Caffeic Acid Phenethyl Ester Treatment Research Articles

Abstract 2591: Caffeic acid phenethyl ester (CAPE) suppresses melanoma tumor growth by inhibiting AKT/XIAP pathway

Abstract The incidence of melanoma is constantly on the rise indicating that current available therapies are not very effective. Moreover, melanoma is highly metastatic and resistant to chemotherapeutic drugs. Our previous studies have demonstrated that caffeic acid phenethyl ester (CAPE) suppress the growth of melanoma cells and induce ROS generation. However, the exact mechanism of the growth suppressive effects of CAPE was not clear. Here we determined the potential mechanism of CAPE against melanoma in vitro and in vivo. In a concentration and time-dependent study, CAPE treatment suppressed the activating phosphorylation of PI3K at Tyr-458, PDK1 at Ser-241, mTOR at Ser-2448 and AKT at Ser-473 in B16F0 and SK-MEL-28 melanoma cells. Furthermore, the expression of XIAP, survivin and BCl2 were down-regulated by CAPE treatment in both the cell lines. Significant apoptosis was observed in both the cell lines by CAPE treatment as indicated by cleavage of caspase-3 and PARP. AKT kinase activity was inhibited by CAPE in a concentration-dependent manner. Since Akt regulates XIAP, their interaction was examined by immunoprecipitation studies. Our results show that CAPE treatment decreased the interaction of AKT with XIAP. To establish the involvement of Akt in the apoptosis-inducing effects of CAPE, cells were transfected with Akt. Our results reveal that AKT over-expression attenuated the decrease in XIAP and significantly blocked CAPE-mediated apoptosis. Similarly, over-expression of XIAP further decreased CAPE-induced apoptosis. To confirm the involvement of ROS in the inhibition of AKT/XIAP pathway, cells were treated with antioxidant NAC prior to CAPE treatment. Our results indicate that NAC blocked CAPE mediated AKT/XIAP inhibition and protected the cells from apoptosis. In addition, oral administration of 10mg/kg/day CAPE substantially suppressed the growth of B16F0 tumor xenografts in C57BL/6 mice. Tumors from CAPE treated mice showed reduced phosphorylation of PI3K, AKT, mTOR and protein level of XIAP and enhanced the cleavage of caspase-3 and PARP. Taken together, our results suggest that CAPE suppresses AKT/XIAP pathway leading to apoptosis in melanoma tumor cells in vitro and in vivo. [Supported in part by R01 grant CA129038 (to S.K.S) awarded by the National Cancer Institute]. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2591. doi:1538-7445.AM2012-2591

Caffeic Acid Phenethyl Ester protects burn wounds against oxidative stress and improves wound healing

Caffeic acid phenethyl ester (CAPE) is an active component of propolis, and has been shown to have anti‐inflammatory and antioxidant effects; in this study we studied its effects on burn wound healing. Twenty one female Wistar rats were divided in three groups: control (no burn)+CAPE, burn and burn+CAPE. A third‐degree burn was created. The CAPE treatment (10 μmol kg‐1; i.p.) began immediately after burn and lasted until euthanasia (14 days after burn). Fourteen days after wounding the burn+CAPE group presented greater wound contraction when compared to burn group. In plasma, lipid peroxidation was higher in burn group compared to control and burn+CAPE group. In wounds, burn+CAPE group presented a smaller lipid peroxidation than burn group. Carbonyl levels in plasma and lesions of the burn group were increased when compared to control group. In burn+CAPE group carbonyls levels were greater than the control only in wounds. Catalase activity was also analysed, and burn+CAPE group presented greater activity when compared to burn, but without difference when compared to the control group. It was also observed that both burn and burn+CAPE groups present a higher myeloperoxidase activity than control group, but the burn+CAPE group presented smaller myeloperoxidase activity compared to burn group. CAPE treatment improved wound contraction and reduced the oxidative damage of burns.Support: CAPES

Role of caffeic acid phenethyl ester on mitomycin C induced clastogenesis: analysis of chromosome aberrations, micronucleus, mitotic index and adenosine deaminase activity in vivo

