Effect of a propolis extract and caffeic acid phenethyl ester on formation of aberrant crypt foci and tumors in the rat colon

Bee Products and Colorectal Cancer—Active Components and Mechanism of Action

Colorectal cancer is one of the most common malignancies in the world. Lifestyle and eating patterns may have a significant impact on the prevention of this type of cancer. Bioactive food ingredients influence the gut microbiome and can have a protective effect. Bee products (honey, propolis, royal jelly, and bee venom) or pharmacologically active fractions obtained from them are widely used in many fields of medicine, pharmacy, and cosmetics. Some evidence suggests that bee products may have anti-cancer potential. The main bioactive components with anti-colon cancer potential from propolis and bee honey are polyphenols such as pinocembrin, galangin, luteolin, CAPE, Artepilin C, chrysin, caffeic, and p-coumaric acids. This review is focused on the new data on epidemiology, risk factors for colon cancer, and current reports on the potential role of bee products in the chemoprevention of this type of cancer.

Caffeic acid phenethyl ester ameliorates imidacloprid-induced acute toxicity in the rat cerebral cortex

This study aimed to investigate the role of caffeic acid phenethyl ester (CAPE), a compound found in propolis, on imidacloprid (IMI), a nicotinic acetylcholine receptor agonist that causes cerebral toxicity. 60 adult rats were randomly divided into five groups: control, IMI (100 mg/kg), and IMI+CAPE (1, 5, 10 mg/kg). Cerebral cortex tissue was examined histopathologically, biochemically, spectrophotometrically and immunohistochemically. The results showed that IMI caused toxicity in the cerebral cortex. However, CAPE (5 and 10 mg/kg) attenuated the deteriorated histopathological score and normalized the apoptotic markers (Bax and Caspase-3). Additionally, CAPE dose-dependently normalized the levels of TNF-α, dopamin, GFAP and NGF, and at the highest dose (10 mg/kg) also normalized the balance of oxidative parameters (MDA, SOD, CAT, and GSH). In conclusion, the antioxidant, anti-inflammatory, and anti-apoptotic effects of CAPE may be a promising treatment for acute IMI-induced cerebral cortex toxicity.

Mechanism of synergistic DNA damage induced by caffeic acid phenethyl ester (CAPE) and Cu(II): Competitive binding between CAPE and DNA with Cu(II)/Cu(I)

Caffeic acid phenethyl ester (CAPE) is an active polyphenol of propolis from honeybee hives, and exhibits antioxidant and interesting pharmacological activities. However, in this study, we found that in the presence of Cu(II), CAPE exhibited pro-oxidative rather than antioxidant effect: synergistic DNA damage was induced by the combination of CAPE and Cu(II) together as measured by strand breakage in plasmid DNA and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation, which is dependent on the molar ratio of CAPE:Cu(II). Production of Cu(I) and H₂O₂ from the redox reaction between CAPE and Cu(II), and subsequent OH formation was found to be responsible for the synergistic DNA damage. DNA sequencing investigations provided more direct evidence that CAPE/Cu(II) caused preferential cleavage at guanine, thymine and cytosine residues. Interestingly, we found there are competitive binding between CAPE and DNA with Cu(II)/Cu(I), which changed the redox activity of Cu(II)/Cu(I), via complementary applications of different analytical methods. The observed DNA damage was mainly attributed to the formation of DNA-Cu(II)/Cu(I) complexes, which is still redox active and initiated the redox reaction near the binding site between copper and DNA. Based on these data, we proposed that the synergistic DNA damage induced by CAPE/Cu(II) might be due to the competitive binding between CAPE and DNA with Cu, and site-specific production of OH near the binding site of copper with DNA. Our findings may have broad biological implications for future research on the pro-oxidative effects of phenolic compounds in the presence of transition metals.

Effects of caffeic acid on epigenetics in the brain of rats with chronic unpredictable mild stress

The present study hypothesized that caffeic acid (3,4-dihydroxycinnamic acid; CaA) may exert antidepressant-like effects in rats with chronic unpredictable mild stress via epigenetic mechanisms, such as DNA methylation and hydroxymethylation. The chronic unpredictable mild stress (CUMS) model was used to analyze the effects of CaA on behavioral phenotypes, and to evaluate the distribution of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in the hippocampus and prefrontal cortex using immunohistochemistry and immunofluorescence. mRNA levels of the genes encoding brain-derived neurotropic factor (BDNF) and catechol-O-methyltransferase (COMT), and key enzymes regulating DNA methylation [DNA methyltransferase (DNMT)1 and DNMT3A] and hydroxymethylation [Ten-eleven translocation (TET)1-3] were examined using quantitative (q)PCR. Furthermore, enrichment of 5mC and 5hmC at the promotor regions of the Bdnf and Comt genes was quantified using chromatin immunoprecipitation-qPCR. Behavioral data showed that CaA exerted a slight antidepressant-like effect. Bdnf and Comt genes showed differential expression patterns due to CUMS. CaA intervention induced different Dnmt1/Dnmt3a and Tet1/Tet2 mRNA levels in the hippocampus and prefrontal cortex, respectively. CaA regulated the ratio of 5mC/5hmC at the promotor region of the Bdnf and Comt genes and therefore influenced gene expression, which may be a valuable therapeutic option for major depressive disorder (MDD). In conclusion, there were epigenetic changes in the hippocampus and prefrontal cortex in CUMS rats, and CaA may function as a modulator of DNA methylation to regulate gene transcription, thus providing a mechanistic basis for the use of this phytochemical agent in the treatment of MDD.

The Impact of Propolis Factor Caffeic Acid Phenethyl-Ester on the Cerebral Vasospasm and Early Brain Damage in the Experimentally Induced Subarachnoid Hemorrhage on Rats

OBJECTIVE

Caffeic acid phenethyl ester (CAPE), a phenolic compound, besides being 1 of the biologically active components of propolis, is a compound with antioxidant, antiinflammatory, antiviral, reperfusion damage prevention, immune stimulant, and carcinostatic, anticancer properties. The aim of this study was to investigate the possible effects of CAPE on cerebral vasospasm and early brain injury, which were experimentally administered intraperitoneally in rats with subarachnoid hemorrhage.

METHODS

Thirty-two Wistar Albino rats weighing 200 to 300 g were used in our study. The rats divided into 3 groups: the control group (n = 10), subarachnoid hemorrhage group (n = 11), and subarachnoid hemorrhage + CAPE group (n = 11). These groups were evaluated according to the Ischemia index in hippocampal CA3 regions and the morphometric analysis of basilar artery diameter after being sacrificed at the end of 72nd hour.

RESULTS

A significant difference was found between group 1 and group 2 for the CA-3 region, it was concluded that early brain damage occurred after subarachnoid hemorrhage. When the neuronal damage in CA-3 region was evaluated between group 2 and group 3, a statistically significant difference was found between the groups. There was a statistically significant difference between group 1 and group 3 in terms of ischemia detection.

