Showing papers in "Planta Medica in 2002"
TL;DR: The most important alkaloids produced by hairy roots are summarised and several different methods have been used to increase the alkaloid accumulation in hairy root cultures.
Abstract: Hairy roots, transformed with Agrobacterium rhizogenes, have been found to be suitable for the production of secondary metabolites because of their stable and high productivity in hormone-free culture conditions. A number of plant species including many medicinal plants have been successfully transformed with Agrobacterium rhizogenes. Transformed root cultures have also been found to be a potential source of high-value pharmaceuticals. In this article the most important alkaloids produced by hairy roots are summarised. Several different methods have been used to increase the alkaloid accumulation in hairy root cultures. The selection of high productive root lines based on somaclonal variation offers an interesting option to enhance the productivity. Elicitors and modification of culture conditions have been shown to increase the growth and the alkaloid production in some cases. Genetic engineering is a modern tool to regulate the secondary metabolism also in hairy roots. However, our knowledge on biosynthesis of many alkaloids is still poor. Only a limited number of enzymes and their respective genes which regulate the biosynthetic pathways are fully characterised.
283 citations
TL;DR: The results indicate that the MTT tetrazolium assay may lead to false positive results when testing natural compounds with intrinsic reductive potential whenTesting the effects of kaempferol on breast cancer cell number and viability and conflicting results were obtained.
Abstract: The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay is a widely used screening method to measure cell viability and proliferation. When testing the effects of kaempferol on breast cancer cell number (crystal violet staining) and viability (MTT tetrazolium assay) conflicting results were obtained. Cell number decreased but MTT formazan formation increased, suggesting a direct interaction of kaempferol with the MTT tetrazolium reduction. Direct reductive potential was observed in a cell-free system for the presumptive phytoestrogens kaempferol and resveratrol, and extracts of Hypericum perforatum L. and Cimicifuga racemosa L. All agents led to instantaneous dark blue formazan formation in the absence of cells. Additionally, antioxidants such as ascorbic acid, vitamin E and N-acetylcysteine interfered with the MTT tetrazolium assay. When MCF7 and HS578 cells treated with kaempferol were washed before addition of MTT tetrazolium, the direct reduction of dye was reduced significantly. These results indicate that the MTT tetrazolium assay may lead to false positive results when testing natural compounds with intrinsic reductive potential.
268 citations
TL;DR: It is suggested that the potent superoxide anion scavenging activity of isorabaichromone may have been due to its caffeoyl group, which may explain, at least in part, the wound healing effects of A.vera.
Abstract: Antioxidant components in Aloe vera were examined for lipid peroxidation using rat liver microsomal and mitochondrial enzymes. Among the aloesin derivatives examined, isorabaichromone showed a potent antioxidative activity. The DPPH radical and superoxide anion scavenging activities were determined. As one of the most potent components, isorabaichromone together with feruloylaloesin and p-coumaroylaloesin showed potent DPPH radical and superoxide anion scavenging activities. Electron spin resonance (ESR) using the spin trapping method suggested that the potent superoxide anion scavenging activity of isorabaichromone may have been due to its caffeoyl group. As A. vera has long been used to promote wound healing, the inhibitory effects of aloesin derivatives for cyclooxygenase (Cox)-2 and thromboxane (Tx) A 2 synthase were examined and the participation of p-coumaroyl and feruloyl ester groups in the aloesin skeleton was demonstrated. These findings may explain, at least in part, the wound healing effects of A.vera. Abbreviations. ADP:adenosine diphosphate ASA:ascorbic acid BHT:butylated hydroxytoluene BSA:bovine serum albumin DMPO:5,5-dimethyl-1-pyrroline N-oxide DPPH:1,1-diphenyl-2-picrylhydrazyl EDTA:edetic acid HEPES: N-(2-hydroxyethyl)-piperazine- N-2'-ethane-sulfonic acid NADH:reduced nicotinamide adenine dinucleotide NADPH:reduced nicotinamide adenine dinucleotide phosphate NBT:nitroblue tetrazolium Pg:prostaglandin SOD:superoxide dismutase TBA:thiobarbituric acid TCA:trichloroacetic acid XOD:xanthine oxidase
213 citations
TL;DR: It is proposed that the galloyl moiety plays a major role for inhibition against the 3'-processing of HIV-1 integrase of these compounds.
