Phytochemical and Over-The-Counter Drug Interactions: Involvement of Phase I and II Drug-Metabolizing Enzymes and Phase III Transporters.

Consumption of plant-derived natural products and over-the-counter (OTC) drugs is increasing on a global scale, and studies of phytochemical-OTC drug interactions are becoming more significant. The intake of dietary plants and herbs rich in phytochemicals may affect drug-metabolizing enzymes (DMEs) and transporters. These effects may lead to alterations in pharmacokinetics and pharmacodynamics of OTC drugs when concomitantly administered. Some phytochemical-drug interactions benefit patients through enhanced efficacy, but many interactions cause adverse effects. This review discusses possible mechanisms of phytochemical-OTC drug interactions mediated by phase I and II DMEs and phase III transporters. In addition, current information is summarized for interactions between phytochemicals derived from fruits, vegetables, and herbs and OTC drugs, and counseling is provided on appropriate and safe use of OTC drugs.

Discovery of Natural Inhibitors of Cholinesterases from Hydrangea: In Vitro and In Silico Approaches.

Alzheimer's disease (AD) is a neurodegenerative disease conceptualized as a clinical-biological neurodegenerative construct where amyloid-beta pathophysiology is supposed to play a role. The loss of cognitive functions is mostly characterized by the rapid hydrolysis of acetylcholine by cholinesterases including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Moreover, both enzymes are responsible for non-catalytic actions such as interacting with amyloid ß peptide (Aß) which further leads to promote senile plaque formation. In searching for a natural cholinesterase inhibitor, the present study focused on two isocoumarines from hydrangea, thunberginol C (TC) and hydrangenol 8-O-glucoside pentaacetate (HGP). Hydrangea-derived compounds were demonstrated to act as dual inhibitors of both AChE and BChE. Furthermore, the compounds exerted selective and non-competitive mode of inhibition via hydrophobic interaction with peripheral anionic site (PAS) of the enzymes. Overall results demonstrated that these natural hydrangea-derived compounds acted as selective dual inhibitors of AChE and BChE, which provides the possibility of potential source of new type of anti-cholinesterases with non-competitive binding property with PAS.

Geraniin Protects PC12 Cells Against Aß25-35-Mediated Neuronal Damage: Involvement of NF-κB and MAPK Signaling Pathways.

ß-amyloid peptide (Aß) has been considered a critical factor that is associated with the development of oxidative stress and neuroinflammation in the pathogenesis of Alzheimer's disease. This study was performed to evaluate the effect of geraniin on Aß25-35-caused oxidative damage and neuroinflammatory response, and its underlying mechanism. Geraniin protected pheochromocytoma12 (PC12) cells from Aß25-35-mediated cell death by reducing oxidative stress and restoring cell cycle dysregulation. Moreover, geraniin markedly attenuated Aß-triggered DNA injury that was partially associated with decreases in caspase-3 activity. Moreover, the compound significantly downregulated the release of neuroinflammatory factors. Upregulation of nuclear factor-κB activity was suppressed by geraniin, which was due to suppression of JNK, ERK1/2, and the p38 mitogen-activated protein kinase (MAPK) pathway. This was the first study to support further understanding of geraniin as a promising agent against neurotoxicity in the reduction of oxidative stress and neuroinflammation.

The fruit of Crataegus pinnatifida ameliorates memory deficits in ß-amyloid protein-induced Alzheimer's disease mouse model.

