Caffeic acid phenethyl ester (CAPE) prevents inflammatory stress in organotypic hippocampal slice cultures

Estimating the therapeutic potential of NSAIDs and linoleic acid-isomers supplementation against neuroinflammation

Nonsteroidal anti-inflammatory drugs (NSAIDs) regulate inflammation, which is associated with their role in preventing neurodegenerative diseases in epidemiological studies. It has sparked interest in their unconventional application for reducing neuroinflammation, opening up new avenues in biomedical research. However, given the pharmacological drawbacks of NSAIDs, the development of formulations with naturally antioxidant/anti-inflammatory dietary fatty acids has been demonstrated to be advantageous for the clinical translation of anti-inflammatory-based therapies. It includes improved blood-brain barrier (BBB) permeability and reduced toxicity. It permits us to speculate about the value of linoleic acid (LA)-isomers in preventing and treating neuroinflammatory diseases compared to NSAIDs. Our research delved into the impact of various factors, such as administration route, dosage, timing of intervention, and BBB permeability, on the efficacy of NSAIDs and LA-isomers in preclinical and clinical settings. We conducted a systematic comparison between NSAIDs and LA-isomers regarding their therapeutic effectiveness, BBB compatibility, and side effects. Additionally, we explored their underlying mechanisms in addressing neuroinflammation. Through our analysis, we've identified challenges and drawn conclusions that could propel advancements in treating neurodegenerative diseases and inform the development of future alternative therapeutic strategies.

Mouse Organotypic Brain Slice Cultures: A Novel Model for Studying Neuroimmune Responses to Cryptococcal Brain Infections

Cryptococcal meningitis affects millions of people worldwide and is especially prevalent in regions with a high burden of HIV/AIDS. The study of the pathophysiology of this often fatal disease has been significantly hindered by the lack of reliable experimental models, especially at the level of the brain, which is the main organ of injury. Here we outline our novel protocol for the use of hippocampal organotypic brain slice cultures (HOCs) to study the host-fungal interactions during cryptococcal infections of the brain. HOCs are a powerful platform for investigating neuroimmune interactions as they allow for the preservation of all innate neuroglial cells including microglia, astrocytes, and neurons, all of which maintain their three-dimensional architecture and functional connectivity. We made HOCs from neonatal mice and infected these with a fluorescent strain of Cryptococcus neoformans for 24 h. Using immunofluorescent staining, we confirmed the presence and morphology of microglia, astrocytes, and neurons in HOCs prior to infection. Using fluorescent and light microscopy, we also confirmed that Cryptococcus neoformans encapsulates and buds in vitro, as it would in a host. Finally, we demonstrate that infection of HOCs with Cryptococcus neoformans results in close association of the fungal cells with host microglial cells. Our results demonstrate the utility of HOCs as a model to study the pathophysiology and host neuroimmune responses in neurocryptococcosis, which may assist in improving our collective understanding of the pathogenesis of this disease.

CAPE and Neuroprotection: A Review

Propolis, a product of the honey bee, has been used in traditional medicine for many years. A hydrophobic bioactive polyphenolic ester, caffeic acid phenethyl ester (CAPE), is one of the most extensively investigated active components of propolis. Several studies have indicated that CAPE has a broad spectrum of pharmacological activities as anti-oxidant, anti-inflammatory, anti-viral, anti-fungal, anti-proliferative, and anti-neoplastic properties. This review largely describes CAPE neuroprotective effects in many different conditions and summarizes its molecular mechanisms of action. CAPE was found to have a neuroprotective effect on different neurodegenerative disorders. At the basis of these effects, CAPE has the ability to protect neurons from several underlying causes of various human neurologic diseases, such as oxidative stress, apoptosis dysregulation, and brain inflammation. CAPE can also protect the nervous system from some diseases which negatively affect it, such as diabetes, septic shock, and hepatic encephalopathy, while numerous studies have demonstrated the neuroprotective effects of CAPE against adverse reactions induced by different neurotoxic substances. The potential role of CAPE in protecting the central nervous system (CNS) from secondary injury following various CNS ischemic conditions and CAPE anti-cancer activity in CNS is also reviewed. The structure–activity relationship of CAPE synthetic derivatives is discussed as well.

Propolis: A useful agent on psychiatric and neurological disorders? A focus on CAPE and pinocembrin components

Propolis consists of a honeybee product, with a complex mix of substances that have been widely used in traditional medicine. Among several compounds present in propolis, caffeic acid phenethyl ester (CAPE), and pinocembrin emerge as two principal bioactive compounds, with benefits in a variety of body systems. In addition to its well-explored pharmacological properties, neuropharmacological activities have been poorly discussed. In an unprecedented way, the present review addresses the current finding on the promising therapeutic purposes of propolis, focusing on CAPE and pinocembrin, highlighting its use on neurological disturbance, as cerebral ischemia, neuroinflammation, convulsion, and cognitive impairment, as well as psychiatric disorders, such as anxiety and depression. In addition, we provide a critical analysis, discussion, and systematization of the molecular mechanisms which underlie these central nervous system effects. We hypothesize that the pleiotropic action of CAPE and pinocembrin, per se or associated with other substances present in propolis may result in the therapeutic activities reported. Inhibition of the pro-inflammatory cascade, antioxidant activity, and positive neurotrophic modulatory effects consist of the main molecular targets attributed to CAPE and pinocembrin in health benefits.

