Caffeic acid phenethyl ester protects rabbit brains against permanent focal ischemia by antioxidant action: a biochemical and planimetric study

Apitherapy in Post-Ischemic Brain Neurodegeneration of Alzheimer's Disease Proteinopathy: Focus on Honey and Its Flavonoids and Phenolic Acids

Neurodegeneration of the brain after ischemia is a major cause of severe, long-term disability, dementia, and mortality, which is a global problem. These phenomena are attributed to excitotoxicity, changes in the blood-brain barrier, neuroinflammation, oxidative stress, vasoconstriction, cerebral amyloid angiopathy, amyloid plaques, neurofibrillary tangles, and ultimately neuronal death. In addition, genetic factors such as post-ischemic changes in genetic programming in the expression of amyloid protein precursor, β-secretase, presenilin-1 and -2, and tau protein play an important role in the irreversible progression of post-ischemic neurodegeneration. Since current treatment is aimed at preventing symptoms such as dementia and disability, the search for causative therapy that would be helpful in preventing and treating post-ischemic neurodegeneration of Alzheimer's disease proteinopathy is ongoing. Numerous studies have shown that the high contents of flavonoids and phenolic acids in honey have antioxidant, anti-inflammatory, anti-apoptotic, anti-amyloid, anti-tau protein, anticholinesterase, serotonergic, and AMPAK activities, influencing signal transmission and neuroprotective effects. Notably, in many preclinical studies, flavonoids and phenolic acids, the main components of honey, were also effective when administered after ischemia, suggesting their possible use in promoting recovery in stroke patients. This review provides new insight into honey's potential to prevent brain ischemia as well as to ameliorate damage in advanced post-ischemic brain neurodegeneration.

Effects of caffeic acid phenethyl ester use and inhibition of p42/44 MAP kinase signal pathway on caveolin 1 gene expression and antioxidant system in chronic renal failure model of rats

Effects of Caffeic acid phenethyl ester (CAPE) and/or PD98059 (PD) on the gene expression of Caveolin-1 (CAV1) and reduced glutathione (GSH), malondialdehyde (MDA), copper-zinc superoxide dismutase (CuZn-SOD), and catalase (CAT) enzyme activities were investigated in an experimental chronic renal failure model in rats. Eighty Wistar rats were divided into eight groups for a 28-day study: Control, CsA (Cyclosporine A), CsA-V (CsA solvent), CsA + PD (CsA + PD98059), CsA + PD + CAPE, CsA + CAPE, CAPE-V (CAPE solvent), and PD-V (PD98059 solvent). Serum blood urea nitrogen and creatinine levels, as well as histopathological findings indicated the development of renal failure in the CsA group. Kidney GSH levels decreased while MDA levels, CuZn-SOD, and CAT activities increased significantly in the CsA group compared to control indicating oxidative stress. CAV1 gene expression significantly decreased in the CsA group compared to the control. PD98059 and CAPE applications made positive improvements in the levels of the parameters investigated. PD98059 and CAPE applications in CsA given animals increased GSH and CAV1 gene expressions and decreased CuZn-SOD and CAT levels compared to the CsA group. In conclusion, it was shown that PD98059 and CAPE could attenuate the effects of chronic renal failure, and CAV1 is suggested as a therapeutic target and the inhibition of the p44/42 MAPK pathway may be a new approach for the treatment of renal degenerations.

Plant based food bioactives: A boon or bane for neurological disorders

Neurological disorders are the foremost occurring diseases across the globe resulting in progressive dysfunction, loss of neuronal structure ultimately cell death. Therefore, attention has been drawn toward the natural resources for the search of neuroprotective agents. Plant-based food bioactives have emerged as potential neuroprotective agents for the treatment of neurodegenerative disorders. This comprehensive review primarily focuses on various plant food bioactive, mechanisms, therapeutic targets, in vitro and in vivo studies in the treatment of neurological disorders to explore whether they are boon or bane for neurological disorders. In addition, the clinical perspective of plant food bioactives in neurological disorders are also highlighted. Scientific evidences point toward the enormous therapeutic efficacy of plant food bioactives in the prevention or treatment of neurological disorders. Nevertheless, identification of food bioactive components accountable for the neuroprotective effects, mechanism, clinical trials, and consolidation of information flow are warranted. Plant food bioactives primarily act by mediating through various pathways including oxidative stress, neuroinflammation, apoptosis, excitotoxicity, specific proteins, mitochondrial dysfunction, and reversing neurodegeneration and can be used for the prevention and therapy of neurodegenerative disorders. In conclusion, the plant based food bioactives are boon for neurological disorders.

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.

Propolis: Its Role and Efficacy in Human Health and Diseases

With technological advancements in the medicinal and pharmaceutical industries, numerous research studies have focused on the propolis produced by stingless bees (Meliponini tribe) and Apis mellifera honeybees as alternative complementary medicines for the potential treatment of various acute and chronic diseases. Propolis can be found in tropical and subtropical forests throughout the world. The composition of phytochemical constituents in propolis varies depending on the bee species, geographical location, botanical source, and environmental conditions. Typically, propolis contains lipid, beeswax, essential oils, pollen, and organic components. The latter include flavonoids, phenolic compounds, polyphenols, terpenes, terpenoids, coumarins, steroids, amino acids, and aromatic acids. The biologically active constituents of propolis, which include countless organic compounds such as artepillin C, caffeic acid, caffeic acid phenethyl ester, apigenin, chrysin, galangin, kaempferol, luteolin, genistein, naringin, pinocembrin, coumaric acid, and quercetin, have a broad spectrum of biological and therapeutic properties such as antidiabetic, anti-inflammatory, antioxidant, anticancer, rheumatoid arthritis, chronic obstruct pulmonary disorders, cardiovascular diseases, respiratory tract-related diseases, gastrointestinal disorders, as well as neuroprotective, immunomodulatory, and immuno-inflammatory agents. Therefore, this review aims to provide a summary of recent studies on the role of propolis, its constituents, its biologically active compounds, and their efficacy in the medicinal and pharmaceutical treatment of chronic diseases.

