Journal of the Cameroon Academy of Sciences

Formulation of category-2 hypoglycemic Improved Traditional Medicines from selected Cameroonian medicinal plants: Mangifera indica, Persea americana and Ageratum conyzoides

2024-03-11T09:47:08+00:00

Diabetes mellitus is the fourth leading cause of death worldwide, and constitutes a major public health crisis. Management of the adverse condition relies mostly on synthetic drugs such as metformin, glibenclamide and insulin. However, treatment with synthetic drugs is challenged by side effects and high cost especially to patients in low-income countries like Cameroon. This study set out to formulate Improved Traditional Medicines (ITMs) in the form of capsules from lyophilized aqueous leaf extracts of Ageratum conyzoides, Mangifera indica and Persea americana, in combination, coded as ITM-1, and leaf extract of Mangifera indica alone, referred to as ITM-2. Phytochemical profiling of individual extracts was carried out using standard methods, while their antioxidant activity was evaluated in vitro by the 2,2-diphenyl-1-picryhadrazyl reducing (DPPH) assay and the Ferric (Iron) reducing antioxidant power assay (FRAP). Capsule formulation was guided by findings from prior Physicochemical and pharmacotechnical analysis of individual extracts and their combination. Safety studies were carried out both in vitro (cytotoxicity testing in Vero cells); and in vivo (acute toxicity tests using the mouse model). Preliminary evaluation of the antidiabetic potential of the formulated ITMs was achieved through determination of their acute hypoglycemic and antihyperglycemic properties in Wistar rats (Oral Glucose Tolerance Test). Major classes of phytochemicals detected were alkaloids, phenols, tannins, flavonoids, anthocyanins, tri-terpenes and anthraquinones. The DPPH and FRAP assays showed dose-dependent antioxidant activity for ITM-1 and ITM-2. Both ITMs showed no toxic effects, be it in vitro, (Cytotoxic Concentration 50% - CC50>1000 µg/mL in cells) or in vivo. At the dose of 25 mg/Kg, both ITMs exhibited significant hypoglycemic effects in Wistar rats. The ITM-2 capsules completely suppressed post-prandial glucose peak in rats as compared to the negative control (distilled water), ITM-1 capsule was able to cause restoration of the glucose levels to normal levels after 120 minutes

The UV-Vis spectrophotometric studies of natural dye absorption on a Sida-rhombifolia/Cotton blended fabric

2024-03-11T10:08:08+00:00

The environmental considerations in natural dye have gained prominence in the contemporary textile processing industry. Natural dyes have been exploited from a variety of plants. Some of these natural dyes have no substantive for cellulose fabrics so requires assistance of mordant during its application. Techniques were developed to extract dyes from red sandal wood (RSW) and avocado seed (AS) for the dyeing of Sida-rhombifolia blended fabric (SRBF). Solvent (ethanol and acetone) extraction method was found suitable for the dye extraction from red sandal wood and avocado seed. UV-Vis spectrophotometric studies were investigated on the dye absorption. Dyeing with RSW exhibited better rate of absorbance colour than AS dye. The concentration of each dye was determined using a calibration curve. The R² = 0.9669 for RSW and R² = 0.9895 for AS values accompanied the calibration curve and were considered good. Absorbance/ exhaustion of dyes were determined and characterization was done by carrying out kinetic/equilibrium absorption and the thermodynamic absorption of isotherms. The kinetic and thermodynamic studies of red sandal wood dyes have higher rate of dyeing and higher affinity value of 28.3KJ/mol^-1 at 80°C for SRBF than avocado seeds with affinity value of 14.09KJ/ mol^-1 . The enthalpy and entropy of dyeing were also found to be positive for both dyes, hence confirming the increasing randomness at the solid/solution interface during the absorption of dyes. Washing and Rubbing Fastness properties were investigated according to the British Standard (EN BS 20105). The results ranged from 4-5 according to grey scale standard indicating that the colour on a dyed fabric can strongly resist fading out when washed or rubbed against a white fabric. It can be concluded that natural plants in Cameroon have considerable potentials as a source of natural dye.

Mineralogical, geochemical, and physico-mechanical features of Bidzar (North Cameroon) termite mound materials and its suitability in producing fired bricks with marble powder additive

2024-03-11T10:33:23+00:00

Les matériaux de termitières de Bidzar (Nord Cameroun) ont été caractérisés pour une potentielle utilisation comme matériau de construction. Pour atténuer le problème environnemental causé par l’exploitation du marbre de Bidzar, ce dernier a été utilisée comme additif (0, 5, 10, 15 et 20%) avant cuisson à 900, 1000, 1100 et 1200°C. Les matériaux de termitières sont composés de quartz, illite- smectite, vermiculite, chlorite, muscovite, calcite, hématite, et anatase avec pour principaux oxydes SiO₂ , Al₂O₃ , et Fe₂O₃ . Ce sont des argiles sableuses et des argiles très sableuses dont la granulométrie est indiquée pour les produits creux, les tuiles et les briques. Certaines briques montrent des gonflements après cuisson jusqu’à 1100°C pendant que les autres présentent des retraits à la cuisson. Les autres caractéristiques des briques cuites sont : densité apparente (1,60–1,96 g/cm³ ), porosité (19,39–34,41%), absorption d’eau (10,41–21,44%), résistance à la flexion (1,25–5,64 MPa) et résistance à la compression (2,89–18,76 MPa). L’ajout de marbre couplé à la présence de matière organique (4,04–5,35%) augmente l’absorption d’eau tout en réduisant le retrait linéaire et la résistance mécanique à cause de la transformation de CaCO₃ durant la cuisson qui entraîne la création d’une porosité secondaire. Ces caractéristiques physico- mécaniques répondent néanmoins aux standards des matériaux de construction.

