197 research outputs found
Phytochemistry and pharmacology of the genus Drypetes: A review
Aims: Traditional medicinal use of species of the genus Drypetes is widespread in the tropical regions. The aim of this review is to systematically appraise the literature available to date on phytochemistry, ethnopharmacology, toxicology and bioactivity (in vitro and in vivo) of crude extracts and purified compounds. Ethnopharmacological relevance: Plants of the genus Drypetes (Putranjivaceae) are used in the Subsaharan African and Asian traditional medicines to treat a multitude of disorders, like dysentery, gonorrhoea, malaria, rheumatism, sinusitis, tumours, as well as for the treatment of wounds, headache, urethral problems, fever in young children, typhoid and several other ailments. Some Drypetes species are used to protect food against pests, as an aphrodisiac, a stimulant/depressant, a rodenticide and a fish poison, against insect bites, to induce conception and for general healing. This review deals with updated information on the ethnobotany, phytochemistry, and biological activities of ethnomedicinally important Drypetes species, in order to provide an input for the future research opportunities. Methods: An extensive review of the literature available in various recognized databases e.g., Google Scholar, PubMed, Science Direct, SciFinder, Web of Science, www.theplantlist.org and www.gbif.org, as well as the Herbier National du Cameroun (Yaoundé) and Botanic Gardens of Limbe databases on the uses and bioactivity of various species of the Drypetes was undertaken. Results: The literature provided information on ethnopharmacological uses of the Subsaharan African and Asian species of the genus Drypetes, e.g., Drypetes aubrévillii, D. capillipes, D. chevalieri, D. gerrardii, D. gossweileri, D. ivorensis, D. klainei, D. natalensis, D. pellegrini (all endemic to Africa) and D. roxburghii (Asian species), for the treatment of multiple disorders. From a total of 19 species, more than 140 compounds including diterpenes, sesquiterpenes, triterpenes (friedelane, oleanane, lupane and hopane-type), flavonoids, lignans, phenylpropanoids and steroids, as well as some thiocyanates, were isolated. Several crude extracts of these plants, and isolated compounds displayed significant analgesic, anthelmintic, antidiabetic, anti-emetic anti-inflammatory, antioxidant, antiparasitic, central nervous system depressant, cytotoxic, and insecticidal activities both in vitro and in vivo. Some toxicities associated with the stem, bark, seed and leaf extracts of D. roxburghii, and the flavonoid, amentoflavone, isolated from the stem extract of D. littoralis as well as D. gerrardii, were confirmed in the animal models and in the rat skeletal myoblast cells assays. As a consequence, traditional medicine from this genus should in future be applied with care. Conclusions: Plants of this genus have offered bioactive samples, both from crude extracts and pure compounds, partly validating their effectivity in traditional medicine. However, most of the available scientific litteratures lacks information on relevant doses, duration of the treatment, storage conditions and positive controls for examining bioefficacy of extract and its active compounds. Additional toxicological studies on the species used in local pharmacopeia are urgently needed to guarantee safe application due to higth toxicity of some crude extracts. Interestingly, this review also reports 10 pimarane dinorditerpenoids structures with the aromatic ring C, isolated from the species collected in Asia Drypetes littoralis (Taiwan), D. perreticulata (China), and in Africa D. gerrardii (Kenya), D. gossweileri (Cameroon). These compounds might turn out to be good candidates for chemotaxonomic markers of the genus
ANALISIS KADAR KLORIN PADA TEH CELUP BERDASARKAN WAKTU SEDUHAN
Background: Tea is the most widely consumed beverages by all levels of society because in addition to economical, tea is also thought to provide health benefits. Compounds that contribute to the health of the body such as tannins, catechins, flavanols and cafein. Along with its development era community prefers tea bag as it is easy and practical use. Without realizing it, the longer the brewed tea bag in the water substance called chlorine bleach paper contained in tea bags rather the bag of tea bags will also be dissolved.
Method: This research includes the study of laboratory experiments. Object in this study is 4 (four) brand of tea bag and then examined in a Laboratory Ambon Pattimura University Biology Education using thiosulfate titration methode.
Result: Anova and Tukey test results indicate that there are differences in the levels of chlorine-based treatment duration and type of tea steeping. The study test showed was obtained at the highest levels of chlorine treatment A1P4 (0,413 ppm) and A4P1 treatment resulted in the lowest levels of chlorine (0,058 ppm).
