Showing papers in "Planta Medica in 2007"
TL;DR: A beneficial effect from the daily intake of POMx and pomegranate juice (PJ) as dietary supplements to augment the human immune system's antioxidant, antimalarial and antimicrobial capacities is suggested.
Abstract: The Punica granatum L. (pomegranate) by-product POMx was partitioned between water, EtOAc and n-BuOH, and the EtOAc and n-BuOH extracts were purified by XAD-16 and Sephadex LH-20 column chromatography to afford ellagic acid (1), gallagic acid (2), punicalins (3), and punicalagins (4). Compounds 1 - 4 and the mixture of tannin fractions (XAD-16 eluates) were evaluated for antioxidant, antiplasmodial, and antimicrobial activities in cell-based assays. The mixture of tannins (TPT), XAD-EtOAc, XAD-H2O, XAD-PJ and XAD-BuOH, exhibited IC50 values against reactive oxygen species (ROS) generation at 0.8 - 19 microg/mL. Compounds 1 - 4 showed IC50 values of 1.1, 3.2, 2.3 and 1.4 microM, respectively, against ROS generation and no toxicity up to 31.25 microg/mL against HL-60 cells. Gallagic acid (2) and punicalagins (4) exhibited antiplasmodial activity against Plasmodium falciparum D6 and W2 clones with IC50 values of 10.9, 10.6, 7.5 and 8.8 microM, respectively. Fractions XAD-EtOAc, XAD-BuOH, XAD-H2O and XAD-PJ compounds 1 - 4 revealed antimicrobial activity when assayed against Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Cryptococcus neoformans, methicillin-resistant Staphylococcus aureus (MRSA), Aspergillus fumigatus and Mycobacterium intracellulare. Compounds 2 and 4 showed activity against P. aeruginosa, C. neoformans, and MRSA. This is the first report on the antioxidant, antiplasmodial and antimicrobial activities of POMx isolates, including structure-activity relationships (SAR) of the free radical inhibition activity of compounds 1 - 4. Our results suggest a beneficial effect from the daily intake of POMx and pomegranate juice (PJ) as dietary supplements to augment the human immune system's antioxidant, antimalarial and antimicrobial capacities.
473 citations
TL;DR: It is found that the active principle of Artemisia annua L., artemisinin, exerts not only antimalarial activity but also profound cytotoxicity against tumor cells, indicating that artesunate is not involved in multidrug resistance.
Abstract: Secondary metabolites from plants serve as defense against herbivores, microbes, viruses, or competing plants. Many medicinal plants have pharmacological activities and may, thus, be a source for novel treatment strategies. During the past 10 years, we have systematically analyzed medicinal plants used in traditional Chinese medicine and focused our interest on Artemisia annua L. (qinhao, sweet wormwood). We found that the active principle of Artemisia annua L., artemisinin, exerts not only antimalarial activity but also profound cytotoxicity against tumor cells. The inhibitory activity of artemisinin and its derivatives towards cancer cells is in the nano- to micromolar range. Candidate genes that may contribute to the sensitivity and resistance of tumor cells to artemisinins were identified by pharmacogenomic and molecular pharmacological approaches. Target validation was performed using cell lines transfected with candidate genes or corresponding knockout cells. The identified genes are from classes with diverse biological functions; for example, regulation of proliferation (BUB3, cyclins, CDC25A), angiogenesis (vascular endothelial growth factor and its receptor, matrix metalloproteinase-9, angiostatin, thrombospondin-1) or apoptosis (BCL-2, BAX, NF-kappaB). Artesunate triggers apoptosis both by p53-dependent and -independent pathways. Antioxidant stress genes (thioredoxin, catalase, gamma-glutamylcysteine synthetase, glutathione S-transferases) as well as the epidermal growth factor receptor confer resistance to artesunate. Cell lines overexpressing genes that confer resistance to established antitumor drugs (MDR1, MRP1, BCRP, dihydrofolate reductase, ribonucleotide reductase) were not cross-resistant to artesunate, indicating that artesunate is not involved in multidrug resistance. The anticancer activity of artesunate has also been shown in human xenograft tumors in mice. First encouraging experience in the clinical treatment of patients suffering from uveal melanoma calls for comprehensive clinical trials with artesunate for cancer treatment in the near future.
273 citations
TL;DR: In this article, some of the opportunities which currently exist to exploit plants for their natural products as templates for new antibacterial substances are discussed. And a summary on future trends and directions in this fruitful and interesting area is also given.
Abstract: This review covers some of the opportunities which currently exist to exploit plants for their natural products as templates for new antibacterial substances. This is a timely exercise given the continuing and developing problems of bacterial resistance, and in particular multidrug-resistance (MDR). Some of the challenges which are evident with bacterial resistance will be described and the strengths and weaknesses of plant natural products are highlighted. Opportunities to characterise antibacterial compounds from several key taxa are described with activity against methicillin-resistant Staphylococcus aureus (MRSA), MDR variants of this species and Mycobacterium tuberculosis (MTB). These pathogens continue to cause problems in terms of their eradication and spread and MTB strains which are extremely-drug resistant (XDR) promise to afford an additional challenge for clinicians. The review also covers plant natural products that modulate or modify bacterial resistance. Specific examples include plant-derived efflux pump inhibitors (EPIs) which inhibit bacterial antibiotic efflux mechanisms that are problematic due to their broadness in substrate specificity. A summary on future trends and directions in this fruitful and interesting area is also given.