CONCLUSIONS

It was shown that CAPE has a preventive effect on early brain injury after subarachnoid hemorrhage and has a positive effect on reducing cerebral vasospasm. Our study is the first study in the literature showing that CAPE inhibits ischemic brain injury following subarachnoid hemorrhage.

Protective effect of caffeic acid phenethyl ester against imidacloprid-induced hepatotoxicity by attenuating oxidative stress, endoplasmic reticulum stress, inflammation and apoptosis

Imidacloprid (IMI) is a widely used neonicotinoid pesticide in the world, its environmental and human health risk has particularly attracted the attention of researchers. Caffeic acid phenethyl ester (CAPE), an active polyphenol of propolis, has many pharmacological activities including free radical scavenger, anti-inflammatory, and anti-oxidant. In this study, protective effect of CAPE against IMI induced liver injury in mice was performed. Administration of 1 and 2.5 mg/kg CAPE markedly prevented serum AST and ALT increase in 5 mg/kg IMI-induced mice. CAPE significantly downregulated liver NO generation and lipid peroxidation, and upregulated glutathione, catalase, superoxide dismutase and glutathione peroxidase in a dose-dependent manner in liver of IMI-induced mice. Endoplasmic reticulum stress represented by the swelling of endoplasmic reticulum was observed by transmission electron microscope in IMI group. Pretreatment of 2.5 mg/kg CAPE significantly attenuated the endoplasmic reticulum stress induced by IMI in liver. Western blot analysis illustrated that pretreatment of CAPE downregulated the upregulation of TNF-α and IFN-γ induced by IMI in liver of mice. Moreover, the increase of positive apoptotic hepatocytes further suggested apoptosis might be involved in IMI-induced hepatotoxicity. Pretreatment of 1 and 2.5 mg/kg CAPE significantly decreased positive apoptotic hepatocytes, suggested that CAPE prevented apoptosis in liver of IMI-induced mice. In conclusion, CAPE prevented liver injury in IMI-induced mice via attenuation of oxidative stress, endoplasmic reticulum stress, inflammation and apoptosis. Our findings may have broad biological and environmental implications for future research on the therapeutic strategy to prevent liver injury induced by pesticides.

Depolarization of pacemaker potentials by caffeic acid phenethyl ester in interstitial cells of Cajal from the murine small intestine

Interstitial cells of Cajal (ICCs) are pacemaker cells in the gastrointestinal (GI) tract and generate pacemaker potentials. In this study, we investigated the effects of caffeic acid phenethyl ester (CAPE) on the pacemaker potentials of ICCs from the mouse small or large intestine. Using the whole-cell patch-clamp configuration, we found that CAPE depolarized the pacemaker potentials of cultured ICCs from the murine small intestine in a dose-dependent manner. The estrogen receptor (ER) β antagonist PHTPP completely inhibited CAPE-induced depolarization, but the ERα antagonist BHPI did not. Intracellular GDP-β-S and pretreatment with Ca²⁺-free solution or thapsigargin also blocked CAPE-induced depolarization. To investigate the mechanisms of CAPE-mediated depolarization of ICCs, we used the nonselective cation channel (NSCC) inhibitor flufenamic acid, the Cl^- channel blocker, mitogen-activated protein kinase (MAPK) inhibitors PD98059, SB203580, or SP600125, and PI3 kinase inhibitor LY294002. All inhibitors blocked the CAPE-induced pacemaker potential depolarization of ICCs. These results suggest that CAPE induces pacemaker potential depolarization through ERβ in a G protein, NSCC, Cl^- channel, MAPK- and PI3 kinase dependent manner via intracellular and extracellular Ca²⁺ regulation in the murine small intestine. CAPE may therefore modulate GI motility by acting on ICCs in the murine small intestine.

Propolis and Its Potential to Treat Gastrointestinal Disorders

There are a number of disorders that affect the gastrointestinal tract. Such disorders have become a global emerging disease with a high incidence and prevalence rates worldwide. Inflammatory and ulcerative processes of the stomach or intestines, such as gastritis, ulcers, colitis, and mucositis, afflict a significant proportion of people throughout the world. The role of herbal-derived medicines has been extensively explored in order to develop new effective and safe strategies to improve the available gastrointestinal therapies that are currently used in the clinical practice. Studies on the efficacy of propolis (a unique resinous aromatic substance produced by honeybees from different types of species of plants) are promising and propolis has been effective in the treatment of several pathological conditions. This review, therefore, summarizes and critiques the contents of some relevant published scientific papers (including those related to clinical trials) in order to demonstrate the therapeutic value of propolis and its active compounds in the treatment and prevention of gastrointestinal diseases.

Migration Rate Inhibition of Breast Cancer Cells Treated by Caffeic Acid and Caffeic Acid Phenethyl Ester: An In Vitro Comparison Study

One of the deadliest cancers among women is a breast cancer. Research has shown that two natural substances occurring in propolis, caffeic acid (CA) and caffeic acid phenethyl ester (CAPE), have significant anticancer effects. The purpose of our in vitro study was to compare cytotoxic activity and migration rate inhibition using CA and CAPE (doses of 50 and 100 µm) against triple-negative, MDA-MB-231 breast adenocarcinoma line cells, drawn from Caucasian women. Viability was measured by XTT-NR-SRB assay (Tetrazolium hydroxide-Neutral Red-Sulforhodamine B) for 24 h and 48 h periods. Cell migration for wound healing assay was taken for 0 h, 8 h, 16 h, and 24 h periods. CAPE displayed more than two times higher cytotoxicity against MDA-MB-231 cells. IC₅₀ values for the XTT assay were as follows: CA for 24 h and 48 h were 150.94 µM and 108.42 µM, respectively, while CAPE was 68.82 µM for 24 h and 55.79 µM for 48 h. For the NR assay: CA was 135.85 µM at 24 h and 103.23 µM at 48 h, while CAPE was 64.04 µM at 24 h and 53.25 µM at 48 h. For the SRB assay: CA at 24 h was 139.80 µM and at 48 h 103.98 µM, while CAPE was 66.86 µM at 24 h and 47.73 µM at 48 h. Both agents suspended the migration rate; however, CAPE displayed better activity. Notably, for the 100 µM CAPE dose, motility of the tested breast carcinoma cells was halted.