Conclusion: There are differences in the levels of chlorine in various brands of tea bag is Sariwangi tea, sosro tea, poci tea and tong tji tea for time 2 minutes, 4 minutes, 6 minutes and 8 minutes
Cytotoxic acridone and indoloquinazoline alkaloids from Zanthoxylum poggei
Two new alkaloids, poggeicridone (1) and 2-methoxy-7,8- dehydroruteacarpine (6), together with nine known compounds, were isolated from the dichloromethane (DCM) extract of the bark of Zanthoxylum poggei (Engl.) P. G. Waterman. The structures of all compounds were determined by comprehensive spectroscopic analyses (1D and 2D NMR and EI- and ESI–MS). Compounds 5-9 exhibited strong suppressive effects on the phagocytosis response upon activation with serum opsonized zymosan in the in vitro oxidative burst studies using whole blood. The IC50 values were in the range of 12.0–25.9 μM. These compounds displayed a moderate level of cytotoxic activity against the human Caucasian prostate adenocarcinoma cell line PC-3, with IC50 values of 15.8 and 22.1 μM (the IC50 value of the positive control standard doxorubicin was IC50 0.9 μM). All isolated compounds were also tested against plant pathogenic bacteria, fungi and oomycetes using the paper disk agar diffusion assay, resulting in no significant activities (MICs > 1 mg/mL). © 2016 Phytochemical Society of Europ
Activité antioxydante des extraits méthanoliques de Phragmanthera capitata (Loranthaceae) récoltée sur Citrus sinensis
Objectif : Évaluer les teneurs en phénols totaux et l’activité antioxydante in vitro des extraits méthanoliques de Phragmanthera capitata (Loranthaceae) utilisé traditionnellement pour le traitement de nombreuses maladies liées au stress oxydatif chez l’homme.Méthodologies et résultats : La teneur en phénols totaux a été déterminée par la méthode de Folin-Ciocalteu et l’activité antioxydante par deux méthodes : le piégeage des radicaux libres du DPPH et la réduction du fer FRAP. L’extrait méthanolique des tiges contient une teneur plus élevée en phénols totaux (445,2 mg EAA/g ES) suivi de l’haustorium (138,1 mg EAA/g ES) et des feuilles (78,6 mg EAA/g ES). La capacité de piégeage du DPPH de l’extrait des feuilles est moins active que ceux de l’haustorium et des tiges. Le pouvoir réducteur de l’extrait des tiges est élevé comparé à celui des feuilles et de l’haustorium.Conclusions et applications : L’activité antioxydante des extraits de P. capitata récoltée sur citrus sinensis mis en évidence dans cette étude pourrait justifier les usages traditionnels de cette plante afin de développer de nouveaux composés bioactifs.Mots clés : Phragmanthera capitata, phénols totaux, DPPH, FRAP, activité antioxydante, Loranthacea
Cytotoxic properties of the stem bark of Citrus reticulata Blanco (Rutaceae)
The bioassay-guided fractionation of the n-hexane extract of Citrus reticulata Blanco (Rutaceae) stem bark yielded scoparone (1), xanthyletin (2), lupeol (3), β-amyrin (4), stigmasterol (5), β-sitosterol (6) and palmitic acid. The structures of these compounds were determined by comprehensive spectroscopic analyses, i.e., 1D and 2D NMR and EI-MS, and by comparison with the reported data. Extracts, fractions and isolated compounds 1-6 were assessed for cytotoxicity by the MTT assay against three human cancer cell lines, i.e., human lung adenocarcinoma cell line A549, human breast adenocarcinoma cell line MCF7 and human Caucasian prostate adenocarcinoma cell line PC3. Significant activity of the n-hexane and the dichloromethane extracts was observed against the breast cancer cell line MCF7 with IC50s of 45.6 and 54.7 μg/mL, respectively. Moreover, the 70% ethyl acetate in n-hexane chromatographic fraction showed significant activity displaying IC50 values of 53.0, 52.4 and 49.1 μg/mL against the cancer cell lines A549, MCF7 and PC3, respectively. Encouragingly, an IC50 of 510.0 µg/mL against the human normal prostate cell line PNT2 indicated very low toxicity, and hence favourable selectivity indices for the 70% ethyl acetate in n-hexane fraction in the range of 9.6-10.4 towards cell lines A549, MCF7 and PC3. Since compounds isolated from the above fraction only delivered IC50 values in the range of 18.2-96.3, 9.2-34.1 and 7.5-97.2 μg/mL against A549, MCF7 and PC3 cell lines, respectively, synergistic action between compounds is suggested. Bioassay results valorize the anticancer effectivity of the stem bark of this plant in Cameroonian pharmacopeia
Identification and phytochemical screening of Endophytic fungi from stems of Phragmanthera capitata (Sprengel) S. Balle (Loranthaceae)
