Showing papers in "Planta Medica in 2008"

Nrf2 as a master redox switch in turning on the cellular signaling involved in the induction of cytoprotective genes by some chemopreventive phytochemicals.

Abstract: A wide array of dietary phytochemicals have been reported to induce the expression of enzymes involved in both cellular antioxidant defenses and elimination/inactivation of electrophilic carcinogens. Induction of such cytoprotective enzymes by edible phytochemicals largely accounts for their cancer chemopreventive and chemoprotective activities. Nuclear factor-erythroid-2-related factor 2 (Nrf2) plays a crucial role in the coordinated induction of those genes encoding many stress-responsive and cytoptotective enzymes and related proteins. These include NAD(P)H:quinone oxidoreductase-1, heme oxygenase-1, glutamate cysteine ligase, glutathione S-transferase, glutathione peroxidase, thioredoxin, etc. In resting cells, Nrf2 is sequestered in the cytoplasm as an inactive complex with the repressor Kelch-like ECH-associated protein 1 (Keap1). The release of Nrf2 from its repressor is most likely to be achieved by alterations in the structure of Keap1. Keap1 contains several reactive cysteine residues that function as sensors of cellular redox changes. Oxidation or covalent modification of some of these critical cysteine thiols would stabilize Nrf2, thereby facilitating nuclear accumulation of Nrf2. After translocation into nucleus, Nrf2 forms a heterodimer with other transcription factors, such as small Maf, which in turn binds to the 5'-upstream CIS-acting regulatory sequence, termed antioxidant response elements (ARE) or electrophile response elements (EpRE), located in the promoter region of genes encoding various antioxidant and phase 2 detoxifying enzymes. Certain dietary chemopreventive agents target Keap1 by oxidizing or chemically modifying one or more of its specific cysteine thiols, thereby stabilizing Nrf2. In addition, phosphorylation of specific serine or threonine residues present in Nrf2 by upstream kinases may also facilitate the nuclear localization of Nrf2. Multiple mechanisms of Nrf2 activation by signals mediated by one or more of the upstream kinases, such as mitogen-activated protein kinases, phosphatidylionositol-3-kinase/Akt, protein kinase C, and casein kinase-2 have recently been proposed. This review highlights the cytoprotective gene expression induced by some representative dietary chemopreventive phytochemicals with the Nrf2-Keap1 system as a prime molecular target.

Chokeberry (Aronia melanocarpa) - A review on the characteristic components and potential health effects.

Abstract: The intention of this review is to contribute to a better understanding of the potentials of the nutritional contribution of Aronia berries (Aronia melanocarpa). The paper gives a short background to their botanical classification and cultivation practice, going in detail to describe the chemical composition of the berries. The emphasis is laid thereby upon the phenolic constituents. The paper finally gives a short resume of their beneficial effects in biological systems in vitro, in animals, and in humans, thus underlining their medicinal potential.

Anti-oxidant, anti-inflammatory and anti-allergic activities of luteolin.

Abstract: Luteolin is a flavone which occurs in medicinal plants as well as in some vegetables and spices. It is a natural anti-oxidant with less pro-oxidant potential than the flavonol quercetin, the best studied flavonoid, but apparently with a better safety profile. It displays excellent radical scavenging and cytoprotective properties, especially when tested in complex biological systems where it can interact with other anti-oxidants like vitamins. Luteolin displays specific anti-inflammatory effects at micromolar concentrations which are only partly explained by its anti-oxidant capacities. The anti-inflammatory activity includes activation of anti-oxidative enzymes, suppression of the NFkappaB pathway and inhibition of pro-inflammatory substances. In vivo, luteolin reduced increased vascular permeability and was effective in animal models of inflammation after parenteral and oral application. Although luteolin is only a minor component in our nutrition (less than 1 mg/day) epidemiological studies indicate that it has the potential to protect from diseases associated with inflammatory processes such as cardiovascular disease. Luteolin often occurs in the form of glycosides in plants, but these are cleaved and the aglycones are conjugated and metabolized after nutritional uptake which has to be considered when evaluating in vitro studies. Some data for oral and topical bioavailability exist, but more quantitative research in this field is needed to evaluate the physiological and therapeutical potential of luteolin.

Potential of spice-derived phytochemicals for cancer prevention

Abstract: Although spices have been used for thousands of years and are known for their flavor, taste and color in the food, they are not usually recognized for their medicinal value. Extensive research within the last two decades from our laboratory and others has indicated that there are phytochemicals present in spices that may prevent various chronic illnesses including cancerous, diabetic, cardiovascular, pulmonary, neurological and autoimmune diseases. For instance, the potential of turmeric (curcumin), red chilli (capsaicin), cloves (eugenol), ginger (zerumbone), fennel (anethole), kokum (gambogic acid), fenugreek (diosgenin), and black cumin (thymoquinone) in cancer prevention has been established. Additionally, the mechanism by which these agents mediate anticancer effects is also becoming increasingly evident. The current review describes the active components of some of the major spices, their mechanisms of action and their potential in cancer prevention.