The aim of the present investigation is to determine whether the caffeic acid phenethyl ester (CAPE) in combination with mitomycine-C (MMC) can ameliorate MMC-induced clastogenesis in the bone marrow cells of mice. The scoring of chromosomal aberrations, mitotic activity and micronuclei were undertaken in the current study as markers of clastogenicity. The action of CAPE in adenosine deaminase enzyme (ADA) activities of serum, thymus and spleen were also investigated. The animals were orally administered CAPE alone at the doses 5 or 10mgkgb.wt.(-1) for 5days then sacrificed 24hours after the CAPE administration. MMC was administered to mice either alone at a single dose (2mgkgb.wt.(-1)) by intraperitoneal injection, before or after CAPE treatment. Pre or post - treatment with two doses of CAPE significantly decreased the number of chromosomal aberrations, micronuclei and adapted the mitotic activity reduction in the bone marrow cells of mice induced by MMC when compared with only MMC given group. In addition, combination treatment with MMC caused a significant decrease in the activities of ADA in serum, thymus and spleen. The results of this study showed that ADA activity probably related to high levels of reactive oxygen species. This study concluded that the protective effect of CAPE against MMC clastogenesis resides at least in part, in its antioxidant effects.

Caffeic Acid Phenethyl Ester Protects Blood–Brain Barrier Integrity and Reduces Contusion Volume in Rodent Models of Traumatic Brain Injury

A number of studies have established a deleterious role for inflammatory molecules and reactive oxygen species (ROS) in the pathology of traumatic brain injury (TBI). Caffeic acid phenethyl ester (CAPE) has been shown to exert both antioxidant and anti-inflammatory effects. The primary objective of the present study was to examine if CAPE could be used to reduce some of the pathological consequences of TBI using rodent models. Male Sprague-Dawley rats and C57BL/6 mice were subjected to controlled cortical impact (CCI) injury. Blood-brain barrier (BBB) integrity was assessed by examining claudin-5 expression and the extravasation of Evans blue dye. The effect of post-injury CAPE administration on neurobehavioral function was assessed using vestibulomotor, motor, and two hippocampus-dependent learning and memory tasks. We report that post-TBI administration of CAPE reduces Evans blue extravasation both in rats and mice. This improvement was associated with preservation of the levels of the tight junction protein claudin-5. CAPE treatment did not improve performance in either vestibulomotor/motor function (tested using beam balance and foot-fault tests), or in learning and memory function (tested using the Morris water maze and associative fear memory tasks). However, animals treated with CAPE were found to have significantly less cortical tissue loss than vehicle-treated controls. These findings suggest that CAPE may provide benefit in the treatment of vascular compromise following central nervous system injury.

Caffeic acid phenethyl ester extends survival of a mouse model of amyotrophic lateral sclerosis

There is currently very limited effective pharmacological treatment for amyotrophic lateral sclerosis. Recent evidence suggests that caffeic acid phenethyl ester has strong anti-inflammatory, anti-oxidative, and anti-neuronal death properties; thus, the present study tested the effects of caffeic acid phenethyl ester in mice expressing a mutant superoxide dismutase (SOD1G93A) linked to human amyotrophic lateral sclerosis. Administration of caffeic acid phenethyl ester after symptom onset significantly increased the post-onset survival and lifespan of SOD1G93A mice. Moreover, immunohistochemical analysis detected less activation of microglia and astrocytes and higher motor neuron counts at an early symptomatic stage (7 days following onset) in the spinal cords of SOD1G93A mice given caffeic acid phenethyl ester treatment. Additionally, lower levels of phosphorylated p38, a mitogen-activated protein kinase that is involved in both inflammation and neuronal death, were observed in the spinal cords of SOD1G93A mice treated with caffeic acid phenethyl ester for 7 days. These results indicate that caffeic acid phenethyl ester may represent a novel and effective therapeutic for the treatment of amyotrophic lateral sclerosis, and these significant neuroprotective effects observed in a commonly used amyotrophic lateral sclerosis mouse model validate the therapeutic potential of caffeic acid phenethyl ester for slowing disease progression by attenuating the neuroinflammation and motor neuron cell death associated with clinical amyotrophic lateral sclerosis pathology.