231 citations
TL;DR: A Cochrane review to provide objective evidence whether the various Echinacea preparations are more effective than no treatment, more Effective than placebo or similarly effective to other treatments in the prevention and the treatment of the common cold found two further meta-analyses to be inadequate.
Abstract: Echinacea preparations are widely used for common cold. Many consumers and healthcare professionals are not aware that products available under the term Echinacea may differ in their composition, due to the use of different species, plant parts, extraction methods and addition of other components. In 2005, a Cochrane review has been published to provide objective evidence whether the various Echinacea preparations are more effective than no treatment, more effective than placebo or similarly effective to other treatments in the prevention and the treatment of the common cold. In contrast to other reviews, the specific criteria for pooling of data from different trials have been predefined to assure a meaningful meta-analysis. In the meantime two further meta-analyses have been published. In the present mini-review, these latest meta-analyses are evaluated and discussed.
206 citations
TL;DR: Current knowledge on the phytochemistry, pharmacology, safety aspects of Noni fruit and Noni-derived products, and health-related claims and benefits is reviewed.
Abstract: Products derived from Noni fruit (Morinda citrifolia) have been commercialised in the USA since the 1990s and are increasingly distributed all over the world. A large number of beneficial effects have been claimed for Noni. Fruit juice of Noni has been approved as a Novel Food by the European Commission in 2003. This article reviews current knowledge on the phytochemistry, pharmacology, safety aspects of Noni fruit and Noni-derived products, and health-related claims and benefits. The knowledge on the chemical composition of Noni fruit has considerably increased over recent years. A number of in vitro and, to a certain extent, in vivo studies demonstrate a range of potentially beneficial effects. However, clinical data are essentially lacking. To what extent the findings from experimental pharmacological studies are of potential clinical relevance is not clear at present. Based on a toxicological assessment, Noni juice was considered as safe. Due to recent reports of cases of hepatotoxicity, the safety issue has been re-examined in Europe. While the European Food Safety Authority sees no link between adverse effects on liver and consumption of Noni juice, a continuing monitoring of the situation is desirable and some vigilance advised.
183 citations
TL;DR: The antiproliferative activities of red American ginseng are augmented when ginsenoside Rg3 is increased, and the activity of the extract from roots steaming for 2 h was greater than that of roots steamed for 1 h.
Abstract: Red Asian ginseng ( Panax ginseng C. A. Meyer, Araliaceae) is used in many Oriental countries. In this study, the saponin constituents and anticancer activities of steamed American ginseng ( Panax quinquefolius L.) roots were evaluated. The contents of 12 ginsenosides in the roots were determined using high performance liquid chromatography (HPLC). After the steaming treatment (100 - 120 degrees C for 1 h and 120 degrees C for 0.5 - 4 h), the quantity of 7 ginsenosides decreased and that of 5 others increased. The content of ginsenoside Rg3, a previously recognized anticancer compound, increased significantly when the root was steamed at 120 degrees C for 0.5 - 3 h. The antiproliferative effects of unsteamed and steamed (120 degrees C for 1 h and 2 h) American ginseng root extracts were assayed by the modified trichrome stain (MTS) method using three cancer cell lines (SW-480, HT-29, NSCLC). Heat-processing increased the antiproliferative effect of American ginseng significantly, and the activity of the extract from roots steamed for 2 h was greater than that of roots steamed for 1 h. Chemical constituents and antiproliferative activities of white and red Asian ginseng have also been evaluated. Five representative ginsenosides, Rb1, Rd, Re, Rg2 and Rg3, were studied. Ginsenoside Rg3 had the most potent effect. The antiproliferative activities of red American ginseng are augmented when ginsenoside Rg3 is increased.
169 citations
TL;DR: The biology and molecular pharmacology of the 5-LO pathway is summarized in order to understand its overall regulation and complexity as well as to comprehend the possible points of attack of compounds that eventually lead to inhibition of 5- LO product formation in intact cells.
Abstract: The biosynthesis of leukotrienes (LTs) is initiated by the transformation of free arachidonic acid to LTA (4) by 5-lipoxygenase (5-LO). Subsequent enzymatic conversion of LTA (4) yields LTB (4) and the cysteinyl-LTs C (4), D (4) and E (4). LTs have prominent functions in pathophysiology and are connected to numerous disorders including bronchial asthma, allergic rhinitis, inflammatory bowel and skin diseases, rheumatoid arthritis, cancer, osteoporosis and cardiovascular diseases. Pharmacological and genetic interruption of the 5-LO pathway or blockade of LT receptors, serving as means for intervention with LTs, may be of therapeutic value for certain related disorders. Natural or plant-derived substances were among the first 5-LO inhibitors identified in the early 1980 s. To date, a huge number of diverse plant-derived compounds have been reported to interfere with 5-LO product synthesis. However, many investigations have addressed the efficacy of a given compound solely in cellular test systems and analysis of direct interference with 5-LO has been neglected. In the first part of this review, the biology and molecular pharmacology of the 5-LO pathway is summarized in order to understand its overall regulation and complexity as well as to comprehend the possible points of attack of compounds that eventually lead to inhibition of 5-LO product formation in intact cells. In the second part, natural compounds that interfere with 5-LO product formation are compiled and grouped into structural classes, and the underlying molecular mechanisms and structure-activity relationships are discussed.