ETHNOPHARMACOLOGICAL RELEVANCE: The fruit of Crataegus pinnatifida is a traditional medicine widely used as digestive drug in East Asia. Although Chinese herbal medicine used it for mental health, scientific evidence does not exist, yet. AIMS OF STUDY: The aim of this study is to show that the ethanol extract of the fruit of Crataegus pinnatifida (CPE) has neuroprotective effect on Alzheimer' disease model mice. MATERIALS AND METHODS: Intracerebroventricular injection of Aß was used to induce Alzheimer's disease-like pathology. Passive avoidance and Y-maze tasks were used to examine the effect of CPE on memory impairments by Aß. Immunohistochemistry was used to examine the effect of CPE on glial activation. ThT assay was used to observe the effect of CPE on Aß aggregation. MTT and LDH release assays were utilized to examine effects of CPE on Aß-induced cytotoxicity. RESULTS: CPE prevented memory deficit in Aß-induced memory impairment model. Moreover, CPE prevented glial activation in the hippocampus of Aß-injected model. In in vitro test, CPE inhibited Aß fibril formation in a concentration-dependent manner. CPE also caused disaggregation of Aß fibrils. Along with this, CPE blocked neuronal cell death induced by Aß. CONCLUSIONS: Collectively, these experimental findings demonstrated that CPE could be a candidate for development of AD therapy.

Thymoquinone-Induced Tristetraprolin Inhibits Tumor Growth and Metastasis through Destabilization of MUC4 mRNA.

Tristetraprolin (TTP), a well-characterized AU-rich element (ARE) binding protein, functions as a tumor suppressor gene. The purpose of this study was to investigate whether a bioactive substance derived from a natural medicinal plant affects the induction of TTP and to elucidate its mechanism. We examined the effects of natural bioactive materials including Resveratrol (RSV), thymoquinone (TQ) and curcumin on the expression of TTP in cancer cell. TQ derived from a natural plant Nigella sativa increased the expression levels of TTP mRNA and proteins in a dose-dependent manner in gastric and breast cancer cells. TQ-induced TTP increased the instability of MUC4 mRNA by direct binding of TTP to ARE in the 3'UTR of MUC4 mRNA. The induction of TTP by TQ also reduced the proliferation, migration and invasion of cancer cells. The expression of the epithelial-mesenchymal (EMT)-related genes, which were target genes of TTP, was also decreased by the TQ treatment. In the in vivo experiments using mouse melanoma cells, TQ-induced TTP inhibited metastasis of tumor cells. We have found that TQ-induced TTP might inhibit metastasis by reducing tumor cell migration and invasion through destabilization of MUC4 mRNA, which suggest the MUC4 as a novel target to TTP.

Biological Evaluation and Docking Analysis of Potent BACE1 Inhibitors from Boesenbergia rotunda.

Alzheimer's disease (AD) is an irreversible neurodegenerative disorder characterized by progressive impairment of cognitive functions. Beta-site amyloid precursor protein cleaving enzyme1 (BACE1) is essential for the formation of ß-amyloid peptide (Aß), a major constituent of amyloid plaques that represent a neuropathological hallmark of this disorder. To find alternative therapies for AD sourced from natural products, the present study focused on three flavonoids from Boesenbergia rotunda, namely, cardamonin, pinocembrin, and pinostrobin. Biological evaluation showed that cardamonin presented the strongest BACE1 inhibition, with an The half maximal inhibitory concentration (IC50) value of 4.35 ± 0.38 µM, followed by pinocembrin and pinostrobin with 27.01 ± 2.12 and 28.44 ± 1.96 µM, respectively. Kinetic studies indicated that the inhibitory constants (Ki) for cardamonin, pinocembrin, and pinostrobin against BACE1 were 5.1, 29.3, and 30.9 µM, respectively. Molecular docking studies showed that the tested compounds did not bind to the BACE1 active site, consistent with the biological results, illustrating non-competitive inhibitory activity for all three compounds. In addition, the lowest binding energy of the most proposed complexes of cardamonin, pinocembrin, and pinostrobin with BACE1 were -9.5, -7.9, and -7.6 kcal/mol, respectively. Overall, we provide the first evidence that these flavonoids from B. rotunda may be considered as promising AD preventative agents through inhibition of Aß formation.