Antiproliferative activity and SARs of caffeic acid esters with mono-substituted phenylethanols moiety

A series of CAPE derivatives with mono-substituted phenylethanols moiety were synthesized and evaluated by MTT assay on growth of 4 human cancer cell lines (Hela, DU-145, MCF-7 and ECA-109). The substituent effects on the antiproliferative activity were systematically investigated for the first time. It was found that electron-donating and hydrophobic substituents at 2'-position of phenylethanol moiety could significantly enhance CAPE's antiproliferative activity. 2'-Propoxyl derivative, as a novel caffeic acid ester, exhibited exquisite potency (IC₅₀=0.4±0.02 & 0.6±0.03μM against Hela and DU-145 respectively).

Biochemical and molecular mechanisms underlying the chemopreventive efficacy of rosmarinic acid in a rat colon cancer

To shed light on colon cancer chemoprevention, natural phytochemicals attract researchers by virtue of their beneficial biological effects. The chemopreventive potential of rosmarinic acid (RA) was tested by using the colon carcinogen, 1,2-dimethylhydrazine (DMH) by evaluating the Aberrant crypt foci (ACF), tumour incidence, lipid peroxidative byproducts, phase I & II drug metabolizing enzymes, cell proliferative and apoptotic proteins. Rats were divided into six groups and received modified pellet diet. Group 1 served as control rats, group 2 rats received RA (5mg/kg b.w. p.o.), rats in groups 3-6 received DMH (20mg/kg b.w., s.c.) for the first fifteen weeks. In addition to DMH, groups 4-6 received RA at the dose of 5mg/kg b.w. during initiation, post initiation stages and also for the entire study period. DMH treated rats showed an increase in the development of ACF, tumour formation and multiplicity and decrease in lipid peroxidative byproducts. Moreover, it modulates xenobiotic enzymes and reduces the expressions of proapoptotic proteins; increases expressions of anti apoptotic proteins at the end of the study. Supplementation with RA to carcinogen treated rats protected them from the above deleterious effects caused by DMH and thus RA may be used as a potent chemopreventive agent.

Advances in proteomic study of colorectal cancer

Colorectal cancer is one of the most common malignant tumors and the fourth cause of cancer-related mortality. It is not easy to be found at the early stage and therefore has a poor prognosis. Thus, new molecular biomarkers are required to improve early diagnosis and discover new effective therapeutic targets. Advances in proteomic technologies have greatly enhanced our understanding of the pathogenesis of colorectal cancer at the protein level, and improved our ability of early diagnosis and treatment. Proteomic studies of colorectal tissues, serum and cell lines have identified differentially expressed proteins, new potential diagnostic biomarkers and clinical drug targets. This article reviews the advances in proteomic study of colorectal cancer in recent years.

Chemopreventive Properties and Toxicity of Kelulut Honey in Sprague Dawley Rats Induced with Azoxymethane

Ethnopharmacological Relevance. Colon cancer has been a major problem worldwide. Kelulut honey (KH) is produced by the stingless bees from Trigona species and has strong antioxidant activities that could be one of the potential chemopreventive agents from natural resources. Aim of This Study. This study investigated the chemopreventive properties and toxicity of KH in Sprague Dawley rats induced with azoxymethane (AOM). Material and Method. Twenty-four male Sprague Dawley rats aged 5 weeks were divided into 4 groups: (G1) untreated group not induced with AOM, (G2) untreated group induced with AOM, (G3) treated group induced with AOM, and (G4) treated group not induced with AOM. Injection of AOM (15 mg/kg) was via intraperitoneal route once a week for two subsequent weeks. The treatment groups were given oral administration of KH (1183 mg/kg body weight) twice daily for 8 weeks. Results. Treatment with KH significantly reduced the total number of aberrant crypt foci (ACF) and aberrant crypts (AC) and crypt multiplicity. KH was not toxic to the animals since the level of blood profile parameters, liver enzymes, and kidney functions was in normal range. Conclusions. The current finding shows that KH has chemopreventive properties in rats induced with colorectal cancer and also was found not toxic towards the animals.

Ethanol-Extracted Brazilian Propolis Exerts Protective Effects on Tumorigenesis in Wistar Hannover Rats

The present study was conducted over a course of 104 weeks to estimate the carcinogenicity of ethanol-extracted Brazilian green propolis (EEP). Groups of 50 male and 50 female Wistar Hannover rats, 6-week-old at commencement were exposed to EEP at doses of 0, 0.5 or 2.5% in the diet. Survival rates of 0.5% and 2.5% EEP-treated male and female rats, respectively, were significantly higher than those of respective control groups. Overall histopathological evaluation of neoplasms in rat tissues after 2 years showed no significant increase of tumors or preneoplastic lesions in any organ of animals administered EEP. Significantly lower incidences of pituitary tumors in 0.5% EEP male and 2.5% EEP female groups, malignant lymphoma/leukemia in both 2.5% EEP-treated males and females and total thyroid tumors in 0.5% EEP male group were found. Administration of EEP caused significant decreases of lymphoid hyperplasia of the thymus and lymph nodes in 2.5% EEP-treated rats, tubular cell hyperplasia of kidneys in all EEP groups, and cortical hyperplasia of adrenals in EEP-treated females. In the blood, significant reduction of neutrophils in all EEP-treated males and band neutrophils in 2.5% EEP-treated females was found indicating lower levels of inflammation. Total cholesterol and triglicerides levels were significantly lower in the blood of 2.5% EEP-treated female rats. In conclusion, under the conditions of the 2-year feeding experiment, EEP was not carcinogenic, did not induce significant histopathological changes in any organ, and further exerted anti-inflammatory and antitumorigenic effects resulting in increase of survival of Wistar Hannover rats.

The role of CAPE in PI3K/AKT/mTOR activation and oxidative stress on testis torsion

Ischemia reperfusion injury arises from testicular torsion resulting in a loss of spermatogenesis and significant germ cell apoptosis. This study evaluates the prooxidant/antioxidant effects of caffeic acid phenethyl ester (CAPE) through PI3K/AKT/mTOR signal pathways on testis torsion. A total of (28) male Wistar rats were divided randomly into 4 groups (n=7 for each group):group A (sham) group,group B torsion/detorsion group, group C (saturation group, during four days of CAPE, one dose (10 μmol/kg, i.p)) and group D (a single dose of CAPE 2h after torsion and before detorsion). At the end of the study, unilateral orchiectomies were performed for measurements of MDA and 8OHdG levels, histopathologic and immunohistochemical and TUNEL apoptotic cell examination. Testicular torsion-detorsion led to a significant decrease in the mean values of the Johnsen's scores and a significant increase in the apoptotic cell values of group B. There were no significant differences between group D and group A. In addition, the MDA and 8OHdG levels increased significantly in group B. The MDA and 8OHdG values were lower in group D. However, the 8OHdG levels were higher in group C than the groups A and D. On the other hand, CAPE suppresses mTOR activation and reduces the apoptosis on ischemia/reperfusion damage in rat testis. These results demonstrate that CAPE suppresses mTOR activation and reduces the apoptosis on ischemia/reperfusion damage in rat testis.

