EVALUATION DE LA TOXICITÉ AIGUË DE L’EXTRAIT AQUEUX DES FEUILLES DE THUNBERGIA ATACORENSIS, UNE ESPÈCE NOUVELLE

Thunbergia atacorensis is a new plant species, discovered in gallery forest of Atacora Province in Benin (West Africa). This beautiful shrub can be used as ornamental. Before introducing the plant in human environment, it will be necessary to know its toxicological parameters. This work was aimed to evaluate, in mice, the acute toxicity at different doses of the aqueous decoction of the plant leaves in order to prevent intoxication. The acute toxicity of leaves aqueous decoction from the plant was assessed after a process which consisted in giving orally, to mice, the crude decoction for increasing doses ranging from 900 to 4500 mg/kg of body weight (b.w.). The use of the plant extract, through oral route (or), at different doses, causes some clinical signs (agitations, poor appetite, motor difficulties and dyspnea). The results made it possible to obtain the dose at bordering on solubility which squares with the Letal Dose of 100% or LD100 (4500 mg/kg/b.w./or). The Tolerated Maximal Dose or TMD was evaluated at 900 mg/kg/b.w./or. The plant extract, administered orally, provided slight toxicity, with a LD50 of 1720.25 mg/kg/b.w./or. Thus, the experimentally found Letal Dose of 50% can justify the domestication of the plant as ornamental

Diversité et Connaissance Ethnobotanique des Espèces de la Famille des Acanthaceae de la Réserve Naturelle Partielle de Dahliafleur, Côte d’Ivoire

This paper focuses on carrying out the biological variety of Acanthaceae and their ethnobotanical interest for the population around the Partial Nature Reserve of Dahliafleur (PNRDF). First, the main goal of this study is to contribute to the knowledge of species of Acanthaceae family and secondly to food, medicine, and ornament for the population around the PNRDF. A botanical inventory was conducted at the PNRDF, followed by an ethnobotanical investigation carried out around the reserve. The study of the flora recorded about 318 species of plants as a whole. A total of 7 species (2.50%) belonging to the family of Acanthaceae distributed in 5 genders were also recorded. The outcome of the investigation around the PNRDF revealed that from a total of 7 species, 4 out of them are essentially used by people in the ornamentation, pharmacopoeia, and in food. These species are Justicia flava, Justicia secunda, Thunbergia erecta, and Thunbergia grandiflora. The knowledge of the population on the use of each species changes from one group to another. The impartial index of the investigation revealed that the vegetal species are not evenly distributed (IE < 0.5). Women usually occupy the top place in regards to the knowledge of this plant. The most important in terms of the cultural value for the population are Justicia secunda (1.87) and Justicia flava (1.61). This study is therefore a sketch for the valorization of these plant species for their preservation or extension.La présente étude porte sur la diversité biologique des Acanthaceae et leur intérêt ethnobotanique pour les populations autour de la Réserve Naturelle Partielle de Dahliafleur (RNPDF). L'objectif principal de cette étude est de contribuer à la connaissance d’une part des espèces de la famille des Acanthaceae et d’autre part de dégager leur importance alimentaire, médicinale et ornementale pour la population autour de la RNPDF. Un inventaire botanique a été conduit dans la RNPDF, suivi d’une enquête ethnobotanique réalisée aux alentours de cette réserve. L’étude de la flore a permis de recenser 318 espèces de plantes dans l’ensemble. Un total de 7 sur 318 espèces soit 2,50 % appartenant à la famille des Acanthaceae réparties en 5 genres ont été recensées. Il ressort de l’enquête ethnobotanique menée aux alentours de la RNPDF que sur 7 espèces recensées, 4 sont essentiellement utilisées par l’homme dans l’ornementation, la pharmacopée et l’alimentation. Ces espèces sont Justicia flava, Justicia secunda, Thunbergia erecta et Thunbergia grandiflora. Le niveau de connaissance de la population sur l’usage de chacune de ces espèces varie d'un groupe à un autre. Les indices d’équitabilité des enquêtés révèlent que ces connaissances sur ces espèces végétales ne sont pas uniformément réparties (IE < 0,5). Ce sont les femmes qui occupent une place de choix dans la détention des connaissances sur ces plantes. Les plus importantes en terme de valeur culturel pour les populations sont Justicia secunda (1,87) et Justicia flava (1,61). Cette étude constitue donc une ébauche pour la valorisation de ces espèces végétales en vue de leur sauvegarde ou de leur vulgarisation

