group in the spatial memory retention test. The CA1 pyramidal cell numbers in the BCCO and CGA15 groups were lower than in the CGA30 and CGA60 groups. The mRNA expressions of Bcl2, SOD2, and CD31 in the BCCO group were lower than in the CGA15, CGA30, and CGA60 groups. The ET-1 expression was higher in the BCCO and CGA15 groups than in the SO, CGA30, and CGA60 groups. CGA improves the spatial memory and prevents the CA1 pyramidal cell death after BCCO by increasing Bcl2, SOD2, and CD31 expressions and decreasing ET-1 expression.

Abstract 732: Attenuation of Tnf-α Induced Injury in Cardiomyocytes by Chlorogenic Acid via Inhibiting Nf-κB and Jnk Signals

The traditional Chinese herb Lonicerae Japonicae Flos has been used to treat various diseases including heart failure, showing significant benefits in the clinical practice. However, the mechanism of its cardioprotective effects remains unclear. As the main active ingredient found in the plasma after oral administration of Lonicerae Japonicae Flos , chlorogenic acid (CGA) has been reported to possess anti-inflammatory, anti-oxidant, anti-apoptosis and analgesic function. To investigate whether the cardioprotective effects of Lonicerae Japonicae Flos is through CGA, we applied Transverse Aortic Constriction (TAC)-induced heart failure mouse model, to access the effects of CGA. The results of in vivo experiments show that CGA has cardioprotective effects and could mitigate the TNF-α(Tumor necrosis factor-alpha) induced toxicity in TAC heart failure mouse model. Therefore, we further used TNF-α-induced cardiac injury in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to explore whether CGA have cardioprotective effects and elucidate the underlying mechanism(s). CGA pretreatment could reverse TNF-α induced cellular injuries, including improved cell viability, increased mitochondrial membrane potential and inhibited cardiomyocytes apoptosis. We then examined the NF-κB/p65 and major MAPKs signaling pathways involved in TNF-α induced apoptosis of hiPSC-CMs. Importantly, both CGA and NF-κB inhibitor (QNZ) can reverse the cell viability impairment and apoptosis phenotypes. Moreover CGA can directly inhibit NF-κB signal by suppressing the phosphorylation of NF-κB/p65. As for the MAPKs, CGA suppressed the activity of JNK only, but enhanced ERK1/2 and had no effect on p38. In summary, our study revealed that CGA has profound cardioprotective effects through inhibiting the activation of NF-κB and JNK pathway, providing a novel therapeutic alternative for prevention and treatment of heart failure.

Adaptive immunoregulation of luteolin and chlorogenic acid in lipopolysaccharide-induced interleukin-10 expression.

Objective:To investigate the mechanism of the adaptive effect of two compounds in Lonicerae japonica flos (LJF), luteolin (LUT) and chlorogenic acid (CGA), on the expression of interleukin (IL) IL-10 and IL-6.Materials and Methods:RAW264.7 cells receiving lipopolysaccharide (LPS) were pretreated with CGA and LJF. The expression of pro-inflammatory cytokines and IL-10 was evaluated by reverse transcription-polymerase chain reaction. Moreover, the concentrations of IL-10 and IL-6 were measured by enzyme-linked immunosorbent assay in the culture medium obtained 24 h after LPS treatment. Nuclear extracts of RAW264.7 cells, pretreated with CGA or LUT and LPS, were prepared after 6 h, and C/EBPβ and C/EBPδ were measured by Western blotting. Nuclear factor-κB (NF-κB) activity was measured by electrophoretic mobility shift assay. The phosphorylated form of IκB, ERK1/2, p38, JNK, and IκB, ERK2, p38, or JNK were also measured by Western blotting.Results:CGA enhanced the LPS-induced expression of IL-10 and IL-6, and increased NF-κB, Sp1, C/EBPβ and δ. The effect of CGA is interfered with Lut by suppressing the phosphorylation of IκB and p38, and NF-κB activity. In the event, IL-6 was suppressed and IL-10 was not influenced.Conclusion:LUT and CGA, which are abundant in LJF that is one of the ingredients in Gingyo-san, have adaptive immunoregulative effect on the expression of IL-10.

