Valorization of the essential oil from Drypetes gossweileri S. Moore (Putranjivaceae): in vitro, in vivo, and in silico nematicidal activity.

The chemical composition, insect antifeedant, in vtro/in vivo nematicidal activity, phytotoxicity, and in silico nematicidal activity of the essential oil (EO) of the African medicinal plant Drypetes gossweileri were studied. Chemical analysis using GC/MS indicated that benzyl isothiocyanate (96.23%) was the major compound, followed by benzyl cyanide (1.38%). The biocidal effects of this oil were tested against insect pests and root-knot nematodes. All the insect species tested were significantly affected by the oil according to their feeding adaptations (Spodoptera littoralis and Myzus persicae were less affected than Rhopalosiphum padi) with efficient doses (EC50) of 29.4 8.3 µg/cm2, 14.744 8.3 µg/cm2, and 8.3 µg/cm2, respectively. The oil was highly effective against juveniles J2 of the nematode Meloidogyne javanica, with LC50-LC90 values of 0.007 mg/mL-0.0113 mg/mL. D. gossweileri EO at minimum lethal concentrations (MLC) and below strongly inhibited egg hatching in vitro, whereas soil treatment caused a strong suppression of nematode population, infection frequency, and multiplication rate. The EO inhibited ryegrass (Lolium perenne) germination at 0.4 mg/mL, while at 0.1 mg/mL, its effects on germination, root and leaf growth were moderate (32.4%, 8.4%, and 18.3%, respectively). The tomato (Solanum lycopersicum) germination was not affected by the EO, but the root growth was reduced (56% at 0.1 mg/mL) at a dose 10 times higher than the LD50 calculated for M. javanica J2 mortality. Molecular docking of the nematicidal effects of the oil using PyRx revealed a strong interaction between potassium chloride transporting KCC3 (PDB ID: 7D90) and benzyl cyanide at a distance of 2.20 A° with GLN C:350, followed by benzyl isothiocyanate at a distance of 2.78 A° with ARG B:294. The in vivo nematicidal effects of D. gossweileri EO on M. javanica penetration and reproduction in tomato roots further support the potential of this EO as a nematicidal agent with insect antifeedant effects, which could be used by local farmers for crop protection.

WITHDRAWN: Ethno-botanical survey and ecological study of anti-pathogenic organisms medicinal plants species used in the Congolese folk medicine.

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Ethnopharmacological survey of plants used against diabetes in Kisangani City (DR Congo).

ETHNOPHARMACOLOGICAL RELEVANCE: An ethnopharmacological survey was conducted in Kisangani City (Democratic Republic of Congo) in order to make an inventory of plant species used in folk medicine for the management of diabetes and their different modes of preparation. MATERIALS AND METHODS: Fifty-five traditional practitioners from different ethnic groups were interviewed about the plants they use against diabetes in folk medicine in Kisangani. All cited plants were collected and identified at the herbarium of the Faculty of Sciences, University of Kisangani. RESULTS: Thirty-one plant species were collected out of which phanerophytes predominate (18 species). Eighty-three percent of herbal remedies are prepared by aqueous decoction. Ninety-seven percents of recipes are administered to patients by oral route. All plant parts are used fresh with water as the sole solvent. Leaves are the most used parts and the treatment lasts one to two weeks. CONCLUSION: Herbal remedies used against diabetes in Kisangani City, DR Congo are widely administered as aqueous decoctions. Chemical and pharmacological studies of these preparations are in progress and might lead to interesting antidiabetic remedies.

Etude par spectroscopie UV-visible de la denaturation thermique de l'hemoglobine S : une nouvelle approche du depistage rapide de la drepanocytose

La denaturation thermique des hemoglobines A et S dans le sang total a ete etudiee par spectrophotometrie UV-visible. Les resultats (exprimes en terme de temperature detransition =Tt) indiquent qu'a pH 7.4 et sans ajout d'electrolyte; la denaturation thermique montre la meilleure discrimination des sangs AA; AS et SS. Les valeurs calculees de Tt; sur base de l'analyse par regression non lineaire d'une fonction sigmoidale; a l'aide du programme Origin 4;0 sont 65;2 ; 61;0 et 58;0 oC respectivement pour les sangs AA; AS et SS. Ces resultats; obtenus dans un milieu ne necessitant pas la purification prealable des hemoproteines; montrent que la temperature de transition offre; comme la mobilite electrophoretique; la possibilite de depister la drepanocytose. L'essai d'utilisation de la denaturation thermique comme technique de caracterisation des hemoglobines a montre la pertinence de la methode

Antisickling activity of anthocyanins from Bombax pentadrum, Ficus capensis and Ziziphus mucronata: photodegradation effect.