Anti-Neuroinflammatory Property of Phlorotannins from Ecklonia cava on Aß25-35-Induced Damage in PC12 Cells.

Alzheimer disease (AD) is a neurodegenerative disorder characterized by excessive accumulation of amyloid-beta peptide (Aß) and progressive loss of neurons. Therefore, the inhibition of Aß-induced neurotoxicity is a potential therapeutic approach for the treatment of AD. Ecklonia cava is an edible brown seaweed, which has been recognized as a rich source of bioactive derivatives, mainly phlorotannins. In this study, phlorotannins including eckol, dieckol, 8,8'-bieckol were used as potential neuroprotective candidates for their anti-apoptotic and anti-inflammatory effects against Aß25-35-induced damage in PC12 cells. Among the tested compounds, dieckol showed the highest effect in both suppressing intracellular oxidative stress and mitochondrial dysfunction and activation of caspase family. Three phlorotannins were found to inhibit TNF-α, IL-1ß and PGE2 production at the protein levels. These result showed that the anti-inflammatory properties of our compounds are related to the down-regulation of proinflammatory enzymes, iNOS and COX-2, through the negative regulation of the NF-κB pathway in Aß25-35-stimulated PC12 cells. Especially, dieckol showed the strong anti-inflammatory effects via suppression of p38, ERK and JNK. However, 8,8'-bieckol markedly decreased the phosphorylation of p38 and JNK and eckol suppressed the activation of p38. Therefore, the results of this study indicated that dieckol from E. cava might be applied as a drug candidate for the development of new generation therapeutic agents against AD.

Major compounds of red ginseng oil attenuate Aß25-35-induced neuronal apoptosis and inflammation by modulating MAPK/NF-κB pathway.

ß-Amyloid (Aß)-induced neuronal toxicity in Alzheimer's disease (AD) is associated with complex mechanisms. Thus, a multi-target approach might be suitable for AD treatment. Following our previous study on the neuroprotective effects of red ginseng oil extract, its major compounds, including linoleic acid (LA), ß-sitosterol (BS), and stigmasterol (SS), were examined to elucidate the mechanism of anti-apoptosis and anti-inflammation in Aß25-35-stimulated PC12 cells. The results showed that the three compounds mitigated Aß25-35 toxicity by regulating oxidative stress, apoptotic responses, and pro-inflammatory mediators. LA and SS strongly regulated intrinsic apoptosis markers, such as mitochondrial membrane potential, intracellular Ca2+, Bax/Bcl-2 ratio, and caspases-9, -3, and -8. However, BS blocked only the intrinsic apoptotic pathway, particularly by suppressing Ca2+ accumulation. Furthermore, all three compounds downregulated iNOS and phospho-nuclear factor-κB, but only LA and SS inhibited the expression of cyclooxygenase-2 and phospho-IκB. In assays to evaluate MAPK expression for confirming upstream signal pathways, BS decreased the phosphorylation of p38 and ERK, but not JNK, while SS markedly decreased the phosphorylation of all three MAPKs, and LA clearly decreased the phosphorylation of ERK and JNK, but not p38. These results indicate that LA, BS, and SS act as neuroprotectives against Aß25-35-induced injury by distinct molecular mechanisms, indicating their preventive and/or therapeutic potential to treat AD.

BACE1 Inhibition by Genistein: Biological Evaluation, Kinetic Analysis, and Molecular Docking Simulation.

ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) plays a role in generating amyloid ß (Aß), thus playing a major part early in the pathogenesis of Alzheimer's disease (AD). BACE1 has emerged as a crucial therapeutic target for decreasing the Aß concentration in the AD brain. To explore natural BACE1 inhibitors, the present study concentrated on isoflavones, including genistein, formononetin, glycitein, daidzein, and puerarin. In this study, in vitro anti-AD activities were assessed using BACE1 inhibition assays, as well as enzyme kinetic predictions. Molecular docking analysis was applied to design potential BACE1 inhibitors. Among the major isoflavones, genistein exerted a notable BACE1 inhibition through reversible noncompetitive mechanism, while other compounds were less potent against BACE1. The docking study revealed that genistein had negative binding energy (-8.5 kcal/mol) and was stably positioned in the allosteric domains of BACE1 residues. It interacted with important amino acid residues in BACE1, such as ASN37, GLN73, and TRP76, through hydrogen bonding. The results suggested that genistein may be beneficial for preventing and/or treating AD. Furthermore, it may provide potential guidelines for the design of new BACE1 inhibitors.

Protective Effects of Red Ginseng Oil against Aß25-35-Induced Neuronal Apoptosis and Inflammation in PC12 Cells.

One of pathological characteristics of Alzheimer's disease (AD), aggregation and deposition of ß amyloid (Aß), has been accepted as a potent activator of neuronal cell death. Red ginseng is well-known for various pharmacological activities, but most studies have been focused on red ginseng water extract (RGW), which has resulted in the conception of the present study of red ginseng oil (RGO) against Aß25-35-induced neurotoxicity. Cytotoxicity and apoptosis induction by Aß were verified and the underlying mechanism by which RGO inhibited neuronal cell death, mitochondria dysfunction and NF-κB pathway related protein markers were evaluated. RGO attenuated Aß25-35-induced apoptosis, not only by inhibiting calcium influx, but also by reducing mitochondrial membrane potential loss. RGO significantly decreased Bax, whereas increased Bcl-2 and inactivated of caspase-3 and -9 and PARP-1 stimulated by Aß25-35. Anti-neuroinflammatory effect of RGO was demonstrated by downregulating c-Jun N-terminal kinase (JNK) and p38, resulting in inhibiting of the NF-κB pathway and thereby suppressing the expressions of pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), nitric oxide (NO) and tumor necrosis factor-α (TNF-α). The present study revealed that RGO is a potential natural resource of the functional foods industry as well as a promising candidate of multi-target neuronal protective agent for the prevention of AD.

Hair Regenerative Mechanisms of Red Ginseng Oil and Its Major Components in the Testosterone-Induced Delay of Anagen Entry in C57BL/6 Mice.

Hair loss (alopecia) is a universal problem for numerous people in the world. The present study was conducted to investigate the effects of red ginseng oil (RGO) and its major components on hair re-growth using testosterone (TES)-induced delay of anagen entry in C57BL/6 mice and their mechanisms of action. Seven-week-old C57BL/6 mice were daily treated with TES for 1 h prior to topical application of 10% RGO, 1% linoleic acid (LA), 1% ß-sitosterol (SITOS), or 1% bicyclo(10.1.0)tridec-1-ene (BICYCLO) once a day for 28 days. Hair regenerative capacity was significantly restored by treatment of RGO and its major compounds in the TES-treated mice. Histological analysis showed that RGO along with LA and SITOS but not BICYCLO promoted hair growth through early inducing anagen phase that was delayed by TES in mice. Treatment of mice with RGO, LA, or SITOS up-regulated Wnt/ß-catenin and Shh/Gli pathways-mediated expression of genes such as ß-catenin, Lef-1, Sonic hedgehog, Smoothened, Gli-1, Cyclin D1, and Cyclin E in the TES-treated mice. In addition, RGO and its major components reduced the protein level of TGF-ß but enhanced the expression of anti-apoptotic protein Bcl-2. These results suggest that RGO is a potent novel therapeutic natural product for treatment of androgenic alopecia possibly through hair re-growth activity of its major components such as LA and SITOS.

The Identification of Biochanin A as a Potent and Selective ß-Site App-Cleaving Enzyme 1 (Bace1) Inhibitor.

Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the enzyme involved in the abnormal production of the amyloidogenic peptide Aß, one of the major causes of histological hallmarks of Alzheimer's disease (AD). Thus, BACE1 represents a key target protein in the development of new potential target for the prevention and treatment of AD. In this study, in vitro anti-AD activity of biochanin A, a dietary isoflavone found in legumes and most notably red clover, were evaluated via human recombinant BACE1 inhibition assay, as well as enzyme kinetic and molecular docking predictions. Enzyme-based assays revealed that biochanin A exhibited a non-competitive inhibitory effect on BACE1 with an IC50 value of 28 µM and a Ki of 43 µM. In addition, docking simulation results demonstrated that ASN37, SER35, SER36, TRP76, and ARG128 residues of BACE1 interacted with biochanin A. Moreover, the binding energy of biochanin A was negative (-8.4 kcal/mol), indicating that it might potentiate a strong binding between the compound and the allosteric site of BACE1, resulting in further effective BACE1 inhibition. The present novel findings raise the possibility that biochanin A may be used as a preventative, developed into a therapeutic agent for AD, or both.

Protective Role of Corilagin on Aß25-35-Induced Neurotoxicity: Suppression of NF-κB Signaling Pathway.

Aggregation and deposition of beta-amyloid peptides (Aß), a pathological hallmark of Alzheimer's disease, has been recognized as a potent activator of neuroinflammation and neuronal dysfunction. In this study, the underlying molecular mechanisms responsible for the neuroprotective effects of corilagin against Aß25-35-triggered neurotoxicity and inflammatory responses were investigated in PC12 cells. Pretreatment with corilagin effectively protected PC12 cells against Aß25-35-induced damage and apoptosis. Aß25-35 induced damage in PC12 cells as revealed by increased production of reactive oxygen species, caspase-3 activity, and cell cycle arrest was attenuated by corilagin pretreatment. Corilagin not only significantly suppressed the production of neurotoxic inflammatory mediators such as tumor necrosis factor-α, nitric oxide, and prostaglandin E2 but also downregulated cyclooxygenase-2 and inducible nitric oxide synthase expression in PC12 cells. It also exerted a beneficial effect by suppressing the degradation of inhibitor of κB (IκB)-α and subsequent activation of transcription factor nuclear factor κB (NF-κB), mostly through inhibition of extracellular signal-regulated kinase activity in comparison to c-Jun N-terminal kinase and p38 MAP kinase (p38) mitogen-activated protein kinase activity. These findings suggest that attenuation of Aß25-35-induced inflammatory responses by downregulating the NF-κB signaling pathway might be a valuable strategy for both Alzheimer's disease prevention and/or treatment.

Quercitrin from Toona sinensis (Juss.) M.Roem. Attenuates Acetaminophen-Induced Acute Liver Toxicity in HepG2 Cells and Mice through Induction of Antioxidant Machinery and Inhibition of Inflammation.

Quercitrin is found in many kinds of vegetables and fruits, and possesses various bioactive properties. The aim of the present study was to elucidate hepatoprotective mechanisms of quercitrin isolated from Toona sinensis (Juss.) M.Roem. (syn. Cedrela sinensis Juss.), using acetaminophen (APAP)-treated HepG2 cell and animal models. In an in vitro study, quercitrin suppressed the production of reactive oxygen species and enhanced expression of nuclear factor E2-related factor 2 (Nrf2), activity of antioxidant response element (ARE)-reporter gene, and protein levels of NADPH: quinone oxidoreductase 1 (NQO1), catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase 2 (SOD-2) in APAP-treated HepG2 cells. In an in vivo study, Balb/c mice were orally administered with 10 or 50 mg/kg of quercitrin for 7 days and followed by the injection with single dose of 300 mg/kg APAP. Quercitrin decreased APAP-caused elevation of alanine aminotransferase and aspartate aminotransferase levels, liver necrosis, the expression of pro-inflammatory factors including inducible nitric oxide synthase, cyclooxygenase 2 and inerleukin-1ß, and phosphorylation of kinases including c-Jun N-terminal kinase and p38. Quercitrin restored protein levels of Nrf2, NQO1 and activities and expressions of CAT, GPx, SOD-2. The results suggested that quercitrin attenuates APAP-induced liver damage by the activation of defensive genes and the inhibition of pro-inflammatory genes via the suppressions of JNK and p38 signaling.

