Chlorogenic Acid Pretreatment Research Articles

Chlorogenic Acid Attenuates Isoproterenol Hydrochloride-Induced Cardiac Hypertrophy in AC16 Cells by Inhibiting the Wnt/β-Catenin Signaling Pathway.

Cardiac hypertrophy (CH) is an important characteristic in heart failure development. Chlorogenic acid (CGA), a crucial bioactive compound from honeysuckle, is reported to protect against CH. However, its underlying mechanism of action remains incompletely elucidated. Therefore, this study aimed to explore the mechanism underlying the protective effect of CGA on CH. This study established a CH model by stimulating AC16 cells with isoproterenol (Iso). The observed significant decrease in cell surface area, evaluated through fluorescence staining, along with the downregulation of CH-related markers, including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and β-myosin heavy chain (β-MHC) at both mRNA and protein levels, provide compelling evidence of the protective effect of CGA against isoproterenol-induced CH. Mechanistically, CGA induced the expression of glycogen synthase kinase 3β (GSK-3β) while concurrently attenuating the expression of the core protein β-catenin in the Wnt/β-catenin signaling pathway. Furthermore, the experiment utilized the Wnt signaling activator IM-12 to observe its ability to modulate the impact of CGA pretreatment on the development of CH. Using the Gene Expression Omnibus (GEO) database combined with online platforms and tools, this study identified Wnt-related genes influenced by CGA in hypertrophic cardiomyopathy (HCM) and further validated the correlation between CGA and the Wnt/β-catenin signaling pathway in CH. This result provides new insights into the molecular mechanisms underlying the protective effect of CGA against CH, indicating CGA as a promising candidate for the prevention and treatment of heart diseases.

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.

Stabilization of mitochondrial function by chlorogenic acid protects against kainic acid-induced seizures and neuronal cell death in rats

The current study investigated the effect of chlorogenic acid, a polyphenolic compound found in numerous plant products, on a kainic acid-induced seizure rat model and its potential mechanism. Rats were administered chlorogenic acid (10 and 50 mg/kg) intraperitoneally for 30 min before kainic acid (15 mg/kg) intraperitoneal administration. Pretreatment with chlorogenic acid decreased the seizure score, increased the latency to onset of the first seizure, and decreased the mortality rate. Chlorogenic acid pretreatment also resulted in a significant reduction in glutamate elevation and neuronal death in the hippocampus of kainic acid-treated rats. In addition, electron microscopy revealed that kainic acid-induced changes in hippocampal mitochondrial structure were prevented by chlorogenic acid pretreatment. Additionally, the levels of mitochondrial function-related proteins, including sirtuin 3, Complex I, glutamate dehydrogenase 1 and ATP synthase, were increased, and the level of the mitochondrial damage marker cytochrome C was decreased in the hippocampus of chlorogenic acid/kainic acid rats. Furthermore, the expression of mitochondrial biogenesis-related proteins [AMP-activated protein kinase (AMPK), sirtuin1, and peroxisome proliferator-activated receptor γ-coactivator-1α (PGC-1α)] and mitophagy-related proteins [phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1), Parkin, and microtubule-associated protein 1 light chain 3 (LC3)] was decreased in the hippocampus of kainic acid-treated rats, which was reversed by chlorogenic acid pretreatment. These observations reveal the marked neuroprotective potential of chlorogenic acid against kainic acid-induced neurotoxicity and seizures through prevention of glutamate increase and preservation of AMPK/sirtuin 1/PGC-1α-mediated mitochondrial biogenesis and PINK1/Parkin-induced mitophagy to maintain adequate mitochondrial homeostasis and function.