Abstract: The bioassay-directed isolation of Terminalia chebula fruits afforded four human immunodeficiency virus type 1 (HIV-1) integrase inhibitors, gallic acid ( 1) and three galloyl glucoses ( 2 - 4). In addition, four flavonol glycoside gallates ( 5 - 8) from Euphorbia pekinensis containing the galloyl moiety also showed the inhibitory activity at a level comparable to those of 2 - 4. By comparison with the activities of the compounds not bearing this moiety, it is proposed that the galloyl moiety plays a major role for inhibition against the 3'-processing of HIV-1 integrase of these compounds.
162 citations
TL;DR: The results have shown that one of the xanthone derivatives which could be identified as garcinone E has potent cytotoxic effect on all HCC cell lines as well as on the other gastric and lung cancer cell lines included in the screen.
Abstract: Treatment of hepatocellular carcinomas (HCCs) with chemotherapy has generally been disappointing and it is most desirable to have more effective new drugs. We extracted and purified 6 xanthone compounds from the rinds (peel) of the fruits of Garcinia mangostana L., using partitioned chromatography and then tested the cytotoxic effects of these compounds on a panel of 14 different human cancer cell lines including 6 hepatoma cell lines, based on the MTT method. Several commonly used chemotherapeutic agents were included in the assay to determine the relative potency of the potential new drugs. Our results have shown that one of the xanthone derivatives which could be identified as garcinone E has potent cytotoxic effect on all HCC cell lines as well as on the other gastric and lung cancer cell lines included in the screen. We suggest that garcinone E may be potentially useful for the treatment of certain types of cancer.
156 citations
TL;DR: The antimalarial and toxicological properties of four tetrahydroquinoline alkaloids from Galipea officinalis trunk bark were studied and cytotoxicity of the extracts and pure alkaloid was assessed on the HeLa cell line and showed IC50 values ranging from 5.8 to above 50 microg/ml.
Abstract: The antimalarial and toxicological properties of four tetrahydroquinoline alkaloids from Galipea officinalis trunk bark were studied. Crude extracts and pure alkaloids were tested for in vitro antimalarial activity on Plasmodium falciparum. The IC50 were evaluated after 24 and 72 h contact between compounds and the parasite culture, and ranged from 1.8 to 40 microg/ml for the chloroquine-sensitive strain (CQS) and from 0.09 to 38 microg/ml for the chloroquine-resistant strains (CQR). Galipinine yielded the best antimalarial effect (IC50: 0.09 - 0.9 microg/ml on CQR strain) and this compound interacted particularly between the 32(nd) and the 40(th) hour of the P. falciparum erythrocytic cycle. The cytotoxicity of the extracts and pure tetrahydroquinoline alkaloids was assessed on the HeLa cell line and showed IC50 values ranging from 5.8 to above 50 microg/ml.
156 citations
TL;DR: A survey of published data regarding the microbial contamination of herbal plants is given, by dealing with methodological aspects and by considering the influence of different commonly used pharmaceutical preparation techniques on the microbiological status of the products are discussed.
Abstract: Medicinal plants may be associated with a broad variety of microbial contaminants, which are represented by bacteria, fungi and viruses. Inevitably, this microbiological background depends on several environmental factors and exerts an important impact on the overall quality of herbal products and preparations. Risk assessment of the microbial load of medicinal plants has therefore become an important subject in the establishment of modern Hazard Analysis and Critical Control Point (HACCP) schemes. This study intends to contribute to this knowledge by giving a survey of published data regarding the microbial contamination of herbal plants, by dealing with methodological aspects and by considering the influence of different commonly used pharmaceutical preparation techniques on the microbiological status of the products. Finally, quality standards are discussed, which could be considered for guidelines and/or possible inclusion in the Ph.Eur. 2000.