Neuroprotective effects of Caffeic acid phenethyl ester on experimental traumatic brain injury in rats

The aim of this study was to evaluate the therapeutic efficacy of caffeicacid phenethyl ester (CAPE) with an experimental traumatic brain injury (TBI) model in rats. Twenty-four adult male Sprague-Dawley rats were randomly divided into three groups of 8 rats each: control, TBI, and TBI+CAPE treatment. In TBI and TBI+CAPE treatment groups, a cranial impact was delivered to the skull from a height of 7cm at a point just in front of the coronal suture and over the right hemisphere. Rats were sacrificed at 4h after the onset of injury. Brain tissues were removed for biochemical and histopathological investigation. To date, no biochemical and histopathological changes of neurodegeneration in the frontal cortex after TBI in rats by CAPE treatment have been reported. The TBI significantly increased tissue malondialdehyde (MDA) levels, and significantly decreased tissue superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, but not tissue catalase (CAT) activity, when compared with controls. The administration of a single dose of CAPE (10μmol/kg) 15min after the trauma has shown protective effect via decreasing significantly the elevated MDA levels and also significantly increasing the reduced antioxidant enzyme (SOD and GPx) activities, except CAT activity. In the TBI group, severe degenerative changes, shrunken cytoplasma and extensively dark picnotic nuclei in neurons, as well as vacuolization indicating tissue edema formation. The morphology of neurons in the CAPE treatment group was well protected. The number of neurons in the trauma alone group was significantly less than that of both the control and TBI +CAPE treatment groups. The caspase 3 immunopositivity was increased in degenerating neurons of the traumatic brain tissue. Treatment of CAPE markedly reduced the immunoreactivity of degenerating neurons. TBI caused severe degenerative changes, shrunken cytoplasma, severely dilated cisternae of endoplasmic reticulum, markedly swollen mitochondria with degenerated cristae and nuclear membrane breakdown with chromatin disorganization in neurons of the frontal cortex. In conclusion, the CAPE treatment might be beneficial in preventing trauma-induced oxidative brain tissue damage, thus showing potential for clinical implications. We believe that further preclinical research into the utility of CAPE may indicate its usefulness as a potential treatment on neurodegeneration after TBI in rats.

Caffeic Acid Phenethyl Ester Inhibits Proliferation and Migration, and Induces Apoptosis in Platelet-Derived Growth Factor-BB-Stimulated Human Coronary Smooth Muscle Cells

Background/Aims: Restenosis after a percutaneous coronary intervention (PCI) during treatment for coronary artery disease is closely related to smooth muscle cell (SMC) proliferation and migration. In this study, we investigated the effects of caffeic acid phenethyl ester (CAPE) and its underlying mechanism on human coronary SMCs (HCSMCs) after platelet-derived growth factor-BB (PDGF-BB) stimulation in vitro. Methods and Results: The results showed that CAPE inhibited proliferation and migration, and induced apoptosis. Concomitantly, CAPE inhibited activation of AKT1, MEK1 and ERK1/2 signaling molecules at 10–60 min after CAPE treatment. As revealed by flow cytometry, DNA fragmentation and TUNEL assay, the cells accumulated at the sub-G₁ phase, and cell apoptosis was observed after 30 and 90 µM CAPE treatment for 72 h. CAPE triggered the release of cytochrome c from mitochondria to cytosol, upregulated the proapoptotic gene Bax and downregulated the antiapoptotic gene Bcl-2. Upregulation of caspase-9 and caspase-3 indicated that CAPE precipitated the mitochondrion-dependent apoptotic signaling pathway. Conclusions: These results provide a molecular explanation for the antiproliferation, antimigration and proapoptotic effects of CAPE on HCSMCs after PDGF-BB stimulation.

Caffeic acid phenethyl ester (CAPE) prevents methotrexate-induced hepatorenal oxidative injury in rats