EVALUATION DE LA TOXICITÉ AIGUË DE L’EXTRAIT AQUEUX DES FEUILLES DE THUNBERGIA ATACORENSIS, UNE ESPÈCE NOUVELLE

Thunbergia atacorensis is a new plant species, discovered in gallery forest of Atacora Province in Benin (West Africa). This beautiful shrub can be used as ornamental. Before introducing the plant in human environment, it will be necessary to know its toxicological parameters. This work was aimed to evaluate, in mice, the acute toxicity at different doses of the aqueous decoction of the plant leaves in order to prevent intoxication. The acute toxicity of leaves aqueous decoction from the plant was assessed after a process which consisted in giving orally, to mice, the crude decoction for increasing doses ranging from 900 to 4500 mg/kg of body weight (b.w.). The use of the plant extract, through oral route (or), at different doses, causes some clinical signs (agitations, poor appetite, motor difficulties and dyspnea). The results made it possible to obtain the dose at bordering on solubility which squares with the Letal Dose of 100% or LD100 (4500 mg/kg/b.w./or). The Tolerated Maximal Dose or TMD was evaluated at 900 mg/kg/b.w./or. The plant extract, administered orally, provided slight toxicity, with a LD50 of 1720.25 mg/kg/b.w./or. Thus, the experimentally found Letal Dose of 50% can justify the domestication of the plant as ornamental

Domestication De Thunbergia Atacorensis Akoegninou & Lisowski (Acanthaceae) : Effet Du Type De Substrat Et Du Mode D’eclairement Sur L’aptitude A La Reprise Vegetative Des Boutures Et La Croissance Des Plants

We studied the possibility of producing seedlings of Thunbergia atacorensis (Acanthaceae) starting from cuttings under controlled cultivation conditions during 3 months. The objective of this work is to determine the optimal conditions for seedling production Thunbergia atacorensis by vegetative reproduction to allow its extension from professional growers and amateur (consumers). The study consisted to analyze their effect the plant growth, seedlings development, and leaves production. At the end the study, we obtained a rate of 91p.c for vegetative recovery for the cutting in shade 97p.c. for the cutting exposing to sun. However, the cuttings exposed sun clearly dissociates cuttings exposed to the shade with a shorter time of recovery. At the end of 3 months, only the sunny seedlings survive despite of the recovery rate of recovery. The study showed that the four environmental factors, the mode of exposure (sun and shade) and time (weeks) have a significant influence on the height and the number of seedlings leaves. The highest seedlings are observed in the shade from weeks 1 to 3. From week 3, only the sunny seedlings continue their growth and their development. The variation of the substrate and the frequency of watering, meanwhile, had no significant influence on the height and number of leaves. In sum, despite of lack of flowering, to produce seedlings of Thunbergia atacorensis, one should initially carry out the propagation by cutting in the shade and then to gradually intensify the light to have well developed seedlings

The thyroid hormone triiodothyronine controls macrophage maturation and functions: protective role during inflammation.

The endocrine system participates in regulating macrophage maturation, although little is known about the modulating role of the thyroid hormones. In vitro results demonstrate a negative role of one such hormone, triiodothyronine (T 3 ), in triggering the differentiation of bone marrow–derived monocytes into unpolarized macrophages. T 3 -induced macrophages displayed a classically activated (M1) signature. A T 3 -induced M1-priming effect was also observed on polarized macrophages because T 3 reverses alternatively activated (M2) activation, whereas it enhances that of M1 cells. In vivo , circulating T 3 increased the content of the resident macrophages in the peritoneal cavity, whereas it reduced the content of the recruited monocyte-derived cells. Of interest, T 3 significantly protected mice against endotoxemia induced by lipopolysaccharide i.p. injection; in these damaged animals, decreased T 3 levels increased the recruited (potentially damaging) cells, whereas restoring T 3 levels decreased recruited and increased resident (potentially beneficial) cells. These data suggest that the anti-inflammatory effect of T 3 is coupled to the modulation of peritoneal macrophage content, in a context not fully explained by the M1/M2 framework. Thyroid hormone receptor expression analysis and the use of different thyroid hormone receptor antagonists suggest thyroid hormone receptor β1 as the major player mediating T 3 effects on macrophages. The novel homeostatic link between thyroid hormones and the pathophysiological role of macrophages opens new perspectives on the interactions between the endocrine and immune systems

Diversite Floristique des Plantes à Potentialité Décorative Issues des Formations Naturelles du Nord de la Côte d’Ivoire