Propolis: a new frontier for wound healing?

Propolis is a resin produced by honeybees by mixing wax, pollen, salivary secretions, and collected natural resins.

The precise composition of propolis varies with the source, and over 300 chemical components belonging to the flavonoids, terpenes, and phenolic acids have been identified in propolis. Moreover, its chemical composition is subjected to the geographical location, botanical origin, and bee species.

Propolis and its compounds have been the focus of many works due to their antimicrobial and anti-inflammatory activity; however, it is now recognized that propolis also possesses regenerative properties.

There is an increasing interest in the healing potential of natural products, considering the availability and low cost of these products. Propolis contains a huge number of compounds that explicate some biological effects that speeds up the healing process and is widely used in folk remedies.

This review aims to condense the results on the mechanism of activity of propolis and its compounds.

Caffeic Acid phenethyl ester and ethanol extract of propolis induce the complementary cytotoxic effect on triple-negative breast cancer cell lines

Chemotherapy of breast cancer could be improved by bioactive natural substances, which may potentially sensitize the carcinoma cells’ susceptibility to drugs. Numerous phytochemicals, including propolis, have been reported to interfere with the viability of carcinoma cells. We evaluated the in vitro cytotoxic activity of ethanol extract of propolis (EEP) and its derivative caffeic acid phenethyl ester (CAPE) towards two triple-negative breast cancer (TNBC) cell lines, MDA-MB-231 and Hs578T, by implementation of the MTT and lactate dehydrogenase (LDH) assays. The morphological changes of breast carcinoma cells were observed following exposure to EEP and CAPE. The IC₅₀ of EEP was 48.35 µg∙mL⁻¹ for MDA-MB-23 cells and 33.68 µg∙mL⁻¹ for Hs578T cells, whereas the CAPE IC₅₀ was 14.08 µM and 8.01 µM for the MDA-MB-231 and Hs578T cell line, respectively. Here, we report that propolis and CAPE inhibited the growth of the MDA-MB-231 and Hs578T lines in a dose-dependent and exposure time-dependent manner. EEP showed less cytotoxic activity against both types of TNBC cells. EEP and, particularly, CAPE may markedly affect the viability of breast cancer cells, suggesting the potential role of bioactive compounds in chemoprevention/chemotherapy by potentiating the action of standard anti-cancer drugs.

The effects of pentoxifylline and caffeic acid phenethyl ester in the treatment of d-galactosamine-induced acute hepatitis in rats

The aim of this study was to investigate histological changes in hepatic tissue and effects of pentoxifylline (PTX) and caffeic acid phenethyl ester (CAPE) on these changes using histochemical and biochemical methods in rats, in which hepatitis was established by D-galactosamine (D-GAL). Rats were divided into five groups as follows: control group, D-GAL (24 h) group, D-GAL group, d-GAL + PTX group, and D-GAL + CAPE group. In histological evaluations, the control group showed normal appearance of the liver cells. However in the d-GAL groups, focal areas consisting of inflammatory, necrotic, and apoptotic cells were detected in parenchyma. Glycogen loss was observed in the hepatocytes localized at the periphery of lobule. It was found that number of mast cells of portal areas were significantly higher in D-GAL groups compared with other groups (p = 0.0001). In addition, the number of cells with positive staining by Ki-67 and caspase-3 were significantly increased in GAL groups compared with the control group (p = 0.0001). In biochemical analysis, there was an increase in malondialdehyde and myeloperoxidase levels, while a decrease was observed in glutathione level and glutathione peroxidase activity in groups treated with d-GAL compared with the control group. On the other hand, it was seen that, in the groups treated with D-GAL, histological and biochemical injuries in the liver were reduced by administration of PTX and CAPE. In this study, we demonstrated the ameliorative effects of PTX and CAPE on D-GAL-induced liver injury.

Caffeic Acid phenethyl ester is a potential therapeutic agent for oral cancer

Head and neck cancers, which affect 650,000 people and cause 350,000 deaths per year, is the sixth leading cancer by cancer incidence and eighth by cancer-related death worldwide. Oral cancer is the most common type of head and neck cancer. More than 90% of oral cancers are oral and oropharyngeal squamous cell carcinoma (OSCC). The overall five-year survival rate of OSCC patients is approximately 63%, which is due to the low response rate to current therapeutic drugs. In this review we discuss the possibility of using caffeic acid phenethyl ester (CAPE) as an alternative treatment for oral cancer. CAPE is a strong antioxidant extracted from honeybee hive propolis. Recent studies indicate that CAPE treatment can effectively suppress the proliferation, survival, and metastasis of oral cancer cells. CAPE treatment inhibits Akt signaling, cell cycle regulatory proteins, NF-κB function, as well as activity of matrix metalloproteinase (MMPs), epidermal growth factor receptor (EGFR), and Cyclooxygenase-2 (COX-2). Therefore, CAPE treatment induces cell cycle arrest and apoptosis in oral cancer cells. According to the evidence that aberrations in the EGFR/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling, NF-κB function, COX-2 activity, and MMPs activity are frequently found in oral cancers, and that the phosphorylation of Akt, EGFR, and COX-2 correlates to oral cancer patient survival and clinical progression, we believe that CAPE treatment will be useful for treatment of advanced oral cancer patients.

Identification of differential proteins in colorectal cancer cells treated with caffeic acid phenethyl ester

AIM: To investigate the molecular mechanisms of the anti-cancer activity of caffeic acid phenethyl ester (CAPE).

METHODS: Protein profiles of human colorectal cancer SW480 cells treated with or without CAPE were analysed using a two-dimensional (2D) electrophoresis gel-based proteomics approach. After electrophoresis, the gels were stained with Coomassie brilliant blue R-250. Digital images were taken with a GS-800 Calibrated Densitometer, and image analysis was performed using PDQuest 2-D Analysis software. The altered proteins following CAPE treatment were further identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry following a database search. The identified proteins were validated by Western blot and immunofluorescence assay.

RESULTS: CAPE induced human colorectal cancer cell apoptosis. Four up-regulated proteins and seven down-regulated proteins in colorectal cancer cells treated with CAPE were found. The identified down-regulated proteins in CAPE-treated colorectal cancer cells were Triosephosphate Isomerase (Tim), Proteasome subunit alpha 4 (PSMA4) protein, Guanine nucleotide binding protein beta, Phosphoserine aminotransferase 1 (PSAT1), PSMA1, Myosin XVIIIB and Tryptophanyl-tRNA synthetase. Notably, CAPE treatment led to the down-regulation of PSAT1 and PSMA1, two proteins that have been implicated in tumorigenesis. The identified up-regulated proteins were Annexin A4, glyceraldehyde-3-phosphate dehydrogenase, Glucosamine-6-phosphate deaminase 1 (GNPDA1), and Glutathione peroxidase (GPX-1). Based on high match scores and potential role in cell growth control, PSMA1, PSAT1, GNPDA1 and GPX-1 were further validated by Western blotting and immunofluorescence assay. PSMA1 and PSAT1 were down-regulated, while GNPDA1 and GPX-1 were up-regulated in CAPE-treated colorectal cancer cells.