151 citations
TL;DR: The results indicate that the effects of NN in preventing diet-induced obesity appear to be due to various flavonoids and that the activation of beta-AR pathway was involved, at least in part.
Abstract: Nelumbo nucifera Gaertn. (Nymphaceae) has been used for various medicinal purposes as in Chinese herbal medicine. In particular, the leaves are known for diuretic and astringent properties, and are used to treat obesity. During our search for a plant-derived anti-obesity agent from natural products, we have found that a 50% ethanol (EtOH) extract prepared from the leaves of N. nucifera (NN) stimulated lipolysis in the white adipose tissue (WAT) of mice and that the beta-adrenergic receptor (beta-AR) pathway was involved in this effect. In subsequent experiments, dietary supplementation of NN resulted in a significant suppression of body weight gain in A/J mice fed a high-fat diet. Bioassay-guided fractionation and repeated chromatography of NN has led to the isolation and identification of quercetin 3-O-alpha-arabinopyranosyl-(1-->2)-beta-galactopyranoside (1), rutin (2), (+)-catechin (3), hyperoside (4), isoquercitrin (5), quercetin (6) and astragalin (7). Of these, compounds 1, 3, 4, 5 and 7 exhibited lipolytic activity, especially in visceral adipose tissue. Our results indicate that the effects of NN in preventing diet-induced obesity appear to be due to various flavonoids and that the activation of beta-AR pathway was involved, at least in part.
129 citations
TL;DR: In this article, the in vitro acetylcholinesterase (AChE) inhibitory potential of the hydroalcoholic extract and of the essential oil from Acorus calamus rhizomes and that of its major constituents were evaluated based on the Ellman's method.
Abstract: The in vitro acetylcholinesterase (AChE) inhibitory potential of the hydroalcoholic extract and of the essential oil from Acorus calamus (AC) rhizomes and that of its major constituents were evaluated based on the Ellman's method. GC/MS analysis of the oil revealed that the major constituents were beta-asarone (79.54%) and alpha-asarone (8.47%). The IC50 values were obtained for the hydroalcoholic extract, the essential oil, beta-asarone and alpha-asarone and were 182.31+/-16.78 microg/mL, 10.67+/-0.81 microg/mL, 3.33+/-0.02 microM and 46.38+/-2.69 microM, respectively. Physostigmine was used as standard inhibitor with an IC50 value of 0.28+/-0.015 microM. The experimental observations revealed that the AC essential oil and its constituents have significant AChE inhibitory potential. beta-Asarone, the major phytoconstituent present in the essential oil, showed the maximum inhibitory potential.
127 citations
TL;DR: Investigation concerning herb-drug interactions have been neglected for a long time and latest research concludes that prolonged use of Echinacea poses a minimal risk for co-medications metabolized by the P450 enzymes.
Abstract: Alkamides are the major lipophilic constituents of ECHINACEA preparations, which are widely used in some European countries and in North America for common colds. In earlier investigations they have been shown to possess stimulatory effects on phagocytosis. Recent experiments have demonstrated that alkamides are detectable in human blood in relevant concentrations after oral administration of Echinacea preparations. Alkamides show structural similarity with anandamide, an endogenous ligand of cannabinoid receptors. Consequently, it was found that alkamides bind significantly to CB (2) receptors, which is now considered as a possible molecular mode of action of Echinacea alkamides as immunomodulatory agents. It was also demonstrated recently in several studies that alkamide-containing Echinacea preparations trigger effects on the pro-inflammatory cytokines. They were therefore suggested as a new class of cannabinomimetics. However, the therapeutic relevance of these findings is still not clear as clinical studies on the common cold show contradictory results. Among the many pharmacological properties reported, investigations concerning herb-drug interactions have been neglected for a long time. Latest research concludes that prolonged use of Echinacea poses a minimal risk for co-medications metabolized by the P450 enzymes.
120 citations
TL;DR: The antiallergic effects of licorice are mainly due to glycyrrhizin, 18beta-glycyrrhetinic acid, and liquiritigenin, which can relieve IgE-induced allergic diseases such as dermatitis and asthma.
Abstract: Licorice (Glycyrrhiza glabra L., Leguminosae) is frequently used in traditional medicine to treat inflammatory and allergic diseases. In this study, the main components (glycyrrhizin, 18beta-glycyrrhetinic acid, isoliquiritin, and liquiritigenin) were isolated from licorice, and their anti-allergic effects, such as antiscratching behavior and IgE production-inhibitory activity, were evaluated both in vitro and in vivo. Liquiritigenin and 18beta-glycyrrhetinic acid most potently inhibited the degranulation of RBL-2H3 cells induced by IgE with the antigen (DNP-HSA) and rat peritoneal mast cells induced by compound 48/80. Liquiritigenin and 18beta-glycyrrhetinic acid potently inhibited the passive cutaneous anaphylactic reaction as well as the scratching behavior in mice induced by compound 48/80. These components inhibited the production of IgE in ovalbumin-induced asthma mice but liquiritigenin had little effect. This suggests that the antiallergic effects of licorice are mainly due to glycyrrhizin, 18beta-glycyrrhetinic acid, and liquiritigenin, which can relieve IgE-induced allergic diseases such as dermatitis and asthma.