Cancer Chemopreventive Potential of Apples, Apple Juice, and Apple Components

Abstract: Apples (Malus sp., Rosaceae) are a rich source of nutrient as well as non-nutrient components and contain high levels of polyphenols and other phytochemicals. Main structural classes of apple constituents include hydroxycinnamic acids, dihydrochalcones, flavonols (quercetin glycosides), catechins and oligomeric procyanidins, as well as triterpenoids in apple peel and anthocyanins in red apples. Several lines of evidence suggest that apples and apple products possess a wide range of biological activities which may contribute to health beneficial effects against cardiovascular disease, asthma and pulmonary dysfunction, diabetes, obesity, and cancer (reviewed by Boyer and Liu, Nutr J 2004). The present review will summarize the current knowledge on potential cancer preventive effects of apples, apple juice and apple extracts (jointly designated as apple products). In brief, apple extracts and components, especially oligomeric procyanidins, have been shown to influence multiple mechanisms relevant for cancer prevention in in vitro studies. These include antimutagenic activity, modulation of carcinogen metabolism, antioxidant activity, anti-inflammatory mechanisms, modulation of signal transduction pathways, antiproliferative and apoptosis-inducing activity, as well as novel mechanisms on epigenetic events and innate immunity. Apple products have been shown to prevent skin, mammary and colon carcinogenesis in animal models. Epidemiological observations indicate that regular consumption of one or more apples a day may reduce the risk for lung and colon cancer.

Genome-Based Approaches to the Authentication of Medicinal Plants

Abstract: Medicinal plants are the source of a large number of essential drugs in Western medicine and are the basis of herbal medicine, which is not only the primary source of health care for most of the world's population living in developing countries but also enjoys growing popularity in developed countries. The increased demand for botanical products is met by an expanding industry and accompanied by calls for assurance of quality, efficacy and safety. Plants used as drugs, dietary supplements and herbal medicines are identified at the species level. Unequivocal identification is a critical step at the beginning of an extensive process of quality assurance and is of importance for the characterization of the genetic diversity, phylogeny and phylogeography as well as the protection of endangered species. DNA-based methods have been developed for the identification of medicinal plants. Nuclear and chloroplast DNA is amplified by the polymerase chain reaction and the reaction products are analyzed by gel electrophoresis, sequencing, or hybridization with species-specific probes. Genomic fingerprinting can differentiate between individuals, species and populations and is useful for the detection of the homogeneity of the samples and presence of adulterants. Although sequences from single chloroplast or nuclear genes have been useful for differentiation of species, phylogenetic studies often require consideration of DNA sequence data from more than one gene or genomic region. Phytochemical and genetic data are correlated but only the latter normally allow for differentiation at the species level. The generation of molecular "barcodes" of medicinal plants will be worth the concerted effort of the medicinal plant research community and contribute to the ongoing effort of defining barcodes for every species on earth.

Selective estrogen receptor modulators and phytoestrogens.

Abstract: Scientific achievements in the last two decades have revolutionized the treatment and prevention of breast cancer. This is mainly because of targeted therapies and a better understanding of the relationship between estrogen, its receptor, and breast cancer. One of these discoveries is the use of synthetic selective estrogen modulators (SERMs) such as tamoxifen in the treatment strategy for estrogen receptor (ER)-positive breast cancer. Hundreds of thousands of lives have been saved because of this advance. Not only is tamoxifen used in the treatment strategy for patients who have breast cancer, but also for prevention in high-risk premenopausal women. Another synthetic SERM, raloxifene, which was initially used to prevent osteoporosis, is also as effective as tamoxifen for prevention in high-risk postmenopausal women. In certain regions of the world, particularly in Asia, a low incidence of breast cancer has been observed. These women have diets that are high in soy and low in fat, unlike the Western diet. Interest in the protective effects of soy derivatives has led to the research of phytoestrogens and metabolites of soy that are described by some as natural SERMs. As a result, many clinical questions have been raised as to whether phytoestrogens, which are also found in other natural foods, can protect against breast cancer. This article reviews the development and role of the more common SERMs, tamoxifen and raloxifene. In addition, this paper will also highlight the emerging studies on phytoestrogens and their similarity and dissimilarity to SERMs.