CONCLUSION: These differentiated proteins in colorectal cancer cells following CAPE treatment, may be potential molecular targets of CAPE and involved in the anti-cancer effect of CAPE.

Inhibition of colon carcinogenesis by a standardized Cannabis sativa extract with high content of cannabidiol

PURPOSE

Colon cancer is a major public health problem. Cannabis-based medicines are useful adjunctive treatments in cancer patients. Here, we have investigated the effect of a standardized Cannabis sativa extract with high content of cannabidiol (CBD), here named CBD BDS, i.e. CBD botanical drug substance, on colorectal cancer cell proliferation and in experimental models of colon cancer in vivo.

METHODS

Proliferation was evaluated in colorectal carcinoma (DLD-1 and HCT116) as well as in healthy colonic cells using the MTT assay. CBD BDS binding was evaluated by its ability to displace [(3)H]CP55940 from human cannabinoid CB1 and CB2 receptors. In vivo, the effect of CBD BDS was examined on the preneoplastic lesions (aberrant crypt foci), polyps and tumours induced by the carcinogenic agent azoxymethane (AOM) as well as in a xenograft model of colon cancer in mice.

RESULTS

CBD BDS and CBD reduced cell proliferation in tumoral, but not in healthy, cells. The effect of CBD BDS was counteracted by selective CB1 and CB2 receptor antagonists. Pure CBD reduced cell proliferation in a CB1-sensitive antagonist manner only. In binding assays, CBD BDS showed greater affinity than pure CBD for both CB1 and CB2 receptors, with pure CBD having very little affinity. In vivo, CBD BDS reduced AOM-induced preneoplastic lesions and polyps as well as tumour growth in the xenograft model of colon cancer.

CONCLUSIONS

CBD BDS attenuates colon carcinogenesis and inhibits colorectal cancer cell proliferation via CB1 and CB2 receptor activation. The results may have some clinical relevance for the use of Cannabis-based medicines in cancer patients.

Caffeic acid phenethyl ester attenuates pro-inflammatory and fibrogenic phenotypes of LPS-stimulated hepatic stellate cells through the inhibition of NF-κB signaling

Hepatic stellate cells (HSCs) are the major cell type involved in liver fibrosis. Lipopolysaccharide (LPS)-mediated signaling through Τoll-like receptor 4 (TLR4) in HSCs has been identified as a key event in liver fibrosis, and as the molecular link between inflammation and liver fibrosis. In this study, we investigated the effects of caffeic acid phenethyl ester (CAPE), one of the main medicinal components of propolis, on the pro-inflammatory and fibrogenic phenotypes of LPS-stimulated HSCs. HSCs from rats were isolated and cultured in Dulbecco's modified Eagle's medium (DMEM). Following treatment with LPS, HSCs showed a strong pro-inflammatory phenotype with an upregulation of pro-inflammatory mediators, and a fibrogenic phenotype with enhanced collagen synthesis, mediated by transforming growth factor-β1 (TGF-β1). CAPE significantly and dose-dependently reduced LPS-induced nitrite production, as well as the transcription and protein synthesis of monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS), as determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blotting and enzyme-linked immunosorbent assays (ELISA). CAPE further reduced the TGF-β1-induced transcription and translation (protein synthesis) of the gene coding for collagen type I α1 (col1A1), in LPS-stimulated HSCs. Following LPS stimulation, the phosphorylation of the nuclear factor-κB (NF-κB) inhibitor IκBα and consequently, the nuclear translocation of NF-κB, were markedly increased in the HSCs, and these changes were reversed by pre-treatment with CAPE. In conclusion, CAPE attenuates the pro-inflammatory phenotype of LPS-stimulated HSCs, as well as the LPS-induced sensitization of HSCs to fibrogenic cytokines by inhibiting NF-κB signaling. Our results provide new insight into the treatment of hepatic fibrosis through regulation of the TLR4 signaling pathway.

Protein phosphatase 2A (PP2A) has a potential role in CAPE-induced apoptosis of CCRF-CEM cells via effecting human telomerase reverse transcriptase activity

Caffeic acid phenethyl ester (CAPE) is one of the most effective components of propolis which is collected by honey bees. The aim of this study was to investigate the cytotoxic and apoptotic effects of CAPE in the CCRF-CEM cell line and to clarify the role of serine/threonine protein phosphatase 2A (PP2A) and human telomerase reverse transcriptase (hTERT) activity as an underlining mechanism of CAPE-induced apoptosis. Trypan blue dye exclusion test and XTT methods were used to evaluate the cytotoxicity and ELISA based oligonucleotide detection, which can be seen during apoptosis, was used to determine apoptosis. Acridine orange/ethidium bromide dye technique was also used to evaluate apoptosis. The cytotoxic effect of CAPE was detected in a dose and time dependent manner with the IC(50) of 1 muM. ELISA and acridine orange/ethidium bromide methods have shown remarkable apoptosis at 48th hour in CAPE treated cells. To investigate the role of PP2A in CAPE-induced apoptosis of CCRF-CEM cells, we performed combination studies with CAPE and, Calyculin A and Okadaic acid, which are very well known inhibitors of PP2A, in IC(20) of inhibitors and IC(50) of CAPE. Combination studies revealed synergistic effect of both drugs by concomitant use. Western blot analyses of PP2A catalytic and regulatory subunits showed down-regulation of expression of PP2A catalytic subunit in CAPE treated cells at 48th hour. Since, PP2A is important in hTERT (telomerase catalytic subunit) activation and deactivation, we also performed hTERT activity in CAPE treated cells simultaneously. Treating cells with IC(50) of CAPE for 96 h with the intervals of 24 h showed marked reduction of hTERT activity. The reduction of hTERT activity in CAPE treated CCRF-CEM cells was more prominent in the initial 48 h. The variation of hTERT activity in CAPE treated CCRF-CEM cells may be the reason for the protein phosphatase interaction that occurred after treatment with CAPE.