Evaluation of the neuroprotective potential of caffeic acid phenethyl ester in a cellular model of Parkinson's disease

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease, and oxidative stress and mitochondrial dysfunction play a major role in the pathogenesis of PD. Since conventional therapeutics are not sufficient for the treatment of PD, the development of new agents with anti-oxidant potential is crucial. Caffeic Acid Phenethyl Ester (CAPE), a biologically active flavonoid of propolis, possesses several biological properties such as immunomodulatory, anti-inflammatory and anti-oxidative. In the present study, we investigated the neuroprotective effects of CAPE against 6-hydroxydopamine (6-OHDA)-induced SH-SY5Y cells. The neuroprotective effects were detected by using cell viability, Annexin V, Hoechst staining, total caspase activity, cell cycle, as well as western blotting. Besides, the anti-oxidative activity was measured by the production of reactive oxygen species and mitochondrial function was determined by measurement of mitochondrial membrane potential (ΔΨm). We found that CAPE significantly increased cell viability and decreased apoptotic cell death (~20%) after 150 μM 6-OHDA exposure following 24 h. 1.25 μM CAPE also prevented 6-OHDA-induced changes in condensed nuclear morphology. Furthermore, treatment with 1.25 μM CAPE increased mitochondrial membrane potential in 6-OHDA-exposed cells. CAPE inhibited 6-OHDA-induced caspase activity (~2 fold) and production of reactive oxygen species. In addition, 150 μM 6-OHDA-induced down-regulation of Bcl-2 and Akt levels and up-regulation of Bax and cleaved caspase-9/caspase-9 levels were partially restored by 1.25 μM CAPE treatment. These results revealed a neuroprotective potential of CAPE against 6-OHDA-induced apoptosis in an in vitro PD model and may be a potential therapeutic candidate for the prevention of neurodegeneration in Parkinson's Disease.

Hydroalcoholic extract of Brazilian green propolis modulates inflammatory process in mice submitted to a low protein diet

The occurrence of inflammation and protein malnutrition is an aggravating risk factor for morbidity and mortality in the clinical setting. The green propolis, a natural product made by Apis mellifera bees from Baccharis dracunculifolia resin, has therapeutic potential to modulate chronic inflammation. However, its effect on inflammation in an impaired nutritional status is not known. The aim of this study was to characterize the effects of the administration of the hydroalcoholic extract of the green propolis in the chronic inflammatory process of mice submitted to a low-protein diet. For this, we used the subcutaneous implantation of sponge disks as an inflammatory model and the animals were distributed in the following groups: standard protein diet (12% protein content), control treatment; standard protein diet, propolis treatment; low-protein diet (3% protein content), control treatment; low-protein diet, propolis treatment. Propolis was given daily at a dose of 500 mg/kg (p.o.) during a period of 7 or 15 days. Our main findings show that animals fed with standard protein diet and treated with propolis had low levels of red blood cells, hemoglobin, and hematocrit, with the subsequent reestablishment of these levels, in addition to monocyte count elevation and higher TNF levels after one week of treatment. In the low-protein diet group, the propolis treatment provided a significant recovery in weight and maintenance of total serum protein levels at the end of two weeks of treatment. Histological analysis showed propolis reduced the inflammatory infiltrate in the sponges of both standard and low-protein diet groups. In addition, the propolis extract presented antiangiogenic effect in both groups. Therefore, our data suggests that the hydroalcoholic extract of the green propolis promotes weight recovery and avoid the reduction of protein levels, in addition to inhibit inflammation and angiogenesis in animals fed with a low-protein diet.

Antioxidant activity and anticancer effect of ethanolic and aqueous extracts of the roots of Ficus beecheyana and their phenolic components

This study aimed to investigate the antioxidant and anticancer effects of ethanolic and aqueous extracts of the roots of Ficus beecheyana (EERFB and AERFB) and their phenolic components. In this study, total phenolic content and antioxidant activity of EERFB were higher than those of AERFB. Major phenolic compounds in the extracts were gallic acid, p-hydroxybenzoic acid, caffeic acid, chlorogenic acid, p-coumaric acid, and rutin; which were identified by high-performance liquid chromatography. Flow cytometric analysis of HL-60 cells exposed to EERFB showed that the percentage of apoptotic cells increased in a dose-dependent manner. EERFB treatment resulted in the loss of mitochondrial membrane potential and induced the apoptosis of HL-60 cells through a Fas- and mitochondrial-mediated pathway. Finally, pretreatment with general caspase-9/−3 inhibitors prevented EERFB from inhibiting cell viability in HL-60 cells. Our finding suggests that EERFB is an agent that may have antioxidant activity and inhibit the growth of cancer cells.