In Vitro and In Vivo Antiangiogenic Activity of Crowberry (Empetrum nigrum var. japonicum).

Crowberry, Empetrum nigrum var. japonicum, is widely used in folk medicine and grows naturally in Korea. Although some constituents and biological activity of Korean crowberry have been examined, there is little detailed information available. In this study, we investigated the effects of ethanol extracts of crowberry (EECB) on the inhibition of angiogenesis, both in vitro and in vivo. The effects of EECB were tested on in vitro models of angiogenesis, that is, tube formation and proliferation of human umbilical vein endothelial cells (HUVECs). EECB exhibited significant inhibitory effects on tube formation of HUVECs in a concentration-dependent manner. In addition, crowberry significantly suppressed the proliferation of HUVECs in a concentration-dependent manner. Furthermore, strong antiangiogenic activity of EECB samples was observed in the in vivo assay using chick embryo chorioallantoic membrane (CAM). These results indicate that crowberry may have potential applications in the prevention and treatment of angiogenesis-dependent human diseases.

Antioxidant and Hepatoprotective Effects of Procyanidins from Wild Grape (Vitis amurensis) Seeds in Ethanol-Induced Cells and Rats.

In the present study, we characterized the antioxidant and hepatoprotective mechanisms underlying of wild grape seed procyanidins (WGP) against oxidative stress damage in ethanol-treated HepG2 cell and Sprague-Dawley (SD)-rat models. In HepG2 cells, WGP not only diminished the ethanol (EtOH, 100 mM)-induced reactive oxygen species (ROS) formation and cytochrome P450 2E1 (CYP2E1) expression, but also renovated both the activity and expression of antioxidant enzymes including catalase, superoxide dismutase, and glutathione peroxidase. Additionally, to investigate the hepatoprotective effect of WGP, rats were orally administered 10 or 50 mg/kg WGP once daily for seven days prior to the single oral administration of EtOH (6 g/kg). The results show that WGP administration decreased the EtOH-induced augment of the levels of serum aspartate transaminase and alanine transaminase as well as serum alcohol and acetaldehyde. WGP treatment upregulated the activities and protein levels of hepatic alcohol dehydrogenase, aldehyde dehydrogenase, and antioxidant enzymes but downregulated the protein expression level of liver CYP2E1 in EtOH-treated rats. Moreover, the decreased phosphorylation levels of mitogen activated protein kinases (MAPKs) by ethanol were induced in both HepG2 cell and rat models. Overall, pretreatment of WGP displayed the protective activity against EtOH-mediated toxicity through the regulation of antioxidant enzymes and alcohol metabolism systems via MAPKs pathways.

Anthocyanin Profile and Antioxidant Activity of Various Berries Cultivated in Korea.

This study examined the anthocyanin composition and antioxidant activity of various berries cultivated in Korea: blueberry, crowberry, Korean black raspberry, mulberry, and strawberry. The anthocyanins in berries were identified by high-performance liquid chromatography (HPLC) analysis, and each component was quantitatively analyzed. Furthermore, the antioxidant activity of berries was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging, 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation decolorization, oxygen radical absorbance capacity (ORAC), and ferric ion reducing antioxidant (FRAP) assays. The results revealed that the total content of anthocyanins in crowberry was 35.1 mg/g of extract, which was higher than that in the other four major berry species (1.9-27.7 mg/g of extract). Nineteen anthocyanins were identified in the various berries. The major anthocyanins of crowberry were cyanidin-3-galactoside and delphinidin-3-galactoside, and those from Korean black raspberry were cyanidin-3-rutinoside and cyanidin-3-sambubioside-5-rhamnoside. These two berries also had relatively strong antioxidant activity accompanied by high total polyphenol contents. Thus, consumption of crowberry and Korean black raspberry may be beneficial in reducing the risk of developing lifestyle-related chronic diseases because of their strong antioxidant activity.