Caffeic Acid phenethyl ester as a potential treatment for advanced prostate cancer targeting akt signaling

Prostate cancer is the fifth most common cancer overall in the world. Androgen ablation therapy is the primary treatment for metastatic prostate cancer. However, most prostate cancer patients receiving the androgen ablation therapy ultimately develop recurrent castration-resistant tumors within 1–3 years after treatment. The median overall survival time is 1–2 years after tumor relapse. Chemotherapy shows little effect on prolonging survival for patients with metastatic hormone-refractory prostate cancer. More than 80% of prostate tumors acquire mutation or deletion of tumor suppressor phosphatase and tensin homolog (PTEN), a negative regulator of PI3K/Akt signaling, indicating that inhibition of PI3K/Akt might be a potential therapy for advanced prostate tumors. Caffeic acid phenethyl ester (CAPE) is a strong antioxidant extracted from honeybee hive propolis. CAPE is a well-known NF-κB inhibitor. CAPE has been used in folk medicine as a potent anti-inflammatory agent. Recent studies indicate that CAPE treatment suppresses tumor growth and Akt signaling in human prostate cancer cells. We discuss the potential of using CAPE as a treatment for patients with advanced prostate cancer targeting Akt signaling pathway in this review article.

Modulatory efficacy of rosmarinic acid on premalignant lesions and antioxidant status in 1,2-dimethylhydrazine induced rat colon carcinogenesis

Colorectal cancer is one of the leading causes of cancer related deaths in Western countries and is becoming increasingly common in Asia. Rosmarinic acid (RA), one of the major components of polyphenol possesses attractive remedial features. The purpose of this study is to investigate the possible chemopreventive mechanism of action of RA against 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the circulatory antioxidant status and colonic bacterial enzymes activities. Additionally, we analyzed the aberrant crypt foci (ACF) formation and multiplicity in the colon of experimental groups. Wistar male rats were divided into six groups. Group 1 was control rats, group 2 rats received RA (10 mg/kg b.w., p.o. everyday), rats in groups 3-6 received DMH (20 mg/kg b.w., s.c.) for the first 4 weeks. In addition to DMH, groups 4-6 received 2.5, 5, and 10 mg/kg b.w. RA respectively. The results revealed that supplementation with RA significantly reduced the formation of ACF and ACF multiplicity in DMH treated rats. Moreover RA supplementation prevented the alterations in circulatory antioxidant enzymes and colonic bacterial enzymes activities. Overall, our results showed that all three doses of RA inhibited carcinogenesis, though the effect of the intermediary dose of 5 mg/kg b.w. was more pronounced.

Caffeic acid phenethyl ester (CAPE), derived from a honeybee product propolis, exhibits a diversity of anti-tumor effects in pre-clinical models of human breast cancer

Breast cancer (BC) patients use alternative and natural remedies more than patients with other malignancies. Specifically, 63-83% use at least one type of alternative medicine and 25-63% use herbals and vitamins. Propolis is a naturopathic honeybee product, and CAPE (caffeic acid phenethyl ester), is a major medicinal component of propolis. CAPE, in a concentration dependent fashion, inhibits MCF-7 (hormone receptor positive, HR+) and MDA-231 (a model of triple negative BC (TNBC) tumor growth, both in vitro and in vivo without much effect on normal mammary cells and strongly influences gene and protein expression. It induces cell cycle arrest, apoptosis and reduces expression of growth and transcription factors, including NF-κB. Notably, CAPE down-regulates mdr-1 gene, considered responsible for the resistance of cancer cells to chemotherapeutic agents. Further, CAPE dose-dependently suppresses VEGF formation by MDA-231 cells and formation of capillary-like tubes by endothelial cells, implicating inhibitory effects on angiogenesis. In conclusion, our results strongly suggest that CAPE inhibits MDA-231 and MCF-7 human breast cancer growth via its apoptotic effects, and modulation of NF-κB, the cell cycle, and angiogenesis.

Caffeic acid phenethyl ester inhibits invasion and expression of matrix metalloproteinase in SK-Hep1 human hepatocellular carcinoma cells by targeting nuclear factor kappa B

Numerous studies have shown that the levels of matrix metalloproteinase (MMP)-2 and/or MMP-9 are associated with the invasive phenotypes of cancer cells. This study investigated the effects of caffeic acid phenethyl ester (CAPE), a chemopreventive phytochemical derived from honeybee propolis, on the invasive phenotype of SK-Hep1 human hepatocellular carcinoma cells (SK-Hep1 cells). CAPE effectively suppressed SK-Hep1 cell invasion in a dose-dependent manner. The constitutive expression of MMP-2 and MMP-9 in SK-Hep1 cells was almost completely abolished by treatment with 12.5 muM CAPE. CAPE also significantly inhibited nuclear factor kappa B (NF-kappaB) DNA-binding activity in SK-Hep1 cells. These results taken together suggest that CAPE exerts antimetastatic potential through inhibition of MMP-2 and MMP-9 expression, possibly by targeting NF-kappaB in hepatocellular carcinoma.

Caffeic Acid Phenethyl Ester (CAPE) derived from propolis, a honeybee product, inhibits growth of breast cancer stem cells

Cancer stem cells (CSC) are chemoresistant and implicated in tumor recurrence, metastasis and high patient mortality; thus substances impairing CSC activity, could be invaluable as novel cancer therapeutics. We previously showed that CAPE (caffeic acid phenethyl ester), a component of propolis, a honeybee product, inhibits growth of MDA-MB-231 (MDA-231) cells, mdr gene expression, NF-κB, EGFR, and VEGF. We hypothesized that CAPE also acts by interfering with CSC-mediated effects. We isolated breast CSC (bCSC) from MDA-231 cells, a model of human triple-negative breast cancer, and mouse xenografts. bCSC grow as mammospheres (MMS) and when dissociated into single cells, form MMS again, a sign of self-renewal. bCSC exhibited the characteristic CD44⁺/CD24^-/low phenotype and generated progenitors in the presence of serum, a CSC trait responsible for regenerating tumor mass. CAPE caused dose-dependent bCSC self-renewal inhibition and progenitor formation. Clonal growth on soft agar was inhibited dose-dependently, but apoptosis was not induced as determined by Annexin-V/PI assay. Instead, bCSC 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%). Treatment of bCSC with CAPE (4.5-days) decreased CD44 levels by 95%, while another cell population containing 10-100-fold lower CD44 content concurrently increased. Results suggest that CAPE causes pronounced changes in bCSC characteristics manifested by inhibition of self renewal, progenitor formation, clonal growth in soft agar, and concurrent significant decrease in CD44 content, all signs of decreased malignancy potential.

Protective effects of caffeic acid phenethyl ester on retinal ischemia/reperfusion injury in rats

PURPOSE

To investigate whether caffeic acid phenethyl ester (CAPE) has a protective effect on retinal ischemia/reperfusion (I/R) injury in rats, and to determine the possible antioxidant mechanisms.