Neurobehavioral and Antioxidant Effects of Ethanolic Extract of Yellow Propolis

Propolis is a resin produced by bees from raw material collected from plants, salivary secretions, and beeswax. New therapeutic properties for the Central Nervous System have emerged. We explored the neurobehavioral and antioxidant effects of an ethanolic extract of yellow propolis (EEYP) rich in triterpenoids, primarily lupeol and β-amyrin. Male Wistar rats, 3 months old, were intraperitoneally treated with Tween 5% (control), EEYP (1, 3, 10, and 30 mg/kg), or diazepam, fluoxetine, and caffeine (positive controls) 30 min before the assays. Animals were submitted to open field, elevated plus maze, forced swimming, and inhibitory avoidance tests. After behavioral tasks, blood samples were collected through intracardiac pathway, to evaluate the oxidative balance. The results obtained in the open field and in the elevated plus maze assay showed spontaneous locomotion preserved and anxiolytic-like activity. In the forced swimming test, EEYP demonstrated antidepressant-like activity. In the inhibitory avoidance test, EEYP showed mnemonic activity at 30 mg/kg. In the evaluation of oxidative biochemistry, the extract reduced the production of nitric oxide and malondialdehyde without changing level of total antioxidant, catalase, and superoxide dismutase, induced by behavioral stress. Our results highlight that EEYP emerges as a promising anxiolytic, antidepressant, mnemonic, and antioxidant natural product.

Caffeic acid phenethyl ester and therapeutic potentials

Caffeic acid phenethyl ester (CAPE) is a bioactive compound of propolis extract. The literature search elaborates that CAPE possesses antimicrobial, antioxidant, anti-inflammatory, and cytotoxic properties. The principal objective of this review article is to sum up and critically assess the existing data about therapeutic effects of CAPE in different disorders. The findings elaborate that CAPE is a versatile therapeutically active polyphenol and an effective adjuvant of chemotherapy for enhancing therapeutic efficacy and diminishing chemotherapy-induced toxicities.

Effect of Achyranthes bidentata Blume on 3T3-L1 Adipogenesis and Rats Fed with a High-Fat Diet

The present study investigated the antiobesity effect of Achyranthes bidentata Blume root water extract in a 3T3-L1 adipocyte differentiation model and rats fed with a high-fat diet. To investigate the effect of Achyranthes bidentata Blume on adipogenesis in vitro, differentiating 3T3-L1 cells in adipocyte-induction media were treated every two days with Achyranthes bidentata Blume at various concentrations (1 to 25 μg/mL) for eight days. We found that Achyranthes bidentata Blume root inhibited 3T3-L1 adipocyte differentiation without affecting cell viability, and Western blot analysis revealed that phospho-Akt expression was markedly decreased, whereas there was no significant change in perilipin expression. Furthermore, administration of Achyranthes bidentata Blume root (0.5 g/kg body weight for six weeks) to rats fed with a high-fat diet significantly reduced body weight gain without affecting food intake, and the level of triglyceride was significantly decreased when compared to those in rats fed with only a high-fat diet. These results suggest that Achyranthes bidentata Blume root water extract could have a beneficial effect on inhibition of adipogenesis and controlling body weight in rats fed with a high-fat diet.

Caffeic acid phenethyl ester reduces the activation of the nuclear factor κB pathway by high-fat diet-induced obesity in mice

OBJECTIVE

The aim of this study was to investigate the effect of CAPE on the insulin signaling and inflammatory pathway in the liver of mice with high fat diet induced obesity.

MATERIAL/METHODS

Swiss mice were fed with standard chow or high-fat diet for 12-week. After the eighth week, animals in the HFD group with serum glucose levels higher than 200 mg/dL were divided into two groups, HFD and HFD receiving 30 mg/kg of CAPE for 4 weeks. After 12 weeks, the blood samples could be collected and liver tissue extracted for hormonal and biochemical measurements, and insulin signaling and inflammatory pathway analyzes.

RESULTS

The high-fat diet group exhibited more weight gain, glucose intolerance, and hepatic steatosis compared with standard diet group. The CAPE treatment showed improvement in glucose sensitivity characterized by an area under glucose curve similar to the control group in an oral glucose tolerance test Furthermore, CAPE treatment promoted amelioration in hepatic steatosis compared with the high-fat diet group. The increase in glucose sensitivity was associated with the improvement in insulin-stimulated phosphorylation of the insulin receptor substrate-2, followed by an increase in Akt phosphorylation. In addition, it was observed that CAPE reduced the induction of the inflammatory pathway, c-jun-N- terminal kinase, the nuclear factor kappa B, and cyclooxygenase-2 expression, respectively.