Bee Products: A Representation of Biodiversity, Sustainability, and Health

Biodiversity strengthens the productivity of any ecosystem (agricultural land, forest, lake, etc.). The loss of biodiversity contributes to food and energy insecurity; increases vulnerability to natural disasters, such as floods or tropical storms; and decreases the quality of both life and health. Wild and managed bees play a key role in maintaining the biodiversity and in the recovery and restoration of degraded habitats. The novelty character of this perspective is to give an updated representation of bee products’ biodiversity, sustainability, and health relationship. The role of bees as bioindicators, their importance in the conservation of biodiversity, their ecosystem services, and the variety of the bee products are described herein. An overview of the main components of bee products, their biological potentials, and health is highlighted and detailed as follows: (i) nutritional value of bee products, (ii) bioactive profile of bee products and the related beneficial properties; (iii) focus on honey and health through a literature quantitative analysis, and (iv) bee products explored through databases. Moreover, as an example of the interconnection between health, biodiversity, and sustainability, a case study, namely the “Cellulose Park”, realized in Rome (Italy), is presented here. This case study highlights how bee activities can be used to assess and track changes in the quality of agricultural ecosystems—hive products could be valid indicators of the quality and health of the surrounding environment, as well as the changes induced by the biotic and abiotic factors that impact the sustainability of agricultural production and biodiversity conservation in peri-urban areas.

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.

From Preclinical Stroke Models to Humans: Polyphenols in the Prevention and Treatment of Stroke

Polyphenols are an important family of molecules of vegetal origin present in many medicinal and edible plants, which represent important alimentary sources in the human diet. Polyphenols are known for their beneficial health effects and have been investigated for their potential protective role against various pathologies, including cancer, brain dysfunctions, cardiovascular diseases and stroke. The prevention of stroke promoted by polyphenols relies mainly on their effect on cardio- and cerebrovascular systems. However, a growing body of evidence from preclinical models of stroke points out a neuroprotective role of these molecules. Notably, in many preclinical studies, the polyphenolic compounds were effective also when administered after the stroke onset, suggesting their possible use in promoting recovery of patients suffering from stroke. Here, we review the effects of the major polyphenols in cellular and in vivo models of both ischemic and hemorrhagic stroke in immature and adult brains. The results from human studies are also reported.

Cardiovascular Effects of Caffeic Acid and Its Derivatives: A Comprehensive Review

Caffeic acid (CA) and its phenethyl ester (CAPE) are naturally occurring hydroxycinnamic acids with an interesting array of biological activities; e.g., antioxidant, anti-inflammatory, antimicrobial and cytostatic. More recently, several synthetic analogs have also shown similar properties, and some with the advantage of added stability. The actions of these compounds on the cardiovascular system have not been thoroughly explored despite presenting an interesting potential. Indeed the mechanisms underlying the vascular effects of these compounds particularly need clarifying. The aim of this paper is to provide a comprehensive and up-to-date review on current knowledge about CA and its derivatives in the cardiovascular system. Caffeic acid, CAPE and the synthetic caffeic acid phenethyl amide (CAPA) exhibit vasorelaxant activity by acting on the endothelial and vascular smooth muscle cells. Vasorelaxant mechanisms include the increased endothelial NO secretion, modulation of calcium and potassium channels, and modulation of adrenergic receptors. Together with a negative chronotropic effect, vasorelaxant activity contributes to lower blood pressure, as several preclinical studies show. Their antioxidant, anti-inflammatory and anti-angiogenic properties contribute to an important anti-atherosclerotic effect, and protect tissues against ischemia/reperfusion injuries and the cellular dysfunction caused by different physico-chemical agents. There is an obvious shortage of in vivo studies to further explore these compounds' potential in vascular physiology. Nevertheless, their favorable pharmacokinetic profile and overall lack of toxicity make these compounds suitable for clinical studies.

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.

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.

Evidence on the Health Benefits of Supplemental Propolis

Propolis is a honey-related product with reported health benefits such as improved immunity, lowered blood pressure, treated allergies and skin conditions. A literature review and narrative synthesis were conducted to investigate the evidence on the reported health benefits and future direction of propolis products. Using a predefined search strategy we searched Medline (OvidSP), Embase and Central for quantitative and qualitative studies (1990-2018). Citation, reference, hand searches and expert consultation were also undertaken. Studies of randomised control trials and observational data on humans with health-related outcomes were included. Collected data were entered into NVivo software (Version 12, QRS International) and analysed using a thematic framework and a narrative synthesis of emergent themes. A total of 63 publications were discussed. The majority were cell-based and animal studies, with a few key human trials conducted. There is significant promise for propolis as an effective antioxidant and anti-inflammatory agent with particular promise in cardiometabolic health.

Caffeic acid phenethyl ester attenuates neuropathic pain by suppressing the p38/NF-κB signal pathway in microglia

Background

Management of neuropathic pain is still a clinical challenge. Evidence has accumulated indicating that propolis is effective in attenuating neuropathic pain; however, the mechanism is not fully understood. Our present study investigated the effects and the possible mechanism of caffeic acid phenethyl ester (CAPE), the main ingredient of propolis, in improving neuropathic pain via its inhibition on p38/NF-κB signal pathway in microglia.

Materials and methods

Chronic constriction injury (CCI) mice model and the microglial cell line BV-2 were used to investigate the effects and the mechanism of CAPE. Cell signaling was measured by real-time PCR, Western blotting and immunofluorescence assay.

Results

CAPE relieved neuropathic pain behaviors induced by CCI in mice. CAPE also inhibited CCI-induced activation of microglia. Furthermore, CAPE suppressed the phosphorylation of p38 mitogen-activated protein kinase, inhibited the translocation of NF-κB and decreased the expression of proinflammatory cytokines tumor necrosis factor-α, IL-1β and IL-6.

Conclusion

CAPE was found to be an effective and safe drug candidate for alleviating neuropathic pain by its powerful inhibition on the P38/NF-κB signal pathway.

Evaluation of an ischemic model in ischemia prone and general Mongolian gerbils by neurological symptom, injury, and sex difference

BACKGROUND

In the previous study, we established an ischemia-prone gerbil population (IG), which was selectively bred to increase the incidence of unilateral carotid arterial occlusion (UCO)-induced ischemia in Mongolian gerbils. However, if the characteristics of ischemia model in IG are the same as those in general gerbils (GG), and if the neurological symptoms are associated with the neurological insults in IG is still unclear.