This study aimed to investigate the antioxidant and anti-inflammatory effects of caffeic acid phenethyl ester (CAPE) on the methotrexate (MTX)-induced hepatorenal oxidative damage in rats. Following a single dose of methotrexate (20 mg/kg), either vehicle (MTX group) or CAPE (10 µmol/kg, MTX + CAPE group) was administered for five days. In other rats, vehicle (control group) or CAPE was injected for five days, following a single dose of saline injection. After decapitation of the rats, trunk blood was obtained, and the liver and kidney tissues were removed for histological examination and for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels and myeloperoxidase (MPO) and sodium potassium-adenosine triphosphatase (Na(+)/K(+) -ATPase) activity. TNF-α and IL-1β levels were measured in the blood. Methotrexate administration increased the tissue MDA levels, MPO activity and decreased GSH levels and Na(+)/K(+) -ATPase activity, while these alterations were reversed in the CAPE-treated MTX group. Elevated TNF-α and IL-1β levels were also reduced with CAPE treatment. The results of this study revealed that CAPE, through its anti-inflammatory and antioxidant actions, alleviates methotrexate-induced oxidative damage, which suggests that CAPE may be of therapeutic benefit when used with methotrexate.

The efficiency of CAPE on retardation of hepatic fibrosis in biliary obstructed rats

The aim of this study was to evaluate the possible protective effects of caffeic acid phenethyl ester (CAPE) against cholestatic oxidative stress and liver damage in the common bile duct ligated rats. A total of 18 male Sprague-Dawley rats were divided into three groups: control, bile duct ligation (BDL) and BDL + received CAPE; each group contain 6 animals. The rats in CAPE treated groups were given CAPE (10 μmol/kg) once a day intraperitoneally (i.p) for 2 weeks starting just after BDL operation. The changes demonstrating the bile duct proliferation and fibrosis in expanded portal tracts include the extension of proliferated bile ducts into lobules, inflammatory cell infiltration into the widened portal areas were observed in BDL group. Treatment of BDL with CAPE attenuated alterations in liver histology. The proliferating cell nuclear antigen and the activity of TUNEL in the BDL were observed to be reduced with the QE treatment. The application of BDL clearly increased the tissue hydroxyproline (HP) content, malondialdehyde (MDA) levels and decreased the antioxidant enzyme (superoxide dismutase (SOD), glutathione peroxidase (GPx)) activities. CAPE treatment significantly decreased the elevated tissue HP content, and MDA levels and raised the reduced of SOD, and GPx enzymes in the tissues. The data indicate that CAPE attenuates BDL-induced cholestatic liver injury, bile duct proliferation, and fibrosis. The hepatoprotective effect of CAPE is associated with antioxidative potential.

Abstract 3344: CAPE-induced inhibition of breast cancer stem cells (CSC) self-renewal and growth by differentiation to a less malignant phenotype

Abstract Introduction: Cancer stem cells (CSC) are implicated in tumor metastasis, recurrence, and high patient mortality, thus, substances impairing their activity, e.g., self-renewal, could be invaluable as novel cancer therapeutics. We propose that CAPE (caffeic acid phenethyl ester), a component of propolis, a honeybee product, could be such an agent. CSC are known for their chemoresistance. We previously showed that CAPE inhibits growth of MDA-231 (231) cells, a model of human triple-negative breast cancer, multidrug resistance gene expression, NF-κB, EGFR, and VEGF. We hypothesized that CAPE could also affect CSC-mediated effects. Methods: We isolated CSC from 231 cells and mouse xenografts, and propagated them in low adherence tissue culture plates without serum. CSC characteristics, ie Hoechst 33342 dye exclusion and CD44+/CD24-/low/EpCAMlow phenotype, were assessed by flow cytometry, while clonal growth was assayed in soft agar. CSC were treated with CAPE (0-40 μM) for 4 or 7 days. Apoptosis was assessed by Annexin V/propidium iodide staining. Cell cycle analysis was done according to standard protocol and analysis by ModFit software. Results: 231-derived CSC grow as mammospheres (MMS), and when dissociated into single cells, form MMS again. This process was repeated for many generations and is considered a sign of self-renewal. These cells excluded Hoechst 33342 dye, exhibited characteristic CD44+/CD24-/low/EpCAMlow phenotype, and generated progenitors in presence of serum, a CSC trait responsible for regenerating tumor mass. CAPE inhibited CSC self-renewal, progenitors’ generation, and growth of CSC-derived tumor cells. Treatment of CSC with CAPE for 4.5 days decreased CD44 levels by ∼95%, while another cell population containing 10-100-fold lower CD44 content concurrently increased. Incubation of CSC with different CAPE doses for 4 days caused dose-dependent cell growth inhibition. After pre-treating cells with CAPE, the same numbers of live cells were taken from each well and plated on soft agar. Clonal growth was also inhibited in a dose-dependent fashion, but apoptosis was not induced as determined by Annexin V/PI assay. Instead, CSC were noted to significantly progress from a quiescent cell cycle state in G0/G1 (82%), S phase (12%) to a cycling state with an increase in S phase (41%) and subsequent decrease in G0/G1 (54%). Conclusions: These results suggest that CAPE causes pronounced changes in CSC characteristics manifested by inhibition of clonal growth in soft agar and concurrent significant decrease in CD44 content, a sign of decreased potential of malignancy. This conclusion is strengthened by the observation that the CSC are induced into a more differentiated state that is less malignant after CAPE treatment. Our results strongly suggest that CAPE could be an inhibitor of CSC making them more susceptible to chemotherapy. [grants BCTR0600476 & ES00260] Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3344. doi:10.1158/1538-7445.AM2011-3344