Sinomenine versus NSAIDs for the treatment of rheumatoid arthritis: a systematic review and meta-analysis

Abstract: Sinomenine (SIN), an alkaloid isolated from CAULIS SINOMENII, has been used in the treatment of rheumatoid arthritis (RA) clinically. This study aimed to systematically evaluate the efficacy and safety of SIN by a comparison between SIN and non-steroidal anti-inflammatory drugs (NSAIDs). Forty-three electronic databases were systematically searched. The quality of eligible trials was assessed by Jadad's scale. Revman 5.0 software was used for data syntheses and meta-analyses. The results showed that (i) of the 121 potential studies identified, 10 clinical trials involving 1185 patients met the inclusion criteria; (ii) improved patients and rheumatoid factor disappearance patients after SIN treatments were significantly more than those treated by NSAIDs ( P 0.05); and (iv) adverse events occurred less frequently in the digestive system during SIN treatment than during NSAID treatment ( P = 0.0003) but occurred more frequently in the dermatomucosal system with SIN treatment ( P = 0.03), while adverse events of the nervous system were similar for both treatments ( P = 0.31). In conclusion, SIN may be a valuable remedy to treat RA clinically, although current evidence needs to be further verified by more high-quality trials.

Anticancer Effects of the Chinese Medicine Matrine on Murine Hepatocellular Carcinoma Cells

Abstract: Matrine is a component of the traditional Chinese medical herb Sophora flavescens Ait, which is widely used to treat diseases such as viral hepatitis, cardiac arrhythmia and skin inflammations. As indicated by previous reports, the molecular mechanism of matrine's anti-cancer effect has been poorly clarified. In this study, we used both in vitro and in vivo models to investigate matrine's antitumor effect and its possible molecular mechanisms. Murine hepatocellular carcinoma H22 cells were cultured in the presence of matrine at various concentrations (0.2 - 2.0 mg/mL). A dose-dependent antiproliferation effect was observed. The 50 % inhibitory concentration (IC (50)) was 0.6 mg/mL. Antiproliferation effects of matrine were associated with an increase in cells arrested in the G (1) phase of the cell cycle. Morphological changes, flow cytometric analysis and expression of the proapoptotic protein Bax indicated that this anticancer effect was mediated via apoptosis. In vivo antitumor efficacy was evaluated following S. C. inoculation of H22 cells in BALB/c mice. Matrine administrated I. P. resulted in strong in vivo anticancer activity. Our results showed that seven doses of matrine at 50 mg/kg/dose inhibited 60.7 % of tumor growth. Transmission electron microscope (TEM) analysis and histoimmunochemical staining for Bcl-2 and Bax proteins also indicated induction of apoptosis in tumor tissues by matrine. Taken together, our results demonstrate that matrine possesses strong antitumor activities in vitro and in vivo. Inhibition of cell proliferation and induction of apoptosis are the likely mechanisms responsible for matrine's antitumor activities.

Phytochemicals as protectors against ultraviolet radiation: versatility of effects and mechanisms.

Abstract: Ultraviolet (UV) radiation is one of the most abundant carcinogens in our environment, and the development of non-melanoma skin cancers, the most common type of human malignancy worldwide, represents one of the major consequences of excessive exposure. Because of growing concerns that the level of UV radiation is increasing as a result of depletion of the stratospheric ozone and climate change, the development of strategies for protection of the skin is an urgent need. Many phytochemicals that belong to various families of secondary metabolites, such as alkaloids (caffeine, sanguinarine), flavonoids [(-)-epigallocatechin 3-gallate, genistein, silibinin], carotenoids ( beta-carotene, lycopene), and isothiocyanates (sulforaphane), offer exciting platforms for the development of such protective strategies. These phytochemicals have been consumed by humans for many centuries as part of plant-rich diets and are presumed to be of low toxicity, an essential requirement for a chemoprotective agent. Mechanistically, they affect multiple signalling pathways and protect against UV radiation-inflicted damage by their ability to act as direct and indirect antioxidants, as well as anti-inflammatory and immunomodulatory agents. Such "pluripotent character" is a critical prerequisite for an agent that is designed to counteract the multiple damaging effects of UV radiation. Especially attractive are inducers of the Keap1/Nrf2/ARE pathway, which controls the gene expression of proteins whose activation leads to enhanced protection against oxidants and electrophiles. Such protection is comprehensive, long-lasting, and unlikely to cause pro-oxidant effects or interfere with the synthesis of vitamin D.

