Cowpea production practices, constraints, and end-users preferred varieties and traits in Southern Benin

Cowpea (Vigna unguiculata L. Walp.) is an important food and nutrition security crop in Benin, though its production is constrained by absence of information necessary for strategic planning. The objective of this study was to evaluate the diversity of preferred traits and production constraints of cowpea in southern Benin. A survey was conducted in three main cowpea-growing districts in southern Benin, namely Ketou, Zakpota and Klouekanmey. Data were collected from 175 respondents through structured survey, as well as using field observations and via focus group discussions. It was clear that the majority of farmers (82%) grew cowpea in association with other crops, though mostly with maize (Zea mays L.). A total of 75.9% of farmers purchased seeds from agro-dealers in local markets. The perception of cowpea production constraints varied among districts, with weeds infestation, unavailability of certified seeds, drought, low yield, and insect pest attacks as the major production constraints across the districts. Factorial analysis showed that for the sociocultural group Adja, selection of cowpea varieties is based on pod hardness and tolerance to Striga gesnerioides; while for the sociocultural group Fon, cooking time, grain colour and seed price were the main selection criteria. On the other hand, for sociocultural groups Nagot and Holli, selection of the cowpea varieties was based on the ease to separate the coat from the cotyledons and seed size (medium to large). These findings could guide cowpea breeders and extension officers in further research and dissemination programmes in Benin

Source of resistance among cowpea accessions to bruchid, Callosobruchus maculatus F. Coleoptera: Chrysomelidae, in Benin

Post-harvest loss in cowpea ( Vigna unguiculata L.) is essentially caused by bruchid (Callosobruchus maculatus F.), the most damaging storage pest causing up to 95% loss of produce kept for long in non-treated conditions. In managing storage pests, host plant resistance proves to be a better approach than chemicals control, especially for food produce. However, no investigation in Benin has tackled resistance of cowpea germplasm to bruchid. The obective of this study was to identify sources of resistance to cowpea bruchid in Benin. A total of 174 cowpea accessions were evaluated in storage. Fourteen cowpea accessions were found resistant to bruchid including: IT06K-123-1, ALEGI*SECOW3B, IT86D-1038, WC35B, IT86D-1033, TOUMKALAM, KPLOBEROUGE, WC66*NE50, IT06K-270, IT84S-2246-4, WC36, TVU1471, TVU-1367-7 and WC66*5T with respective Dobie susceptibility indices of : 2.96, 2.71, 2.67, 2.58, 2.55, 2.49, 2.46, 2.36, 2.11, 1.42, 1.15, 0.53, 0.00 and 0.00. Pest tolerance of cowpea (0.00 to 100.00%) varied according to the resistance and susceptibility statuses of accessions screened. Correlations showed that seed damage, number of adult emerged, weight loss and Dobie susceptibility index, could be considered essential while selecting bruchid tolerant accessions. The resistant accessions observed during this experiment can serve as parental lines in breeding programmes.Le ni\ue9b\ue9 ( Vigna unguiculata L.) est fortement attaqu\ue9 par les bruches du ni\ue9b\ue9 ( Callosobruchus maculatus F.) causant 95% de d\ue9g\ue2ts. L\u2019usage des plantes r\ue9sistantes constitue une alternative aux produits chimiques. Ainsi, au B\ue9nin, en absence d\u2019\ue9tudes ant\ue9rieures sur la r\ue9sistance du ni\ue9b\ue9 aux bruches les accessions susceptibles sont toujours cultiv\ue9es. L\u2019objectif g\ue9n\ue9ral de cette \ue9tude est l\u2019\ue9valuation de la r\ue9sistance des diff\ue9rentes accessions de ni\ue9b\ue9 cultiv\ue9 au B\ue9nin. En effet, 174 accessions de ni\ue9b\ue9 ont \ue9t\ue9 \ue9valu\ue9es en stock. Plusieurs param\ue8tres ont \ue9t\ue9 d\ue9termin\ue9s : poids initial et final des graines; pourcentage d\u2019insecte \ue9merg\ue9; pourcentage de perte de poids, de graines endommag\ue9es et de tol\ue9rance des insectes; p\ue9riode m\ue9diane de d\ue9veloppement; indice de susceptibilit\ue9 de Dobie; indice de croissance; nombre moyen de trous, nombre moyen d\u2019\u153ufs pondus. Les donn\ue9es collect\ue9es ont \ue9t\ue9 soumises \ue0 ANOVA One-way, corr\ue9lation de Pearson et \ue0 une r\ue9gression lin\ue9aire multiple. Quatorze accessions \ue9taient r\ue9sistantes aux bruches \ue0 savoir\ua0: IT06K-123-1, ALEGI*SECOW3B, IT86D-1038, WC35B, IT86D-1033, TOUMKALAM, KPLOBEROUGE, WC66*NE50, IT06K-270, IT84S-2246-4, WC36, TVU1471, TVU-1367-7 et WC66*5T respectivement avec la susceptibilit\ue9 de Dobie: 2.96, 2.71, 2.67, 2.58, 2.55, 2.49, 2.46, 2.36, 2.11, 1.42, 1.15, 0.53, 0.00 et 0.00. La corr\ue9lation de Pearson montre que pourcentage de graine endommag\ue9e, nombres d\u2019insectes \ue9merg\ue9s, la perte de poids et l\u2019indice de susceptibilit\ue9 de Dobie sont les param\ue8tres \ue0 prendre en compte dans un processus de s\ue9lection des accessions r\ue9sistantes aux bruches. En cons\ue9quence, les accessions r\ue9sistantes observ\ue9es dans ce travail peuvent \ueatre utilis\ue9es dans des programmes d\u2019am\ue9lioration