METHODS

In the present study, we evaluated the UCO model in IG by analyzing neurological symptoms, neurological injury in the hippocampal CA1 region and compared with GG.

RESULTS

The data showed that the ratios of neurological symptom scores ≥ 2 in the IG and GG groups were 65.0% vs 30.0%, respectively, and were significantly different (P < .01).The neuronal damage following a UCO ischemic insult in the IG group was more severe compared to the GG group. There was a high correlation between the neurological insults' scale and the neurological symptom score in the IG and GG groups (r = .979 and .943 in the IG and GG groups, respectively). In animals with mild neurological symptom scores (2 and 3), the neuronal insults were significantly different between female and male gerbils in both IG and GG.

CONCLUSION

Our findings suggest that IG population would likely be more advantageous to establish an ischemic model.

Caffeic acid phenethyl ester protects against photothrombotic cortical ischemic injury in mice

In this study, we aimed to investigate the neuroprotective effects of caffeic acid phenethyl ester (CAPE), an active component of propolis purified from honeybee hives, on photothrombotic cortical ischemic injury in mice. Permanent focal ischemia was achieved in the medial frontal and somatosensory cortices of anesthetized male C57BL/6 mice by irradiation of the skull with cold light laser in combination with systemic administration of rose bengal. The animals were treated with CAPE (0.5–5 mg/kg, i.p.) twice 1 and 6 h after ischemic insult. CAPE significantly reduced the infarct size as well as the expression of tumor necrosis factor-α, hypoxiainducible factor-1α, monocyte chemoattractant protein-1, interleukin-1α, and indoleamine 2,3-dioxygenase in the cerebral cortex ipsilateral to the photothrombosis. Moreover, it induced an increase in heme oxygenase-1 immunoreactivity and interleukin-10 expression. These results suggest that CAPE exerts a remarkable neuroprotective effect on ischemic brain injury via its anti-inflammatory properties, thereby providing a benefit to the therapy of cerebral infarction.

3,4-dihydroxybenzalacetone and caffeic acid phenethyl ester induce preconditioning ER stress and autophagy in SH-SY5Y cells

3,4-dihydroxybenzalacetone (DBL) and Caffeic acid phenethyl ester (CAPE) are both catechol-containing phenylpropanoid derivatives with diverse bioactivities. In the present study, we analyzed the ability of these compounds to activate the unfolded protein response (UPR) and the oxidative stress response. When human SH-SY5Y neuroblastoma cells were treated with DBL or CAPE, the expression of endoplasmic reticulum (ER) stress-related genes such as HSPA5, HYOU1, DDIT3, and SEC61b increased to a larger extent in response to CAPE treatment, while that of antioxidant genes such as HMOX1, GCLM, and NQO1 increased to a larger extent in response to DBL treatment. DNA microarray analysis confirmed the strong link of these compounds to ER stress. Regarding the mechanism, activation of the UPR by these compounds was associated with enhanced levels of oxidized proteins in the ER, and N-acetyl cysteine (NAC), which provides anti-oxidative effects, suppressed the induction of the UPR-target genes. Furthermore, both compounds enhanced the expression of LC3-II, a marker of autophagy, and 4-Phenylbutyric acid (4-PBA), a chemical chaperone that reduces ER stress, suppressed it. Finally, pretreatment of cells with DBL, CAPE or low doses of ER stressors protected cells against a neurotoxin 6-hydroxydopamine (6-OHDA) in an autophagy-dependent manner. These results suggest that DBL and CAPE induce oxidized protein-mediated ER stress and autophagy that may have a preconditioning effect in SH-SY5Y cells.

Caffeic acid phenethyl ester protects the brain against hexavalent chromium toxicity by enhancing endogenous antioxidants and modulating the JAK/STAT signaling pathway

Hexavalent chromium [Cr(VI)] is commonly used in industry, and is a proven toxin and carcinogen. However, the information regarding its neurotoxic mechanism is not completely understood. The present study was designed to scrutinize the possible protective effects of caffeic acid phenethyl ester (CAPE), a bioactive phenolic of propolis extract, on Cr(VI)-induced brain injury in rats, with an emphasis on the JAK/STAT signaling pathway. Rats received 2mg/kgK₂CrO₄ and concurrently treated with 20mg/kg CAPE for 30 days. Cr(VI)-induced rats showed a significant increase in cerebral lipid peroxidation, nitric oxide and pro-inflammatory cytokines, with concomitantly declined antioxidants and acetylcholinesterase. CAPE attenuated oxidative stress and inflammation and enhanced antioxidant defenses in the cerebrum of rats. Cr(VI) significantly up-regulated JAK2, STAT3 and SOCS3, an effect that was reversed by CAPE. In conclusion, CAPE protects the brain against Cr(VI) toxicity through abrogation of oxidative stress, inflammation and down-regulation of JAK2/STAT3 signaling in a SOCS3-independent mechanism.

Derivatives of caffeic acid, a natural antioxidant, as the basis for the discovery of novel nonpeptidic neurotrophic agents

Neurodegenerative disorders, such as Parkinson's disease and Alzheimer's disease, threaten the lives of millions of people and the number of affected patients is constantly growing with the increase of the aging population. Small molecule neurotrophic agents represent promising therapeutics for the pharmacological management of neurodegenerative diseases. In this study, a series of caffeic acid amide analogues with variable alkyl chain lengths, including ACAF3 (C3), ACAF4 (C4), ACAF6 (C6), ACAF8 (C8) and ACAF12 (C12) were synthesized and their neurotrophic activity was examined by different methods in PC12 neuronal cells. We found that all caffeic acid amide derivatives significantly increased survival in PC12 neuronal cells in serum-deprived conditions at 25μM, as measured by the MTT assay. ACAF4, ACAF6 and ACAF8 at 5µM also significantly enhanced the effect of nerve growth factor (NGF) in inducing neurite outgrowth, a sign of neuronal differentiation. The neurotrophic effects of amide derivatives did not seem to be mediated by direct activation of tropomyosin receptor kinase A (TrkA) receptor, since K252a, a potent TrkA antagonist, did not block the neuronal survival enhancement effect. Similarly, the active compounds did not activate TrkA as measured by immunoblotting with anti-phosphoTrkA antibody. We also examined the effect of amide derivatives on signaling pathways involved in survival and differentiation by immunoblotting. ACAF4 and ACAF12 induced ERK1/2 phosphorylation in PC12 cells at 5 and 25µM, while ACAF12 was also able to significantly increase AKT phosphorylation at 5 and 25µM. Molecular docking studies indicated that compared to the parental compound caffeic acid, ACAF12 exhibited higher binding energy with phosphoinositide 3-kinase (PI3K) as a putative molecular target. Based on Lipinski's rule of five, all of the compounds obeyed three molecular descriptors (HBD, HBA and MM) in drug-likeness test. Taken together, these findings show for the first time that caffeic amides possess strong neurotrophic effects exerted via modulation of ERK1/2 and AKT signaling pathways presumably by activation of PI3K and thus represent promising agents for the discovery of neurotrophic compounds for management of neurodegenerative diseases.