CONCLUSIONS

Overall, these findings indicate that CAPE exhibited anti-inflammatory activity that partly restores normal metabolism, reduces the molecular changes observed in obesity and insulin resistance, and therefore has a potential as a therapeutic agent in obesity.

Caffeic acid phenethyl ester protects nigral dopaminergic neurons via dual mechanisms involving haem oxygenase-1 and brain-derived neurotrophic factor

BACKGROUND AND PURPOSE

Caffeic acid phenethyl ester (CAPE) is a component of honey bee propolis that can induce expression of haem oxygenase-1 (HO-1). Because HO-1 induction has been suggested to protect dopaminergic neurons in the substantia nigra, we examined the effect of CAPE in experimental models of dopaminergic neurodegeneration.

EXPERIMENTAL APPROACH

Neuroprotective effect of CAPE was investigated in rat organotypic midbrain slice cultures and in vivo, using a mouse model of dopaminergic neurodegeneration induced by intranigral injection of LPS and intrastriatal injection of 6-hydroxydopamine.

KEY RESULTS

CAPE protected dopaminergic neurons in slice cultures from IFN-γ/LPS-induced injury. The effect of CAPE was inhibited by zinc protoporphyrin IX, an HO-1 inhibitor, and by neutralizing antibody against brain-derived neurotrophic factor (BDNF). A p38 MAPK inhibitor SB203580 prevented activation of NF-E2-related factor 2, attenuated increased expression of HO-1 and BDNF, and blocked the neuroprotective actions of CAPE. In the LPS-injected mouse model, daily intraperitoneal administration of CAPE protected dopaminergic neurons, up-regulated HO-1 and BDNF, and reduced the increase of activated microglia/macrophages. Neuroprotective effects of CAPE against LPS-induced injury was prevented by zinc protoporphyrin IX or anti-BDNF antibody. CAPE protected dopaminergic neurons and alleviated methamphetamine-induced rotational behaviour also in 6-hydroxydopamine hemiparkinsonian mice.

CONCLUSION AND IMPLICATIONS

CAPE is a novel type of neuroprotective agent whose actions are mediated by both HO-1 and BDNF. These findings may provide novel clues to develop neuroprotective agents for treatment of neurodegenerative disorders.

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 caffeic acid 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 7 cm at a point just in front of the coronal suture and over the right hemisphere. Rats were sacrificed at 4 h 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 (10 μmol/kg) 15 min 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.

Protective effects of caffeic acid phenethyl ester (CAPE) on intestinal damage in necrotizing enterocolitis

OBJECTIVE

To determine the preventative effect of caffeic acid phenethyl ester (CAPE) in necrotizing enterocolitis (NEC) in an experimental rat model of NEC.

MATERIALS AND METHODS

Thirty newborn Sprague-Dawley rats were randomly divided into three groups; as NEC, NEC + CAPE and control. NEC was induced by enteral formula feeding, subjected to hypoxia-hyperoxia and cold stress. Pups in the NEC + CAPE group were treated with CAPE at a dose of 30 mg/kg daily by intraperitoneal route from the first day to the end of the study. All pups were executed on the fourth day. Proximal colon and ileum were allocated for histopathologic and biochemical evaluation, including xanthine oxidase (XO), total antioxidant status (TAS), total oxidant status (TOS), malonaldehyde (MDA) and myeloperoxidase (MPO) activities.

RESULTS

The pups in the NEC + CAPE group had better histopathologic and apoptosis evaluations (TUNEL and caspase-9) and the severity of bowel damage was significantly lower in the NEC + CAPE group compared to the NEC group (P < 0.01). The clinical sickness scores and body weight in the NEC + CAPE group was significantly better compared to the NEC group (P < 0.05). Tissue MDA, MPO, XO levels and TOS were remarkably reduced in the NEC + CAPE group, however, TAS was significantly increased in the NEC + CAPE group (P < 0.05).

CONCLUSION

Treatment with CAPE reduces the intestinal damage in NEC.

[Inflammation, angiogenesis and epilepsy]

It is well admitted now that gliosis participates in epileptogenesis, particularly in symptomatic focal epilepsies, like temporal lobe epilepsy. Indeed, astrocytic and microglial activation was shown to release numerous inflammatory factors that modify neuronal excitability or contribute to neuronal loss. These redundant processes maintain chronic epilepsy. However, other sources of inflammation exist. Several studies pointed out the epileptogenicity of blood-brain barrier disruption due to the leakage of leukocytes and serum proteins, triggering inflammatory and immune responses which disturb the neuronal environment. Recently, it was proposed that peripheral inflammation plays a key-role in epilepsy, mainly mediated by circulating cytokines which promote leukocyte extravasation.