Biological/Chemopreventive Activity of Stilbenes and their Effect on Colon Cancer

Abstract: Colon cancer is one of the leading causes of cancer death in men and women in Western countries. Epidemiological studies have linked the consumption of fruits and vegetables to a reduced risk of colon cancer, and small fruits are particularly rich sources of many active phytochemical stilbenes, such as resveratrol and pterostilbene. Recent advances in the prevention of colon cancer have stimulated an interest in diet and lifestyle as an effective means of intervention. As constituents of small fruits such as grapes, berries and their products, stilbenes are under intense investigation as cancer chemopreventive agents. One of the best-characterized stilbenes, resveratrol, has been known as an antioxidant and an anti-aging compound as well as an anti-inflammatory agent. Stilbenes have diverse pharmacological activities, which include cancer prevention, a cholesterol-lowering effect, enhanced insulin sensitivity, and increased lifespan. This review summarizes results related to the potential use of various stilbenes as cancer chemopreventive agents, their mechanisms of action, as well as their pharmacokinetics and efficacy for the prevention of colon cancer in animals and humans.

Anti-influenza virus activities of flavonoids from the medicinal plant Elsholtzia rugulosa.

Abstract: ELSHOLTZIA RUGULOSA (Lamiaceae), a common Chinese herb, is widely used in the treatment of cold and fever. In order to elucidate the action mechanism and the active principles from the plant against anti-influenza virus, the influenza virus neuraminidase (NA) activity assay and IN VITRO antiviral activity assay were established, and the isolation of the active principles was guided by NA activity. Finally, 5 active constituents were obtained, namely apigenin ( 1), luteolin ( 2), apiin ( 3), galuteolin ( 4) and luteolin 3'-glucuronyl acid methyl ester ( 5), respectively. They all belong to the flavonoids. The IN VITRO antiviral assay using a cytopathic effect (CPE) reduction method showed that they all possessed anti-influenza virus activity. Among them, apigenin and luteolin exhibited the highest activities against influenza virus (H3N2) with IC (50) values of 1.43 microg/mL and 2.06 microg/mL, respectively. The structure-activity relationship (SAR) of these flavonoids with different chemical structures and their anti-influenza virus activities was addressed in this study.

Cancer chemopreventive activity of terpenoid coumarins from Ferula species.

Abstract: Several natural products have been found to have anti-tumor promoting activity. In the present study, we carried out a primary screening of ten terpenoid coumarins isolated from plants of the Ferula species, examining their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12- O-tetradecanoylphorbol 13-acetate (TPA) in Raji cells. Auraptene (7-geranyloxycoumarin, 1) and umbelliprenin (7-farnesyloxycoumarin, 2) were found to significantly inhibit EBV-EA activation and preserved the high viability of Raji cells, suggesting that they might be valuable anti-tumor-promoting agents (IC (50) 8.3 and 9.1 nM, respectively). Our findings revealed that the presence of a prenyl moiety in the terpenoid coumarins plays an important role in anti-tumor promoting activity as previously reported for xanthones, coumarins, flavonoids and phenylpropanoids.

Fishing for drugs from nature: zebrafish as a technology platform for natural product discovery.

Abstract: Emerging challenges within the current drug discovery paradigm are prompting renewed interest in natural products as a source of novel, bioactive small molecules. With the recent validation of zebrafish as a biomedically relevant model for functional genomics and in vivo drug discovery, the zebrafish bioassay-guided identification of natural products may be an attractive strategy to generate new lead compounds in a number of indication areas. Here, we review recent natural product research using zebrafish and evaluate the potential of this vertebrate model as a discovery platform for the systematic identification of bioactive natural products.

Occurrence and properties of proteases in plant latices.

Abstract: Proteases appear to play key roles in the regulation of biological processes in plants, such as the recognition of pathogens and pests and the induction of effective defence responses. On the other side these enzymes are able to activate protease-activated receptors (PARs) and in that way to act as agents with pharmacological and toxicological significance. An important source of plant proteases used in traditional medicine and industry is latex. Over 110 latices of different plant families are known to contain at least one proteolytic enzyme. Most of them belong to the cysteine or serine endopeptidases family and only one to the aspartatic endopeptidases family. This review focuses on the characterization of proteases found in latices of several plant families (Apocynaceae, Asclepiadaceae, Asteraceae, Caricaceae, Convolvulaceae, Euphorbiaceae, Moraceae), and summarizes the known chemical and biological properties of the isolated proteases as well as their importance in pharmacology and toxicology.

Role of reactive oxygen intermediates in cellular responses to dietary cancer chemopreventive agents.