152 citations
TL;DR: The data indicate that the hypoglycemic effect of NSO may be mediated by extrapancreatic actions rather than by stimulated insulin release, and the direct antidiabetic effect of Nigella sativa is not yet established.
Abstract: A plant mixture containing extracts of Nigella sativa possesses blood glucose lowering effects, but the direct antidiabetic effect of Nigella sativa is not yet established. Therefore, the effect of Nigella sativa oil (NSO) on blood glucose concentrations was studied in streptozotocin diabetic rats. In addition, the effect of NSO, nigellone and thymoquinone were studied on insulin secretion of isolated rat pancreatic islets in the presence of 3, 5.6 or 11.1 mM glucose. NSO significantly lowered blood glucose concentrations in diabetic rats after 2, 4 and 6 weeks. The blood lowering effect of NSO was, however, not paralleled by a stimulation of insulin release in the presence of NSO, nigellone or thymoquinone. The data indicate that the hypoglycemic effect of NSO may be mediated by extrapancreatic actions rather than by stimulated insulin release.
150 citations
TL;DR: It appears vital that extracts of St. John's wort which are designed for the therapy of depressive disorders should be manufactured using plant material with sufficient amounts of rutin, as first experiments suggest that this re-activation is not dose-dependent, indicating that r Rutin must be present above a threshold limit.
Abstract: It has been shown that aqueous alcoholic extracts of Hypericum perforatum (St. John's wort) are active in the forced swimming test (FST), an animal model for antidepressant activity. In this study, a series of ethanolic and methanolic extracts were investigated and, in almost all cases, the extracts showed strong activity. Only one methanolic research extract had no effect in the in vivo pharmacological experiments. Analytical characterisation using HPLC showed that the inactive extract had a reduced level of the diglycoside flavonoid rutin. Addition of rutin to the inactive extract, to produce a concentration within the normal range, resulted in a strong pharmacological effect comparable to that of the other extracts. First experiments suggest that this re-activation is not dose-dependent, indicating that rutin must be present above a threshold limit. It therefore appears vital that extracts of St. John's wort which are designed for the therapy of depressive disorders should be manufactured using plant material with sufficient amounts of rutin.
143 citations
TL;DR: In this review both simple assays on blood glucose (after or without a glucose load), plasma insulin and extrapancreatic effects] are described as well as specific in vivo tests in diabetic animals and in vitro tests with respect to the mechanism of compounds.
Abstract: Diabetic disease is increasing rapidly and vast amounts of resources are spent in all countries. Thus, the screening of new compounds including plant extracts for antidiabetic effects is mandatory. In this review both simple assays [e.g., on blood glucose (after or without a glucose load), plasma insulin and extrapancreatic effects] are described as well as specific in vivo tests in diabetic animals and in vitro tests with respect to the mechanism of compounds. In total, approx. 30 selected tests are evaluated and references are given. Thus, the investigator is guided through the tests and is advised that measuring only one parameter such as glucose will not be sufficient. In the case that the financial resources are poor for the investigator, more than glucose still has to be measured. A balance is made by describing absolutely necessary investigations while concentrating on those at low cost. It has to be started with simple assays; to use one test only, however, means oversimplifying the diabetes disease; additionally antidiabetic effects may be missing. The investigator is guided through the advantages and limitations of diabetic animal models and is advised about specific in vitro tests to look at the mechanism of action. All investigators should profit from these details, not only the phytoresearchers.
134 citations
TL;DR: Chemical investigation of the EtOH extract of Morus alba L. (Moraceae), as guided by free radical scavenging activity, furnished 5,7-dihydroxycoumarin 7-methyl ether, which showed hepatoprotective effects with EC(50) values of 10.3 +/- 0.62 micro, on tacrine-induced cytotoxicity in human liver-derived Hep G2 cells.