Caffeic Acid Phenethyl Ester: A Review of Its Antioxidant Activity, Protective Effects against Ischemia-reperfusion Injury and Drug Adverse Reactions

Propolis, a honey bee product, has been used in folk medicine for centuries for the treatment of abscesses, canker sores and for wound healing. Caffeic acid phenethyl ester (CAPE) is one of the most extensively investigated active components of propolis which possess many biological activities, including antibacterial, antiviral, antioxidant, anti-inflammatory, and anti-cancer effects. CAPE is a polyphenolic compound characterized by potent antioxidant and cytoprotective activities and protective effects against ischemia-reperfusion (I/R)-induced injury in multiple tissues such as brain, retina, heart, skeletal muscles, testis, ovaries, intestine, colon, and liver. Furthermore, several studies indicated the protective effects of CAPE against chemotherapy-induced adverse drug reactions (ADRs) including several antibiotics (streptomycin, vancomycin, isoniazid, ethambutol) and chemotherapeutic agents (mitomycin, doxorubicin, cisplatin, methotrexate). Due to the broad spectrum of pharmacological activities of CAPE, this review makes a special focus on the recently published data about CAPE antioxidant activity as well as its protective effects against I/R-induced injury and many adverse drug reactions.

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.

Neuroprotective effects of caffeic acid phenethyl ester against sevoflurane‑induced neuronal degeneration in the hippocampus of neonatal rats involve MAPK and PI3K/Akt signaling pathways

Millions of infants and children are exposed to anesthesia every year during medical care. Sevoflurane is a volatile anesthetic that is frequently used for pediatric anesthesia. However, previous reports have suggested that the administration of sevoflurane promotes neurodegeneration, raising concerns regarding the safety of its usage. The present study aimed to investigate caffeic acid phenethyl ester (CAPE) and its protective effect against sevoflurane‑induced neurotoxicity in neonatal rats. Rat pups were administered with CAPE at 10, 20 or 40 mg/kg body weight from postnatal day 1 (P1) to P15. The P7 rats were exposed to sevoflurane (2.9%) for 6 h. Control group rats received no sevoflurane or CAPE. Neuronal apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick‑end labeling assay. The expression levels of caspases (caspase‑3, ‑8 and ‑9), apoptotic pathway proteins [Bcl‑2‑associated X protein (Bax), B cell CCL/lymphoma 2 (Bcl‑2), Bcl‑2‑like 1 (Bcl‑xL), Bcl‑2‑associated agonist of cell death (Bad) and phosphorylated (p)‑Bad], mitogen‑activated protein kinases (MAPK) signaling pathway proteins [c‑Jun N‑terminal kinase (JNK), p‑JNK, extracellular signal‑regulated kinase (ERK)1/2, p‑ERK1/2, p38, p‑p38 and p‑c‑Jun] and the phosphoinositide 3‑kinase (PI3K)/Akt cascade were evaluated by western blotting following sevoflurane and CAPE treatment. In addition, the expression of cleaved caspase‑3 was analyzed by immunohistochemistry. CAPE significantly reduced sevoflurane‑induced apoptosis, downregulated the expression levels of caspases and pro‑apoptotic proteins (Bax and Bad) and elevated the expression levels of Bcl‑2 and Bcl‑xL when compared with sevoflurane treatment. Furthermore, CAPE appeared to modify the expression levels of MAPKs and activate the PI3K/Akt signaling pathway. Thus, the present study demonstrated that CAPE effectively inhibited sevoflurane‑induced neuroapoptosis by modulating the expression and phosphorylation of apoptotic pathway proteins and MAPKs, and by regulating the PI3K/Akt pathway.

Dichloromethane extracts of propolis protect cell from oxygen-glucose deprivation-induced oxidative stress via reducing apoptosis

BACKGROUND

Bee propolis, a mixture of the secretion from bee tongue gland and wax gland, was collected from the tree bud and barked by bees. The components were rich in terpenes, phenolics, and flavonoids, and had anti-cancer, anti-bacterial, anti-inflammatory, hepatoprotective, and neuroprotection abilities. However, the potential anti-oxidative stress of propolis was not well documented. This study aimed to study the protective effect of propolis on high-incident nonfatal diseases, such as stroke and cerebral infarction caused by ischemia.

OBJECTIVE

Oxidative stress caused by acute stroke results in inflammation and injury followed by cell damage and apoptosis. Clarification of the anti-oxidative stress effect of propolis may contribute to stroke prevention and damage reduction.

DESIGN

Propolis was separated and purified into 70% ethanol and dichloromethane extracts systematically. The fraction three (Fr.3) of dichloromethane was further separated into pinocembrin, pinobanksin, pinobanksin-3-acetate, chrysin, and galangin by chromatography. Compounds extracted from propolis were tested for cell-protection effects in an oxygen-glucose deprivation (OGD) N2a cell model. MTT assay, oxidative stress markers measurement, flow cytometry, and QPCR were used to evaluate cell viability and apoptosis.

RESULTS

All compounds, especially pinocembrin and galangin, enhanced cell viability in OGD-treated N2a cells. In addition, anti-oxidative enzymes were elevated and cellular Ca(2+) was reduced. They also had extreme anti-apoptosis effects by up-regulating the expression of Bcl-2 mRNA and down-regulating caspase-3 and Bax expression. Taken together, propolis had anti-oxidative effects on stress and protected cells from damage.