Abstract: Epidemiological studies continue to support the premise that diets rich in fruits and vegetables may offer protection against cancer of various anatomic sites. This correlation is quite persuasive for vegetables including ALLIUM (e. g., garlic) and cruciferous (e. g., broccoli and watercress) vegetables. The bioactive food components responsible for the cancer chemopreventive effects of various edible plants have been identified. For instance, the anticancer effects of ALLIUM and cruciferous vegetables are attributed to organosulfur compounds (e. g., diallyl trisulfide) and isothiocyanates (e. g., sulforaphane and phenethyl isothiocyanate), respectively. Bioactive food components with anticancer activity are generally considered to be antioxidants due to their ability to modulate expression/activity of antioxidative and phase 2 drug-metabolizing enzymes and scavenging free radicals. At the same time, more recent studies have provided convincing evidence to indicate that certain dietary cancer chemopreventive agents cause generation of reactive oxygen species (ROS) to trigger signal transduction culminating in cell cycle arrest and/or programmed cell death (apoptosis). Interestingly, the ROS generation by some dietary anticancer agents is tumor cell specific and does not occur in normal cells. This review summarizes experimental evidence supporting the involvement of ROS in cellular responses to cancer chemopreventive agents derived from common edible plants.

Plant-Derived Leading Compounds for Chemotherapy of Human Immunodefiency Virus (HIV) Infection-An Update (1998-2007)

Abstract: The high number of citations of the previous review on anti-HIV compounds from plants published in 1998 in Planta Medica indicates the importance of natural products research in the battle against HIV. Therefore, we have decided to write an update of our previous review paper, this time covering the time span 1998 - 2007. The following antiviral chemical classes are discussed in detail: alkaloids, carbohydrates, coumarins, flavonoids, lignans, phenolics, proteins, quinones/xanthones, tannins and terpenes. If available, chemical structures, antiviral activity and selectivity, mechanism of action, and structure-activity relationship are presented.

Madecassoside isolated from Centella asiatica herbs facilitates burn wound healing in mice.

Abstract: The current study was designed to investigate the effect of madecassoside, the major triterpene in CENTELLA ASIATICA, on burn wound healing and its possible mechanism of action. An oral administration of madecassoside (6, 12, 24 mg/kg) facilitated wound closure in a time-dependent manner and reached its peak effect, nearly completely wound closure, on day 20 in the group receiving the highest dose of 24 mg/kg of madecassoside. Further histopathological analysis revealed that madecassoside alleviated infiltration of inflammatory cells as well as enhanced epithelisation resulting from dermal proliferation of fibroblasts. Madecassoside at higher doses (12 and 24 mg/kg) decreased nitric oxide (NO) levels and malondialdehyde (MDA) content in the burn skin tissue. However, reduced glutathione (GSH) and hydroxyproline levels were increased in the same skin tissue. In addition, madecassoside promoted skin angiogenesis IN VIVO, correlating with our findings IN VITRO that it stimulated endothelial cell growth in a rat aortic ring assay. These data suggest that madecassoside has significant wound-healing activity and is one of the major reasons for the use of C. ASIATICA herbs in the successful treatment of burn injury. Moreover, the results from the present study indicate that the effect of madecassoside on wound healing may involve several mechanisms including antioxidative activity, collagen synthesis and angiogenesis.

Isolation and characterization of new Cannabis constituents from a high potency variety.

Abstract: Phytochemical investigation of a high potency variety of Cannabis sativa L. resulted in the isolation of six new metabolites, (+/-)-6,7-trans-epoxycannabigerolic acid ( 2), (+/-)-6,7- CIS-epoxycannabigerolic acid ( 3), (+/-)-6,7- CIS-epoxycannabigerol ( 4), (+/-)-6,7-trans-epoxycannabigerol ( 5), 5'-methyl-4-pentylbiphenyl-2,2',6-triol ( 7), and 7-methoxycannabispirone ( 8), along with seven known compounds namely, cannabigerolic acid ( 1), 5'-methoxycannabigerolic acid ( 6), cannabispirone ( 9), beta-cannabispiranol ( 10), dehydrocannabifuran ( 11), cannflavin B ( 12) and cannabigerol ( 13). The antimicrobial as well as the antileishmanial activities were investigated.

Quality and functionality of saffron: quality control, species assortment and affinity of extract and isolated saffron compounds to NMDA and sigma1 (sigma-1) receptors.

Abstract: Extracts from saffron, the dried stigmata from Crocus sativus L., are being used more and more in preclinical and clinical trials for the treatment of cancer and depression. Because of the known quality problems of saffron, HPLC methods on RP(18) 2.5 microm and monolithic RP(18) material have been developed and validated for quality control including the quantification of crocins 1 to 5, crocetin, picrocrocin and the degradation products, the CIS-crocins. Additionally, a GC-MS method has allowed detection and quantification of the volatile compounds from the pentane extract of saffron. Both systems together allowed the comprehensive characterisation of saffron herbal material and extracts for clinical/preclinical trials. For effective preparation of the respective reference standards, a fast centrifugal partition chromatography (FCPC) method was developed allowing the quick isolation of crocins 1, 2, 5 and picrocrocin in good yields. Using these chromatographic methods and the reference standards, a representative survey of saffron from the global market indicated a high variability of quality, especially concerning the amounts of volatile compounds in saffron samples. A specification for high-quality saffron of >20% crocins, >6% picrocrocin and not less than 0.3% of volatiles, calculated as sum of safranal, isophorone and ketoisophorone, was developed. Because no detailed pharmacological studies are available to explain the clinical effects of saffron for the treatment of cancer and depression, receptor binding studies were performed. Saffron extracts and crocetin had a clear binding capacity at the PCP binding side of the NMDA receptor and at the sigma(1) receptor, while the crocins and picrocrocin were not effective. These data could give biochemical support for the above-mentioned pharmacological effects of saffron.