(-)-Epigallocatechin gallate but not chlorogenic acid upregulates osteoprotegerin synthesis through regulation of bone morphogenetic protein-4 in osteoblasts.

Chlorogenic acid (CGA) is a primary phenolic component of coffee and (-)-epigallocatechin gallate (EGCG) is a primary flavonoid component of green tea, both of which have been documented to possess beneficial health properties. A previous study by the present authors demonstrated that p38 mitogen-activated protein kinase (MAPK) may be associated with osteoprotegerin synthesis stimulated by bone morphogenetic protein-4 (BMP-4) in osteoblast-like MC3T3-E1 cells. In the present study, the effects of CGA and EGCG on BMP-4-stimulated osteoprotegerin synthesis in MC3T3-E1 cells were investigated. It was observed that CGA had no effect on osteoprotegerin release stimulated by BMP-4, whereas EGCG significantly enhanced BMP-4-stimulated osteoprotegerin release (P=0.003). Levels of osteoprotegerin mRNA expression induced by BMP-4 were also significantly increased by EGCG (P=0.03). By contrast, EGCG had no significant effect on phosphorylation of Smad1 or p38 MAPK induced by BMP-4. In addition, EGCG had little effect on BMP-induced phosphorylation of p70 S6 kinase; however rapamycin, as an inhibitor of p70 S6 kinase, significantly suppressed osteoprotegerin release (P=0.007). These data suggest that EGCG but not CGA may upregulate the synthesis of osteoprotegerin induced by BMP-4 in osteoblasts.

Chlorogenic acid induces reactive oxygen species generation and inhibits the viability of human colon cancer cells.

Chlorogenic acid (CGA) is one of the polyphenols identified in the human diet. Previous studies have shown that CGA plays a protective role against liver diseases. The colon plays a pivotal role in CGA metabolism. However, little is known about the direct effects and the underlying molecular mechanisms of CGA in colon cancer. Here, we investigate these mechanisms of CGA activity in human colon cancer cells. The effects of CGA on the viability of two human colon cancer cell lines, HCT116 and HT29, were determined using the MTT assay. The intracellular reactive oxygen species (ROS) were detected using fluorescence microscopy and flow cytometry. In addition, changes in cell proliferation were detected by cell cycle analysis. Immunoblotting analysis was used to observe the underlying molecular changes. CGA inhibited the viability of HCT116 and HT29 cells in a dose-dependent manner. CGA induced ROS production, whereas the combined use of ROS scavenger N-acetylcysteine attenuated the CGA-induced viability inhibition. Moreover, CGA induced cell cycle arrest at the S phase and suppressed the activation of extracellular signal-related kinase in both cell types, which likely contributes toward the ROS-induced viability inhibition caused by CGA treatment. CGA-induced ROS production inhibited cell viability in human colon cancer cells. CGA caused S-phase arrest and extracellular signal-related kinase inactivation that may have led to the observed viability inhibition. CGA is therefore a potential treatment against CRC.

Chlorogenic Acid Prevents Osteoporosis by Shp2/PI3K/Akt Pathway in Ovariectomized Rats.