Chlorogenic acid improves the cognitive deficits of sleep-deprived mice via regulation of immunity function and intestinal flora

BackgroundSleep deprivation (SD) has become a global health concern with serious consequences containing memory deficits and gastrointestinal dysfunctions. The gut-brain axis serves as a crucial link between the brain and gut, and the utilization of chlorogenic acid (CGA) presents a compelling strategy for mitigating or potentially resolving various neuroinflammation-associated disorders. However, it is still unknown how CGA may interact with the gut, microbiota and the brain during SD. PurposeThis study aims to explore the therapeutic effect and underlying mechanism of microbiota-gut-brain axis by which CGA prevents SD-induced cognitive deficits. Study design and methodsCGA (30, 60 mg/kg.bw.) was gavaged to C57BL/6 mice, and then they were submitted to 48-h SD. The cognitive and spatial learning abilities were investigated through behavioral tests. Furthermore, we explored the action mechanism of this compound with haematological analysis, histopathological examination, Western blot, ELISA and 16S rRNA gene pyrosequencing from colonic contents. ResultsThe cognitive deficits induced by SD were significantly relieved by administration of CGA in a dose-dependent manner. The hematoxylin and eosin staining of hippocampus and colon tissues indicated that pretreatment of CGA not only protected brain tissue from SD, but also maintained intestinal integrity. In the hippocampus, the increased pro-inflammatory neurometabolites were significantly prevented by CGA, and an immune profile capable of hippocampal-dependent spatial memory was improved via Nrf2/PPAR signaling pathways. The observed immunomodulatory effect was concomitant with augmentation of the intestinal barrier, as evidenced by the heightened expressions of tight junction proteins. 16S rRNA analysis of colonic contents revealed that levels of Clostridia_UCG-014 and lipopolysaccharide were significantly inhibited, and those of Lactobacillus and intestinal tight junction proteins were upregulated in the CGA group. Pathways of ko05322 (immune disease) and ko04610 (immune system) were significantly regulated by CGA. Based on PICRUSt2 algorithm, CGA probably influenced gut microbial functions via several metabolism pathways, such as arginine biosynthesis, pyrimidine metabolism and purine metabolism. ConclusionThe present study first proved the efficacy and mechanism of CGA in alleviating SD-induced cognitive impairment and neuroinflammation via creating a systemic protection, a bidirectional communication system connecting the gut with the brain. The intestinal barrier improvement and the reshaped “SD microbiota” profiles restored immunity functions, which were probably the main contributors to Nrf2/PPAR activation and the neuroprotective effect of CGA. Overall, this work provided novel insights of CGA, which might guide the more reasonable clinical use of CGA in the pathogenesis of sleep-related disorders.

Chlorogenic acid ameliorates the heat stress-induced impairment of porcine Sertoli cells by suppressing oxidative stress and apoptosis

Sertoli cells are an important type of somatic cell in the testis that are in direct contact with spermatogonia in vivo and play an important role in the process of spermatogenesis. Chlorogenic acid (CGA) plays a pivotal role in the regulation of the mammalian cell heat stress response. For example, CGA treatment protects porcine oocytes from heat stress-induced apoptosis and prevents reduced embryo quality. However, the role of CGA treatment in protecting porcine testicular Sertoli cells against heat-induced damage has rarely been studied. This study aimed to identify the protective effects of CGA on oxidative stress and apoptosis in Sertoli cells under heat stress. The present results demonstrated that the addition of CGA significantly inhibited the accumulation of reactive oxygen species (ROS) and apoptosis in Sertoli cells induced by heat stress and decreased the expression of CASP3 protein and the BAX/BCL-2 protein ratio. CGA pretreatment also prevented the heat stress-induced reductions in the mitochondrial membrane potential, PCNA protein expression, and SOD and CAT activities. Moreover, CGA treatment reversed S phase cell cycle arrest and increased the HSP70 protein expression levels. Overall, these results suggest that oxidative damage participates in the inhibition of the proliferation of Sertoli cells and the increase in their apoptosis induced by heat stress, and the protective effects of CGA treatment on Sertoli cells under heat stress provide a theoretical basis for preventing heat stress injury in animals.