Abstract: Chemical investigation of the EtOH extract of Morus alba L. (Moraceae), as guided by free radical scavenging activity, furnished 5,7-dihydroxycoumarin 7-methyl ether (1), two prenylflavones, cudraflavone B (2) and cudraflavone C (3), and oxyresveratrol (4). Compounds 1 and 4 showed superoxide scavenging effects with the IC(50) values of 19.1 +/- 3.6 and 3.81 +/- 0.5 microM, respectively. Compound 4 exhibited a DPPH free radical scavenging effect (IC(50) = 23.4 +/- 1.5 microM). Compounds 2 and 4 showed hepatoprotective effects with EC(50) values of 10.3 +/- 0.42 and 32.3 +/- 2.62 micro, respectively, on tacrine-induced cytotoxicity in human liver-derived Hep G2 cells.
TL;DR: The antimalarial properties of Tithonia diversifolia, an Asteraceae traditionally used to treat malaria, were investigated in vitro against three strains of Plasmodium falciparum, demonstrating good antiplasmodial activity and cytotoxic properties.
Abstract: The antimalarial properties of Tithonia diversifolia, an Asteraceae traditionally used to treat malaria, were investigated in vitro against three strains of Plasmodium falciparum. The ether extract from aerial parts of the plant collected in Sao Tome e Principe, demonstrated good antiplasmodial activity (IC 50 on FCA strain: 0.75 microg/ml). A bioassay guided fractionation of this extract led to the isolation of the known sesquiterpene lactone tagitinin C as an active component against Plasmodium (IC 50 on FCA strain: 0.33 microg/ml), but also possessing cytotoxic properties (IC 50 on HTC-116 cells: 0.706 microg/ml).
TL;DR: During a re-investigation of phenolic compounds from the dried crude drug material of St. John's wort, 22phenolic compounds were detected by HPLC; 14 of them were quantified using the same system and quercetin-3-O-(2"-O-acetyl)-beta-D-galactoside was identified as a new natural product.
Abstract: During a re-investigation of phenolic compounds from the dried crude drug material of St. John's wort (Hypericum perforatum L.) 22 phenolic compounds were detected by HPLC; 14 of them were quantified using the same system. Twelve phenolic compounds were isolated from the plant material and their structures identified mainly by spectroscopic methods, among them quercetin-3-O-(2"-O-acetyl)-beta-D-galactoside as a new natural product. Cryptochlorogenic acid, protocatechuic acid, 3-O-[Z]-p-coumaroylquinic acid, isoorientin, cyanidin-3-O-alpha-L-rhamnoside, and astilbin were obtained for the first time from this source; the earlier suspected neochlorogenic acid, 3-O-[E]-p-coumaroylquinic acid, mangiferin, miquelianin and guaijaverin were confirmed.
TL;DR: Bioassay-guided fractionation of an extract of Artemisia annua L. (Asteraceae) yielded the flavones chrysosplenol-D and chrysoplenetin, which themselves had very weak growth inhibitory action, but which made a potent combination with berberine, likely due to the inhibition of an S. aureus multidrug resistance (MDR) pump.
Abstract: Bioassay-guided fractionation of an extract of Artemisia annua L (Asteraceae) was conducted in order to assess the possible presence in the plant material of inhibitors of bacterial multidrug resistance pumps Fractions were tested for Staphylococcus aureus growth inhibition in the presence of a subinhibitory dose of the weak antibacterial alkaloid berberine Active fractions yielded the flavones chrysosplenol-D and chrysoplenetin, which themselves had very weak growth inhibitory action, but which made a potent combination with berberine In comparison with work on other flavonols, it is likely that potentiation is due to the inhibition of an S aureus multidrug resistance (MDR) pump These same two flavonols were earlier reported to potentiate the activity of artemisinin against Plasmodium falciparum
TL;DR: Comparing the effects of the flavonoids from Scutellaria baicalensis Georgi in cultured human hepatoma cells suggested that baicalein, baicalin and wogonin might be effective candidates for inducing apoptosis or inhibiting proliferation in varioushuman hepatoma cell lines.