Cortex Eucommiae is used worldwide in traditional medicine, various constituents of Cortex Eucommiae, such as chlorogenic acid (CGA), has been reported to exert anti-osteoporosis activity in China, but the mechanism about their contribution to the overall activity is limited. The aims of this study were to determine whether chlorogenic acid can prevent estrogen deficiency-induced osteoporosis and to analyze the mechanism of CGA bioactivity. The effect of CGA on estrogen deficiency-induced osteoporosis was performed in vivo. Sixty female Sprague-Dawley rats were divided randomly among a sham-operated group and five ovariectomy (OVX) plus treatment subgroups: saline vehicle, 17α-ethinylestradiol (E2), or CGA at 9, 27, or 45 mg/kg/d. The rats’ femoral metaphyses were evaluated by micro-computed tomography (μCT). The mechanism of CGA bioactivity was investigated in vitro. Bone mesenchymal stem cells (BMSCs) were treated with CGA, with or without phosphoinositide 3-kinase (PI3K) inhibitor LY294002. BMSCs proliferation and osteoblast differentiation were assessed with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and alkaline phosphatase, with or without Shp2 interfering RNA (RNAi). The results display that CGA at 27 and 45 mg/kg/day inhibited the decrease of bone mineral density (BMD) that induced by OVX in femur (p< 0.01), significantly promoted the levels of bone turnover markers, and prevented bone volume fraction (BV/TV), connectivity density (CoonD), trabecular number (Tb.N), trabecular thickness (Tb.Th) (all p< 0.01) to decrease and prevented the trabecular separation (Tb.Sp), structure model index (SMI)(both p< 0.01) to increase. CGA at 1 or 10 μM enhanced BMSC proliferation in a dose-dependent manner. CGA at 0.1 to 10 μM increased phosphorylated Akt (p-Akt) and cyclin D1. These effects were reversed by LY294002. CGA at 1 or 10 μM increased BMSC differentiation to osteoblasts (p< 0.01), Shp2 RNAi suppressed CGA-induced osteoblast differentiation by decreasing Shp2, p-Akt, and cyclin D1. This study found that CGA improved the BMD and trabecular micro-architecture for the OVX-induced osteoporosis. Therefore, CGA might be an effective alternative treatment for postmenopausal osteoporosis. CGA promoted proliferation of osteoblast precursors and osteoblastic differentiation of BMSCs via the Shp2/PI3K/Akt/cyclin D1 pathway.

Prunus mume Sieb. et Zucc. fruit ameliorates alcoholic liver injury in mice by inhibiting apoptosis and inflammation through oxidative stress

The effects of Prunus mume Sieb. et Zucc. extract (PME) on alcohol-induced liver injury were investigated. These functions of PME were linked to antioxidant activity that suppress lipogenesis in liver tissue, in part inhibiting activation of sterol response element binding protein-1 through ROS-mitogen-activated protein kinase signalling axis, and by suppressing hepatic apoptosis and inflammation through ROS-mediated p53 signalling pathway. Eight compounds and their structures in PME were also identified by LC-MS analysis, and chlorogenic acid (CGA) and neochlorogenic acid (NeoCGA) were validated using standard compounds by HPLC. The effects of CGA against cellular damage caused by alcohol-induced oxidative stress were confirmed using AML-12 cells. CGA significantly inhibited alcohol-induced apoptosis and MAPK activation in the cells. Moreover, antioxidant activities of CGA in the alcohol treatment were demonstrated regarding to cellular redox status and oxidative damage. These studies validated therapeutic value of PME in the prevention of alcoholic liver disease.

Cognitive and neuroprotective effects of chlorogenic acid

Objectives: The aim of this review was to provide an overview of studies conducted to determine the effects of chlorogenic acid (CGA) on cognition and neurological health.Methods: A literature search was conducted using PubMed and various search terms including chlorogenic acid, CGA, memory, neuroscience, cognition, nutrition, antioxidant, pharmacokinetics, neuroprotection, and neurodegeneration.Results: Many studies have linked CGA consumption to a wide range of health benefits, including neuroprotection, cardioprotection, weight loss, chemopreventive properties, anti-inflammatory activity, decreased blood pressure, decreased diet-induced insulin resistance, decreased blood pressure, anxiolytic effects, and antihyperalgesic effects. Pre-clinical and clinical studies both provide evidence that CGA supplementation could protect against neurological degeneration and the resulting diseases associated with oxidative stress in the brain; however, no formal, well-controlled studies have been performed to date.Discussion: Recent research suggests that dietary consumption of CGA could produce a wide range of health benefits and physiological effects. There is also mounting evidence that the consumption of polyphenols, including CGA, in the diet could reduce the risk of developing neurodegenerative conditions. Further studies should be conducted with a focus on the effects of CGA on cognition and the nervous system and employing well-designed clinical studies.