Saponins and flavonoid glycosides from the leaves of Ziziphus mauritiana Lam. native of a forest area of Ivory Coast

International audienceZiziphus mauritiana Lam (Rhamnaceae) is traditionally used in the treatment of various ailments. The aim of the present study is to identify the major compounds of the methanol extract of the leaves of Ziziphus mauritiana growing in Ivory Coast. The methanol extract of this plant was purified by combining silica gel and RP18 HPLC to give an undescribed compounds, 6’’’-O-malonyl-ziziphus saponin I (1) along with nine known compounds from which two saponins, six flavonoids, and one chalcone derivate.The structures of these compounds were elucidated by analysis of 1D- and 2D-NMR spectroscopic data and mass spectrometry (HR-ESI-MS). A part from zizyphus saponin I (2), all the others compounds were isolated for the first time from the leaves of this species

Phytothérapie traditionnelle des conjonctivites en milieu urbain ivoirien : enquête sur les deux marchés aux plantes médicinales d’Abidjan

National audienceA semi-directed ethnobotanic survey of the traditional treatment of ophthalmic diseases was conducted among the medicinal plant retailers in the markets of Adjamé and Abobo, in the District of Abidjan (Côte d’Ivoire). Seventeen female informers from five ethnic groups (mostly Baoulé and Malinké), aged from 20 to 60 years (mean 39.1 years) were interviewed about their knowledge of eye diseases. ‘Conjunctivitis’ and ‘redness of the eye’ were frequently cited, sometimes with a precise traditional definition of the ailment (‘koko’, possibly corresponding to allergic conjunctivitis; ‘apollo’, for viral conjunctivitis). Phytotherapy is largely used to treat these specific ailments and symptoms of conjunctivitis: each informer cited an average of five plant species, with no obvious differences related to ethnic origin. Overall, 44 plant parts from 36 species, belonging to 26 botanical families, among which six were from the Fabaceae, were cited (Table 1). These plants were mostly Fabids and Malvids (Figure 2), in contrast with those used in Europe. Disparate phytotherapeutic uses were found (19 plants, i.e. 54%, were cited only once), but consensus existed for several species, the most cited being Ocimum gratissimum (Lamiaceae; 14 citations, 82% of informers), Dissotis rotundifolia (Melastomataceae; 11 citations), Kalanchoe crenata (Crassulaceae; eight citations), Desmodium adscendens (Fabaceae; five citations), Combretum paniculatum (Combretaceae), Manotes longiflora (Connaraceae), Adenia lobata (Passifloraceae) and Phyllanthus muellerianus (Phyllanthaceae) - all four citations each. Several of these plants had been inventoried in the 1970s, have convergent uses in neighbouring countries [e.g. O. gratissimum, Nauclea latifolia (Rubiaceae)], and/or constitute ‘classical’ plants of the Ivorian popular pharmacopoeia [Spondias mombin (Anacardiaceae), Abrus precatorius (Fabaceae), O. gratissimum, Zanthoxylum zanthoxyloides (Rutaceae)]. Interestingly, their main traditional therapeutic indications, as softeners in sore throats or for antiseptic purposes, can be regarded as evocative of the uses inventoried here. Leaves are used in 64.0% of cases. Roots and flowers are poorly (4.4%) and never cited, respectively. Direct use of latex or of sap was mentioned three times (3.7%). Half of the uses of leaves are performed in a fresh form, as expressed juice. Decoction is, however, the main mode of preparation (56%), the extracts being kept for 3–5 days. These traditional herbal drugs are used as ocular instillations or as an eye bath, and less frequently for face wash (Figure 3). We hypothesized that uses of plants in conjunctivitis could be linked to antiseptic potential, in order to treat the infectious condition, to prevent infection of the injured eye, or to allow conservation of traditional preparations. To test this hypothesis, all plants were harvested in their natural habitats. Aqueous and methanol extracts of dried material were screened for antimicrobial activity, by dilution in solid culture medium, against six bacterial species responsible for ocular infections (Gram-negative bacilli: Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa; Gram-positive cocci: Enterococcus hirae, Staphylococcus aureus, Staphylococcus epidermidis). 52.3% of the extracts and 88.8% of plants inhibited bacterial growth of at least one strain (2 mg/ml, 48 h) (Table 2, Figure 5). Seven extracts were active against all bacteria [methanol extracts of Hibiscus asper (Malvaceae), Hoslundia opposita (Lamiaceae), O. gratissimum, S. mombin, Vitellaria paradoxa (Sapotaceae) and Z. zanthoxyloides (bark); aqueous extracts of Piliostigma thonningii (Fabaceae) and S. mombin]. However, there was no correlation between the displayed spectra and the frequencies of citation, except for O. gratissimum, a readily available species for which the antibacterial potential and safety have been largely studied. In contrast, some poorly cited species are known, or can be suspected, to be toxic, as reported in the literature. From a general point of view, investigation of the benefit/risk ratio of these widespread ocular traditional practices should be pursued for promotion and valorization of safe primary care remedies among the inhabitants of Abidjan.Une enquête ethnobotanique semi-dirigée, focalisée sur le traitement traditionnel des ophtalmies, a été menée auprès de 17 vendeuses de plantes médicinales, issues d’ethnies diverses, installées sur les marchés d’Adjamé et d’Abobo, communes du District d’Abidjan (Côte d’Ivoire). Les pathologies oculaires prises en charge sont notamment les conjonctivites telles que le koko ou l’apollo. Les vendeuses citent chacune, en moyenne, l’emploi de cinq plantes utilisées dans ces affections. 44 drogues végétales issues de 36 plantes appartenant à 26 familles botaniques ont été recensées et identifiées. Leur emploi se fait à l’état sec ou frais, sous forme de décoction ou de jus exprimé, pour instillation ou bain oculaire et parfois lavage du visage. Les espèces les plus citées sont Ocimum gratissimum L. (Lamiaceae), Dissotis rotundifolia (Sm.) Triana (Melastomataceae) et Kalanchoe crenata (Andrews) Haw. (Crassulaceae). Les plantes ont été récoltées et l’activité antibactérienne d’extraits aqueux et méthanoliques préparés à partir des drogues végétales sèches a été évaluée vis-à-vis de six espèces bactériennes couramment responsables d’infections oculaires. Les résultats de ce criblage ne montrent pas de corrélation avec la fréquence de citation des espèces