This study carried out in the Sudanese field of Côte d'Ivoire aims to contribute to the safeguarding of Ivorian flora through the valorization of plants with decorative potentiality of the North of Côte d'Ivoire. The inventory method used is the roaming survey. It consisted of walking in different directions around large cities with different backgrounds and listing all the plant species with decorative potential encountered, regardless of their size. These species have been analyzed at the National Center for Floristics (NCF). These surveys allowed usto collect 287 plant species divided between 220 genera and 79 botanical families, with a predominance of herbs. The most abundant families are Fabaceae, Apocynaceae and Acanthaceae. Of these species, 73.5% are Phanerophytes and 0.3% epiphytes. Also, an Ivorian endemic species (GCI) Cyphostemma ornatum A.Chev. exHutch. & Dalziel (Vitaceae) was also enumerated. Thirteen species or 4.52% are considered introduced species (i). At the ecological level, hydrophytic species and the species like Senna podocarpus Guill. & Perr. (Fabaceae) which is a hardy plant has been inventoried. These results show a great decorative floristic richness in the Sudanian field. This work contributed to the knowledge of the composition and the diversity of the plants with decorative potentiality of the Sudanese field of Côte d'Ivoire.Cette étude réalisée dans le domaine soudanais de la Côte d’Ivoire a pour objectif de contribuer à la sauvegarde de la flore ivoirienne à travers la valorisation des plantes à potentialité décorative du Nord de la Côte d’Ivoire. La méthode d’inventaire utilisée est le relevé itinérant. Elle a consisté à parcourir dans différentes directions autour des grandes villes ayant différents milieux et à recenser toutes les espèces végétales à potentialité décorative rencontrées, sans tenir compte de leur taille. Ces espèces ont été analysées au Centre National de Floristique (CNF). Ces relevés nous ont permis de récolter 287 espèces végétales réparties entre 220 genres et 79 familles botaniques, avec une prédominance des herbes. Les familles les plus abondantes sont celles des Fabaceae, des Apocynaceae et des Acanthaceae. Parmi ces espèces, 73,5 % sont des Phanérophytes et 0,3 % des épiphytes. Aussi, une espèce endémique ivoirienne (GCI) Cyphostemma ornatum A.Chev. exHutch. & Dalziel (Vitaceae) a été également recensée. Treize espèces soit 4,52% sont considérées comme espèces introduites (i). Au niveau écologique, des espèces hydrophytes et l’espèce comme Senna podocarpus Guill. &Perr. (Fabaceae) qui est une des plantes rustiques a été inventoriée. Ces résultats montrent une grande richesse floristique décorative dans le domaine soudanien. Ces travaux ont contribué à la connaissance de la composition et de la diversité des plantes à potentialité décorative du domaine soudanais de la Côte d’Ivoire

Autoantibodies against the glial glutamate transporter GLT1/EAAT2 in Type 1 diabetes mellitus-Clues to novel immunological and non-immunological therapies

: Islet cell surface autoantibodies were previously found in subjects with type 1 diabetes mellitus (T1DM), but their target antigens and pathogenic mechanisms remain elusive. The glutamate transporter solute carrier family 1, member 2 (GLT1/EAAT2) is expressed on the membrane of pancreatic β-cells and physiologically controls extracellular glutamate concentrations thus preventing glutamate-induced β-cell death. We hypothesized that GLT1 could be an immunological target in T1DM and that autoantibodies against GLT1 could be pathogenic. Immunoprecipitation and ELISA experiments showed that sera from T1DM subjects recognized GLT1 expressed in brain, pancreatic islets, and GLT1-transfected COS7-cell extracts. We validated these findings in two cohorts of T1DM patients by quantitative immunofluorescence assays. Analysis of the combined data sets indicated the presence of autoantibodies against GLT1 in 32 of the 87 (37%) T1DM subjects and in none of healthy controls (n = 64) (p < 0.0001). Exposure of pancreatic βTC3 cells and human islets to purified IgGs from anti-GLT1 positive sera supplemented with complement resulted in plasma membrane ruffling, cell lysis and death. The cytotoxic effect was prevented when sera were depleted from IgGs. Furthermore, in the absence of complement, 6 out of 16 (37%) anti-GLT1 positive sera markedly reduced GLT1 transport activity in βTC3 cells by inducing GLT1 internalization, also resulting in β-cell death. In conclusion, we provide evidence that GLT1 is a novel T1DM autoantigen and that anti-GLT1 autoantibodies cause β-cell death through complement-dependent and independent mechanisms. GLT1 seems an attractive novel therapeutic target for the prevention of β-cell death in individuals with diabetes and prediabetes