TL;DR: The triterpene acid content of neutral plant extracts above the solubility limit could be due to interactions with biocolloids, and different mechanisms of the dissolution at pH 7.3 and pH 10.2 are discussed.
Abstract: Mistletoe (Viscum album L.) contains the triterpene acids oleanolic acid (OA) and betulinic acid (BA), which were found to have anti-tumour properties. In this study, the solubilities of OA and BA were studied in water (up to 0.02 microg/mL in each case) and in alkaline solutions of 10 mM trisodium phosphate (pH 11.5; OA: 77.2 microg/mL; BA: 40.1 microg/mL). Furthermore, triterpene acids were quantified in aqueous mistletoe extracts (pH 7.3; drug to extract ratio 1:25). OA (1.1 microg/mL) and BA (0.9 microg/mL) were extracted with a yield of less than 5%. Preparing plant extracts with basic pH values resulted in a triterpene acid content of 9.3 microg/mL OA and 5.2 microg/mL BA (pH 12.1), reaching neither the solubility limits nor a complete extraction of the plant material. The triterpene acid content of neutral plant extracts above the solubility limit could be due to interactions with biocolloids. Interaction studies were performed by gel permeation chromatography. Different mechanisms of the dissolution at pH 7.3 and pH 10.2 are discussed.
TL;DR: Antroquinonol, an ubiquinone derivative, was isolated from the solid-state fermented mycelium of Antrodia camphorata (Polyporaceae, Aphyllophorales), a parasitic fungus indigenous to Taiwan, and the structure of compound 1 was elucidated by the analysis of their spectroscopic data.
Abstract: Antroquinonol ( 1), an ubiquinone derivative, was isolated from the solid-state fermented mycelium of Antrodia camphorata (Polyporaceae, Aphyllophorales), a parasitic fungus indigenous to Taiwan. The structure of compound 1 was elucidated by the analysis of their spectroscopic data. Its cytotoxic activities were evaluated against MCF-7, MDA-MB-231 (human breast carcinoma), Hep3B, HepG2 (human liver carcinoma) and DU-145, LNCaP (human prostate carcinoma) cell lines, and the IC (50) values ranged from 0.13 +/- 0.02 to 6.09 +/- 0.07 microM.
TL;DR: From structure-activity relationships of the pairs morphine+cineole and naloxone+beta-pinene, it was shown that similarities exist in the stereochemistry and in the respective atomic charges of these molecules.
Abstract: 1,8-cineole (cineole) and beta-pinene, two monoterpenes isolated from the essential oil obtained from Eucalyptus camaldulensis Dehn leaves were tested for antinociceptive properties Tail-flick and hot-plate methods, reflecting the spinal and supraspinal levels, respectively, were used in mice and/or rats using morphine and naloxone for comparison Cineole exhibited an antinociceptive activity comparable to that of morphine, in both algesic stimuli A significant synergism between cineole and morphine was observed, but naloxone failed to antagonize the effect of cineole Beta-pinene exerted supraspinal antinociceptive actions in rats only and it reversed the antinociceptive effect of morphine in a degree equivalent to naloxone, probably acting as a partial agonist through the mu opioid receptors From structure-activity relationships of the pairs morphine+cineole and naloxone+beta-pinene, it was shown that similarities exist in the stereochemistry and in the respective atomic charges of these molecules Further studies are in progress in order to elucidate the mechanism of action of the two terpenoids
TL;DR: The results derived from the whole blood assay for cyclooxygenase (COX) and the reverse transcription-polymerase chain reaction (RT-PCR) assay indicate that luteolin may be a potent selective inhibitor of cyclo oxygengenase-2 (COx-2) and that the inhibition is attributable to its down-regulation of the mRNA expression of COX-2 in inflammatory responses.
Abstract: Luteolin, a flavonoid abundant in plants worldwide, demonstrates a spectrum of biological activities. This study is aimed at evaluating its inhibiting effects on inflammatory responses in vivo. We investigated the anti-inflammatory activity of luteolin in acute and chronic models in mice. We found that oral administration of luteolin (10 and 50 mg/kg) efficiently suppressed paw edema when induced by injecting carrageenan, and a similar tendency was also observed in the cotton pellet granuloma test. In the air pouch test, luteolin markedly reduced the number of infiltrated leukocytes and the elevated level of 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha) in the exudate. The results derived from the whole blood assay for cyclooxygenase (COX) and from the reverse transcription-polymerase chain reaction (RT-PCR) assay indicate that luteolin may be a potent selective inhibitor of cyclooxygenase-2 (COX-2) and that the inhibition is attributable to its down-regulation of the mRNA expression of COX-2 in inflammatory responses.
TL;DR: Results provide unequivocal evidence that, through the synergistic action of its antioxidants, honey by reducing and removing ROS, may lower the risks and effects of acute and chronic free radical induced pathologies in vivo.