Antioxidant defense and hepatoprotection by procyanidins from almond (Prunus amygdalus) skins.

Procyanidins, polymeric flavan-3-ols, are known to possess antioxidant, antiatherogenic, and anticarcinogenic properties. In the present study, we investigated the role of almond (Prunus amygdalus) skin procyanidins (ASP) in regulating the protein expression of phase II detoxifying and antioxidant enzymes in HepG2 cells and acetaminophen (APAP)-treated hepatotoxic mice. Treatments of ASP significantly induced the expression of phase II enzymes including NAD(P)H: quinoneoxidoreductase 1, catalase, glutathione peroxidase, and superoxide dismutase in the cells and mice. ASP also potently enhanced the expression of nuclear factor-E2-related factor 2 (Nrf2) and antioxidant response element (ARE)-reporter gene activity in vitro. APAP-induced hepatotoxic markers including AST and ALT in mice were inhibited by ASP administration. However, regulation of upstream kinases by ASP was different between in vitro and in vivo models. Collectively, ASP could induce the activation of Nrf2/ARE-mediated phase II detoxifying/antioxidant enzymes but with differential regulation on upstream kinases between in vitro and in vivo.

Korean propolis suppresses angiogenesis through inhibition of tube formation and endothelial cell proliferation.

Propolis, a sticky material that honeybees collect from living plants, has been used for its pharmaceutical properties since ancient times. In this study, we examined the effects of ethanol extracts of Korean propolis (EEKP) from various geographic regions on the inhibition of angiogenesis, both in vitro and in vivo. The effects of EEKP were tested on in vitro models of angiogenesis, that is, tube formation and proliferation of human umbilical vein endothelial cells (HUVECs). All EEKP samples exhibited significant inhibitory effects on tube formation of HUVECs in a concentration-dependent manner (6.25-25 microg/mL). In addition, two EEKP samples, prepared from Uijeongbu and Pyoseon propolis, significantly suppressed the proliferation of HUVECs in a concentration-dependent manner (3.13-25 microg/mL). Furthermore, in an in vivo angiogenesis assay using the chick embryo chorioallantoic membrane (CAM) system, we found that the two EEKP samples significantly reduced the number of newly formed vessels. These results indicate that Korean propolis may have potential applications in the prevention and treatment of angiogenesis-related diseases such as cancer.

p-Coumaric acid and ursolic acid from Corni fructus attenuated ß-amyloid(25-35)-induced toxicity through regulation of the NF-κB signaling pathway in PC12 cells.

Neuroinflammatory responses induced by amyloid-beta peptide (Aß) are important causes in the pathogenesis of Alzheimer's disease (AD). Blockade of Aß has emerged as a possible therapeutic approach to control the onset of AD. This study investigated the neuroprotective effects and molecular mechanisms of p-coumaric acid (p-CA) and ursolic acid (UA) from Corni fructus against Aß(25-35)-induced toxicity in PC12 cells. p-CA and UA significantly inhibited the expression of iNOS and COX-2 in Aß(25-35)-injured PC12 cells. Blockade of nuclear translocation of the p65 subunit of nuclear factor κB (NF-κB) and phosphorylation of IκB-α was also observed after p-CA and UA treatment. For the upstream kinases, UA exclusively reduced ERK1/2, p-38, and JNK phosphorylation, but p-CA suppressed ERK1/2 and JNK phosphorylation. Both compounds comprehensively inhibited NF-κB activity, but possibly with different upstream pathways. The results provide new insight into the pharmacological modes of p-CA and UA and their potential therapeutic application to AD.