CONCLUSION

The anti-oxidative effect of propolis can be applied to daily food supplements and may benefit stroke patients.

Advantages of Pure Platelet-Rich Plasma Compared with Leukocyte- and Platelet-Rich Plasma in Treating Rabbit Knee Osteoarthritis

Background

Concentrated leukocytes in leukocyte- and platelet-rich plasma (L-PRP) may deliver increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage. However, to date no relevant studies have substantiated that in vivo.

Material/Methods

Autologous L-PRP and pure platelet-rich plasma (P-PRP) were prepared, measured for componential composition, and injected intra-articularly after 4, 5, and 6 weeks post-anterior cruciate ligament transection. Caffeic acid phenethyl ester (CAPE) was injected intraperitoneally to inhibit NF-κB activation. All rabbits were sacrificed after 8 weeks postoperative. Enzyme-linked immunosorbent assays were performed to determine interleukin 1β (IL-1β) and prostaglandin E2 (PGE2) concentrations in the synovial fluid, Indian ink staining was performed for gross morphological assessment, and hematoxylin and eosin staining and toluidine blue staining were performed for histological assessment.

Results

Compared with L-PRP, P-PRP injections achieved better outcomes regarding the prevention of cartilage destruction, preservation of cartilaginous matrix, and reduction of IL-1β and PGE2 concentrations. CAPE injections reversed the increased IL-1β and PGE2 concentrations in the synovial fluid after L-PRP injections and improved the outcome of L-PRP injections to a level similar to P-PRP injections, while they had no influence on the therapeutic efficacy of P-PRP injections.

Conclusions

Concentrated leukocytes in L-PRP may release increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage, and finally, result in a inferior efficacy of L-PRP to P-PRP for the treatment of osteoarthritis.

Protective Effects of Dihydrocaffeic Acid, a Coffee Component Metabolite, on a Focal Cerebral Ischemia Rat Model

We recently reported the protective effects of chlorogenic acid (CGA) in a transient middle cerebral artery occlusion (tMCAo) rat model. The current study further investigated the protective effects of the metabolites of CGA and dihydrocaffeic acid (DHCA) was selected for further study after screening using the same tMCAo rat model. In the current study, tMCAo rats (2 h of MCAo followed by 22 h of reperfusion) were injected with various doses of DHCA at 0 and 2 h after onset of ischemia. We assessed brain damage, functional deficits, brain edema, and blood-brain barrier damage at 24 h after ischemia. For investigating the mechanism, in vitro zymography and western blotting analysis were performed to determine the expression and activation of matrix metalloproteinase (MMP)-2 and -9. DHCA (3, 10, and 30 mg/kg, i.p.) dose-dependently reduced brain infarct volume, behavioral deficits, brain water content, and Evans Blue (EB) leakage. DHCA inhibited expression and activation of MMP-2 and MMP-9. Therefore, DHCA might be one of the important metabolites of CGA and of natural products, including coffee, with protective effects on ischemia-induced neuronal damage and brain edema.

The protective effect of caffeic acid on global cerebral ischemia-reperfusion injury in rats

Ischemic stroke is a major cause of death and disability all over the world. Ischemic stroke results from a temporary or permanent reduction of cerebral blood flow that leads to functional and structural damage in different brain regions. Despite decades of intense research, the beneficial treatment of stroke remains limited. In light of this, the search for effective means ameliorating cerebral ischemia-reperfusion injury (CIRI) is one of the major problems of experimental medicine and biology. Recently, the 5-Lipoxygenase (5-LO, a key enzyme metabolizing arachidonic acid to produce leukotrienes) inhibitors have been showed to protect brain against ischemic damage in animal model of cerebral ischemia. Caffeic acid, an inhibitor of 5-LO, is a phenolic compound widely distributed in medicinal plants. The aim of this study was to investigate the effect of caffeic acid on global cerebral ischemia-reperfusion injury in rats. The study was carried out on 45 rats that were randomly divided into five groups: the sham group (n = 9), I/R non-treated group (n = 9), I/R-caffeic acid group (10 mg · kg⁻¹) (n = 9), I/R-caffeic acid group (30 mg · kg⁻¹) (n = 9) and I/R-caffeic acid group (50 mg · kg⁻¹) (n = 9). Global cerebral ischemia was induced by bilateral carotid artery occlusion for 20 min followed by reperfusion. Spatial learning and memory was evaluated using Morris water maze. Histopathological changes of hippocampus neurons was observed using HE staining. Superoxide dismutase (SOD, the antioxidant enzyme) activities and malondialdehyde (MDA, an oxidative stress biomarker) contents were detected. NF-κBp65 expression was detected by the methods of immunohistochemistry. Caffeic acid markedly reduced the escape latency, relieved hippocampal neurons injury and increased neuron count compared with those of I/R non-treated rat. NF-κBp65 expression and MDA content decreased significantly, and SOD activities increased significantly in hippocampus. Compared with sham group, 5-LO expression increase significantly in I/R non-treated group rat, and caffeic acid markedly reduced 5-LO expression. The results of the study suggest that caffeic acid has a significant protective effect on global cerebral ischemia-reperfusion injury in rats. The neuroprotective effects is likely to be mediated through the inhibition of 5-LO.

Caffeic acid, a phenol found in white wine, modulates endothelial nitric oxide production and protects from oxidative stress-associated endothelial cell injury

Introduction

Several studies demonstrated that endothelium dependent vasodilatation is impaired in cardiovascular and chronic kidney diseases because of oxidant stress-induced nitric oxide availability reduction. The Mediterranean diet, which is characterized by food containing phenols, was correlated with a reduced incidence of cardiovascular diseases and delayed progression toward end stage chronic renal failure. Previous studies demonstrated that both red and white wine exert cardioprotective effects. In particular, wine contains Caffeic acid (CAF), an active component with known antioxidant activities.

Aim of the study

The aim of the present study was to investigate the protective effect of low doses of CAF on oxidative stress-induced endothelial injury.