Abstract: The effects of the flavonoids from Scutellaria baicalensis Georgi (baicalein, baicalin and wogonin) in cultured human hepatoma cells (Hep G2, Hep 3B and SK-Hep1) were compared by MTT assay and flow cytometry. All three flavonoids dose-dependently decreased the cell viabilities accompanying the collapse of mitochondrial membrane potential and the depletion of glutathione content. However, the influence of baicalein, baicalin or wogonin on cell cycle progression was different. All three flavonoids resulted in prominent increase of G2/M population in Hep G2 cells, whereas an accumulation of sub G1 (hypoploid) peak in Hep 3B cells was observed. In SK-Hep1 cells, baicalein and baicalin resulted in dramatic boost in hypoploid peak, but wogonin made mainly in G1 phase accumulation. These data, together with the previous findings in other hepatoma cell lines, suggest that baicalein, baicalin and wogonin might be effective candidates for inducing apoptosis or inhibiting proliferation in various human hepatoma cell lines.
TL;DR: Current views of the mechanisms of fibrogenesis and recent findings on the antifibrotic potential of plant-derived antioxidants are summarized.
Abstract: There is accumulating evidence that oxidative stress plays a considerable role in the development of liver fibrosis by acting in different cell types and in different signaling pathways. Consequently, antioxidants, particularly those of plant origin, have emerged as potent antifibrotic agents. This review briefly summarizes current views of the mechanisms of fibrogenesis and recent findings on the antifibrotic potential of plant-derived antioxidants.
TL;DR: The ensemble of results indicates that FS/PME produced a more potent in vivo antioxidant action than alpha-Toc by virtue of their ability to enhance hepatic mitochondrial glutathione antioxidant status and that the differential potency of FS and PME can be attributed to the difference in in vivo antioxidants potential between Sch B and emodin.
Abstract: The in vivo antioxidant action of a lignan-enriched extract of the fruit of Schisandra chinensis (FS) and an anthraquinone-containing extract of the root of Polygonum multiflorum (PME) was compared with their respective active constituents schisandrin B (Sch B) and emodin by examining their effect on hepatic mitochondrial glutathione antioxidant status in control and carbon tetrachloride (CCl 4 )-intoxicated mice. FS and PME pretreatments produced a dose-dependent protection against CCl 4 hepatotoxicity, with the effect of FS being more potent. Pretreatment with Sch B, emodin or alpha-tocopherol (alpha-Toc) also protected against CCl 4 hepatotoxicity, with the effect of Sch B being more potent. The extent of hepatoprotection afforded by FS/Sch B and PME/emodin pretreatment against CCl 4 toxicity was found to correlate well with the degree of enhancement in hepatic mitochondrial glutathione antioxidant status, as evidenced by increases in reduced glutathione level and activities of glutathione reductase, glutathione peroxidase as well as glutathione S-transferases, in both control and CCl 4 -intoxicated mice. alpha-Toc, which did not enhance mitochondrial glutathione antioxidant status, seemed to be less potent in protecting against CCl 4 hepatotoxicity. The ensemble of results indicates that FS/PME produced a more potent in vivo antioxidant action than alpha-Toc by virtue of their ability to enhance hepatic mitochondrial glutathione antioxidant status and that the differential potency of FS and PME can be attributed to the difference in in vivo antioxidant potential between Sch B and emodin. Abbreviations. ALT:alanine aminotransferases CCl 4 :carbon tetrachloride FS:lignan-enriched extract of Schisandra fruit GRD:glutathione reductase GSH:reduced glutathione GSH-Px: Se-glutathione peroxidase GST:glutathione S-transferases mt:mitochondrial MDA:malondialdehyde PME:anthraquinone-containing fraction of Polygonum root Sch B:schisandrin B SDH:sorbitol dehydrogenase alpha-Toc:alpha-tocopherol
TL;DR: The O-glycosidic flavonoids and the oligomeric proanthocyanidins exhibited significant inhibitory activity against herpes simplex virus type 1 (HSV-1), which was shown to be due to an extracellular mechanism for procyanidin C-1.