Chlorogenic acid protects against myocardial ischemia–reperfusion injury in mice by inhibiting Lnc Neat1/NLRP3 inflammasome-mediated pyroptosis

Increasing evidences demonstrate that chlorogenic acid (CGA), a polyphenol with multiple effects such as anti-inflammatory and anti-oxidation, protects against myocardial ischemia–reperfusion injury (MIRI) in vitro and in vivo. But its detailed cardiac protection mechanism is still unclear. The MIRI mice model was established by ligating the left anterior descending branch (LAD) of the left coronary artery in C57BL/6 mice. Sixty C57BL/6 mice were randomly divided into four groups. CGA group and CGA + I/R group (each group n = 15) were gavaged with 30 mg/kg/day CGA for 4 weeks. Sham group and I/R group mice (each group n = 15) were administered equal volumes of saline. In vitro MIRI model was constructed by hypoxia and reoxygenation of HL-1 cardiomyocytes. The results showed that CGA pretreatment reduced myocardial infarction size and cTnT contents in serum, simultaneously reduced the levels of Lnc Neat1 expression and attenuated NLRP3 inflammasome-mediated pyroptosis in myocardial tissue. Consistent with in vivo results, the pretreatment of 0.2 μM and 2 μM CGA for 12 h in HL-1 cardiomyocytes depressed hypoxia/reoxygenation-induced Lnc Neat1 expression, NLRP3 inflammasome activation and pyroptosis. Lnc Neat1 shRNA transfection mediated by lentivirus in HL-1 cardiomyocytes significantly reduced activation of NLRP3 inflammasome and pyroptosis. Our findings suggest that CGA protects against MIRI by depressing Lnc Neat1 expression and NLRP3 inflammasome-mediated pyrotosis. Inhibiting the levels of Lnc Neat1 expression may be a therapeutic strategy for MIRI.

Chlorogenic Acid Alleviates LPS-Induced Inflammation and Oxidative Stress by Modulating CD36/AMPK/PGC-1α in RAW264.7 Macrophages.

Chlorogenic acid (CGA) is a bioactive substance with anti-inflammatory activities. Clusters of CD36 have been suggested to be widely involved in inflammatory damage. However, the mechanism of CGA protecting against LPS-induced inflammation involving the CD36 regulation is unclear. Here, we demonstrated that CGA protected against LPS-induced cell death and decreased the production of ROS. Moreover, the SOD, CAT, and GSH-Px activities were also upregulated in CGA-treated cells during LPS stimulation. CGA reduced COX-2 and iNOS expression and IL-1β, IL-6, and TNF-α secretion in LPS-stimulated RAW264.7 macrophages. In addition, CGA treatment widely involved in immune-related signaling pathways, including NF-κB signaling, NOD-like receptor signaling, and IL-17 signaling using transcriptomic analysis and CD36 also markedly reduced during CGA pretreatment in LPS-induced RAW264.7 cells. Furthermore, the CD36 inhibitor SSO attenuated inflammation and oxidative stress by enabling activation of the AMPK/PGC-1α cascade. These results indicate that CGA might provide benefits for the regulation of inflammatory diseases by modulating CD36/AMPK/PGC-1α to alleviate oxidative stress.

Chlorogenic Acid Alleviates Hepatic Ischemia–Reperfusion Injury by Inhibiting Oxidative Stress, Inflammation, and Mitochondria-Mediated Apoptosis In Vivo and In Vitro

Hepatic ischemia–reperfusion injury (HIRI) is the main reason for organ failure following liver surgery; however, its underlying causes are complex, and include oxidative stress, sterile inflammatory, and mitochondrial damage. Unfortunately, treatments for HIRI are based on supportive therapy, and no specific drugs or methods are currently available. Chlorogenic acid (CGA) is a dietary polyphenol with a wide range of pharmacological effects and it has a protective effect on HIRI; however, its specific mechanism remains unclear. In this study, we investigated that CGA pretreatment exerts protective effects against HIRI and the potential underlying mechanisms. We found that CGA pretreatment reduced ALT, AST, MDA, TNF-α, and IL-1β levels following HIRI, improved SOD and GSH levels, and alleviated pathological liver tissue damage, with the highest CGA dose (100 mg/kg.d) exerted the strongest effect. In addition, we showed that CGA pretreatment significantly decreased the levels of reactive oxygen species following HIRI, inhibited HMGB1 release by decreasing IRF-1 expression, inhibited the expression of HMGB1, TLR-4, MyD88, P-IκB-α, NF-κB P65, and P-P65, and promoted IκB-α degradation. Thus, CGA appears to inhibit oxidative stress and inflammatory responses during HIRI. Furthermore, we found that CGA pretreatment reduced hepatocyte apoptosis following HIRI, alleviated mitochondrial damage, promoted BCL-2 expression, inhibited Bax upregulation, and inhibited cytochrome C release to prevent caspase activation, thereby reducing the expression of the caspase-independent pathway components, ENDOG and AIF. Together, our findings suggest that CGA can protect against HIRI by inhibiting oxidative stress, the HMGB1/TLR-4/NF-κB signaling pathway–mediated inflammatory responses, and mitochondria-mediated apoptosis. Thus, CGA appears to be a promising therapeutic approach for treating HIRI.