Protective Effects of CAPE on Liver Injury Induced by CCL4: An Electron Microscopy Study

This study was designed to investigate the protective effects of caffeic acid phenethyl ester on carbon tetrachloride-induced liver damage in rats. Twenty-four male Wistar rats were divided in three groups. Group I was used as control. Rats in group II were injected with carbon tetrachloride every other day for 1 month, whereas rats in group III were injected with carbon tetrachloride and caffeic acid phenethyl ester every other day for 1 month. At the end of the experiment, all animals were killed by decapitation and their livers were removed. Liver tissues were processed for electron microscopy. Histopathologically, hepatocytes of rats treated with carbon tetrachloride had damage in the cytoplasmic organelles and nuclei membranes as well as an excessive lipid accumulation in the hepatocytes. However, those histopathological changes were reduced with the coadministration of carbon tetrachloride and caffeic acid phenethyl ester. We conclude that caffeic acid phenethyl ester treatment has the capability to prevent carbon tetrachloride-induced liver damage in rats.

Inhibition of AMPK-Associated Autophagy Enhances Caffeic Acid Phenethyl Ester-Induced Cell Death in C6 Glioma Cells

An increasing number of studies show that AMP-activated protein kinase (AMPK) activation can inhibit apoptosis. To clarify the antitumor mechanism of caffeic acid phenethyl ester (CAPE) and achieve increased therapeutic efficiency, we investigated the potential roles of AMPK and autophagy in CAPE treatment against C6 glioma cells. The roles of AMPK and autophagy inhibition in CAPE's cytotoxic action were investigated. Phosphorylation of AMPK and mitogen-activated protein kinases (MAPKs) were observed in tumor cells following CAPE treatment. A combination of CAPE and the AMPK inhibitor, compound C, resulted in augmented cell death. Similar effects of compound C were observed in response to changes in the mitochondrial membrane potential ( ΔΨ(m)). Small interfering RNA-mediated AMPK downregulation increased CAPE-induced cell death. The results suggest that AMPK activation plays a role in diminishing apoptosis. CAPE treatment induced an increase in LC3 conversion as represented by the LC3-II/LC3-I ratio. Enlarged lysosomes and autophagosomes were present according to electron microscopy. The autophagy inhibitor, 3-MA, caused increased CAPE cytotoxicity, which suggests that autophagy induction protected glioma cells from CAPE. The combination of CAPE with autophagy and AMPK inhibitors markedly enhanced the cytotoxicity toward C6 glioma cells. Accordingly, CAPE-triggered activation of AMPK and the autophagic response protected tumor cells from apoptotic death. This provides new insights for combined therapy to enhance the therapeutic potential of cancer treatments.