Abstract: The antiviral and antioxidant activity of some fractions and of a series of flavonoids and proanthocyanidins obtained from Crataegus sinaica (Rosaceae) was evaluated. The O-glycosidic flavonoids and the oligomeric proanthocyanidins exhibited significant inhibitory activity against herpes simplex virus type 1 (HSV-1), which was shown to be due to an extracellular mechanism for procyanidin C-1. Procyanidin C-1 also had the highest antioxidant activity in both the microsomal lipid peroxidation and the hydroxyl radical scavenging assay. In addition to the previously reported phenolic compounds, the pentacyclic triterpenoid ursolic acid (1) and a tetrameric (2) and pentameric procyanidin (3) are reported for the first time.
TL;DR: Investigation of the fungus Chaetomium globosum KMITL-N0802 led to the isolation of a novel anthraquinone-chromanone compound named chaetomanone along with seven known compounds that exhibited activity towards Mycobacterium tuberculosis.
Abstract: Investigation of the fungus Chaetomium globosum KMITL-N0802 led to the isolation of a novel anthraquinone-chromanone compound named chaetomanone along with seven known compounds, ergosterol, ergosteryl palmitate, chrysophanol, chaetoglobosin C, alternariol monomethyl ether, echinuline and isochaetoglobosin D. These compounds were characterized by spectroscopic methods. Chaetomanone and echinulin exhibited activity towards Mycobacterium tuberculosis.
TL;DR: The effect of oleanolic acid on the growth of human immunodeficiency virus-1 in cultures of human peripheral mononuclear cells (PBMC) and of monocyte/macrophages (M/M) was described and its inhibitory activity was evaluated.
Abstract: Oleanolic acid is a triterpenoid which is quite common in nature in the form either of free acid or in triterpenoid saponin glycosides. This study describes the effect of oleanolic acid on the growth of human immunodeficiency virus-1 (HIV-1) in cultures of human peripheral mononuclear cells (PBMC) and of monocyte/macrophages (M/M). Its inhibitory activity was also evaluated on PBMC obtained from HIV-1 infected patients. Results obtained show that oleanolic acid inhibits the HIV-1 replication in all the cellular systems used (EC50 values: 22.7 microM, 24.6 microM and 57.4 microM for in vitro infected PBMC, naturally infected PBMC and M/M, respectively). As regards the mechanism of action, oleanolic acid inhibits in vitro the HIV-1 protease activity.
TL;DR: For the first time, the ability of prenylated naringenins not only to act via the estrogen receptor but also through the androgen receptor is demonstrated.
Abstract: Chemically synthesized naringenin derivatives, identical to natural occurring compounds, were tested for their estrogenic activity using two independent estrogen screening assays. Using a yeast based estrogen receptor assay, strong estrogenic activities were demonstrated for 6-(1,1-dimethylallyl)naringenin and 8-prenylnaringenin, while the parent compound naringenin did not show recognizable estrogenic activity. In MVLN cells, a bioluminescent MCF-7-derived cell line, the estrogenic activity of 8-prenylnaringenin and 6-(1,1-dimethylallyl)naringenin was detected at concentrations of 10(-6) M and 5 x 10(-6) M respectively. Naringenin demonstrated estrogenic activity but only at a concentration of 10(-5) M. These estrogenic effects are mediated by the ER, as the antiestrogen 4-hydroxytamoxifen inhibited these activities. In summary, this study provides the further confirmation that 8-prenylnaringenin demonstrates high estrogenic activity, and demonstrated for the first time for 6-(1,1-dimethylallyl)naringenin a reasonable high estrogenic activity, while naringenin exhibit low or no estrogenic activity.