Chlorogenic acid alleviates hypoxic-ischemic brain injury in neonatal mice.

Recent studies have shown that chlorogenic acid (CGA), which is present in coffee, has protective effects on the nervous system. However, its role in neonatal hypoxic-ischemic brain injury remains unclear. In this study, we established a newborn mouse model of hypoxic-ischemic brain injury using a modified Rice-Vannucci method and performed intraperitoneal injection of CGA. We found that CGA intervention effectively reduced the volume of cerebral infarct, alleviated cerebral edema, restored brain tissue structure after injury, and promoted axon growth in injured brain tissue. Moreover, CGA pretreatment alleviated oxygen-glucose deprivation damage of primary neurons and promoted neuron survival. In addition, changes in ferroptosis-related proteins caused by hypoxic-ischemic brain injury were partially reversed by CGA. Furthermore, CGA intervention upregulated the expression of the key ferroptosis factor glutathione peroxidase 4 and its upstream glutamate/cystine antiporter related factors SLC7A11 and SLC3A2. In summary, our findings reveal that CGA alleviates hypoxic-ischemic brain injury in neonatal mice by reducing ferroptosis, providing new ideas for the treatment of neonatal hypoxic-ischemic brain injury.

Protective effects of chlorogenic acid on isoflurane-induced cognitive impairment of aged mice.

Postoperative cognitive dysfunction (POCD) is characterized by impairment in cognitive functions in patients following anesthesia and surgery. Chlorogenic acid (CGA) is a plant‐derived compound possessing numerous bioactive properties. The aim of this study was to investigate the therapeutic potential of CGA in isoflurane (ISO)‐induced cognitive dysfunction of aged mice, and further identify the mechanisms involved in the protective effects of CGA. A total of 80 male C57BL/6 mice, 20‐month‐old, were randomly divided into control group, isoflurane group (ISO), and ISO + 30 mg/kg CGA group and ISO + 60 mg/kg CGA. CGA was given orally once daily for 7 days to the mice and they were exposed to ISO (1.5%; 4 h). The open‐field and Morris water maze tests were used to investigate the cognitive function of mice. Pretreatment with CGA significantly attenuated ISO‐induced cognitive impairment. The levels of IL‐1β, TNF‐α, IL‐6, nuclear p65 NF‐kB, cleaved caspase‐3, and Bax were significantly increased, while the levels of IkBα and Bcl‐2 were decreased in the hippocampus 24 h after the ISO anesthesia. All the mentioned effects induced by ISO were reversed by CGA pretreatment. Furthermore, ISO exposure induced marked downregulation of SOD, CAT, HO‐1, and NQO‐1 and elevation of MDA and nuclear translocation of Nrf2 in the hippocampus tissue. All these parameters were reversed by CGA treatment. Importantly, the higher dose of CGA (60 mg/kg) showed a greater neuroprotective effect. In conclusion, these findings suggest that CGA attenuates the ISO‐induced cognitive impairment via its anti‐inflammatory, anti‐oxidative, and anti‐apoptotic properties in aged mice.