Results

CAF increased basal as well as acetylcholine—induced NO release by a mechanism independent from eNOS expression and phosphorylation. In addition, low doses of CAF (100 nM and 1 μM) increased proliferation and angiogenesis and inhibited leukocyte adhesion and endothelial cell apoptosis induced by hypoxia or by the uremic toxins ADMA, p-cresyl sulfate and indoxyl sulfate. The biological effects exerted by CAF on endothelial cells may be at least in part ascribed to modulation of NO release and by decreased ROS production. In an experimental model of kidney ischemia-reperfusion injury in mice, CAF significantly decreased tubular cell apoptosis, intraluminal cast deposition and leukocyte infiltration.

Conclusion

The results of the present study suggest that CAF, at very low dosages similar to those observed after moderate white wine consumption, may exert a protective effect on endothelial cell function by modulating NO release independently from eNOS expression and phosphorylation. CAF-induced NO modulation may limit cardiovascular and kidney disease progression associated with oxidative stress-mediated endothelial injury.

LC-MS/MS profiling and neuroprotective effects of Mentat® against transient global ischemia and reperfusion-induced brain injury in rats

OBJECTIVE

The aim of this study was to evaluate the possible beneficial effects of Mentat against transient global ischemia and reperfusion-induced brain injury in rats.

METHODS

The neuroprotective effects of Mentat were evaluated against transient global ischemia and reperfusion (I/R)-induced brain injury in rats. Various neurobehavioral and biochemical parameters were assessed, followed by morphologic and histopathologic evaluation of brain tissue to conclude the protective effect of Mentat. Additionally, in vitro antioxidant assays were performed to explore the antioxidant capacity of Mentat and detailed liquid chromatography-mass spectrometry (LC-MS/MS) profiling was carried out to identify the active phytoconstituents responsible for the protective effects of Mentat.

RESULTS

Sixty minutes of transient global ischemia followed by 24 h reperfusion (I/R) caused significant alterations in the cognitive and neurologic functions in the ischemia control group (P < 0.01) compared with the sham control. Furthermore, 2,3,5-triphenyltetrazolium chloride staining of the ischemia control group showed 20.85% ± 0.39% of cerebral infarct area (P < 0.01), increased brain volume (% edema 17.81% ± 1.576%; P < 0.01), and increased lipid peroxidation (P < 0.01) in the brain homogenate. Additionally, the histopathology of the ischemia control group showed severe brain injury compared with the sham control group. Interestingly, pretreatment with Mentat (250 and 500 mg/kg, p.o.) and quercetin (20 mg/kg, p.o.) for 7 d has alleviated all pathological changes observed due to I/R injury. Mentat also showed very good antioxidant activity in in vitro assays (2,2-diphenyl-l-picrylhydrazyl, ferric-reducing antioxidant power, and oxygen radical absorbance capacity assays). Furthermore, the detailed LC-MS/MS analysis of Mentat was performed and enclosed for identifying the actives responsible for its protective effects.

CONCLUSIONS

These findings suggest that Mentat is a neuroprotective agent that may be a useful adjunct in the management of ischemic stroke and its rehabilitation especially with respect to associated memory impairment and other related neurologic conditions.

Fibrinolytic activity and dose-dependent effect of incubating human blood clots in caffeic acid phenethyl ester: in vitro assays

Background. Caffeic acid phenethyl ester (CAPE) has been reported to possess time-dependent fibrinolytic activity by in vitro assay. This study is aimed at investigating fibrinolytic dose-dependent activity of CAPE using in vitro assays. Methods. Standardized human whole blood (WB) clots were incubated in either blank controls or different concentrations of CAPE (3.75, 7.50, 15.00, 22.50, and 30.00 mM). After 3 hours, D-dimer (DD) levels and WB clot weights were measured for each concentration. Thromboelastography (TEG) parameters were recorded following CAPE incubation, and fibrin morphology was examined under a confocal microscope. Results. Overall, mean DD (μg/mL) levels were significantly different across samples incubated with different CAPE concentrations, and the median pre- and postincubation WB clot weights (grams) were significantly decreased for each CAPE concentration. Fibrin removal was observed microscopically and indicated dose-dependent effects. Based on the TEG test, the Ly30 fibrinolytic parameter was significantly different between samples incubated with two different CAPE concentrations (15.0 and 22.50 mM). The 50% effective dose (ED50) of CAPE (based on DD) was 1.99 mg/mL. Conclusions. This study suggests that CAPE possesses fibrinolytic activity following in vitro incubation and that it has dose-dependent activities. Therefore, further investigation into CAPE as a potential alternative thrombolytic agent should be conducted.

Novel antidepressant-like activity of caffeic Acid phenethyl ester is mediated by enhanced glucocorticoid receptor function in the hippocampus

Caffeic acid phenethyl ester (CAPE) is an active component of propolis that has a variety of potential pharmacological effects. Although we previously demonstrated that propolis has antidepressant-like activity, the effect of CAPE on this activity remains unknown. The present study assessed whether treatment with CAPE (5, 10, and 20 µmol/kg for 21 days) has an antidepressant-like effect in mice subjected to chronic unpredictable stress via tail suspension (TST) and forced swim (FST) tests. CAPE administration induced behaviors consistent with an antidepressant effect, evidenced by decreased immobility in the TST and FST independent of any effect on serum corticosterone secretion. Western blots, conducted subsequent to behavioral assessment, revealed that CAPE significantly decreased glucocorticoid receptor phosphorylation at S234 (pGR(S234)), resulting in an increased pGR(S220/S234) ratio. We also observed negative correlations between pGR(S220)/(S234) and p38 mitogen-activated protein kinase (p38MAPK) phosphorylation, which was decreased by CAPE treatment. These findings suggest that CAPE treatment exerts an antidepressant-like effect via downregulation of p38MAPK phosphorylation, thereby contributing to enhanced GR function.

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.