TL;DR: Data indicate that licochalcone A might be of interest as a new class of antibacterial drug in the treatment of severe lung-infections.
Abstract: Licochalcone A, extracted and purified from Chinese licorice roots, showed in vitro inhibitory effect on human pathogenic Mycobacteria species and Legionella species. M. tuberculosis, M. bovis and BCG were inhibited by 20 mg/l Legionella pneumophila (serogroups 1 - 7) and L. bozemanii, L. dumoffii, L. feelei, L. longbeacheae and L. wadsworthii were inhibited by licochalcone A 1 - 4 mg/l, whereas L. gormanii and L. micdadei were inhibited by licochalcone A 500 - 1000 mg/l. These data indicate that licochalcone A might be of interest as a new class of antibacterial drug in the treatment of severe lung-infections.
TL;DR: It was shown that the inhibitory potency of 11 alpha,13-dihydrohelenalin derivatives being the main Sls in the Spanish flowers depend on their esterfication, and compounds with unsaturated acyl moieties exhibited a stronger activity in the NF-kappa B EMSA as well as in the croton oil ear test in mice than the acetate derivative.
Abstract: Phytopharmaceuticals prepared from flowerheads of Arnica montana of Spanish origin and of the new type "Arbo", which can be easily and economically cultivated, were studied for their capability to impair activation of the transcription factors NF-kappa B and NF-AT. Both proteins are responsible for the transcription of genes encoding various inflammatory mediators. Additionally, their influence on the release of the cytokines IL-1 and TNF-alpha were examined. The inhibitory activities correlate with their quantitative and qualitative content of sesquiterpene lactones (Sls). Moreover, it was shown that the inhibitory potency of 11 alpha,13-dihydrohelenalin derivatives being the main Sls in the Spanish flowers depend on their esterfication. Compounds with unsaturated acyl moieties, such as methacrylate and tiglinate, exhibited a stronger activity in the NF-kappa B EMSA as well as in the croton oil ear test in mice than the acetate derivative.
TL;DR: The results suggest that mucilage of yam tuber might play roles as antiradicals and antioxidants.
Abstract: The yam (Dioscorea batatas Decne) tuber mucilage (YTM) was extracted and partially purified by SDS and heating treatments. This purified YTM exhibited antioxidant activities in a series of in vitro tests, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (half-inhibition concentration, IC 50, was 0.86 mg/mL) and hydroxyl radical (IC 50 was 22 microg/mL) scavenging activity assays, reducing power test, anti-lipid peroxidation and anti-human low density lipoprotein peroxidation tests (IC 50 was 145.46 microg/mL) using butylated hydroxytoluene (BHT), reduced glutathione, or ascorbic acid for comparisons. With electron paramagnetic resonance (EPR) spectrometry for DPPH radical detection, the intensities of the EPR signals were decreased by the increased amounts of YTM added (IC 50 was 1.62 mg/mL). These results suggest that mucilage of yam tuber might play roles as antiradicals and antioxidants.
TL;DR: Bioassay-guided fractionation of the aqueous acetone extract of the leaves afforded three active ellagitannins, lagerstroemin, flosin B and reginin A, which could be responsible for lowering the blood glucose level.
Abstract: Glucose transport enhancers were searched for in Lagerstroemia speciosa, a Philippine local herbal medicine used for diabetes mellitus. Bioassay-guided fractionation of the aqueous acetone extract of the leaves afforded three active ellagitannins, lagerstroemin, flosin B and reginin A, identified by NMR and optical rotation. These compounds increased glucose uptake of rat adipocytes, and could be responsible for lowering the blood glucose level.
TL;DR: Baicalein, but not baicalin or wogonin, given orally at 20 mg/kg for ten days, ameliorates all the considered inflammatory symptoms of the induced colitis, such as body weight loss, blood haemoglobin content, rectal bleeding and other histological and biochemical parameters.