Anxiolytic activity of a phytochemically characterized Passiflora incarnata extract is mediated via the GABAergic system.

Abstract: The purpose of this research was to assess the anxiolytic properties of a phytochemically characterized commercial extract from Passiflora incarnata (PI; Passifloraceae) in the elevated plus maze test in mice. Using an HPLC method, the flavonoids homoorientin, orientin, vitexin, and isovitexin were identified as major compounds. Following oral administration, the extract exerted an anxiolytic effect that was comparable to diazepam (1.5 mg/kg) at a dose of 375 mg/kg and exhibited a U-shaped dose-response curve. In addition, antagonism studies using the GABA (A)/benzodiazepine receptor antagonist flumazenil and the 5-HT (1A)-receptor antagonist WAY-100 635 were conducted. The active dose was effectively antagonized by flumazenil, but not by WAY-100 635. This study is the first demonstration of the IN VIVO, GABA-mediated anxiolytic activity of an HPLC- characterized extract of Passiflora incarnata.

Estrogenic activities of isoflavones and flavones and their structure-activity relationships.

Abstract: In this study, we assessed the relationships between the structure and estrogenicity of flavonoid derivatives. We evaluated estrogenicity via yeast transactivation assays, E-screen assays, and ER binding assays. Genistein and coumestrol in the yeast transactivation assay and biochanin A, genistein, and equol in the E-screen assay, have been shown to have profound estrogenic activities. Flavonoids, with the exception of biochanin A and daidzein, exhibit more profound selectivity for ER beta than for ER alpha. We compared several flavonoids in terms of estrogenicity, as well as relatively small structural differences including the position of the phenol ring and hydroxy groups, the substitution of hydroxy groups or methoxy groups, the opening of the phenol ring; glycitein vs. 4',6,7-trihydroxyisoflavone, biochanin A vs. genistein, apigenin vs. genistein, 7,4'-dihydroxyflavone vs. isoliquiritigenin. A quantitative structure-activity relationship study design was utilized to develop model equations for the estrogenic activities of flavonoid derivatives. The prediction of estrogenicity with regard to ER alpha shows a positive correlation with MW and AlogP, and a negative correlation with Apol and Area (r2 = 0.89 and q2 = 0.83). The prediction of estrogenicity with regard to ER beta reveals a positive correlation with the AlogP and Hbond acceptors, and a negative correlation with RadOfGyration (r2 = 0.77 and q2 = 0.72).

Antibacterial and antiparasitic activity of oleanolic acid and its glycosides isolated from marigold (Calendula officinalis).

Abstract: The antibacterial and antiparasitic activities of free oleanolic acid and its glucosides and glucuronides isolated from marigold (Calendula officinalis) were investigated. The MIC of oleanolic acid and the effect on bacterial growth were estimated by A600 measurements. Oleanolic acid's influence on bacterial survival and the ability to induce autolysis were measured by counting the number of cfu. Cell morphology and the presence of endospores were observed under electron and light microscopy, respectively. Oleanolic acid inhibited bacterial growth and survival, influenced cell morphology and enhanced the autolysis of Gram-positive bacteria suggesting that bacterial envelopes are the target of its activity. On the other hand, glycosides of oleanolic acid inhibited the development of L3 Heligmosomoides polygyrus larvae, the infective stage of this intestinal parasitic nematode. In addition, both oleanolic acid and its glycosides reduced the rate of L3 survival during prolonged storage, but only oleanolic acid glucuronides affected nematode infectivity. The presented results suggest that oleanolic acid and its glycosides can be considered as potential therapeutic agents.

Paeonol and paeoniflorin, the main active principles of Paeonia albiflora, protect the heart from myocardial ischemia/reperfusion injury in rats.