Discovery of bile salt hydrolase inhibitors using an efficient high-throughput screening system

The global trend of restricting the use of antibiotic growth promoters (AGP) in animal production necessitates the need to develop valid alternatives to maintain productivity and sustainability of food animals. Previous studies suggest inhibition of bile salt hydrolase (BSH), an intestinal bacteria-produced enzyme that exerts negative impact on host fat digestion and utilization, is a promising approach to promote animal growth performance. To achieve the long term goal of developing novel alternatives to AGPs, in this study, a rapid and convenient high-throughput screening (HTS) system was developed and successfully used for identification of BSH inhibitors. With the aid of a high-purity BSH from a chicken Lactobacillus salivarius strain, we optimized various screening conditions (e.g. BSH concentration, reaction buffer pH, incubation temperature and length, substrate type and concentration) and establish a precipitation-based screening approach to identify BSH inhibitors using 96-well or 384-well microplates. A pilot HTS was performed using a small compound library comprised of 2,240 biologically active and structurally diverse compounds. Among the 107 hits, several promising and potent BSH inhibitors (e.g. riboflavin and phenethyl caffeate) were selected and validated by standard BSH activity assay. Interestingly, the HTS also identified a panel of antibiotics as BSH inhibitor; in particular, various tetracycline antibiotics and roxarsone, the widely used AGP, have been demonstrated to display potent inhibitory effect on BSH. Together, this study developed an efficient HTS system and identified several BSH inhibitors with potential as alternatives to AGP. In addition, the findings from this study also suggest a new mode of action of AGP for promoting animal growth.

Design, synthesis and pharmacological evaluation of (E)-3,4-dihydroxy styryl sulfonamides derivatives as multifunctional neuroprotective agents against oxidative and inflammatory injury

A novel class of (E)-3,4-dihydroxy styryl sulfonamides and their 3,4-diacetylated derivatives as caffeic acid phenethyl ester (CAPE) analogs was designed and prepared for improving stability and solubility of the lead compound. Their neuroprotective properties were assessed by several models. The results showed that target compounds displayed positive free radical quenching abilities, superior to that of CAPE. Compounds 6j-k and 7j-k demonstrated remarkable protection effects against damage induced by hydrogen peroxide which were apparently stronger than that of CAPE. Most of target compounds could inhibit nitric oxide production. Additionally, target compounds showed high blood-brain barrier permeability.

The effects of caffeic acid phenethyl ester in acute methanol toxicity on rat retina and optic nerve

PURPOSE

We aimed to test caffeic acid phenethyl ester (CAPE) as an antidote for acute methanol (MeOH) toxicity and to compare it with ethanol.

METHODS

This study included five groups, each containing eight rats. The groups were control, methotrexate (MTX), MeOH, ethanol and CAPE. All rats except control group were treated with intraperitoneal (i.p.) MTX (0.3 mg/kg/d) for 7 d. At the 8th day of the experiment, i.p. injection of MeOH (3 g/kg) was administered in MeOH, ethanol and CAPE groups. Four hours after MeOH treatment, 0.5 g/kg ethanol was injected i.p. in ethanol group; 10 μmol/kg CAPE i.p. in CAPE group; serum physiologic i.p. in other groups. After 8 h, rats were anaesthetized and sacrificed. Total anti-oxidant status (TAS), total oxidant status (TOS) were measured on the dissected and excised retina and optic nerve samples. Fellow eyes were used for histopathologic evaluation and the cell count of retinal ganglion cell (RGC) layer. In addition, interactions of alcohol dehydrogenase with CAPE, ethanol, MeOH and pyrazole derivatives were investigated.

RESULTS

Either CAPE or ethanol co-treatment decreased the TOS levels and increased the TAS levels compared to the MeOH group. MeOH treatment decreased the mean cell count in RGC layer. CAPE co-treatment significantly prevented cell loss (p = 0.040). Besides, in silico calculations showed that binding affinity of CAPE to alcohol dehydrogenase was higher than those of MeOH, ethanol, and pyrazole derivatives were.

CONCLUSION

This study demonstrated that CAPE treatment decreased the oxidative stress in acute MeOH intoxication in the retina and optic nerve; beside that, protected RGC layer histology. In silico, CAPE had higher affinity score than MeOH, ethanol, pyrazole and pyrazole derivatives in the case of interaction with alcohol dehydrogenase.

Chrysin: a histone deacetylase 8 inhibitor with anticancer activity and a suitable candidate for the standardization of Chinese propolis

Chinese propolis (CP) is a natural product collected by honeybees and a health food raw material. Previous studies have shown that CP exhibits a broad spectrum of biological activities including anticancer, antioxidant, antibacterial, anti-inflammatory, and antiviral activities. The focuses of the present study were the standardization of CP and the possible mechanisms of its active anticancer ingredients. Nine samples of CP were collected from different locations in China. Analyses of the CP samples revealed that all 9 had similar chemical compositions. Parameters analyzed included the CP extract dry weight, total phenolic content, and DPPH free radical scavenging activities. The active anticancer ingredient was isolated, characterized against human MDA-MB-231 breast cancer cells, and identified as chyrsin, a known potent anticancer compound. Chrysin is present at high levels in all 9 of the CP samples, constituting approximately 2.52% to 6.38% of the CP extracts. However, caffeic acid phenethyl ester (CAPE), another potent active ingredient is present in low levels in 9 samples of CP, constituting approximately 0.08% to 1.71% of the CP extracts. Results from analyses of enzymatic activity indicated that chrysin is a histone deacetylase inhibitor (HDACi) and that it markedly inhibited HDAC8 enzymatic activity (EC(50) = 40.2 μM). In vitro analyses demonstrated that chrysin significantly suppressed cell growth and induced differentiation in MDA-MB-231 cells. In a xenograft animal model (MDA-MB-231 cells), orally administered chrysin (90 mg/kg/day) significantly inhibited tumor growth. Despite the geographical diversity of the 9 samples' botanical origins, their chemical compositions and several analyzed parameters were similar, suggesting that CP is standardized, with chrysin being the major active ingredient. Overall, in vitro and in vivo data indicated that chrysin is an HDAC8 inhibitor, which can significantly inhibit tumor growth. Data also suggested that chrysin might represent a suitable candidate for standardization of CP.

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.

(E)-Methyl 2-({2-eth-oxy-6-[(E)-(hy-droxy-imino)-meth-yl]phen-oxy}meth-yl)-3-phenyl-acrylate

In the title compound, C₂₀H₂₁NO₅, the dihedral angle between the mean planes through the two rings is 47.1 (8)°. The enoate group assumes an extended conformation. The hy­droxy­ethanimine group is essentially coplanar with the benzene ring, the largest deviation from the mean plane being 0.061 (1) Å for the O atom. In the crystal, mol­ecules are linked into cyclic centrosymmetric dimers with an R₂²(6) motif via pairs of O—H⋯N hydrogen bonds. Inter­molecular C—H⋯O hydrogen bonds form a C(8) chain along the b axis. The crystal packing is further stabilized by C—H⋯π inter­actions.