Chlorogenic acid exerts neuroprotective effect against hypoxia-ischemia brain injury in neonatal rats by activating Sirt1 to regulate the Nrf2-NF-κB signaling pathway

BackgroundNeonatal hypoxic-ischemic brain injury (HIE) is caused by perinatal asphyxia, which is associated with various confounding factors. Although studies on the pathogenesis and treatment of HIE have matured, sub-hypothermia is the only clinical treatment available for HIE. Previous evidence indicates that chlorogenic acid (CGA) exerts a potential neuroprotective effect on brain injury. However, the role of CGA on neonatal HI brain damage and the exact mechanism remains elusive.Here, we investigate the effects of CGA on HI models in vivo and in vitro and explore the underlying mechanism.MethodsIn the in vivo experiment, we ligated the left common carotid artery of 7-day-old rats and placed the rats in a hypoxic box for 2 h. We did not ligate the common carotid artery of the pups in the sham group since they did not have hypoxia. Brain atrophy and infarct size were evaluated by Nissl staining, HE staining and 2,3,5-triphenyltetrazolium chloride monohydrate (TTC) staining. Morris Water Maze test (MWM) was used to evaluate neurobehavioral disorders. Western-blotting and immunofluorescence were used to detect the cell signaling pathway. Malondialdehyde (MDA) content test, catalase (CAT) activity detection and Elisa Assay was used to detect levels of inflammation and oxidative stress. in vitro experiments were performed on isolated primary neurons.ResultIn our study, pretreatment with CGA significantly decreased the infarct volume of neonatal rats after HI, alleviated brain edema, and improved tissue structure in vivo. Moreover, we used the Morris water maze to verify CGA’s effects on enhancing the learning and cognitive ability and helping to maintain the long-term spatial memory after HI injury. However, Sirt1 inhibitor EX-527 partially reversed these therapeutic effects. CGA pretreatment inhibited neuronal apoptosis induced by HI by reducing inflammation and oxidative stress. The findings suggest that CGA potentially activates Sirt1 to regulate the Nrf2-NF-κB signaling pathway by forming complexes thereby protecting primary neurons from oxygen-glucose deprivation (OGD) damage. Also, CGA treatment significantly suppresses HI-induced proliferation of glial.ConclusionCollectively, this study uncovered the underlying mechanism of CGA on neonatal HI brain damage. CGA holds promise as an effective neuroprotective agent to promote neonatal brain recovery from HI-induced injury.Graphical 8NePktn-RrRjrUAHAHCXyYVideo

Chlorogenic acid ameliorates torsion/detorsion-induced testicular injury via decreasing endoplasmic reticulum stress

Testicular torsion (TT) is an urological emergency situation especially in adolescents and young men. The main pathophysiology of testicular torsion/detorsion (T/D) is ischemia-reperfusion (I/R) injury. I/R induces the production of reactive oxygen species (ROS) thought to play a critical role in tissue injury. Increasing evidence suggests that ER stress may play an important role in I/R-induced cell death. During ischemia, oxygen and glucose deprivation also causes abnormalities in protein folding processes. Antioxidants suppress oxidative stress directly as well as ER stress and thus gain importance in the treatment of pathologies associated with oxidative stress and ER stress, such as I/R damage. Chlorogenic acid (CGA) which is formed by the esterification of caffeic and quinic acids and is one of the most abundant phenolic acids in nature. There is also a growing body of studies reporting protective effects of CGA against I/R injury in different tissues, including intestinal, heart and brain. To investigate the effects of CGA on oxidative stress and ER stress in an experimental testicular I/R injury model. Rats were divided into three groups: control, T/D, and T/D+CGA. In the T/D+CGA group, 100mg/kg CGA was given intraperitoneally 30min before detorsion. While tissue malondialdehyde (MDA) levels were determined manually using a colorimetric method, tissue superoxide dismutase (SOD), 78-kDa glucose regulatory protein (GRP78), activating transcription factor 6 (ATF6) and C/EBP homologous protein (CHOP) levels were determined enzyme-linked immunosorbent assay (ELISA) kits. Johnsen's testicle scoring system was used for histological evaluation. In T/D group, tissue MDA, GRP78, ATF6 and CHOP levels were significantly higher than control group (p<0.05). These increases were significantly reversed with CGA pre-treatment (p<0.05). The histopathological Johnsen score was significantly lower in the T/D group compared to the control group, but the level of histopathological Johnsen score was significantly restored by CGA pre-treatment (p<0.05). The relationship between I/R injury and ER stress has been emphasized frequently in recent years. This study in which the effects of CGA on TT were examined for the first time, showed that CGA can inhibit I/R-induced testicular damage. These results may provide a new insight into CGA and may form the first clinical theoretical basis for the possible use of CGA in the treatment of TT in the future. However, the real function of CGA in TT patients needs further investigation.