Caffeic Acid Phenethyl Ester Suppresses the Production of Adipocytokines, Leptin, Tumor Necrosis Factor -Alpha and Resistin, during Differentiation to Adipocytes in 3T3-L1 Cells

We previously reported that caffeic acid phenethyl ester (CAPE) suppresses 3T3-L1 differentiation to adipocytes through the inhibition of peroxisome proliferator-activated receptor (PPAR) gamma, CCAAT/enhancer-binding protein (C/EBP) alpha, fatty acid synthase (Fas) and adipocytes-specific fatty acid binding protein 2 (aP2) expressions (Juman et al., Biol. Pharm. Bull., 33, 1484-1488 (2010)). In the present study, we confirmed that CAPE had inhibitory effects on increased glycerol-3-phosphate dehydrogenase (GPDH) activity and an increased insulin receptor substrate 1 (IRS-1). Our data show that treatment with 50 µM CAPE significantly reduced the levels of leptin (p<0.05), resistin (p<0.05) and tumor necrosis factor (TNF)-alpha (p<0.05) which are known to aid adipocytokines production in adipocytes. In 3T3-L1 cells, treatment of CAPE decreased the triglyceride deposition similar to resveratrol, which is known to have an inhibitory effect on 3T3-L1 differentiation to adipocytes. In conclusion, we found that CAPE suppresses the production and secretion of adipocytokines from mature adipocytes in 3T3-L1 cells.

Effects of Caffeic Acid Phenethyl Ester (CAPE) on Hepatopulmonary Syndrome

The aim of this study was to investigate the effects of caffeic acid phenethyl ester (CAPE) on inflammatory and related histopathological changes in the lung and liver in experimental hepatopulmonary syndrome (HPS) model. Forty Sprague Dawley rats were used in this study. The animals were divided into four groups of ten rats each. Group 1 and 2 was subjected the common bile duct (CBD) but not ligated, Group 3; (cirrhosis + saline): the CBD was ligated and was given intraperitoneal saline infusion treatment during 5 weeks. Group 4; (cirrhosis + CAPE): the CBD was ligated and was given intraperitoneal CAPE infusion treatment during 5 weeks. A 5-week waiting period was observed for the development of cirrhosis and the rats' lungs and liver were taken for histopathological examination. The induction of HPS resulted in a significant increase in serum bilurubin, AST, ALT, and NO levels, and decrease PO2 and O2 saturation. The use of CAPE significant decrease these parameters. Histopathological examination revealed less congestion, portal inflammation, and nodular formations of the liver, and less congestion, emphysematous and inflammatory changes and smallest perialviolar vascular diameters, in the lung in the cirrhosis + CAPE groups than in the other groups. CAPE treatment may be a potential approach for the treatment of hepatopulmonary syndrome in the future.

Antitumor progression potential of caffeic acid phenethyl ester involving p75 NTR in C6 glioma cells

The previous data showed that caffeic acid phenethyl ester (CAPE), a component of propolis, possesses inducing cell cycle arrest and antiproliferation effect on C6 glioma cells in vitro and in vivo. In the present study, C6 glioma cells treated with CAPE resulted in morphological changes to an astrocytic phenotype and increased the expression of glial differentiation marker proteins including glial fibrillary acidic protein (GFAP) and S-100β. In addition, with scratch assay and Boyden chamber assay, CAPE exhibited inhibitory effects on the motility and invasion of C6 glioma cells. Furthermore, CAPE induced the expression of nerve growth factor (NGF) and p75 neurotrophin receptor (p75 NTR), which were involved in neural cell differentiation. CAPE could also inhibit the activity of matrix metalloproteinases (MMPs) and induce the expression of RhoB, a tumor suppressor. To examine the involvement of p75 NTR in the anti-invasive property of CAPE, Western blotting and Boyden Chamber assay were performed by addition of an anti-p75 NTR antibody in C6 cells. The results showed that blocking p75 NTR could decrease the CAPE-induced expression of RhoB and the inactivation of MMP-2, -9 as well as the anti-invasion effect in C6 glioma cells. Furthermore, CAPE suppressed IκB-α phosphorylation which was down stream of p75 NTR. Finally, the effect of CAPE on metastasis by lung colonization of the tumor cell in nude mice was also evaluated. It was found that the groups of nude mice injected with CAPE-pretreated cells could decrease both lung size and weight as compared to the positive control group which did not receive CAPE treatment. In addition, histological examination of the mouse lung sections showed that the CAPE-treated group inhibited the metastasis of C6 glioma cells. These data suggest CAPE possesses antitumor progression potential.