Effects of caffeic acid phenethyl ester on endotoxin-induced cardiac stress in rats: a possible mechanism of protection

Endotoxins (lipopolysaccharides; LPS) are known to cause multiple organ failure, including myocardial dysfunction. The present study aimed to investigate the mechanism of caffeic acid phenethyl ester (CAPE) protection against LPS-induced cardiac stress. Rats were allocated into three groups; group 1 served as a normal control group, group 2 (LPS) received a single intraperitoneal injection of LPS (10 mg/kg), group 3 (LPS + CAPE) was injected intraperitoneally with CAPE (10 mg/kg/day; solubilized in saline containing 20% tween 20) throughout a period of 10 days prior to LPS injection. Rats were maintained 4 h before sacrifice. Caffeic acid phenethyl ester pretreatment normalized LPS-enhanced activities of serum creatine kinase (CK) and lactate dehydrogenase (LDH) as well as glutathione peroxidase (GPx), and myeloperoxidase (MPO) in cardiac tissue. A significant reduction of the elevated levels of serum tumor necrosis factor-alpha (TNF-α) as well as serum and cardiac nitrite/nitrate (NOx) ) was achieved after CAPE pretreatment. CAPE also restored malondialdelyde (MDA), reduced glutathione (GSH), and cytosolic calcium (Ca2+ ) levels in the heart. A marked induction of cardiac heme oxygenase-1 (HO-1) protein level was detected in CAPE-pretreated group. Whereas, LPS-induced reduction of adenosine triphosphate (ATP) and phosphocreatine (PCr) levels was insignificantly changed. Conclusively, the early treatment with CAPE maintained antioxidant defences, reduced oxidative injury, cytokine damage, and inflammation but did not markedly improve energy status in cardiac tissue. The beneficial effect of CAPE might be mediated, at least in part, by the superinduction of HO-1.

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.

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.

Caffeic Acid Derivatives: In Vitro and In Vivo Anti-inflammatory Properties

Caffeic acid and some of its derivatives such as caffeic acid phenetyl ester (CAPE) and octyl caffeate are potent antioxidants which present important anti-inflammatory actions. The present study assessed the in vitro and in vivo effects of five caffeic acid derivatives (caffeic acid methyl, ethyl, butyl, octyl and benzyl esters) and compared their actions to those of CAPE. In the model of LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages, the pre-incubation of all derivatives inhibited nitrite accumulation on the supernatant of stimulated cells, with mean IC50 (microM) values of 21.0, 12.0, 8.4, 2.4, 10.7 and 4.80 for methyl, ethyl, butyl, octyl, benzyl and CAPE, respectively. The effects of caffeic acid derivatives seem to be related to the scavenging of NO, as the compounds prevented SNAP-derived nitrite accumulation and decreased iNOS expression. In addition, butyl, octyl and CAPE derivatives significantly inhibited LPS-induced iNOS expression in RAW 264.7 macrophages. Extending the in vitro results, we showed that the pre-treatment of mice with butyl, octyl and CAPE derivatives inhibited carrageenan-induced paw edema and prevented the increase in IL-1beta levels in the mouse paw by 30, 24 and 36%, respectively. Butyl, octyl and CAPE derivatives also prevented carrageenan-induced neutrophil influx in the mouse paw by 28, 49 and 31%, respectively. Present results confirm and extend literature data, showing that caffeic acid derivatives exert in vitro and in vivo anti-inflammatory actions, being their actions mediated, at least in part by the scavenging of NO and their ability to modulate iNOS expression and probably that of other inflammatory mediators.

Identification of a bioactive compound isolated from Brazilian propolis type 6

A prenylated benzophenone, hyperibone A, was isolated from the hexane fraction of Brazilian propolis type 6. Its structure was determined by spectral analysis including 2D NMR. This compound exhibited cytotoxic activity against HeLa tumor cells (IC(50)=0.1756microM), strong antimicrobial activity (MIC range-0.73-6.6microg/mL; MBC range-2.92-106microg/mL) against Streptococcus mutans, Streptococcus sobrinus, Streptococcus oralis, Staphylococcus aureus, and Actinomyces naeslundii, and the results of its cytotoxic and antimicrobial activities were considered good.