Chlorogenic acid co-administration abates tamoxifen-mediated reproductive toxicities in male rats: An experimental approach.

Reports over the years have demonstrated toxic side effect-including reproductive toxicity- of tamoxifen (TAM), a drug of choice in the management of primary breast cancer. Chlorogenic acid (CGA), a dietary polyphenol, reportedly elicits beneficial pharmacological effects. However, the impact of CGA on TAM-associated reproductive toxicity is absent in the literature. We, therefore, experimented on CGA's effect and TAM-mediated reproductive toxicity in rats. Cohorts of rats were treated with TAM (50mg/kg) or co-treated with CGA (25 or 50mg/kg) for 14 consecutive days. The result showed that treatment of CGA significantly increases testosterone, LH, and FSH levels compared to the TAM group. However, prolactin level was markedly decreased after pretreatment of CGA in TAM-treated rats. CGA abated TAM-induced decreases acid phosphatase, alkaline phosphatase, and antioxidant enzymes in the testis. CGA alleviated TAM-facilitated surges of reactive oxygen and nitrogen species, myeloperoxidase, nitric oxide, interleukin-1β, and tumor necrosis factor-alpha in rats epididymis and testes. Additionally, CGA increased anti-inflammatory cytokine -interleukin-10-, suppressed caspase-3 activity, and reduced pathological lesions in the examined organs of rats co-treated with CGA and TAM. CGA phytoprotective effect improved reproductive function occasioned by TAM-mediated toxicities in rats, by abating oxido-inflammatory damages and downregulating apoptotic responses. PRACTICAL APPLICATIONS: CGA protects against the damaging oxido-inflammatory responses incumbent on TAM metabolism. As an antioxidant abundant in plant-derived foods, CGA reportedly protects against inflammatory damage, hypertension, and neurodegenerative diseases. We present evidence that CGA ameliorates TAM-induced reproductive dysfunction by suppressing oxidative and inflammation stress downregulate apoptosis and improve reproductive function biomarker in rats.

Dietary chlorogenic acid ameliorates oxidative stress and improves endothelial function in diabetic mice via Nrf2 activation.

ObjectivesChlorogenic acid (CGA) is an antioxidant dietary factor. We investigated the effects of CGA on endothelial cell dysfunction in diabetic mice and the mechanistic role of nuclear factor erythroid-related factor 2 (Nrf2) in the antioxidant effect of CGA.MethodsDiabetic (db/db) mice were fed normal chow or chow containing 0.02% CGA for 12 weeks. Human umbilical vein endothelial cells (HUVECs) and mouse aortas were treated with normal or high glucose.ResultsCGA treatment induced upregulation of Nrf2 in HUVECs in a dose-dependent manner. CGA pretreatment prevented reactive oxygen species generation and preserved nitric oxide bioavailability in HUVECs and aortas from wild-type but not Nrf2−/− mice. CGA improved endothelium-dependent relaxation in high glucose-treated aortas from wild-type and db/db mice, but not Nrf2−/− mice. Dietary CGA improved endothelium-dependent relaxation in db/db mice.ConclusionsCGA ameliorates endothelial dysfunction in diabetic mice through activation of the Nrf2 anti-oxidative pathway.