Abstract: The therapeutic properties of honey, once considered a form of folk or preventive medicine, are acquiring importance for the treatment of acute and chronic free radical-mediated diseases (atherosclerosis, diabetes and cancer). The aim of this work was to study the protective activity of a honey of multifloral origin, standardized for total antioxidant power and analytically profiled (HPLC-MS) in antioxidants, in a cultured endothelial cell line (EA.hy926) subjected to oxidative stress. Cumene hydroperoxide (CuOOH) was used as free radical promoter. Native honey (1% w/v pH 7.4, 10(6) cells) showed strong quenching activity against lipophilic cumoxyl and cumoperoxyl radicals, with significant suppression/prevention of cell damage, complete inhibition of cell membrane oxidation, of intracellular ROS production and recovery of intracellular GSH. Experiments with endothelial cells fortified with the isolated fraction from native honey enriched in antioxidants, exposed to peroxyl radicals from 1,1-diphenyl-2-picrylhydrazyl (AAPH, 10 mM) and to hydrogen peroxide (H2O2, 50-100 microM), indicated that phenolic acids and flavonoids were the main causes of the protective effect. These results provide unequivocal evidence that, through the synergistic action of its antioxidants, honey by reducing and removing ROS, may lower the risks and effects of acute and chronic free radical induced pathologies in vivo.
TL;DR: It is shown, for the first time, that naturally-occurring flavonoids inhibit M MP-1 and down-regulate MMP-1 expression via an inhibition of the AP-1 activation although the cellular inhibitory mechanisms differ depending on their chemical structures.
Abstract: Some plant flavonoids in the form of whole plant extracts have been used topically for skin inflammatory disorders. Since matrix metalloproteinase-1 (MMP-1, collagenase-1) plays an important role in unbalanced turn-over or rapid breakdown of collagen molecules in human inflamed/UV-irradiated skin, the effects of natural flavonoids on MMP-1 activity and MMP-1 expression were studied to establish the therapeutic potential. Against recombinant human MMP-1, flavonols such as quercetin and kaempferol were strong inhibitors with IC50 values of 39.6 and 43.7 microM, respectively, while flavones such as apigenin and wogonin showed only weak inhibitory activity. In addition, quercetin, kaempferol, apigenin and wogonin (12.5-25.0 microM) strongly inhibited MMP-1 induction in 12-O-tetradecanoylphorbol 13-acetate-treated human dermal fibroblasts, but naringenin (a flavanone) did not. By means of the electrophoretic mobility shift assay, these flavonoids were also found to inhibit activation of the transcription factor, activator protein-1 (AP-1). Moreover, quercetin inhibited extracellular signal-regulated protein kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) activation, and kaempferol inhibited p38 MAPK and c-Jun N-terminal kinase (JNK) activation among the MAPKs tested. In contrast, flavones and naringenin did not inhibit the activation of these three MAPKs. These results have shown, for the first time, that naturally-occurring flavonoids (quercetin, kaempferol, apigenin and wogonin) inhibit MMP-1 and down-regulate MMP-1 expression via an inhibition of the AP-1 activation although the cellular inhibitory mechanisms differ depending on their chemical structures. Therefore, certain plant flavonoids or plant extracts with these flavonoids as major components may be beneficial to treat some skin inflammatory disorders and to protect skin from photoaging.
TL;DR: The designed primers were proven to be suitable for a broad application in the authentication of herbal materials and led to an accurate PCR product of the specific region in ITS2, which was confirmed with DNA extracted from 55 processed medicinal herbs belonging to 48 families.
Abstract: Different parts of medicinal herbs have long been used as traditional Chinese drugs for treating many diseases, whereas materials of similar morphology and chemical fingerprints are often misidentified. Analyses of sequence variations in the nuclear ribosomal DNA (rDNA) internal transcribed spacer (ITS) have become a valid method for authentication of medicinal herbs at the intergenic and interspecific levels. DNA extracted from processed materials is usually severely degraded or contaminated by microorganisms, thus generates no or unexpected PCR products. The goal of this study is to apply the ITS fragments selectively amplified with two designed primer sets for efficient and precise authentication of medicinal herbs. The designed primers led to an accurate PCR product of the specific region in ITS2, which was confirmed with DNA extracted from 55 processed medicinal herbs belonging to 48 families. Moreover, the selectively amplified ITS2 authenticated five sets of easily confusable Chinese herbal materials. The designed primers were proven to be suitable for a broad application in the authentication of herbal materials.
TL;DR: The data suggest that the clearance of a variety of drugs may be diminished by concomitant use of these herbs via inhibition of P450 enzymes, but less so by Pgp-mediated effects.
Abstract: Drug-herb interactions can result from the modulation of the activities of cytochrome P450 (P450) and/or drug transporters. The effect of extracts and individual constituents of goldenseal, Ginkgo biloba (and its hydrolyzate), grape seed, milk thistle, and ginseng on the activities of cytochrome P450 enzymes CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4 in human liver microsomes were determined using enzyme-selective probe substrates, and their effect on human P-glycoprotein (Pgp) was determined using a baculovirus expression system by measuring the verapamil-stimulated, vanadate-sensitive ATPase activity. Extracts were analyzed by HPLC to standardize their concentration(s) of constituents associated with the pharmacological activity, and to allow comparison of their effects on P450 and Pgp with literature values. Many of the extracts/constituents exerted > or = 50 % inhibition of P450 activity. These include those from goldenseal (normalized to alkaloid content) inhibiting CYP2C8, CYP2D6, and CYP3A4 at 20 microM, ginkgo inhibiting CYP2C8 at 10 microM, grape seed inhibiting CYP2C9 and CYP3A4 at 10 microM, milk thistle inhibiting CYP2C8 at 10 microM, and ginsenosides F1 and Rh1 (but not ginseng extract) inhibiting CYP3A4 at 10 microM. Goldenseal extracts/constituents (20 microM, particularly hydrastine) and ginsenoside Rh1 stimulated ATPase at about half of the activity of the model substrate, verapamil (20 microM). The data suggest that the clearance of a variety of drugs may be diminished by concomitant use of these herbs via inhibition of P450 enzymes, but less so by Pgp-mediated effects.