METHODS

Seventy-six female Wistar rats were randomized evenly into Sham, I/R injury model (M group), model plus vehicle (MV), and model plus CAPE (MC) groups. Retinal ischemia/reperfusion injury was induced by increasing the intraocular pressure to 110 mmHg for 60 min. Rats in the MV and MC groups were injected with vehicle and CAPE (10 µmol/kg i.p.), respectively, before reperfusion and once a day for one or seven days after I/R. The levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in the retinal tissues were determined 24 hr after I/R. Retinal cells apoptosis was detected 24 hr after I/R injury by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling staining. On day 7 after reperfusion, the electroretinogram (ERG) was recorded, and the retinal histology was examined and quantified using light microscopy.

RESULTS

CAPE significantly decreased the MDA levels and increased the activities of SOD, GSH-Px, and CAT in the retina compared with the ischemia group (p< 0.05). CAPE attenuated the I/R-induced apoptosis of retinal cells in the inner nuclear and ganglion cells of the rat retina. CAPE also suppressed the I/R-induced reduction in the a- and b-wave amplitudes of the ERG (p<0.05). The thickness of the entire retina, inner nuclear layer, and inner plexiform layer and the number of cells in the ganglion cell layer in the MC group were significantly greater than those in the M group (p<0.05).

CONCLUSIONS

CAPE can protect the rat retina from I/R injury by enhancing the antioxidation ability and inhibiting the apoptosis of retinal cells, which suggests that CAPE is potentially useful for treating I/R-induced eye disorders.

Inhibitory effect of caffeic acid phenethyl ester, a plant-derived polyphenolic compound, on rat intestinal contractility

Caffeic acid phenethyl ester (CAPE) exerts pharmacological actions (e.g. anti-inflammatory, chemopreventive) which are relevant for potential clinical application in the digestive tract. However, no study has been published on its possible effects on intestinal motility, to date. In the present study, we investigated the effect of this plant-derived polyphenolic compound on the spontaneous contractions of the rat isolated ileum. CAPE reduced (in a tetrodotoxin-insensitive manner) spontaneous ileal contractions and this effect was reduced by the L-type Ca2+ channel blocker nifedipine and the chelant of calcium ethylenediaminetetraacetic acid. However, the effect of CAPE was not modified by a number of inhibitors/antagonists such as of phentolamine plus propranolol, atropine, tetrodotoxin, cyclopiazonic acid, omega-conotoxin, apamin, NG-nitro-L-arginine methyl ester, 3-isobutyl-1-methylxanthine, 9-(tetrahydro-2-furanyl)-9H-purin-6-amine, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one or a combination of SR 140333, SR48968 and SR142801. In conclusion our study shows that (i) CAPE relaxed myogenic contractions of rat ileum and that (ii) this effect occurs, at least in part, throughout a mechanism involving L-type Ca2+ channels.

Inhibitory effect of caffeic acid phenethyl ester on mice bearing tumor involving angiostatic and apoptotic activities

This study aims at investigating the anti-tumor effect of caffeic acid phenethyl ester (CAPE) against animal carcinogenesis. In order to substantiate this fact implanted tumor Ehrlich carcinoma cells were assessed in vivo to Swiss mice strain. We found that administrating of CAPE (15 mg/kg S.C.) showed that the tumor volume decreased significantly by 51%. As a result, it improved animal chances of survival and they became healthier. An anti-angiogenic effect of CAPE in vivo was observed, as determined by a significant serum matrix metalloproteinase (MMP-9) reduction (142.1 ng/ml), activation of endostatin serum level (1.9 ng/ml), as well as DNA fragmentation in tumor treated mice when compared with untreated ones.

CONCLUSION

CAPE has a significant inhibitory effect on tumor in vivo. This inhibition may be related to its angiostatic and apoptotic effects. It also reduced angiogenic factors which may shift the equilibrium to the angiostatic effect of CAPE. These findings provide the possibility for the future use of CAPE as tumor therapy in human clinical trials.

Caffeic acid phenethyl ester triggers apoptosis through induction of loss of mitochondrial membrane potential in CCRF-CEM cells

PURPOSE

CAPE (caffeic acid phenethyl ester) is one of the most valuable and investigated component of propolis which is composed by honeybees. In the current study, we aimed at examining apoptotic effects of CAPE on CCRF-CEM leukemic cells and at determining the roles of mitochondrial membrane potential (MMP) in cell death.

METHODS

Trypan blue and XTT methods were used to evaluate the cytotoxicity. Apoptosis was examined by ELISA-based oligonucleotide and acridine orange/ethidium bromide dye techniques. Loss of mitochondrial membrane potential was evaluated using JC-1 dye by flow cytometric analysis and under fluorescent microscope.

RESULTS

We detected the time- and dose-dependent increases in cytotoxic effect of CAPE on CCRF-CEM cells. ELISA and acridine orange/ethidium bromide results showed that apoptotic cell population increased significantly in CCRF-CEM cells exposed to increasing concentrations of CAPE. On the other hand, there was significant loss of MMP determined in response to CAPE in CCRF-CEM cells.

CONCLUSION

This in vitro data by being supported with clinical data may open the way of the potential use of CAPE for the treatment of leukemia.

Caffeic acid phenethyl ester decreases cholangiocarcinoma growth by inhibition of NF-kappaB and induction of apoptosis

Caffeic acid phenethyl ester (CAPE) inhibits the growth of tumor cells and is a known inhibitor of nuclear factor kappa beta (NF-kappaB), which is constitutively active in cholangiocarcinoma (CCH) cells. We evaluated the effects of CAPE on CCH growth both in vitro and in vivo. Inhibition of NF-kappaB DNA-binding activity was confirmed in nuclear extracts treated with CAPE at 50, 40 and 20 microM. CAPE decreases the expression of NF-kappaB1 (p50) and RelA (p65). CAPE decreased the growth of a number of CCH cells but not normal cholangiocytes. Cell cycle decrease was seen by a decrease in PCNA protein expression and the number of BrdU-positive cells treated with CAPE at 20 microM compared to vehicle. Inhibition of growth and increased cell cycle arrest of Mz-ChA-1 cells by CAPE were coupled with increased apoptosis. Bax expression was increased, whereas Bcl-2 was decreased in cells treated with CAPE compared to vehicle. In vivo studies were performed in BALB/c nude (nu/nu) mice implanted subcutaneously with Mz-ChA-1 cells and treated with daily IP injections of DMSO or CAPE (10 mg/kg body weight in DMSO) for 77 days. Tumor growth was decreased and tumor latency was increased 2-fold in CAPE compared to vehicle-treated nude mice. In tumor samples, decreased CCH growth by CAPE was coupled with increased apoptosis. CAPE both in vivo and in vitro decreases the growth of CCH cells by increasing apoptosis. These results demonstrate that CAPE might be an important therapeutic tool in the treatment of CCH.