AIM OF THE STUDY: A survey was conducted in Lubumbashi city (Democratic Republic of Congo) in order to: (a) identify medicinal plants used by traditional healers in the management of sickle cell anaemia, (b) verify their antisickling activity in vitro, (c) determine the most active plants, and (d) verify if anthocyanins are responsible of the bioactivity and study their photodegradation effect. MATERIALS AND METHODS: The Emmel test was used in vitro, for the antisickling activity assays of aqueous and ethanolic extracts of different parts of these plants when a UV lamp and solar irradiations were used to induce the photodegradation effect. RESULTS: The survey revealed that 13 medicinal plants are used in the treatment of drepanocytosis among which 12 plants exhibited the in vitro antisickling activity for at least one of the used parts or extracts. These plants are Bombax pentadrum, Bougainvillea sp., Byarsocarpus orientalis, Dalberigia bochmintaub, Diplorrhynbchus condolocarpus, Euphorbia heterophylla, Ficus capensis, Harungana madagascariensis, Parinari mobola, Pothmania witfchidii, Syzygium guineense, Temnocalys verdickii and Ziziphus mucronata of which four (Bombax pentadrum, Ficus capensis, Parinari mobola and Ziziphus mucronata) revealed a high antisickling activity. The biological activity of three of these plants is due to anthocyanins. The antisickling activity and photodegradation effect of anthocyanins extracts were studied and minimal concentration of normalization determined. The biological activity of Bombax pentadrum anthocyanins decreased to half of its value after 40 min of irradiation under a lamp emitting at a wavelength of 365 nm and after about 10h of solar irradiation. For Ziziphus mucronata and Ficus capensis, the antisickling activity decreased to half after about 6h under a lamp exposition and after about 50h of solar exposition. CONCLUSION: In vitro Antisickling activity justifies the use of these plants by traditional healers and this activity would be due to anthocyanins. But these natural pigments are instable towards UV-Visible irradiations. The conservation of these plants should then be performed in a shield from the sun radiation.

Activite antifalcemiante et thermodegradation d'une fraction d'anthocyanes extraits de Zizyphus mucronata

L'activite antifalcemiante de Zizyphus mucronata; une plante utilisee en medecine traditionnelle congolaise pour la prise en charge de l'anemie SS; a ete evaluee en utilisant le test d'Emmel. Les anthocyanes extraits des feuilles de Zizyphus mucronata; ont montre in vitro une bonne activite antifalcemiante. La concentration minimale de normalisation a ete determinee; et la chromatographie sur couche mince utilisant le melange dichloromethane-benzene comme solvant d'elution dans le rapport 6 :4 a indique la presence de deux spots differents avec comme valeurs des rapports frontaux (Rf) 0;24 et 0;31 (fraction 1 et fraction 2 respectivement). La premiere fraction (Rf : 0;24) d'anthocyanes isolee a montre une grande activite. L'etude de l'effet de la chaleur sur la fraction 1 a indique l'instabilite des anthocyanes extraits de Zizyphus mucronata vis-a-vis de la chaleur. Conclusion : L'activite antifalcemiante de Zizyphus mucronata a ete confirmee in vitro. Cette activite serait due aux anthocyanes dont la fraction 1 isolee est la plus active. Cette fraction est instable vis-a-vis de la chaleur. Il serait donc mieux d'eviter de soumettre la plante a la chaleur lors de la preparation des recettes traditionnelles

In vitro antidrepanocytary actvity (anti-sickle cell anemia) of some congolese plants.

Thirty aqueous and ethanolic extracts from 13 congolese plants were evaluated for their antidrepanocytary activity. Twelve of these plants, Alchornea cordifolia, Afromomum albo violaceum, Annona senegalensis, Cymbopogon densiflorus, Bridelia ferruginea, Ceiba pentandra, Morinda lucida, Hymenocardia acida, Coleus kilimandcharis, Dacryodes edulis, Caloncoba welwithsii, and Vinga unguiculata exhibited significant activities, thus, supporting the claims of the traditional healers and suggesting a possible correlation between the chemical composition of these plants and their uses in traditional medicine.