University of Antananarivo

About: University of Antananarivo is a education organization based out in Antananarivo, Madagascar. It is known for research contribution in the topics: Population & Lemur. The organization has 1561 authors who have published 1703 publications receiving 30922 citations. The organization is also known as: Tananarive University & Antananarivo University.

Antioxidant, Anti-Inflammatory, and Antidiabetic Activities of Leaves and Stems of Uapaca bojeri Bail. (EUPHORBIACEAE), an Endemic Plant of Madagascar.

Abstract: Uapaca bojeri is an endemic Malagasy plant used by the local population. This work aimed to evaluate antioxidant, anti-inflammatory, and antidiabetic activities of the methanol extracts of U. bojeri leaves and stems and to report their total phenolic content and the bioactive compound content by HPLC methods. Antioxidant capacity was determined by DPPH and ferric reducing antioxidant power (FRAP) assays. An in vivo carrageenan-induced paw oedema and acetic acid-induced writhing test in mice were used for anti-inflammatory activity evaluation. An oral glucose tolerance test was performed in mice to evaluate antidiabetic activity. The total bioactive compound content of leaves was higher than that of stems. Stem methanol extract inhibited the free radical DPPH more than the leaf methanol extract. Leaf methanol extract inhibited, in a dose-dependent manner, the carrageenan-induced paw oedema more than the stem extract, but their inhibition of the pain symptoms caused an acetic acid-induced decrease similar to the number of writhes in the dose-dependent case. The leaf and stem methanol extracts significantly reduced blood glucose levels after 30 min of glucose loading in mice compared to the control group blood glucose reduction. The presence of several bioactive compounds in U. bojeri contributed to the different biological activities, but isolation and identification of these bioactive molecules are necessary to confirm these pharmacological properties.

The bark essential oil composition and chemotaxonomical appraisal of Cedrelopsis grevei H. Baillon from Madagascar

Abstract: Cedrelopsis grevei is an aromatic and endemic tree of Madagascar. Its essential oil, resulting from its bark, and known under the name katrafay oil, is used in Madagascar in traditional medicine and in aromatherapy in the areas of the North. The chemical composition of this oil shows a great variability. This work proposed to study some determinants of this variability. Sampling was carried out tree by tree, in six representative sites of the distribution area of the species, followed by distillation and analysis by GC-MS. Twenty one samples were thus analyzed and 71 molecules were identified in at least one sample. A principal components analysis was performed considering the thirteen principal compounds identified in these essential oils. Four chemical patterns were distinguished. The first is characterized by eudesmane skeletons, mainly represented by selinenes (3.417.2%) and eudesmols (9.9-37.8% and 0-11.1% for the [alpha]- and [gamma]- isomers, respectively); the second is rich in a-pinene (2.1-30.0%) and copaborneol (4.7-20.0%); the third is dominated by [alpha]-copaene (5.9-11.8%) and ishwarane (13.7-22.1%), and the last by cadinane skeletons (cadinenes 0.5-35.2%, T-muurolol 0-11.8% and [alpha]-cadinol 0-6.7%). Variable amounts of [alpha]-bisabolol were found in samples belonging to these four groups. Our study indicates a linkage between the zone of gathering and the essential oil chemical composition. There was not much variability between trees in the same zone, but there were big differences from one zone to another. These results make it possible to propose methods for sustainable collection and durable management of the species. (Resume d'auteur)

Molecular characterization of a new alphasatellite associated with a cassava mosaic geminivirus in Madagascar

Abstract: Two complete nucleotide sequences of an alphasatellite isolated from a cassava plant with mosaic disease symptoms in Madagascar are described and analyzed. While the helper begomovirus was identified as an isolate of East African cassava mosaic Kenya virus (EACMKV), its associated alphasatellite was most closely related (80 % nucleotide sequence identity) to cotton leaf curl Gezira alphasatellite. These satellite molecules have typical features of alphasatellites, with a single gene in the virion sense, an A-rich region and a stem-loop structure. According to the proposed species demarcation threshold of alphasatellites (83 % nucleotide identity), they are isolates of a new species for which we propose the name “Cassava mosaic alphasatellite”.

Composition and antimicrobial activity of leaf oil of Pittosporum senacia var. coursii Cufodontis

Abstract: Volatile constituents of the leaves of Pittosporum senacia var. coursii Cufodontis were investigated by GC and GC/MS. Among the sesquiterpenoid compounds found, the oil was determined to contain δ-cadinene (11.3%), α-muurolol (15.9%) and α-cadinol (19.0%) as major components. It was also found to possess some antimicrobial properties.

Record of two species of Culicoides (Diptera, Ceratopogonidae) new for Madagascar and molecular study showing the paraphylies of the subgenus Oecacta and the Schultzei group.

Abstract: CulicoidesarevectorsofdiseasesofVeterinaryMed- icine importance (bluetongue, African horse sickness, Schmal- lenberg virus) all over the world. In the present study, we report two species new for Madagascar: C. nevilli and C. enderleini. They belong to the Schultzei group which is sometimes classi- fied in the subgenus Oecacta and sometimes in the subgenus Remmia, depending on authors. Consequently, we carried out a molecular cladistics of these groups based on cytochrome C oxidase subunit I mtDNA sequences. We processed the Mala- gasy specimens and some C. furens (the Oecacta type-species) caught in Florida and we analyzed their sequences and those available in Genbank: C. schultzei, C. oxystoma, C. festivipen- nis,C. brunnicans, C. kibunensis, C. truncorum and C. vexans. C.( Avaritia) imicola have been selected as an outgroup. The maximum parsimony analysis showed the paraphylies of the Schultzei group (=Remmia) and of the subgenus Oecacta if the first group is excluded from the latter. Our results underline the doubtful current classification and need to be validated by other molecular markers in the future.