TL;DR: Bromelain significantly reduced the number of lung metastasis induced by LLC transplantation, as observed with 5-FU, and the unchanged tumor progression in the metastatic model suggests that the antimetastatic action results from a mechanism independent of the primary antitumoral effect.
Abstract: Stem bromelain (EC 3.4.22.32) is a major cysteine proteinase, isolated from pineapple ( Ananas comosus) stem. Its main medicinal use is recognized as digestive, in vaccine formulation, antitumoral and skin debrider for the treatment of burns. To verify the identity of the principle in stem fractions responsible for the antitumoral effect, we isolated bromelain to probe its pharmacological effects. The isolated bromelain was obtained from stems of adult pineapple plants by buffered aqueous extraction and cationic chromatography. The homogeneity of bromelain was confirmed by reverse phase HPLC, SDS-PAGE and N-terminal sequencing. The in vivo antitumoral/antileukemic activity was evaluated using the following panel of tumor lines: P-388 leukemia, sarcoma (S-37), Ehrlich ascitic tumor (EAT), Lewis lung carcinoma (LLC), MB-F10 melanoma and ADC-755 mammary adenocarcinoma. Intraperitoneal administration of bromelain (1, 12.5, 25 mg/kg), began 24 h after tumor cell inoculation in experiments in which 5-fluorouracil (5-FU, 20 mg/kg) was used as positive control. The antitumoral activity was assessed by the survival increase (% survival index) following various treatments. With the exception of MB-F10 melanoma, all other tumor-bearing animals had a significantly increased survival index after bromelain treatment. The largest increase ( approximately 318 %) was attained in mice bearing EAT ascites and receiving 12.5 mg/kg of bromelain. This antitumoral effect was superior to that of 5-FU, whose survival index was approximately 263 %, relative to the untreated control. Bromelain significantly reduced the number of lung metastasis induced by LLC transplantation, as observed with 5-FU. The antitumoral activity of bromelain against S-37 and EAT, which are tumor models sensitive to immune system mediators, and the unchanged tumor progression in the metastatic model suggests that the antimetastatic action results from a mechanism independent of the primary antitumoral effect.
TL;DR: DNA harvested from cancer cell cultures treated with Sonoran propolis exhibited a ladder of internucleosomal DNA cleavage characteristic of apoptosis, and propolis constituents CAPE, galangin, xanthomicrol and chrysin showed significant antiproliferative activity on most of the cancer cells tested.
Abstract: In this study, we have analyzed the chemical composition and antiproliferative activity of propolis from three different arid and semiarid regions of Sonora, Mexico. We identified and quantitated the main chemical constituents of propolis by HPLC-MS. The most abundant constituents of propolis were pinocembrin, pinobanksin 3-acetate, and chrysin. Sonoran propolis had a strong antiproliferative activity on both murine and human cancer cell lines in a concentration-dependent manner. The propolis constituents CAPE, galangin, xanthomicrol and chrysin showed significant antiproliferative activity on most of the cancer cells tested. DNA harvested from cancer cell cultures treated with Sonoran propolis exhibited a ladder of internucleosomal DNA cleavage characteristic of apoptosis. In summary, we have identified and quantitated the main constituents of Sonoran propolis. These propolis samples possess a strong antiproliferative activity on cancer cell lines.
TL;DR: The results of this study suggest that vascular smooth muscle is the major site of these hypotensive effects of both AP3 and A.paniculata extracts, and the consumption of A. paniculata products containing high levels of AP3 may be responsible for causing hypotension in some patients taking this herbal drug.
Abstract: Andrographis paniculata has been widely used as a traditional medicine for the treatment of common cold, diarrhea and hypertension. The three major active diterpenoids are andrographolide (AP1), 14-deoxy-11,12-didehydroandrographolide (AP3) and neoandrographolide (AP4). It has been reported that AP3 has hypotensive and vasorelaxation effects. However, there is only limited information on the cardiovascular effects of the other diterpenoids and crude extracts containing different levels of AP3. Therefore, the present study investigated the effects of these diterpenoids, AP1, AP3, and AP4, isolated from A. paniculata, and different aqueous plant extracts on blood pressure, vascular and chronotropic responses by using conscious rats and their isolated aortas and right atria as the test models. Among the three major diterpenoids, AP3 was the most potent compound for inducing vasorelaxation and decreasing heart rate. In addition, Extract B (high level of AP3) had greater hypotensive effect in conscious rats than Extract A (low level of AP3). Verapamil, a Ca2+ channel blocker, also had a hypotensive effect less than that of Extract C containing a high level of AP3. At the doses and durations of Extract A and B which produced hypotension, the responses of the Extract A-treated aorta to norepinephrine, and the vascular muscarinic responses to acetylcholine of both extracts were decreased. However, repeated doses of both extracts did not alter cardiac beta-adrenoceptor and muscarinic responses of extract-treated rats to NE and ACh, respectively. The results of this study suggest that vascular smooth muscle is the major site of these hypotensive effects of both AP3 and A. paniculata extracts. Furthermore, the consumption of A. paniculata products containing high levels of AP3 may be responsible for causing hypotension in some patients taking this herbal drug.