Effects of caffeic acid phenethyl ester on thioacetamide-induced hepatic encephalopathy in rats

Hepatic encephalopathy (HE) is a major neurological complication secondary to severe liver failure. The aim of the present study was to examine the possible neuroprotective effects of caffeic acid phenethyl ester (CAPE) with or without laxative treatment against thioacetamide-induced HE by investigating behavioral and motor activities in rats as well as blood ammonia level and oxidant–antioxidant parameters of cortex, brain stem and cerebellum. After induction of HE by thioacetamide, the rats were treated with lactulose, CAPE (CAPE treatment was started one day before the first dose of thioacetamide) or CAPE plus lactulose. The behavioral and motor scales were measured at the 54th hour after the first thioacetamide injection, the blood samples and brains were taken under anesthesia at the 60th hour for biochemical analysis. The survival rates were 37.5% in HE group, 70% in HE + lactulose group, 80% in HE + CAPE group, and 100% in HE + CAPE + lactulose group. Increased ammonia, ALT and AST levels in blood along with impaired sensory-motor behavior tests were reversed to proximate control values in CAPE + lactulose treated group. There were increased lipid peroxidation and protein oxidation and decreased antioxidant enzyme activities in almost all brain parts of HE group. CAPE or lactulose treatment alone ameliorated those oxidant and antioxidant parameters; however, CAPE treatment together with lactulose reversed them to almost control level. In conclusion, thioacetamide-induced HE injury in rats was reversed almost fully by CAPE and laxative combination. There was no death in CAPE and laxative treated group animals and it may be due to the direct neuroprotective effect of CAPE together with the prevention of the body from ammonia production.

Effects of caffeic acid phenethyl ester on isoproterenol-induced myocardial infarction in rats

Caffeic acid phenethyl ester (CAPE) is a natural product with potent anti-inflammatory, antitumor and antioxidant activities and attenuates inflammation and lipid peroxidation induced by ischemia-reperfusion injury. The purpose of the present study was to investigate the effects of CAPE on isoproterenol (ISO) -induced myocardial infarction. A randomized controlled experimental design was used in this study. Rats were divided into four groups and treated with saline, CAPE, ISO and ISO+CAPE. Rats were treated with CAPE (10 micromol kg/day i.p.) or saline starting 3 days before injecting ISO (150 mg /kg s.c., 24 hours). Seven days later, rats were sacrificed and the hearts were excised for biochemical analyses and microscopic examination. One-way ANOVA test with post hoc multiple comparisons using LSD method were used for statistical analysis of the data. The administration of ISO alone resulted in higher myeloperoxidase (MPO) activity, lipid peroxidation, superoxide dismutase (SOD) and catalase (CAT) than in the control. The enzyme activities did not change in rat given CAPE alone. CAPE treatment prevented the increase in MPO activity and malondialdehyde, but did not affect the activities SOD and CAT enzymes. In light of these results, we conclude that CAPE prevents MPO-and lipid peroxidation-mediated myocardial injury via inhibition of neutrophil's MPO activity.

Inhibition of triple-negative breast cancer (TNBC) and breast cancer stem cells (bCSC) by caffeic acid phenethyl ester (CAPE).

e13587 Background: TNBC is a high mortality disease with a paucity of therapeutics. Our preclinical data used CAPE, a main component of propolis, a honeybee product credited with antiinflammatory, antioxidant, and antitumor properties. CAPE, which is innocuous to normal human mammary epithelial cells, inhibits growth of MDA-MB-231 (231) cells, MDR gene expression, NF-kB, EGFR and VEGF. We used 231 cells, a model of human TNBC, to show that CAPE can combat TNBC as a therapeutic, and/or adjuvant to chemotherapeutic drugs like Taxol. Cancer stem cells (CSC) are implicated in tumor metastasis and recurrence, thus, agents impairing their self-renewal, could be invaluable as novel cancer therapeutics. We show that CAPE could be such an agent, because it inhibits CSC growth and self renewal. We propose that the mechanism for this inhibition is due to the induction of CSC apoptosis. Methods: Nude mice bearing 231 xenografts were fed CAPE diets and/or treated topically with CAPE and tumors measured 2x/week. bCSC were isolated from 231 cells and xenografts and propagated as mammospheres. Cell growth was analyzed using MTT and cell cycle by flow cytometry. Apoptosis was determined by co-staining of bCSC with Annexin V and propidium iodide. Results: Dietary CAPE significantly inhibited growth of 231 xenografts. Subsequent topical CAPE treatment further decreased tumor volume. 231 cells contain bCSC thought to be responsible for metastasis and recurrence. CAPE decreased bCSC clonal growth and inhibited their self-renewal and progenitors as evidenced by decreased growth in soft agar after pretreatment with CAPE. Further, CAPE induced apoptosis of bCSC in a dose-dependent manner up to 20μM CAPE, but apoptosis was decreased at 40μM. Conclusions: Our results strongly suggest that low doses of CAPE reduce TNBC growth by oral and/or topical routes, most likely by suppressing bCSC self-renewal at least partly by inducing apoptosis. CAPE could be a powerful inhibitor of CSC-mediated recurrence of aggressive types of breast cancer including TNBC. Research is ongoing to delineate in detail the mechanism(s) contributing to CSC inhibition by CAPE as it relates to the changes in CSC characteristics and differentiation. No significant financial relationships to disclose.