Abstract: The aim of this study was to investigate the effects of paeoniflorin (PF) and paeonol (PN), the main active compounds of the Paeonia albiflora Pallas, on myocardial ischemia and reperfusion (I/R)-induced injury in Sprague-Dawley rats IN VIVO. Under anesthesia, the rats were subjected to 25 min of ischemia by ligation of the left anterior descending coronary artery (LAD) followed by 6 h (Western blot analysis) or 24 h (hemodynamics and infarct size) of reperfusion. When the infarct size was measured as the percentage of the area at risk, both PF (25.0 % +/- 7.0 %) and PN (24.1 % +/- 5.5 %) significantly (P < 0.05) reduced it compared to I/R control (54.8 % +/- 2.6 %). Administration of 10 mg/kg PF or PN 1 h prior to I/R injury also resulted in a significant improvement of the hemodynamic parameters. Furthermore, both PF and PN decreased the caspase-3 and Bax expressions but up-regulated Bcl-2 in the left ventricles. The results show that both PF and PN reduced myocardial damage in rat through protection from apoptosis, suggesting that Paeonia albiflora Pallas might be useful in treating myocardial infarction.

In vitro BACE-1 inhibitory phenolic components from the seeds of Psoralea corylifolia.

Abstract: A new isoflavone, neocorylin ( 1) was isolated from the seeds extract of Psoralea corylifolia L. (Fabaceae), together with eight known constituents ( 2 - 9), i. e., bakuchiol ( 2), psoralen ( 3), bavachromene ( 4), isobavachromene ( 5), bavachalcone ( 6), isobavachalcone ( 7), 7,8-dihydro-8-(4-hydrophenyl)-2,2-dimethyl-2 H,6 H-[1,2- B:5,4- B']dipyran-6-one ( 8), and bavachinin ( 9). The structure of the new isoflavone 1 was elucidated as 7-hydroxy-3-[2-methyl-2-(4-methylpenten-3-yl)-2 H-chromen-6-yl]-4 H-chromen-4-one by spectroscopic analyses. Neocorylin ( 1) as well as related compounds 2, 4 - 6, 8 and 9 exhibited a significant inhibitory effect on baculovirus-expressed BACE-1 in vitro.

Modulation of GABAA Receptors by Valerian Extracts is Related to the Content of Valerenic Acid

Abstract: Valeriana Officinalis L . is a traditionally used sleep remedy, however, the mechanism of action and the substances responsible for its sedative and sleep-enhancing properties are not fully understood. As we previously identified valerenic acid as a subunit-specific allosteric modulator of GABAA receptors, we now investigated the relation between modulation of GABAA receptors by Valerian extracts of different polarity and the content of sesquiterpenic acids (valerenic acid, acetoxyvalerenic acid). All extracts were analysed by HPLC concerning the content of sesquiterpenic acids. GABAA receptors composed of alpha 1, beta 2 and gamma 2S subunits were expressed in Xenopus laevis oocytes and the modulation of chloride currents through GABAA receptors (IGABA) by Valerian extracts was investigated using the two-microelectrode voltage clamp technique. Apolar extracts induced a significant enhancement of IGABA, whereas polar extracts showed no effect. These results were confirmed by fractionating a highly active ethyl acetate extract: again fractions with high contents of valerenic acid exhibited strong receptor activation. In addition, removal of sesquiterpenic acids from the ethyl acetate extract led to a loss of I (GABA) enhancement. In conclusion, our data show that the extent of GABAA receptor modulation by Valerian extracts is related to the content of valerenic acid.

Content, Composition, and Bioactivity of theEssential Oils of Three Basil Genotypes as aFunction of Harvesting

Abstract: A study was conducted to evaluate the effect of cut on biomass productivity, oil content, composition, and bioactivity of Ocimum basilicum L. (cvs. German and Mesten) and Ocimum sanctum L. (syn. O. tenuiflorum L.) (cv. Local) in Mississippi. Yields of basil herbage and essential oil were high and comparable to those reported in the literature. Essential oil content of O. basilicum cv. German varied from 0.40 to 0.75%, the oil content of cv. Mesten varied from 0.50 to 0.72%, and the oil content of cv. Local (of O. sanctum) ranged from 0.17 to 0.50% in air-dried basil. Herbage and essential oil yields of cvs. German and Mesten of O. basilicum increased with the second and then again with the third cut, whereas herbage and oil yields of cv. Local of O. sanctum increased with the third cut relative to the previous cuts. Overall, essential oil yields were 115, 123, and 51 kg/ha for the cvs. German, Mesten, and Local, respectively. The major oil constituents of cvs. German and Mesten (of O. basilicum) were (-)-linalool (30-40%) and eugenol (8-30%), whereas the major oil constituents of cv. Local (of O. sanctum) were eugenol (8-43%) and methylchavicol (15-27%). Essential oils from both species grown in Mississippi showed in vitro activity against Leishmania donovani (IC50 = 37.3-49.6 microg/mL), which was comparable to the activity of commercial oil (IC50 = 40-50 microg/mL). Minor basil oil constituents (+)-delta-cadinene, 3-carene, alpha-humulene, citral, and (-)- trans-caryophyllene had antileishmanial activity, whereas other constituents were ineffective. None of the oil was cytotoxic to mammalian cells.