TMEM219 regulates the transcription factor expression and proliferation of beta cells

Pancreatic beta cells replenishment is considered the next therapeutic option for type 1 diabetes; while stimulating endogenous beta cells proliferation is the “holy grail” for those patients with exhausted beta cell mass. Here we are demonstrating that the pro-apoptotic receptor TMEM219 is expressed in fetal pancreas, in beta cell precursors and in in vitro embryonic-derived endocrine progenitors. TMEM219 signaling negatively regulates beta cells at early stages and induces Caspase 8-mediated cell death. Pharmacological blockade of TMEM219 further rescued beta cell precursor and proliferation markers, and decreased cell death, both in islets and in in vitro-derived endocrine progenitors, allowing for beta cell preservation. While addressing the upstream controlling TMEM219 expression, we determined the TMEM219 miRNet; indeed, one of those miRNAs, miR-129-2, is highly expressed in human islets, particularly in patients at risk or with established type 1 diabetes. miR-129-2 mimic downregulated TMEM219 expression in islets, in in vitro embryonic-derived endocrine progenitors and in highly proliferating insulinoma-derived cells. Moreover, miR-129-2 inhibitor induced a TMEM219 overexpression in insulinoma-derived cells, which restored cell proliferation and functional markers, thus acting as endogenous regulator of TMEM219 expression. The TMEM219 upstream regulator miR129-2 controls the fate of beta cell precursors and may unleash their regenerative potentials to replenish beta cells in type 1 diabetes

Differential regulation of nuclear and mitochondrial Bcl-2 in T cell apoptosis

Activated T cells require anti-apoptotic cytokines for their survival. The anti-apoptotic effects of these factors are mediated by their influence on the balance of expression and localisation of pro- and anti-apoptotic members of the Bcl-2 family. Among the anti-apoptotic Bcl-2 family members, the expression level of Bcl-2 itself and its interaction with the pro-apoptotic protein Bim are now regarded as crucial for the regulation of survival in activated T cells. We studied the changes in Bcl-2 levels and its subcellular distribution in relation to mitochondrial depolarisation and caspase activation in survival factor deprived T cells. Intriguingly, the total Bcl-2 level appeared to remain stable, even after caspase 3 activation indicated entry into the execution phase of apoptosis. However, cell fractionation experiments showed that while the dominant nuclear pool of Bcl-2 remained stable during apoptosis, the level of the smaller mitochondrial pool was rapidly downregulated. Signals induced by anti-apoptotic cytokines continuously replenish the mitochondrial pool, but nuclear Bcl-2 is independent of such signals. Mitochondrial Bcl-2 is lost rapidly by a caspase independent mechanism in the absence of survival factors, in contrast only a small proportion of the nuclear pool of Bcl-2 is lost during the execution phase and this loss is a caspase dependent process. We conclude that these two intracellular pools of Bcl-2 are regulated through different mechanisms and only the cytokine-mediated regulation of the mitochondrial pool is relevant to the control of the initiation of apoptosis

Prostaglandin E2 Stimulates the Expansion of Regulatory Hematopoietic Stem and Progenitor Cells in Type 1 Diabetes

Hematopoietic stem and progenitor cells (HSPCs) are multipotent stem cells that have been harnessed as a curative therapy for patients with hematological malignancies. Notably, the discovery that HSPCs are endowed with immunoregulatory properties suggests that HSPC-based therapeutic approaches may be used to treat autoimmune diseases. Indeed, infusion with HSPCs has shown promising results in the treatment of type 1 diabetes (T1D) and remains the only “experimental therapy” that has achieved a satisfactory rate of remission (nearly 60%) in T1D. Patients with newly diagnosed T1D have been successfully reverted to normoglycemia by administration of autologous HSPCs in association with a non-myeloablative immunosuppressive regimen. However, this approach is hampered by a high incidence of adverse effects linked to immunosuppression. Herein, we report that while the use of autologous HSPCs is capable of improving C-peptide production in patients with T1D, ex vivo modulation of HSPCs with prostaglandins (PGs) increases their immunoregulatory properties by upregulating expression of the immune checkpoint-signaling molecule PD-L1. Surprisingly, CXCR4 was upregulated as well, which could enhance HSPC trafficking toward the inflamed pancreatic zone. When tested in murine and human in vitro autoimmune assays, PG-modulated HSPCs were shown to abrogate the autoreactive T cell response. The use of PG-modulated HSPCs may thus provide an attractive and novel treatment of autoimmune diabetes