TL;DR: The phytochemical investigation of the acetone and methanol extracts of the flowers of Magydaris tomentosa (Desf.) DC afforded six known coumarins as well as (+)-meranzin hydrate, not previously reported as a natural product, which inhibited growth of all bacterial strains tested.
Abstract: The phytochemical investigation of the acetone and methanol extracts of the flowers of Magydaris tomentosa (Desf.) DC afforded six known coumarins as well as (+)-meranzin hydrate (7), not previously reported as a natural product. The antibacterial activity of umbelliprenin (1), osthol (2), imperatorin (3), citropten (4) and (+)-meranzin hydrate (7) was tested against Gram-positive and Gram-negative bacteria. All coumarins (1-7) isolated in this study inhibited growth of all bacterial strains tested (MIC between 16 and 256 microg/mL), the most active being imperatorin (3) (MICs between 32 and 128 microg/mL) and citropten (4) (MICs between 16 and 256 microg/mL). The anticoagulant activity of compounds 1-4 and 7 was also evaluated.
TL;DR: It was showed that osthole not only promoted the proliferation and activity of alkaline phosphatase of osteoblasts in neonatal calvaria cultures, but also inhibited the bone resorption by decreasing the formation, differentiation and TRAP activity of osteoclasts derived from rat marrow cells.
Abstract: Bioactivity-guided fractionation has led to the successful isolation of antiosteoporotic components, i. e., osthole, imperatorin and bergapten from an ethanolic extract of the fruits of Cnidium monnieri (L.) Cusson. Among them, osthole was determined as the major compound possessing antiosteoporotic activity. Further study showed that osthole not only promoted the proliferation and activity of alkaline phosphatase of osteoblasts in neonatal calvaria cultures, but also inhibited the bone resorption by decreasing the formation, differentiation and TRAP activity of osteoclasts derived from rat marrow cells.
TL;DR: This review focuses on natural compounds which have been demonstrated to inhibit the enzyme itself or its release from neutrophils, and some of the natural compounds discussed here may serve as lead structures suitable for the development of semi-synthetic inhibitors.
Abstract: The imbalance between human neutrophil elastase (HNE) and endogenous serine proteinase inhibitors is considered to cause a variety of HNE-mediated inflammatory disorders. Thus, HNE has been the object of intensive research to find potent inhibitors that target its destructive and pro-inflammatory action. This review focuses on natural compounds which have been demonstrated to inhibit the enzyme itself or its release from neutrophils. Some of the natural compounds discussed here may serve as lead structures suitable to be used for the development of semi-synthetic inhibitors, but up to now none has been found active enough to be directly used in therapy.
TL;DR: It is suggested that gastrodin has a neuroprotective action against hypoxia in the cultured cortical neuron, and the mechanism may involve a decreasing of the extracellular glutamate level.
Abstract: The phenolic glucoside gastrodin is the main component extracted from the rhizome of Gastrodia elata (Orchidaceae), a Chinese herbal medicine, which has long been used for treating dizziness, epilepsy, stroke and dementia. The present study aims to investigate the effect of gastrodin on hypoxia-induced neurotoxicity in cultured rat cortical neurons. Neuron survival and extracellular glutamate level were measured after an insult by hypoxia. Glutamate concentrations were determined by an HPLC-ECD system. The results demonstrated that neurons were significantly damaged by hypoxia for 24 h. When pretreated with gastrodin (100, 200 microg/mL) in hypoxia, neuron survival was significantly increased compared with no gastrodin treatment. Moreover, the enhancement of extracellular glutamate level stimulated by hypoxia was inhibited by pretreatment with gastrodin (100 microg/mL). Further studies demonstrated that gastrodin prevented glutamate- and NMDA-induced neurotoxicity. In addition, gastrodin also inhibited the extracellular glutamate level induced by NMDA insult. These findings suggest that gastrodin has a neuroprotective action against hypoxia in the cultured cortical neuron, and the mechanism may involve a decreasing of the extracellular glutamate level.
TL;DR: Evidence is provided that mangiferin affords gastroprotection against gastric injury induced by ethanol and indomethacin most possibly through the antisecretory and antioxidant mechanisms of action.
Abstract: In search of novel gastroprotective agents, mangiferin, a naturally occurring glucosylxanthone from Mangifera indica L. (Anacardiaceae), was evaluated in mice on gastric injury induced by ethanol and indomethacin. The effects of mangiferin on gastric mucosal damage were assessed by determination of changes in mean gastric lesion area or ulcer score in mice and on gastric secretory volume and total acidity in 4-h pylorus-ligated rats. Mangiferin (3, 10 and 30 mg/kg, P. O.) significantly attenuated the gastric damage induced by ethanol by 30, 35, and 63 %, and of indomethacin by 22, 23 and 57 %, respectively. N-Acetylcysteine (750 mg/kg, I. P.) and lansoprazole (30 mg/kg, P. O.) used as positive controls in these ulcerogenic models resulted in 50 % and 76 % suppression of gastric injury, respectively. In 4-h pylorus-ligated rats, intraduodenally applied mangiferin (30 mg/kg) caused significant diminutions in gastric secretory volume and total acidity. In addition, like N-acetylcysteine, a donor of sulfhydryls, mangiferin effectively prevented the ethanol-associated depletion of gastric mucosal non-protein sulfhydryl content in mice, suggesting an antioxidant action. These findings provide evidence that mangiferin affords gastroprotection against gastric injury induced by ethanol and indomethacin most possibly through the antisecretory and antioxidant mechanisms of action.