Effect of chlorogenic acid on alleviating inflammation and apoptosis of IPEC-J2 cells induced by deoxyniyalenol

Deoxynivalenol (DON) is extensively detected in many kinds of foods and feeds to harm human and animal health. This research aims to investigate the effect of chlorogenic acid (CGA) on alleviating inflammation and apoptosis of swine jejunal epithelial cells (IPEC-J2) triggered by DON. The results demonstrated that cell viability was decreased when DON concentrations increased or incubation time expanded. The pretreatment with CGA (40 μg/mL) for 1 h increased cell viability, decreased lactate dehydrogenase (LDH) release and apoptosis in cells triggered by DON at 0.5 μg/mL for 6 h, compared with the DON alone-treated cells. Moreover, the mRNA abundances of IL-8, IL-6, TNF-α, COX-2, caspase-3, Bax and ASCT2 genes, and protein expressions of COX-2, Bax and ASCT2 were significantly down-regulated; while the mRNA abundances of ZO-1, claudin-1, occludin, PePT1 and GLUT2 genes, and protein expressions of ZO-1, claudin-1 and PePT1 were significantly up-regulated in the CGA + DON group, compared with the DON alone group. This study indicated that CGA pretreatment alleviated cytotoxicity, inflammation and apoptosis in DON-triggered IPEC-J2 cells, and protected intestinal cell integrity from DON damages.

Experimental Pretreatment with Chlorogenic Acid Prevents Transient Ischemia-Induced Cognitive Decline and Neuronal Damage in the Hippocampus through Anti-Oxidative and Anti-Inflammatory Effects.

Chlorogenic acid (CGA), an ester of caffeic acid and quinic acid, is among the phenolic acid compounds which can be naturally found in green coffee extract and tea. CGA has been studied since it displays significant pharmacological properties. The aim of this study was to investigate the effects of CGA on cognitive function and neuroprotection including its mechanisms in the hippocampus following transient forebrain ischemia in gerbils. Memory and learning following the ischemia was investigated by eight-arm radial maze and passive avoidance tests. Neuroprotection was examined by immunohistochemistry for neuronal nuclei-specific protein and Fluoro-Jade B histofluorescence staining. For mechanisms of the neuroprotection, alterations in copper, zinc-superoxide dismutase (SOD1), SOD2 as antioxidant enzymes, dihydroethidium and 4-hydroxy-2-nonenal as indicators for oxidative stress, and anti-inflammatory cytokines (interleukin (IL)-4 and IL-13) and pro-inflammatory cytokines (tumor necrosis factor α (TNF-α) and IL-2) were examined by Western blotting and/or immunohistochemistry. As a result, pretreatment with 30 mg/kg CGA attenuated cognitive impairment and displayed a neuroprotective effect against transient forebrain ischemia (TFI). In Western blotting, the expression levels of SOD2 and IL-4 were increased due to pretreatment with CGA and, furthermore, 4-HNE production and IL-4 expressions were inhibited by CGA pretreatment. Additionally, pretreated CGA enhanced antioxidant enzymes and anti-inflammatory cytokines and, in contrast, attenuated oxidative stress and pro-inflammatory cytokine expression. Based on these results, we suggest that CGA can be a useful neuroprotective material against ischemia-reperfusion injury due to its antioxidant and anti-inflammatory efficacies.

Nephroprotective effects of chlorogenic acid against sodium arsenite-induced oxidative stress, inflammation, and apoptosis.

Chronic exposure to arsenic (As) leads to serious renal disorders. Chlorogenic acid (CGA), a phenolic compound, has several well known physiological benefits, including antioxidant and anti-inflammatory activities. The present study investigated the potential renoprotective effects of CGA on sodium arsenite (NaAsO2 )-induced kidney damage in mice. The mice were randomly allocated into five groups to receive daily treatment with CGA (200 mg kg-1 ), NaAsO2 (5 mg kg-1 ), NaAsO2 + CGA (100 mg kg-1 ), NaAsO2 + CGA (200 mg kg-1 ), or a control for 28 days. In the NaAsO2 -treated group, NaAsO2 induced significant renal dysfunction, oxidative damage, inflammation, and apoptosis, as demonstrated by marked increases in urea and creatinine levels accompanied by a decrease in the kidney index. Considerable increases in malondialdehyde and nitric oxide levels and parallel decreases in various antioxidant markers (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione) levels were also detected in the renal tissues of NaAsO2 -treated mice. NaAsO2 exposure was associated with marked increases in renal inflammatory markers (interleukin-1β and tumor necrosis factor-α) and apoptosis indicators including Bax and caspase-3 levels contaminant, with a marked decrease in Bcl-2, an anti-apoptotic protein, in the NaAsO2 -treated group compared with the control group. However, pretreatment with CGA substantially mitigated the renal injury and dysfunction associated with NaAsO2 exposure by reducing tissue inflammation and apoptosis and improving the antioxidant status. The CGA pretreatment also alleviated the NaAsO2 -induced histological alterations in renal tissues. Taken together, our results suggest the efficacy of CGA in alleviating As-mediated renal tissue damage. © 2020 Society of Chemical Industry.