Phenolic compounds: evidence for inhibitory effects against obesity and their underlying molecular signaling mechanisms

Phenolic compounds are widely present in the plant kingdom. Many epidemiological studies have indicated that consumption of some plant-derived foodstuffs with high phenolic content is associated with the prevention of some diseases and that these compounds may have similar properties to antioxidants, antimutagenic agents, antithrombotic agents, anti-inflammatory agents, anti-HIV-1, and anticancer agents. However, obesity is an important topic in the world of public health and preventive medicine. Relationships between body mass index, waist circumference, or waist-to-hip ratio and the risk of development of some diseases (such as heart disease, dyslipidemia, hypertension, non-alcoholic fatty liver disease, diabetes, kidney failure, cancer, stroke, osteoarthritis, and sleep apnea) have been observed. Evidence that phenolic compounds have beneficial effects in fighting obesity is increasingly being reported in the scientific literature. These in vitro and in vivo effects of phenolic compounds on the induction of pre-adipocytic and adipocytic apoptosis and inhibition of adipocytic lipid accumulation are considered in detail here. This review presents evidence of their inhibitory effects on obesity and their underlying molecular signaling mechanisms.

Protective role of caffeic acid against alcohol-induced biochemical changes in rats

Caffeic acid is a well-known phenolic compound mainly present in plants. In this study, caffeic acid was evaluated for its protective effect against chronic ethanol-induced biochemical changes in male Wistar rats. Administration of ethanol (7.9 g/kg/day) for 45 days induced liver and kidney damage as manifested by a significant increase in the levels of serum hepatic and renal markers namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), bilirubin, urea, creatinine, and a significant decrease in creatinine clearance and levels of hemoglobin. Plasma thiobarbituric acid-reactive substances and hydroperoxide were significantly elevated where as the levels of nonenzymic antioxidants [reduced glutathione, vitamin E and vitamin C] were significantly decreased in alcohol-intoxicated rats. Administration of caffeic acid along with alcohol significantly decreased the serum levels of liver and kidney markers to near-normal levels. In addition, administration of caffeic acid significantly decreased the levels of lipid peroxidation markers while the levels of antioxidants were significantly increased in circulation of alcohol-fed rats. All these results were accompanied by histological observations in liver. The results demonstrate that caffeic acid has a beneficial effect in reducing the adverse effect of alcohol.

Effects of flavonoids and phenolic acids on the inhibition of adipogenesis in 3T3-L1 adipocytes

Obesity has become a global epidemic in both developed and developing countries, and it is a significant risk factor for various diseases such as diabetes, cancer, heart disease, and hypertension. In the present study, the effect of naturally occurring antioxidants (flavonoids and phenolic acids) on the inhibition of adipogenesis in 3T3-L1 adipocytes was investigated. The results showed that o-coumaric acid and rutin had the highest inhibition on intracellular triglyceride (61.3 and 83.0%, respectively) among 15 phenolic acids and 6 flavonoids tested. However, the oil red o stained material (OROSM) showed that cell number in 3T3-L1 adipocytes was not influenced by those compounds. For glycerol-3-phosphate dehydrogenase (GPDH) activity, the data indicated that o-coumaric acid and rutin had the highest inhibition on GPDH activity (54.2 and 66.8%, respectively) among the compounds tested. o-Coumaric acid and rutin also inhibited the expression of PPARgamma, C/EBPalpha and leptin and then up-regulated expression of adiponectin at the protein level. Some naturally occurring antioxidants efficiently suppressed adipogenesis in 3T3-L1 adipocytes. These results suggest that o-coumaric acid and rutin targeted for adipocyte functions could be effective in improving the symptoms of metabolic syndrome.

Caffeic acid attenuates neuronal damage, astrogliosis and glial scar formation in mouse brain with cryoinjury

Traumatic brain injury induces neuron damage in early phase, and astrogliosis and the formation of the glial scar in late phase. Caffeic acid (3, 4-dihydroxycinnamic acid), one of the natural phenolic compounds, exerts neuroprotective effects against ischemic brain injuries with anti-oxidant and anti-inflammatory properties, and by scavenging reactive species. However, whether caffeic acid has protective effects against traumatic brain injury is unknown. Therefore, we determined the effect of caffeic acid on the lesion in the early (1 day) and late phases (7 to 28 days) of cryoinjury in mice. We found that caffeic acid (10 and 50 mg/kg, i.p., for 7 days after cryoinjury) reduced the lesion area and attenuated the neuron loss around the lesion core 1 to 28 days, but attenuated the neuron loss in the lesion core only 1 day after cryoinjury. Moreover, caffeic acid attenuated astrocyte proliferation, glial scar wall formation and glial fibrillary acidic protein (GFAP) protein expression in the late phase of cryoinjury (7 to 28 days). Caffeic acid also inhibited the reduction of superoxide dismutase activity and the increase in malondialdehyde content in the brain 1 day after cryoinjury. These results indicate that caffeic acid exerts a protective effect in traumatic brain injury, especially on glial scar formation in the late phase, which at least is associated with its anti-oxidant ability.