Metabolic profiling of the Mexican anxiolytic and sedative plant Galphimia glauca using nuclear magnetic resonance spectroscopy and multivariate data analysis

Abstract: Galphimia glauca is popularly employed in Mexico for the treatment of central nervous system disorders. Pharmacological and phytochemical studies have resulted in the identification of the anxiolytic and sedative principle consisting of a mixture of nor-secofriedelanes, named the galphimine series (1 - 9). These active constituents were found in plants collected in the vicinity of a restricted region in Central Mexico, where this species is abundant. A metabolic profiling carried out by means of 1H-NMR spectroscopy and multivariate data analysis was applied to crude extracts from wild plant populations, collected from six different locations as a quality control assessment, in order to differentiate their chemical profile. Principal component analysis (PCA) of the 1H-NMR spectra revealed clear variations among the populations, with two populations out of the six studied manifesting differences, when the principal components PC-1 and PC-2 were analyzed. These two PCs permitted the differentiation of the various sample populations, depending on the presence of galphimines. This information consistently correlated with the corresponding HPLC analysis. The neuropharmacological effects of the crude extracts were evaluated by using ICR mice in the elevated plus maze, as well as the sodium pentobarbital-induced hypnosis models. Both assays demonstrated anxiolytic and sedative responses only among those sample populations which had previously been differentiated by PC-1. Partial least square regression-discriminant analysis (PLS-DA) also confirmed a strong correlation between the observed effects and the metabolic profiles of the plants. The overall results of this study confirm the benefits of using metabolic profiling for the in silico analysis of active principles in medicinal plants.

Perspective on recent developments on sulfur-containing agents and hydrogen sulfide signaling.

Abstract: The last couple of years have witnessed the coming together of several initially unconnected lines of investigation which now link natural sulfur products to hydrogen sulfide release and wide ranging cardiovascular protection It has become apparent that sulfur compounds contained within garlic, onions, mushrooms and various edible beans and fruits may be transformed chemically or enzymatically in the human body with subsequent formation of hydrogen sulfide The latter has emerged during the last decade from a shadowy existence as toxic gas to be recognized as the third gaseous transmitter besides nitric oxide ( ()NO) and carbon monoxide (CO) Hydrogen sulfide is formed endogenously in the human body by enzymes such as cystathionine beta-synthase (CBS) in the brain and cystathionine gamma-lyase (CSE) in liver, vascular and non-vascular smooth muscle Although its exact chemical and biochemical modes of action are still not fully understood, levels of hydrogen sulfide in the brain and vasculature have unambiguously been associated with human health and disease Not surprisingly, agents releasing hydrogen sulfide, as well as inhibitors of hydrogen sulfide synthesis (CBS and CSE inhibitors) have been investigated Apart from linking our daily diet to a healthy brain and cardiovasculature, these findings may also provide new leads for drug design Future studies will therefore need to focus on how such compounds are formed and transformed in the relevant plants, how food processing affects their chemical constitution, and how they release hydrogen sulfide (or control its levels) in the human body Such multidisciplinary research should ultimately answer the all-important question if a hearty diet is also good for the heart

Dietary cancer chemopreventive agents - targeting inflammation and Nrf2 signaling pathway

Abstract: Accumulating epidemiological and clinical evidence shows that chronic inflammation plays a critical role in neoplastic transformation and progression. Long-term users of selective cycloxygenase-2 (Cox-2) inhibitors (coxibs) and non-steroidal anti-inflammatory drugs (NSAIDs) have been reported to have a reduced risk of developing colorectal cancer. However, the adverse gastrointestinal and cardiovascular side effects associated with these drugs have limited their routine use for cancer chemoprevention. Basic leucine zipper (bZIP) protein Nrf2, a key transcription factor mediating the antioxidant response is an important modulator of tumor susceptibility in mouse models. Mice lacking Nrf2 are more susceptible to carcinogenesis induced by carcinogens. Moreover, induction of the Nrf2 signaling pathway is essential for many food phytochemicals to exert their cancer chemopreventive activity as demonstrated in many preclinical studies. It has been recently shown that the combination of coxibs or NSAIDs and natural phytochemicals can synergistically inhibit carcinogenesis in rodent models. This review will focus on the role of chronic inflammation and the Nrf2 signaling pathway in carcinogenesis and the feasibility of targeting these signaling pathways with dietary cancer chemopreventive agents and for cancer chemoprevention.