(E)-2-({2-[(E)-(Hy-droxy-imino)-meth-yl]phen-oxy}meth-yl)-3-p-tolyl-acrylonitrile

In the title compound, C(18)H(16)N(2)O(2), the hy-droxy-ethanimine group is essentially coplanar with the ring to which it is attached (C-C-N-O torsion angle = -176.9°). Mol-ecules are linked into cyclic centrosymmetric R(2) (2)(6) dimers via O-H⋯N hydrogen bonds.

(E)-N-Butyl-3-(3,4-dihy-droxy-phen-yl)acryl-amide hemihydrate

In the title compound, C(13)H(17)NO(3)·0.5H(2)O, a new caffeic acid amide derivative, the solvent water mol-ecule lies on a twofold axis and the terminal ethyl group appears disordered with occupancy factors of 0.525 (6) and 0.475 (6). The benzene ring makes an angle of 17.3 (2)° with the C=C-C-O linker. The presence of an ethyl-enic spacer in the caffeic acid amide mol-ecule allows the formation of a conjugated system, strongly stabilized through π-electron delocalization. The C=C double bond in the linker is trans, similar to those previously reported in caffeic esters. The crystal is stabilized by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds. The mol-ecules of the caffeic acid amide form a supermolecular planar structure through O-H⋯O hydrogen bonds between a hy-droxy group of one caffeic acid mol-ecule and a carbonyl O atom of another. These planes inter-act via C-H⋯O, O-H⋯O and N-H⋯O hydrogen bonds to form a three-dimensional network.

Assessment of imidacloprid toxicity on reproductive organ system of adult male rats

In the current study it was aimed to investigate the toxicity of low doses of imidacloprid (IMI) on the reproductive organ systems of adult male rats. The treatment groups received 0.5 (IMI-0.5), 2 (IMI-2) or 8 mg IMI/kg body weight by oral gavage (IMI-8) for three months. The deterioration in sperm motility in IMI-8 group and epidydimal sperm concentration in IMI-2 and IMI-8 groups and abnormality in sperm morphology in IMI-8 were significant. The levels of testosterone (T) and GSH decreased significantly in group IMI-8 compared to the control group. Upon treatment with IMI, apoptotic index increased significantly only in germ cells of the seminiferous tubules of IMI-8 group when compared to control. Fragmentation was striking in the seminal DNA from the IMI-8 group, but it was much less obvious in the IMI-2 one. IMI exposure resulted in elevation of all fatty acids analyzed, but the increases were significant only in stearic, oleic, linoleic and arachidonic acids. The ratios of 20:4/20:3 and 20:4/18:2 were decreased and 16:1n-9/16:0 ratio was increased. In conclusion, the present animal experiments revealed that the treatment with IMI at NOAEL dose-levels caused deterioration in sperm parameters, decreased T level, increased apoptosis of germ cells, seminal DNA fragmentation, the depletion of antioxidants and change in disturbance of fatty acid composition. All these changes indicate the suppression of testicular function.

Protective role of caffeic acid on lambda cyhalothrin-induced changes in sperm characteristics and testicular oxidative damage in rats

The synthetic pyrethroids are expected to cause deleterious effects on most of the organs and especially on the male reproductive system. The current study was performed to assess the adverse effect of lambda cyhalothrin (LC) on reproductive organs and fertility in male rats and to evaluate the protective role of caffeic acid phenethyl ester (CAPE) in alleviating the detrimental effect of LC on male fertility. A total of 48 male rats were divided into 4 groups (12 rats each): control group received distilled water ad libitum and 1 ml of vehicle solution given intraperitoneally (i.p.); CAPE-treated group received a single i.p. dose of CAPE (10 μmol kg⁻¹ day⁻¹); LC-treated group received 668 ppm of LC through drinking water; and CAPE + LC-treated group received an i.p. injection of CAPE (10 μmol kg⁻¹ day⁻¹) 12 h before the LC administration. The experiment was conducted for 10 consecutive weeks. LC caused a significant increase in testicular malondialdehyde, catalase, superoxide dismutase, glutathione-S-transferase activities, and sperm abnormalities and a significant reduction in testicular glutathione concentration, sperm count, sperm motility, and a live sperm percentage. Conversely, treatment with CAPE improved the reduction in the sperm characteristics, LC-induced oxidative damage of testes and the testicular histopathological alterations. Results indicate that LC exerts significant harmful effects on the male reproductive system and that CAPE reduced the deleterious effects of LC on male fertility.

(E)-Methyl 3-(4-chloro-phen-yl)-2-{2-[(E)-(hy-droxy-imino)-meth-yl]phen-oxy-meth-yl}acrylate

In the title compound, C₁₈H₁₆ClNO₄, the dihedral angle between the mean planes through the aromatic rings is 83.8 (8)°. The hy­droxy­ethanimine group is essentially coplanar with the ring to which it is attached [O—N—C—C torsion angle = −177.96 (13)°]. The mol­ecules are linked into centrosymmetric R₂²(6) dimers via O—H⋯N hydrogen bonds. The crystal packing is further stabilized by C—H⋯O inter­actions.

Antioxidant activity of uruguayan propolis. In vitro and cellular assays

The antioxidant capacity of propolis from the southern region of Uruguay was evaluated using in vitro as well as cellular assays. Free radical scavenging capacity was assessed by ORAC, obtaining values significantly higher than those of other natural products (8000 μmol Trolox equiv/g propolis). ORAC values correlated well with total polyphenol content (determined by Folin-Ciocalteu method) and UV absorption. Total polyphenol content (150 mg gallic acid equiv/g propolis) and flavonoids (45 mg quercetin equiv/g propolis) were similar to values reported for southern Brazilian (group 3) and Argentinean propolis. Flavonoid composition determined by RP-HPLC indicates a strong poplar-tree origin. Samples high in polyphenols efficiently inhibit low-density lipoprotein lipoperoxidation and tyrosine nitration. In addition, Uruguayan propolis was found to induce the expression of endothelial nitric oxide synthase and inhibit endothelial NADPH oxidase, suggesting a potential cardiovascular benefit by increasing nitric oxide bioavailability in the endothelium.