TL;DR: A hybrid chromatographic/precipitative technique was developed, whereby mixtures were chromatographed at high concentrations so as to induce formation of a precipitate in the column fractions, yielding samples that were more enriched in the desired compounds than would be obtained solely by the Chromatographic steps alone.
Abstract: Extracts of milk thistle ( Silybum marianum, Asteraceae), termed "silymarin," are used worldwide, primarily for hepatoprotective applications and recently for prostate cancer chemoprevention. Silymarin is a mixture of at least eight compounds, and four major constituents are a group of structurally related flavonolignans: silybin A, silybin B, isosilybin A, and isosilybin B. The initiation of IN VIVO studies to compare the respective preclinical activities of each compound required that gram quantities of these diastereoisomers be prepared. Procedures were developed and optimized to produce multigram-scale quantities of each of these in > 97 % purity. A hybrid chromatographic/precipitative technique was developed, whereby mixtures were chromatographed at high concentrations so as to induce formation of a precipitate in the column fractions, yielding samples that were more enriched in the desired compounds than would be obtained solely by the chromatographic steps alone.
TL;DR: It was concluded that salvipisone and aethiopinone synergized the action of beta-lactam antibiotics towards MRSA and MRSE probably by alteration of cell surface hydrophobicity and cell wall/membrane permeability, but not by changing penicillin-binding protein, PBP2a expression andpenicillinase production or by direct binding to the cell wall peptidoglycan and teichoic acids.
Abstract: Two diterpenoids, salvipisone (Salv) and aethiopinone (Aeth), isolated from hairy roots of Salvia sclarea, were tested with respect to their activity against methicillin-resistant Staphylococcus aureus (MRSA) and S. epidermidis (MRSE) strains, cultured as planktonic cells or as adherent biofilms. The standard CLSI method, MTT reduction assay or confocal laser scanning microscopy (CLSM) were used for this purpose and also applied for testing the susceptibility to oxacillin, vancomycin, linezolid and their potential synergy with diterpenoids (evaluated as a fractional inhibitory concentration (FIC) index). Salv and Aeth were shown to be bactericidal or bacteriostatic against S. aureus and S. epidermidis planktonic cultures. Both diterpenoids, at the concentrations of 1/2 MIC, showed synergy with antibiotics representing the beta-lactam, glycopeptide and oxazolidinone groups. None of the antibiotics used at a high concentration killed the staphylococcal biofilms. On the contrary, Salv and Aeth decreased the number of live biofilm cells by 45.7 - 77.1% and slightly reduced the biofilm inhibitory concentration of oxacillin. Diterpenoids also changed the parameters of biofilm morphology, as shown by the CLSM image processing package (PHLIP). It was concluded that salvipisone and aethiopinone (relatively highly lipophilic, log P respectively = 3.4; 4.8) synergized the action of beta-lactam antibiotics towards MRSA and MRSE probably by alteration of cell surface hydrophobicity and cell wall/membrane permeability, but not by changing penicillin-binding protein, PBP2a expression and penicillinase production or by direct binding to the cell wall peptidoglycan and teichoic acids.
TL;DR: Salvinorin A seems to be the most promising approach to new treatment options for a variety of CNS illnesses, however, many further investigations are necessary to fully understand and elucidate the various medicinal properties of the plant itself and to provide the legislative authorities with enough information to cast judgement on S. divinorum.
Abstract: SALVIA DIVINORUM L. (Lamiaceae) has been used for centuries by the Mazatecan culture and has gained popularity as a recreational drug in recent years. Its potent hallucinogenic effects seen in case reports has triggered research and led to the discovery of the first highly selective non-nitrogenous κ opioid receptor agonist salvinorin A. This review critically evaluates the reported pharmacological and toxicological properties of S. DIVINORUM and one of its major compounds salvinorin A, its pharmacokinetic profile, and the analytical methods developed so far for its detection and quantification. Recent research puts a strong emphasis on salvinorin A , which has been shown to be a selective opioid antagonist and is believed to have further beneficial properties , rather than the leaf extract of S. DIVINORUM. Currently animal studies show a rapid onset of action and short distribution and elimination half-lives as well as a lack of evidence of short- or long-term toxicity. Salvinorin A seems to be the most promising approach to new treatment options for a variety of CNS illnesses. However, many further investigations are necessary to fully understand and elucidate the various medicinal properties of the plant itself and to provide the legislative authorities with enough information to cast judgement on S. DIVINORUM. CNS: central nervous system FST: forced swimming test I. T.: intrathecal KOR: kappa opioid receptor LSD: lysergic acid diethylamide norBNI: norbinaltorphimine P. O.: per os S. C.: subcutaneous ssp.: subspecies