Inhibitory effect of phenolic acids on the proliferation of 3T3-L1 preadipocytes in relation to their antioxidant activity

Obesity is an important topic in the world of public health and preventive medicine. Inhibition of preadipocyte proliferation plays an important role in the mechanisms of proposed antiobesity. In this in vitro study, the inhibitory effect of phenolic acids on 3T3-L1 preadipocytes was evaluated, and a relationship analysis was then conducted. The results showed that the addition of phenolic acids to the growth medium decreased the cell population growth of 3T3-L1 preadipocytes. The IC50 values of chlorogenic acid, gallic acid, o-coumaric acid and m-coumaric acid on 3T3-L1 preadipocytes were 72.3, 43.3, 48.2, and 49.2 microM, respectively. A relationship analysis indicated that there is a significant linear correlation between the influence of phenolic acids on cell population growth and their antioxidant activity (r = 0.77, p < 0.01). The cell cycle assay indicated that the treatment of 3T3-L1 preadipocytes with chlorogenic acid, o-coumaric acid, and m-coumaric acid caused cell cycle arrest in the G1 phase. Gallic acid did not affect the cell cycle profile; however, it increased the number of apoptotic cells (sub-G1 phase) in a time- and dose-dependent manner. Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) apoptosis flow cytometric assay showed that gallic acid increased the number of early apoptotic (annexin V-FITC+/PI-) and late apoptotic cells (annexin V-FITC+/PI+) but not necrotic cells (annexin V-FITC-/PI+). The treatment of cells with gallic acid caused the loss of mitochondrial membrane potential (delta psi(m)). These results indicate that the inhibition of preadipocyte population growth by some phenolic acids might have further implication in in vivo antiobesity effects.

Molecular targets of dietary polyphenols with anti-inflammatory properties

There is persuasive epidemiological and experimental evidence that dietary polyphenols have anti-inflammatory activity. Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) have long been used to combat inflammation. Recently, cyclooxygenase (COX) inhibitors have been developed and recommended for treatment of rheumatoid arthritis (RA) and osteoarthritis (OA). However, two COX inhibitors have been withdrawn from the market due to unexpected side effects. Because conventional therapeutic and surgical approaches have not been able to fully control the incidence and outcome of many inflammatory diseases, there is an urgent need to find safer compounds and to develop mechanism-based approaches for the management of these diseases. Polyphenols are found in many dietary plant products, including fruits, vegetables, beverages, herbs, and spices. Several of these compounds have been found to inhibit the inflammation process as well as tumorigenesis in experimental animals; they can also exhibit potent biological properties. In addition, epidemiological studies have indicated that populations who consume foods rich in specific polyphenols have lower incidences of inflammatory disease. This paper provides an overview of the research approaches that can be used to unravel the biology and health effects of polyphenols. Polyphenols have diverse biological effects, however, this review will focus on some of the pivotal molecular targets that directly affect the inflammation process.

The selective inhibition of nitric oxide production in the avian macrophage cell line HD11

The production of reactive nitrogen, nitric oxide (NO), has previously been demonstrated to be a major mechanism by which the innate immune system defends against microbial invasion. The induction of many antimicrobial mechanisms is regulated by numerous components during the transduction of the signal from the cell surface to the cell nucleus where response genes are upregulated. Toll-like cell surface receptor activation often leads to sequential modulation of protein tyrosine kinases (PTK), mitogen activated protein kinases (MAPK), degradation of I kappa B (IkappaB) regulatory molecules which, in turn, release the nuclear factor-kappa B (NF-kappaB) family proteins for translocation into the nucleus and subsequent gene transcription. The purpose of this study was to investigate components of the upstream signal transduction pathway induced by bacterial and viral-like stimulation of NO for antimicrobial defense by the transformed chicken macrophage cell line, HD11. We quantified the production of nitrite by chicken macrophages after exposure to selective pharmacological inhibitors of specific signal transduction components prior to stimulation by polyinosinic polycytidylic acid (poly I:C), formalin-fixed Enterococcus gallinarum (EG) or formalin-fixed Klebsiella pneumoniae (KP). We found that NO production induced by dsRNA or bacteria was reduced in a dose dependent manner by specific inhibitors of PTK, p38 MAPK, IkappaB, and NF-kappaB. Inhibition efficacy varied dependent on stimulation by bacterial or viral-like ligands. In general, NO production induced by bacterial stimulation was most effectively reduced by inhibition of p38 MAPK and least effectively reduced by inhibition of IkappaB. NF-kappaB and IkappaB inhibition affected NO production induced by dsRNA more than that induced by bacterial stimulation.