Objective: The purpose of this study was to identify some endophytic fungi, which were associated with the stems of Phragmanthera capitata (Loranthaceae), and to determine the phytochemical composition of their extracts.Methodology and results: The isolation of endophytic fungi was made on PDA medium (Potato dextrose agar) and the identification was based on macroscopic and microscopic observations of the different strains isolated and using identification keys. The qualitative phytochemical analysis of acetate ethyl extracts of the endophytes was carried out using standard procedures. Eleven fungi species belonging to 4 genera were isolated: Aspergillus (06 species), Penicillium (03), Trichoderma (01) and Fusarium (01). The phytochemical analysis revealed the presence of flavonoids, anthroquinones, tannins, phenols, steroids, coumarins and terpenoids and absence of alkaloids and saponins in all the extracts.Conclusion and application of results: The study shows that endophytic fungi of P. capitata could be a potential source of new bioactive compounds, which can be used in the fields of health and agriculture
Field opacity and practice-outcome decoupling: private regulation of labor standards in global supply chains
Although firms in diverse industries increasingly adopt private regulation of labor standards for workers in their global supply chains, growing scholarly evidence suggests that this approach has not generated sustainable improvements in working conditions for those workers. The authors draw on recent developments in institutional theory regarding the development of opaque institutional fields that cause the decoupling between practices and outcomes to develop a new explanation for the lack of sustainable improvement in labor practices in supply chains. Using qualitative and quantitative data from a global apparel supplier and a global home products retailer, they demonstrate the various ways in which opacity causes decoupling between private regulation practices of global firms and outcomes for workers in supply chains
CONSTITUENTS OFERYTHRINA SIGMOIDEA
. The study of the secondary metabolites of the chloroform extract of the stem wood of Erythrina sigmoidea afforded a new compound a -sophoradiol (1), and the known compounds: acetate of b -amyrin (2), acetate of oleanolic acid (3), n-isocosanyl-isocosanoate (4), and n-hexatetracontanol (5). Their structures were characterised by spectroscopic methods.
(Received February 12, 2001, revised July 3, 2001)
Bull.Chem.Soc.Ethiop. 2001, 15(2), 151-15
In vitro antioxidant properties and inhibitory effect of extracts and fractions of Plectranthus glandulosus leaves on copper sulfate (CuSO4)-induced oxidation in human low-density lipoprotein
Oxidation of LDL has been suggested to be an initial step in the development of atherosclerosis. This research work deals with the evaluation of antioxidant potential of Plectranthus glandulosus leaves extracts and fractions as well as its protective effects against human LDL oxidation. A preliminary quantitative phytochemical screening was carried out. Antioxidant potential was evaluated employing in vitro hydrogen peroxide, nitric oxide scavenging assays and TAOC test. The human LDL oxidation induced by CuSO4 inhibition test was also performed. Plectranthus glandulosus leaves exhibited the presence of 18.3% of saponines, 25.6% of terpenoids and 36.2% of flavonoids. EAF exhibited highest hydrogen peroxide and nitric oxide scavenger activity (IC50 13.63µg/ml and 24.59 µg/ml respectively). Ascorbic acid exhibited an IC50 value of 15.39µg/ml in hydrogen peroxide assay and 22.96 µg/ml in nitric oxide scavenging activity. EAF exhibited a higher TAOC (optical density 0.186±0.00) than that of ascorbic acid (0.162±0.001) at the concentration of 25µg/ml while at 200µg/ml N-BUTF exhibited a higher optical density (1.261±0.001) than that of ascorbic acid (1.065±0.001). EAF lengthened the lag time of the CD formation up to 150mins at the concentration 1mg/ml. TBARS formation inhibition at the concentration 0.5mg/ml, were no significant different between n-butanol (68.55%) ethyl acetate fraction (68.21%) and quercetin 67.69%). Plectranthus glandulosus is a promising prospect as an anti-atherosclerotic agent and needs a detailed study to establish the same.
Key words: Plecthrantus glandulosus; oxidation; LDL; atherosclerosis, antioxidant
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