Termite mound materials (TMM) from Bidzar (North Cameroon) were characterized for their potential use as raw materials for the fired brick industry. To alleviate the environmental problem caused by the exploitation of the Bidzar marble, marble powder (0, 5, 10, 15, and 20 wt%) has been used as an additive in the formulation of bricks before firing at 900, 1000, 1100, and 1200°C. The TMM are made up of quartz, illite-smectite vermiculite, chlorite, muscovite, calcite, hematite, and anatase, with SiO₂ , Al₂O₃ , and Fe₂O₃ being the main oxides. These materials are sandy clays or strongly sandy clays, which can be used for the manufacture of hollow products, roofing tiles, and masonry bricks. Some studied materials exhibit expansion up to 1100°C, while others show shrinkage at all studied temperatures. The varied characteristics of fired bricks are bulk density (1.60–1.96 g/cm³ ), apparent porosity (19.39– 34.41%), water absorption (10.41– 21.44%), flexural strength (1.25–5.64 MPa), and compressive strength (2.89–18.76 MPa). The addition of marble powder coupled with the presence of organic matter (4.04– 5.35%) increases the water absorption while decreasing the linear shrinkage, flexural strength, and compressive strength of bricks due to the transformation of CaCO₃ during firing, which leads to the creation of secondary porosity. Nevertheless, these physico-mechanical characteristics meet the standards of construction materials.

Orthographic Errors Analysis of English as a Second Language Learners’ writing: lessons from the use of WhatsApp language

2024-03-11T10:56:07+00:00

This article investigates the impact of WhatsApp language on English as a Second Language (ESL) learners’ writing performance. The study is based on the assumption that secondary schools learners’ essay scripts are full of orthographic errors caused by the use of WhatsApp language. Data collection tools included questionnaires and learners essays. The descriptive survey design within the social learning theory and the constructivist theory of error analysis was adopted in the analysis of data. The study concluded that WhatsApp language negatively affects the orthographic performance of the Government Bilingual High School ESL students of Bertoua. The way forward proposes the development of teachers’ skills in error analysis as well as the active involvement of learners in reflecting on the source of their errors as part of the remediation process.

Science Diplomacy in West and Central Africa: State, Trends and Patterns

2024-03-11T11:12:34+00:00

Review and reflection have been made on the evolving discipline of science diplomacy from the point of view of state, pattern and trend in West and Central Africa. While the state is embryonic and implemented consciously or unconsciously, the pattern indicates business is done with friends other than former colonial powers. From the three roles of science diplomacy – science in diplomacy, science for diplomacy and diplomacy for science – West and Central African states have been engaged with the latter. The priority areas involved aimed at creating capacity for science, technology and innovation through education and technology transfer. The players involved included governments, private sectors and individual scientists. Challenges were many but most important was the non-respect of commitments made by partners leading to failure to achieve stated objectives and targets. Suggestions for improvement have been made. Most important among these are transparency, clarity and respect of commitments earlier agreed. To benefit from the three roles of science diplomacy, states of the region need to create adequate critical capacity/mass based on a common vision founded on collective aims.

Une revue et une réflexion ont été effectués sur l’évolution de la discipline de la diplomatie scientifique du point de vue de l’état, du modèle et de la tendance en Afrique de l’Ouest et Centrale. Alors que l’état est embryonnaire et mis en œuvre consciemment ou inconsciemment, le modèle indique que les affaires se font avec des amis autres que les anciennes puissances coloniales. Des trois rôles de la diplomatie scientifique - la science dans la diplomatie, la science pour la diplomatie et la diplomatie pour la science - les États d’Afrique de l’Ouest et Centrale ont été engagés avec cette dernière. Les domaines prioritaires concernés visaient à créer des capacités pour la science, la technologie et l’innovation par le biais de l’éducation et du transfert de technologie. Les acteurs impliqués comprenaient les gouvernements, le secteur privé et les scientifiques individuels. Les défis étaient nombreux, mais le plus important était le non-respect des engagements pris par les partenaires, ce qui a conduit à l’échec de la réalisation des objectifs et des cibles fixés. Des suggestions d’amélioration ont été faites. Les plus importantes d’entre elles sont la transparence, la clarté et le respect des engagements pris antérieurement. Pour tirer parti des trois rôles de la diplomatie scientifique, les États de la région doivent créer une capacité/masse critique adéquate fondée sur une vision commune reposant sur des biens communs collectifs.

Science Advisory to Governments and Regional/Sub-Regional Organizations in West and Central Africa

2024-03-11T11:45:52+00:00

Science advice to governments and regional and sub-regional organizations in West and Central Africa has been reviewed. The objectives were to analyze its evolution and characterize the sources of advice. During the colonial period, it was by the colonial administrations and for their needs. At independence, in general, the new nations (particularly French speaking) entered into agreements with the former colonial powers to develop science, technology and innovation capacity for sustainable development. English speaking nations sought more partners outside the colonial experience. Colonial research institutes were increasingly transformed into national research institutes/institutions with national development mandates. Governments increasingly turned to science advice from consultants, inter- ministerial committees, advisory bodies, ad hoc experts’ groups, or a combination of these. Regional/sub-regional organizations sought advice from consultants, ad hoc technical experts’ groups, advisory bodies or a combination of these. Increasingly, science advice is delivered by Africans. Science advice by science academies is most rigorous. The arrival of more science academies, with varying links with governments, indicates that evidence-based science advice is growing in the region.

Cover and Preliminary pages

2024-03-13T07:50:55+00:00

No Abstract