Absence of chemopreventive influence of propolis on the rat liver altered foci development

Propolis (bee glue) is a complex mixture of natural substances that exhibits a broad spectrum of biological activities. As the possibility exists that it may exert a chemopreventive role against cancer development, the present study aimed to evaluate the chemopreventive influence of a Brazilian aqueous propolis extract (APE) in a rat two-stage (initiation-promotion) medium-term bioassay for chemical liver carcinogenesis. Male Wistar rats were sequentially initiated with diethylnitrosamine (DEN, 200mg/kgb.w.) and, 2 weeks later, exposed to a diet containing hexachlorobenzene (HCB, 100ppm) and to APE 0.1% through drinking water for 6 weeks. Appropriate control groups were also established. The animals were sacrificed at the weeks 8th and 30th when liver samples were processed to evaluate the development of altered hepatocyte foci (AHF) identified under hematoxylin and eosin (H&E) staining and by the immunohistochemical expression of the enzyme glutathione S-transferase placental form (GST-P). The results indicate that APE 0.1% did not protect against the development of any of the differentially identified putative preneoplastic foci in DEN-initiated animals, exposed or not to the promoting agent HCB. Also, APE 0.1% by itself did not significantly induce any AHF, what is in line with its already known absence of genotoxic potential. Our results indicate that an aqueous extract of Brazilian propolis did not exert chemoprevention on the hepatocarcinogenesis process chemically induced in the rat.

Effects of caffeic acid phenethyl ester on pancreatitis in rats

BACKGROUND

This study investigated the effect of caffeic acid phenethyl ester (CAPE) on acute necrotizing pancreatitis (ANP) induced by glycodeoxycholic acid in rats. CAPE, an active component of honeybee propolis, has previously been determined to have antioxidant, anti-inflammatory, antiviral, and anticancer activities.

MATERIALS AND METHODS

Forty-eight rats were divided into four groups of 12. Group 1 animals received intraductal saline and intravenous saline infusion treatment. Group 2 was given intraductal saline and intraperitoneal CAPE infusion treatment. ANP was induced in the animals in group 3 (ANP with saline infusion), and group 4 had induced ANP plus CAPE infusion treatment (ANP with CAPE infusion). Sampling was performed 48 h after treatment.

RESULTS

ANP induction significantly increased mortality rate, pancreatic necrosis, and bacterial infection in pancreatic and extrapancreatic organs. ANP also increased levels of amylase and alanine aminotransferase (ALT) in serum, increased levels of urea and lactate dehydrogenase in bronchoalveolar lavage fluid (BAL LDH), increased the activities of myeloperoxidase (MPO) and malondialdehyde (MDA) in pancreas and lung tissue, and decreased the serum calcium levels. The use of CAPE did not significantly reduce the mortality rate but significantly reduced the ALT and BAL LDH levels, the activities of MPO and MDA in the pancreas, the activity of MDA in the lungs, and pancreatic damage. The administration of CAPE did not reduce the bacterial infection.

CONCLUSIONS

These results indicate that CAPE had beneficial effects on the course of ANP in rats and suggest that CAPE shows promise as a treatment for ANP.

Effects of the potential chemopreventive agent DMU-135 on adenoma development in the ApcMin+ mouse

DMU-135 (3,4-Methylenedioxy-3',4',5'-trimethoxy chalcone) is a novel anticancer prodrug designed to be activated into a potent tyrosine kinase inhibitor by the tumour selective enzyme activity of the cytochrome P450 enzyme CYP1B1. CYP1B1 is selectively expressed in a wide variety of tumours including colon. The hypothesis was tested that DMU-135 would inhibit Apc(Min/+) mouse gastrointestinal adenoma formation. From 4-18 weeks of age animals received DMU-135 (0.2% w:w) in AIN93G diet. DMU-135 was well tolerated, induced no systemic side-effects and reduced adenoma multiplicity by 46 +/- 18.3% compared to controls (p < 0.001). Further characterisation of this promising chemopreventive agent is required.

Effectiveness of mesalamine and propolis in experimental colitis

This study was conducted to investigate the effects of propolis and mesalamine on experimental colitis in rats. Distal colitis was induced in rats by intracolonic instillation of 2 mL of 4% acetic acid. The animals were randomly assigned to 5 groups: group 1, control, (n=8); group 2, colitis, received no treatment (n=8); group 3, colitis+mesalamine, 2 mL once a day via an enema (n=8); group 4, colitis+propolis, 600 mg/kg once a day via intragastric lavage (n=8); and group 5, colitis+mesalamine+propolis for 1 wk (n=8). Levels of nitric oxide were statistically significantly different in comparisons between groups 1 and 2, groups 2 and 3, and groups 4 and 5. Malondialdehyde levels were significantly different when group 2 was compared with groups 3, 4, and 5. A significant difference was observed when group 3 was compared with group 4 for myeloperoxidase. Most propolis-treated rats had normal histology; mesalamine-treated and propolis+mesalamine-treated rats had inflammatory cell infiltration at rates of 50% and 33%, respectively. The investigators concluded that propolis and mesalamine are efficient independently and in combination, but that their combined effect was not observed to be additive in experimental colitis.

Caffeic acid phenethyl ester induces growth arrest and apoptosis of colon cancer cells via the beta-catenin/T-cell factor signaling

Caffeic acid phenethyl ester, an active component of propolis, has been implicated in the regulation of cell growth and apoptosis, although the exact mechanism of this activity has not been elucidated. In this study, we explored the effects of caffeic acid phenethyl ester on growth, cell cycle, apoptosis and beta-catenin/T-cell factor signaling in human colon cancer cells. Using two human sporadic colon cancer cell lines (HCT116 and SW480), we assayed for cell growth inhibition, cell cycle and apoptosis induction. We also assayed for beta-catenin and downstream target genes (cyclin D1 and c-myc) mRNA and protein expression by reverse transcriptase-polymerase chain reaction and Western blot analysis. Beta-catenin localization was detected by indirect immunofluorescence. Beta-catenin/T-cell factor transcriptional activity was determined by transient transfection and reporter gene assay. Caffeic acid phenethyl ester completely inhibited growth, and induced G1 phase arrest and apoptosis in a dose-dependent manner in both HCT116 and SW480 cells. Treatment of human colon cancer cells with apoptotic concentrations of caffeic acid phenethyl ester resulted in a dose-dependent and time-dependent loss of total beta-Catenin protein, associated with decreased nuclear beta-catenin. Caffeic acid phenethyl ester reduced the expression of cyclin D1 and c-myc in a dose-dependent and time-dependent manner. We proved that caffeic acid phenethyl ester markedly suppressed the transcriptional activity of beta-catenin/T-cell factor in both HCT116 and SW480 cells depending on the concentration of caffeic acid phenethyl ester. These results indicate that caffeic acid phenethyl ester is an excellent inhibitor of beta-catenin/T-cell factor signaling in colon cancer cell lines and suggest that caffeic acid phenethyl ester merits further study as an agent against colorectal cancers.