The Protective Effect of Chlorogenic Acid on Vascular Senescence via the Nrf2/HO-1 Pathway.

The world faces the serious problem of aging. In this study, we aimed to investigate the effect of chlorogenic acid (CGA) on vascular senescence. C57/BL6 female mice that were 14 ± 3 months old were infused with either Angiotensin II (AngII) or saline subcutaneously for two weeks. These mice were administered CGA of 20 or 40 mg/kg/day, or saline via oral gavage. AngII infusion developed vascular senescence, which was confirmed by senescence associated-β-galactosidase (SA-β-gal) staining. CGA administration attenuated vascular senescence in a dose-dependent manner, in association with the increase of Sirtuin 1 (Sirt1) and endothelial nitric oxide synthase (eNOS), and with the decrease of p-Akt, PAI-1, p53, and p21. In an in vitro study, with or without pre-treatment of CGA, Human Umbilical Vein Endothelial Cells (HUVECs) were stimulated with H2O2 for an hour, then cultured in the absence or presence of 0.5–5.0 μM CGA for the indicated time. Endothelial cell senescence was induced by H2O2, which was attenuated by CGA treatment. Pre-treatment of CGA increased Nrf2 in HUVECs. After H2O2 treatment, translocation of Nrf2 into the nucleus and the subsequent increase of Heme Oxygenase-1 (HO-1) were observed earlier in CGA-treated cells. Furthermore, the HO-1 inhibitor canceled the beneficial effect of CGA on vascular senescence in mice. In conclusion, CGA exerts a beneficial effect on vascular senescence, which is at least partly dependent on the Nuclear factor erythroid 2-factor 2 (Nrf2)/HO-1 pathway.

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.

Chlorogenic acid promotes the Nrf2/HO-1 anti-oxidative pathway by activating p21Waf1/Cip1 to resist dexamethasone-induced apoptosis in osteoblastic cells

In a previous study, p21Waf1/Cip1 (p21) promoted activation of the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway, which has an important role in regulating apoptosis triggered by oxidative stress and inhibiting development of osteoporosis. Chlorogenic acid (CGA) has a strong protective effect on osteoporosis, closely related to activating the Nrf2/HO-1 pathway. However, whether CGA can resist apoptosis by regulating p21 and consequently promote activation of the Nrf2/HO-1 pathway needs further investigation. MC3T3-E1 cells were treated with dexamethasone (Dex), with or without CGA pre-treatment. Cell proliferation and cytotoxicity were measured using MTT assay and LDH release assay, respectively, and apoptosis assessed by flow cytometry. CGA significantly attenuated mitochondrial apoptosis and reversed down-regulation of p21 in osteoblastic MC3T3-E1 cells exposed to Dex. Additionally, CGA decreased Keap1 expression and promoted activation of the Nrf2/HO-1 pathway, quenching intracellular reactive oxygen species (ROS), hydrogen peroxide (H2O2) and mitochondrial superoxide overproduction boosted by Dex. Importantly, depletion of p21 by siRNA blocked activation of the Nrf2/HO-1 pathway, enhanced oxidative stress and increased apoptosis induced by CGA in MC3T3-E1 cells challenged with Dex. Therefore, CGA promoted the Nrf2/HO-1 anti-oxidative pathway by activating p21 to prevent Dex-induced mitochondrial apoptosis in osteoblastic cells. This pathway has potential as a therapeutic target for prevention and treatment of osteoporosis.