Abstract: The anti-inflammatory effect of three flavonoids from the root of Scutellaria baicalensis (baicalein, baicalin and wogonin) was evaluated in a murine model of acute experimental colitis induced by dextran sulfate sodium (DSS). Baicalein, but not baicalin or wogonin, given orally at 20 mg/kg for ten days, ameliorates all the considered inflammatory symptoms of the induced colitis, such as body weight loss, blood haemoglobin content, rectal bleeding and other histological and biochemical parameters. The effect of baicalein was similar to that of sulfasalazine, the reference drug given at 50 mg/kg.
TL;DR: Two new triterpenoids, guajavolide and guavenoic acid, along with one known triterpene oleanolic acid, were isolated from the fresh leaves of Psidium guajava by spectroscopic experiments, including 2D-NMR techniques.
Abstract: Two new triterpenoids, guajavolide (2 alpha,3 beta,6 beta,23-tetrahydroxyurs-12-en-28,20 beta-olide; 1) and guavenoic acid (2 alpha,3 beta,6 beta,23-tetrahydroxyurs-12,20(30)-dien-28-oic acid; 2) along with one known triterpene oleanolic acid (3) were isolated from the fresh leaves of Psidium guajava. Their structure elucidation and stereochemistry were determined by spectroscopic experiments, including 2D-NMR techniques.
TL;DR: Results suggest that isovitexin in rice may protect cells from oxidative stress and exhibited the lowest cytotoxicity toward HL-60 cells compared to the other flavonoids examined.
Abstract: The antioxidant properties of isovitexin and related flavonoids were studied. Isovitexin inhibited xanthine oxidase with an IC50 value of = 15.2 microM. The flavonoid analogues, apigenin, kaempferol, quercetin, myricetin, and genistein also inhibited xanthine oxidase with IC50 values of 0.58, 2.18, 1.09, 9.90, and 4.83 microM, respectively. Isovitexin protected DNA from the Fenton reaction-induced breakage in a dose-dependent manner with an IC50 value of 9.52 microM. Isovitexin also protected HL-60 cells from the ROS damage induced by the xanthine/xanthine oxidase reaction. Isovitexin exhibited the lowest cytotoxicity toward HL-60 cells (LD50 >400 microM) compared to the other flavonoids examined. In addition, excess hydrogen peroxide induced by cadmium in A2780 ovarian cells was significantly suppressed by isovitexin. These results suggest that isovitexin in rice may protect cells from oxidative stress.
TL;DR: The anti-trypanosomal activity of six sesquiterpene lactones against the African Trypanosoma brucei rhodesiense and American T. cruzi was investigated and helenalin type compounds may be interesting candidates for further evaluation.
Abstract: The anti-trypanosomal activity of six sesquiterpene lactones (helenalin, mexicanin I, 11alpha,13-dihydrohelenalin acetate, chamissonolide, ivalin and isoalantolactone) against the African Trypanosoma brucei rhodesiense and American T cruzi was investigated All tested compounds were found active towards both parasites, the former being generally more sensitive Helenalin was the most active compound in the series with IC50 values of 0051 and 0695 microM against T brucei rhodesiense and T cruzi, respectively The low IC50 value for T b rhodesiense indicates that helenalin type compounds may be interesting candidates for further evaluation
TL;DR: Extracts of 8 taxa of the genus Echinacea were found to have antiviral activity against Herpes simplex (HSV) virus Type I in vitro when exposed to visible and UV-A light.
Abstract: Extracts of 8 taxa of the genus Echinacea were found to have antiviral activity against Herpes simplex (HSV) virus Type I in vitro when exposed to visible and UV-A light n-Hexane extracts of roots containing alkenes and amides were more active in general than ethyl acetate extracts containing caffeic acids The most potent inhibitors of HSV were E pallida var sanguinea crude (70 % ethanol) inflorescence extract (MIC = 0026 mg/mL), cichoric acid (MIC = 0045 mg/mL) and Echinacea purpurea n-hexane root extract (MIC = 012 mg/mL)