[Vitamin D status in Gabonese children]. / Statut et besoins en vitamine D chez le nourrisson au Gabon.

OBJECTIVE: To analyse the status of vitamin D and the influence of a supplement of vitamin D in neonates and infants during the first 6 months of life in the african equatorial environnement of Gabon. DESIGN: Clinical (weight, height, head circumference, and diseases) and biological (calcemia, phosphatemia, serum alkaline phosphatase activity and plasma 25-hydroxyvitamin D levels) parameters were compared between 2 groups of children: group 1: 41 infants receving a daily supplement of 1000 IU of vitamin D, and group 2: 38 infants without vitamin D supplement. RESULTS: No significant differences were observed between the 2 groups concerning clinical and biological parameters. In particular plasma levels of 25-hydroxyvitamin D were normal and similar in both groups. CONCLUSION: A vitamin D supplement appears to be useless in 0 to 6 months infants living in Gabon.

Acaricidal activity of Uvaria versicolor and Uvaria Klaineana (Annonaceae).

Three Uvaria species, namely U. klaineana, U. mocoli and U. versicolor were tested in vitro against Dermatophagoides pteronyssinus, the European house dust mite. The most active extracts were the Uvaria versicolor stems crude methanol and hexane extracts with EC(50) values of 0.095 g/m(2 )and 0.12 g/m(2), respectively. The bioassay-guided fractionation of the hexane extract led to the isolation of benzyl benzoate (1). which exhibited an EC(50) value of 0.045 g/m(2). A new fl avanone, versuvanone (2). and the known oxoaporphine liriodenine (3). were also isolated from this species and showed EC(50) values > 1.5 g/m(2). A weak acaricidal activity (0.85 g/m(2)) was observed for the dichloromethane extract of Uvaria klaineana, due to the presence of benzyl benzoate. Uvaria mocoli was inactive. The structures of compounds were elucidated using 2D-NMR techniques.

Antiplasmodial activity of Uvaria klaineana.

Crude extracts of Uvaria klaineana Engler and Diels (Annonaceae) stems showed in vitro activity against chloroquine-resistant K1 strain of Plasmodium falciparum. The most active extract was the basic dichloromethane extract containing crude alkaloids (IC50 = 3.55 microg/mL). The bioassay-guided fractionation of this extract led to the isolation of the major alkaloid crotsparine (1) which showed an antiplasmodial activity against the chloroquine-sensitive Thai strain of P. falciparum and the chloroquine-resistant K1 and FcB1 strains of P. falciparum. Two minor alkaloids were also identified as crotonosine (2) and zenkerine (3). Their structures were elucidated using 2D-NMR techniques.

Coronin from roots of Annona muricata, a putative intermediate in acetogenin biosynthesis (1).

A novel acetogenin, coronin, was isolated from the roots of Annona muricata L. The structure was elucidated by a combination of chemical and spectral methods including MS and NMR measurements. Coronin is probably an intermediate in the biosynthetic pathway of bis-tetrahydrofuran acetogenins, and is proposed as a biogenetic precursor of neoannonin-B.

Recent advances in the fight against leishmaniasis with natural products.

The active compounds obtained from some medicinal plants used traditionally worldwide for the treatment of leishmaniasis are reviewed. Among these active molecules, described in recent literature are quinoline alkaloids such as alkyl-2 quinoline and aryl-2 quinoline from Galipea longiflora, isoquinoline alkaloids such as isoguattouregidine from Guatteria foliosa, indole alkaloids such as conodurine and gabunine from Pescheiera van heurkii, terpenes such as jatrogrossidione from Jatropha grossidentata, acetogenins such as senegalene from Annona senegalensis and lignans such as (+)nyasol from Asparagus africanus. Other natural compounds with antileishmanial activity are coumarins, chalcones, lactones, tetralones and saponins. Some of them are known antiprotozoal natural products. These compounds could be used as templates to discover new and effective drugs against leishmaniasis.

Medicinal plants used by the Masango people in Gabon.

Plant species listed are used by the Masango people in two selected villages--Ibagha and Muyanama--in the Ngounie province of Gabon. For each species listed, the family, botanical name, vernacular name, voucher specimen number and medicinal uses are given.

Medicinal plants used by the Fang traditional healers in Equatorial Guinea.

This work is an ethnobotanical study of some medicinal plants used by the Fang traditional healers of two regions of Equatorial Guinea in Central Africa: Malabo and Bata. For each species listed, the family, the botanical name, the voucher specimen number, the vernacular name, the pharmacological and therapeutical properties are given.