COMPARATIVE STUDY OF CHEMICAL COMPOSITION, PHYSICO-CHEMICAL AND ANTIOXIDANT PROPERTIES OF OILS EXTRACTED BY TRADITIONAL AND HEXANE METHODS FROM TERMINALIA CATAPPA L. KERNELS

The comparative study of physico-chemical characteristics of Terminalia catappa L. kernel oils extracted by two methods has been done. The oil yields were 28.13 % and 61.78 % respectively for traditional and hexane methods and the fatty acid profiles showed palmitic acid (40.79 % and 40.03 % respectively) oleic acid (25.55 % and 26.09 % respectively), linoleic acid (26.72 % and 26.64 % respectively) and stearic acid (4.35 % and 4.49 % respectively) as major components. The oils extracted by the two ways showed similar physico-chemical properties, good calorific values and non-toxicity against Artemia salina L. Oil obtained by traditional method exhibited more antioxidant capacity (1.40) than the hexane one (0.15). This traditional method helps to extract 45 % of the total oil. It gives oil free of organic solvent, with good physico-chemical properties that could be useful as edible oil and for industrial applications

In vitro antitrypanosomal and antiplasmodial activities of crude extracts and essential oils of Ocimum gratissimum Linn from Benin and influence of vegetative stage

ETHNOPHARMACOLOGICAL RELEVANCE: Different parts of Ocimum gratissimum Linn are largely used in folk medicine for the treatment of many diseases, some of which related to parasitical infections as fevers and headaches. In order to validate their use and to clarify the plant part which possesses the best antiparasitic properties, we decided to evaluate the in vitro antiplasmodial and antitrypanosomal activities of essential oils and crude extracts from leaves, stems and seeds of Ocimum gratissimum as well as their cytotoxicity. MATERIALS AND METHODS: The essential oils and ethanol crude extracts of leaves and stems of Ocimum gratissimum from Benin, were obtained in pre and full flowering stages. Seeds obtained only in full flowering stage, were also extracted. The oils were isolated by hydrodistillation and analyzed by GC/MS and GC/FID. Extracts and essential oils were tested in vitro against Trypanosoma brucei brucei and Plasmodium falciparum. Cytotoxicity was evaluated in vitro against Chinese Hamster Ovary (CHO) cells and the human non cancer fibroblast cell line (WI38) through MTT assay to evaluate the selectivity and toxicity was assessed against Artemia salina Leach. RESULTS: The essential oils and non-volatile crude extracts of Ocimum gratissimum were more active on Trypanosoma brucei brucei than on Plasmodium falciparum (3D7). This activity varies according to the vegetative stage (pre and full flowering) and the plant part (seeds, stems and leaves) extracted. The best growth inhibition of Trypanosoma brucei brucei was observed with ethanol crude extracts of leaves (IC50=1.66 ± 0.48 μg/mL) and seeds (IC50=1.29 ± 0.42 μg/mL) in full flowering stage with good selectivity (SI>10). The chemical composition of the essential oil from aerial parts (47 compounds), characterized by the presence as main constituents of p-cymene, thymol, γ-terpinene, β-myrcene and α-thujene, depends on the vegetative stage. The oil contained some minor compounds such as myrcene (IC50=2.24 ± 0.27μg/mL), citronellal (IC50=2.76 ± 1.55μg/mL), limonene (IC50=4.24 ± 2.27μg/mL), with good antitrypanosomal activities. These oils and crude extracts were not toxic against Artemia salina Leach and had a low cytotoxicity except leaves and seeds ethanol extracts obtained in full flowering which showed toxicity against CHO and WI38 cells. CONCLUSIONS: Our study shows that ethanol crude extracts of leaves and seeds of Ocimum gratissimum in full flowering stage can be a good source of antitrypanosomal agents. This is the first report about the relation between the plant part extracted, the vegetative stage of the plant, the antitrypanosomal and antiplasmodial activities and the cytotoxicity of essential oils and non-volatile extracts of Ocimum gratissimum from Benin

Synthesis, spectrometric characterization and trypanocidal activity of some 1,3,4-thiadiazolines derivatives

