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

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

Étude ethnobotanique des plantes médicinales commercialisées dans les marchés de la ville de Douala, Cameroun

Objectif: L’objectif de cette étude est d’inventorier et d’identifier les vertus thérapeutiques des plantes médicinales commercialisées dans la ville de Douala (Cameroun).Méthodologie et résultats: Des enquêtes ethnobotaniques ont été conduites de juillet à août 2012, auprès de 54 herboristes dans cinq marchés en utilisant des interviews directes et semi-structurées. L’étude a permis d’identifier 84 espèces réparties en 78 genres et 50 familles dont les plus représentées ont été les Asteraceae (9 espèces), Fabaceae (6 espèces) et Lamiaceae (4 espèces). Les troubles infectieux (66,7 %) et gynécoobstétriques et urologiques ont été majoritairement représentés. La recherche du degré de consensus (ICF) révèle que 3 catégories ont atteint des valeurs élevées : les troubles asthéniques (0,8), dermatologiques (0,6), gynéco-obstétriques et urologiques (0,5).Conclusion et application des résultats: Cette étude montre l’importance des enquêtes ethnobotaniques dans la phytothérapie et les limites des herboristes de la pharmacopée traditionnelle.Mots clés: Ethnobotanique, plantes médicinales commercialisées, maladiesEnglish AbstractObjective: The objective of this study was to make an inventory and to identify therapeutic properties of medicinal plants sold in the city of Douala (Cameroon).Methodology and Results: Ethnobotanical surveys were conducted from July to August 2012 beside 54 herbalists in five markets using direct and semi-structured interviews. The study identified 84 species distributed in 78 genera and 50 families, the most represented were Asteraceae (9 species), Fabaceae (6 species) and Lamiaceae (4 species). Infectious disorders (66.7%) and gyneco-obstetrical and urological disorders were mostly represented. Research on the degree of consensus (ICF) reveals that three categories reached high values: asthenic (0.8), skin (0.6), gyneco-obstetrical and urological (0.5) disorders.Conclusion and applications of results: This study shows the importance of ethnobotanical surveys in herbal medicine and limitations of herbalists of traditional medicine.Keys: Ethnobotany, sold medicinal plants, disease

Kaurane diterpenes from the fruits of Zanthoxylum leprieurii (Rutaceae)

Abstract: The fruits of Zanthoxylum leprieurii Guill. & Perr. (Rutaceae) are traditionally used in Africa, particularly in Cameroon, as a spice and in the treatment of sickle cell anaemia. Phytochemical investigation on the fruits of this plant afforded five kaurane diterpenes, i.e., kaurenoic acid (1), xylopic acid (2), ent-kauran-16β-ol (3), ent-16β-hydroxykauran-19-al (4) and ent-16β-hydroxykauran-19-oic acid (5). The structures of these diterpenes were determined comprehensively by spectroscopic means (1D and 2D NMR spectroscopy and MS analyses) and also by comparison with respective literature data. Among the isolated compounds, only kaurenoic acid (1) exhibited cytotoxicity against the PC3 cell line with an IC50 value of 33.28 ± 9.14 μg/mL. To the best of our knowledge, this is the first report on the isolation of these kaurane diterpenes (1-5) from the genus Zanthoxylum

Cytotoxicity of the Roots of Trillium govanianum Against Breast (MCF7), Liver (HepG2), Lung (A549) and Urinary Bladder (EJ138) Carcinoma Cells.

Trillium govanianum Wall. (Melanthiaceae alt. Trilliaceae), commonly known as 'nag chhatri' or 'teen patra', is a native species of the Himalayas. It is used in various traditional medicines containing both steroids and sex hormones. In folk medicine, the rhizomes of T. govanianum are used to treat boils, dysentery, inflammation, menstrual and sexual disorders, as an antiseptic and in wound healing. With the only exception of the recent report on the isolation of a new steroidal saponin, govanoside A, together with three known steroidal compounds with antifungal property from this plant, there has been no systematic pharmacological and phytochemical work performed on T. govanianum. This paper reports, for the first time, on the cytotoxicity of the methanol extract of the roots of T. govanianum and its solid-phase extraction (SPE) fractions against four human carcinoma cell lines: breast (MCF7), liver (HEPG2), lung (A549) and urinary bladder (EJ138), using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide cytotoxicity assay and liquid chromatography and electrospray ionization quadrupole time-of-flight mass spectrometry analysis of the SPE fractions. The methanol extract and all SPE fractions exhibited considerable levels of cytotoxicity against all cell lines, with the IC50 values ranging between 5 and 16 µg/mL. Like other Trillium species, presence of saponins and sapogenins in the SPE fractions was evident in the liquid chromatography mass spectrometry data. Copyright © 2016 John Wiley & Sons, Ltd