Effect of caffeic acid phenethyl ester on gastric acid secretion in vitro

Caffeic acid phenethyl ester (CAPE), one of the major components of propolis (honeybee resin), has demonstrated a wide spectrum of activities including suppression of eicosanoids by inhibition of cyclooxygenase-1 and cyclooxygenase-2 enzyme activities. The aim of this study was to investigate the effect of CAPE on basal and secretagogues-stimulated gastric acid secretion in vitro. In the isolated, lumen-perfused, stomach preparation of mouse, CAPE (10-100 microM) did not affect the basal gastric acid secretion nor the secretion stimulated by histamine, pentagastrin, isobutyl methylxanthine and high levels of K+. By contrast, CAPE increased the gastric acid secretion induced by the muscarinic receptor agonist, 5-methylfurmethide (5-MEF). CAPE also inhibited the acetylcholinesterase activity in an in vitro colorimetric assay. Eserine (10 microM), a well known acetylcholinesterase inhibitor, also increased 5-MEF-stimulated acid secretion. Our results show that CAPE increases gastric acid secretion stimulated by an acetylcholine agonist receptor likely through inhibition of acetylcholinesterase activity.

Protective effects of caffeic acid phenethyl ester (CAPE) on carbon tetrachloride-induced hepatotoxicity in rats

In the present study, protective effects of caffeic acid phenethyl ester (CAPE) have been evaluated on carbon tetrachloride (CCl4)-induced hepatotoxicity in rat. Twenty-four male Wistar rats were divided in three groups. Group I was used as control. Rats in group II were injected every other day with CCl4 for 1 month, whereas rats in group III were injected every other day with CCl4 and CAPE for 1 month. At the end of the experiment, all animals were killed by decapitation and blood samples were obtained. Serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total and conjugated bilirubin levels and hepatic malondialdehyde (MDA) contents were determined. For histopathological evaluation, livers of all rats were removed and processed for light microscopy. All biochemical parameters in serum and the hepatic MDA content were significantly higher in animals treated with CCl4 than in the controls. Rats treated with CCl4 and CAPE showed a significant reduction in biochemical parameters in serum and hepatic MDA content. Livers of rats treated with CCl4 showed classic histology of cirrhosis, whereas the histopathological changes were reduced after administration of CCl4 and CAPE. A normal lobular appearance was observed in livers in this group except for fatty degeneration. The results of our study indicate that CAPE treatment prevents CCl4-induced liver damage in rats.

Cytotoxicity of phenolic acid phenethyl esters on oral cancer cells

Many phenolic acid phenethyl esters possess diverse biological effects including anti-cancer activity. A series of 14 derivatives were synthesized for the evaluation of their cytotoxic effect on oral cancer cells. These derivatives were tested by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric and trypan blue dye exclusion assay on the growth of oral squamous cell carcinoma (SAS), oral epidermoid carcinoma-Meng 1 (OEC-M1), and normal human oral fibroblast (NHOF) cells, respectively. Caffeic acid phenethyl esters, 3a (CAPE), and 3b, 3c, and 3d showed cytotoxic effects on the SAS and OEC-M1 cell lines, but not the NHOF cell line at a 5-100 microM dose range. Flow cytometric analysis showed that 3c caused OEC-M1 cell arrest at G2/M phase. Such differential effects on representative cancer and normal cells suggested these compounds might be useful in oral cancer chemotherapy.

Stimulatory actions of caffeic acid phenethyl ester, a known inhibitor of NF-kappaB activation, on Ca2+-activated K+ current in pituitary GH3 cells

Caffeic acid phenethyl ester (CAPE), a phenolic antioxidant derived from the propolis of honeybee hives, is known to be an inhibitor of activation of nuclear transcript factor NF-kappaB. Its effects on ion currents have been investigated in pituitary GH(3) cells. This compound increased Ca(2+)-activated K(+) current (I(K(Ca))) in a concentration-dependent manner with an EC(50) value of 14 +/- 2 microm. However, the magnitude of CAPE-induced stimulation of I(K(Ca)) was attenuated in GH(3) cells preincubated with 2,2'-azo-bis-(2-amidinopropane) hydrochloride (100 microm) or t-butyl hydroperoxide (1 mm). CAPE (50 microm) slightly suppressed voltage-dependent L-type Ca(2+) current. In inside-out configuration, CAPE (20 microm) applied to the intracellular face of the detached patch enhanced the activity of large conductance Ca(2+)-activated K(+) (BK(Ca)) channels with no modification in single-channel conductance. After BK(Ca) channel activity was increased by CAPE (20 microm), subsequent application of nordihydroguaiaretic acid (20 microm) did not further increase the channel activity. CAPE-stimulated channel activity was dependent on membrane potential. CAPE could also increase Ca(2+) sensitivity of BK(Ca) channels in these cells. Its increase in the open probability could primarily involve a decrease in the mean closed time. In current-clamp conditions, CAPE hyperpolarized the membrane potential and reduced the firing of action potentials. The stimulatory effects on these channels may partly contribute to the underlying mechanisms through which this compound influences the functional activities of neurons or neuroendocrine cells. Caution has to be used in attributing its response in the activation of NF-kappaB.