Ameliorative effect of caffeic acid phenethyl ester on histopathological and biochemical changes induced by cigarette smoke in rat kidney

It was aimed to investigate the histopathological and biochemical changes in kidney tissues of rats exposed to cigarette smoke and possible protective effects of caffeic acid phenethyl ester (CAPE) on these changes. Twenty one male Wistar albino rats were divided into three equal groups. Animals in group I were used as control. Rats in group II were exposed to cigarette smoke and rats in group III were exposed to cigarette smoke and daily administration of CAPE. At the end of the 60-day experimental period, all the animals were sacrificed by decapitation. The serum samples obtained from the animals were studied for uric acid, creatinine and blood urine nitrogen (BUN) levels. Following routine histological procedures, kidney tissue specimens were examined under a light microscope. In addition, dismutase (SOD) and glutathione peroxidase (GSH-Px) enzyme activities and malondialdehyde (MDA) and nitric oxide (NO) contents were determined spectrophotometrically in tissue samples. It was found that serum uric acid and BUN levels of the rats exposed to cigarette smoke alone were elevated, although serum creatinine levels did not significantly change. Furthermore, renal SOD, GSH-Px, NO and MDA levels were significantly increased. These increases in serum BUN, and renal SOD, GSH-Px, NO and MDA levels were significantly inhibited by CAPE treatment. In light microscopic observations of tissues from rats exposed to smoke, mesangial cell proliferation in the renal corpuscles, dilatation and congestion in the peritubular capillaries and degenerative alterations in the proximal tubules were noted. There were also atrophic renal corpuscles. However, these histopathological changes were partially disappeared in the rats exposed to cigarette smoke plus CAPE. The present findings indicate that cigarette smoke causes impairment in renal structure and function, which can be prevented by CAPE administration.

Cigarette smoke enhances -defensin 2 expression in rat airways via nuclear factor- B activation

β-defensin 2 (BD-2), an antimicrobial peptide, participates in airway defence. Cigarette smoke (CS) is a major risk factor for the development of chronic obstructive pulmonary disease. This study mainly aims to investigate the effect of CS on rat BD-2 (rBD-2) expression in rat airways. Rats were exposed to CS and treated with caffeic acid phenethyl ester (CAPE), a nuclear factor (NF)-κB inhibitor, or astragaloside IV (AS-IV), an active ingredient of Astragalus mongholicus. Besides the analysis of bronchoalveolar lavage fluid (BALF) and histological changes after CS exposure, rBD-2 expression was investigated with immunohistochemistry, reverse transcription PCR and ELISA. Total glutathione and nitric oxide (NO) levels in rat lungs were also detected. CS exposure markedly increased rBD-2 immunoreactivity, as well as rBD-2 mRNA and protein levels in rat airways, which were inhibited by CAPE treatment. Moreover, associated airway inflammation induced by CS was demonstrated by histological changes, increased cell counts and pro-inflammatory cytokines in BALF, and NF-κB activation and high levels of total glutathione and NO, which were all reversed by AS-IV in a dose-dependent fashion. In conclusion, CS exposure induces rBD-2 expression in rat airways via a NF-κB-dependent pathway, and AS-IV attenuates CS-induced airway inflammation due to its anti-inflammatory and antioxidant properties, at least partly through NF-κB inactivation.