Six 1,3,4-thiadiazolines derivatives were synthesized by cyclization of thiosemicarbazones under acetylating condition with yields going from 27 to 94%. The products purity was confirmed by LC/MS (Mass Spectrometry Coupled with High-Performance Liquid Chromatography) and they were characterized using spectrometry IR, NMR 1H and 13C (Nuclear Magnetic Resonance). These compounds were then tested in vitro on Trypanosoma brucei brucei according to the “LILIT, Alamar Blue” method to estimate their trypanocidal activity. 1,3,4-thiadiazoline 6 (IC50 = 38,79 ìM) was the most active of all compounds

Justicia anselliana (Nees) T. Anders Essential Oils Compounds and Allelopathic Effects on Cowpea Vigna unguiculata (L.) Walp Plant

Analysis of justicia ancelliana essential oils by GC and GUMS revealed the presence of beta-phellandrene (51.2%), delta-2-carene (43.4%), dihydrotagetone (0.4%), propylbutyrate(0.3%) in the aertial parts and phenylacetaldehyde(39.2%), delta-3-carene (31.71%), 6-methyl-5-hepten-2-one (16.4%) and alpha-phellandrene (12.6%) in the roots. These oils and their compounds induced it reduction in the growth of the roots, the apparition of yellow leaves after two weeks of the treatment and the death of the Vigna unguiculata young plants and showed a specific action oil the germination and the growth of Zea mays, Vigna unguiculetta and Arachis hypogeae plants. beta-Phellandrene and phenylacetaldehyde showed maximum inhibition to germination and growth of Vigna unguiculata

Synthesis, characterization and anti-trypanosomal activity of R-(-)carvone and arylketones-thiosemi carbazones and toxicity against Artemia salina Leach

This work is focused on the synthesis and characterization of a series of N(4)- substituted thiosemicarbazones and the evaluation of their in-vitro anti-trypanosomal activity and toxicity. A series of thiosemicarbazones (1-4) and N(4)-phenyl-3-thiosemicarbazones (5-8) have been synthesized on R-(-)carvone, acetophenone, 4’-methylacetophenone and benzophenone by condensation reaction with good yields. All compounds were characterized by spectrometrical analysis methods infrared IR, nuclear magnetic resonance NMR (1H &13C) and mass spectrometry MS, confirming their structures respectively, and were evaluated for their invitro parasitic activity against the bloodstream form of the strain 427 of Trypanosoma brucei brucei using the “LILIT, Alamar Blue” method (Baltzet al., 1985; Hirumi et al., 1994; Räz et al.,1997). Their toxicity against brine shrimp larvae (Artemia salina Leach) was studied, according to the method of Michael et al. (1956) resumed byVanhaecke et al. (1981) and bySleet and Brendel (1983). Some of them have exhibited a strong trypanocidal activity, especially compounds 8, 3, 1 and 4 with their half-inhibitory concentrations (IC50) values equal to 8.48, 8.73, 39.71 and 67.17 micro-molar (µM) respectively. Except compounds 1 and 4whose half-lethal concentration (LC50) values were20.58 and 33.72 µM respectively and then toxics, all synthesized compounds showed negligible toxicity against Artemia salinaL. (LC50> 280 µM) and good selectivity (S) (SI “index” =1)

Trypanocidal and cytotoxic evaluation of synthesized thiosemicarbazones as potential drug leads against sleeping sickness

Thiosemicarbazones have become one of the promising compounds as new clinical candidates due to their wide spectrum of pharmaceutical activities. The wide range of their biological activities depends generally on their related aldehyde or ketone groups. Here, we report the pharmacological activities of some thiosemicarbazones synthesized in this work. Benzophenone and derivatives were used with N(4)-phenyl-3-thiosemicarbazide to synthesize corresponding five thiosemicarbazones (1-5). Their structures were characterized by spectrometrical methods analysis IR, NMR (1)H & (13)C and MS. The compounds were then screened in vitro for their antiparasitic activity and toxicity on Trypanosoma brucei brucei and Artemia salina Leach respectively. The selectivity index of each compound was also determined. Four thiosemicarbazones such as 4, 2, 3 and 1 reveal interesting trypanocidal activities with their half inhibitory concentration (IC50) equal to 2.76, 2.83, 3.86 and 8.48 μM respectively, while compound 5 (IC50 = 12.16 μM) showed a moderate anti-trypanosomal activity on parasite. In toxicity test, except compound 1, which showed a half lethal concentration LC50 >281 μM, the others exerted toxic effect on larvae with LC50 of 5.56, 13.62, 14.55 and 42.50 μM respectively for thiosemicarbazones 4, 5, 3 and 2. In agreement to their selectivity index, which is greater than 1 (SI >1), these compounds clearly displayed significant selective pharmaceutical activities on the parasite tested. The thiosemicarbazones 2-5 that displayed significant anti-trypanosomal and cytoxicity activities are suggested to have anti-neoplastic and anti-cancer activities