Utilisation ethnobotanique de Garcinia lucida, Scorodophloeus zenkeri et Alstonia boonei dans la localité de Ngovayang I (Sud Cameroun)

Les forêts d’Afrique centrale contiennent plusieurs produits d’origine animale et végétale. Les produits d’origine végétale peuvent se distinguer en produits forestiers ligneux et non ligneux. Le présent travail de recherche porte sur l’importance et la gestion durable de quelques Produits Forestiers Non Ligneux (PFNL), notamment l’écorce de trois arbres (Garcinia lucida, Scorodophloeus zenkeri, Alstonia boonei) dans la localité de Ngovayang I. À l’aide d’un questionnaire semi-structuré, les caractéristiques du secteur des PFNL, les stratégies de gestion, ainsi que l’impact de la valorisation des PFNL ont été déterminés. Il ressort des enquêtes que les écorces de ces trois espèces sont connues et utilisées à des fins diverses telles que la consommation, l’automédication et la vente. L’initiation à l’utilisation de l’écorce de ces espèces est liée au sexe et est également fonction de l’âge des enquêtés. Leurs écorces sont approvisionnées sur le marché et vendues en majorité par les hommes. G. lucida et S. zenkeri sont utilisées à des fins nutritionnelles, médicinales et lucratives, tandis qu’Alstonia boonei est utilisée exclusivement à des fins médicinales. Pour des personnes plus jeunes, d’une tranche d’âge comprise entre 15 et 35 ans, l’exploitation de l’écorce de ces trois espèces n’a aucun impact néfaste sur la disponibilité des ressources forestières. S’agissant des personnes âgées de 35 à 65 ans, l’exploitation non contrôlée et l’écorçage anarchique de G. lucida et de S. zenkeri peuvent entrainer leur pénurie et même leur disparition dans cette région. Toutefois, la récolte échelonnée de l’écorce de G. lucida, S. zenkeri et A. boonei est utilisée comme stratégie de gestion de l’écorce de ces arbres dans cette localité. Central African forests are teemed with several goods of animal and plant origin. Goods of plant origin are forest products and non-timber forest products. This research work focused on the identification and importance of some non-timber forest products (NTFPs), especially the bark of tree species (Garcinia lucida, Scorodophloeus zenkeri and Alstonia boonei) in the locality of Ngovayang I. Using a semi-structured questionnaire, the characteristics of the NTFP sector, management strategies, and the impact of NTFP exploitation were determined in Ngovayang I. Surveys show that the bark of these three species is well known and used for various purposes such as consumption, self-medication and sale. The initiation of the use of the bark of these species is linked to sex and also depends on the age of the respondents. Their bark is supplied on the market and sold mostly by men. G. lucida and S. zenkeri are used for food, medicinal and profit-making purposes, while A. boonei is used exclusively for medicinal purposes. For younger people, aged between 15 and 35 years old, the exploitation of the bark of these three species has no negative impact on forest resources. For old people (35 to 65 years), the uncontrolled exploitation and uncontrolled debarking of G. lucida and S. zenkeri can lead to the shortage and even extinction of these two tree species in the region. However, the planned harvest of the bark of Garcinia lucida, Scorodophloeus zenkeri and Alstonia boonei is used as strategy of management of the bark of these trees in this locality.

Cussonia arborea Hochst (Araliaceae): Ethnobotany, Pharmacology and Phytochemistry

Background: C. arborea belonging to Araliaceae family is used traditionally to cure many alien diseases including gonorrhoeae infection, diarrhea, malaria, and diabetes mellitus. The plant has been examined on the basis of scientific in vitro and in vivo evaluations possessing the major pharmacological activities including antimicrobial, antibacterial, antihyperglycemic, antiplasmodial and anticancer properties. Aim of the study: In the present paper, we reported the isolation and characterization of secondary metabolites from the methanol extract of the stem bark of Cussonia arborea Hochst after a short review of the traditional and pharmacological studies done on this important medicinal plant. Materials and methods: MeOH extract of stem bark of C. arborea was suspended in water and successively extracted with EtOAc and n-BuOH. The EtOAc extract (18 g) was subjected to repeated column chromatography to yield seven (1-7) compounds. Their structures were determined by means of NMR, and published data. Results: The isolated compounds were identified as: protocatechuic acid (1), mixture of 3,23-dihydroxyolean-12-en-28-oic acid (2a) and 3,23-dihydroxyurs-12-en-28-oic acid (2b) in ratio 5/4, 3-O-β-D-xylopyranosylolean-12-en-28-oic acid (3), 3-O-α-L-arabinopyranosylolean-12-en-28-oic acid (4), β-resorcylic acid (5), mixture of 3-O-β-D-glucopyranosyl-23-hydroxyolean-12-en-28-oic acid (6a) and 3-O-β-D-glucopyranosyl-23-hydroxyurs-12-en-28-oic acid (6b) in ration 4/1, 3-O-β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosyl-3β-hydroxyolean-12-en-28-oic acid (7). Compounds 3, 4, 5, 7, 2b and 6b are herein reported for the first time in this plant

Cytotoxic and antimicrobial activities of phytoconstituents of the stem bark extract of Psychotria djumaensis

Phytochemical investigation of the stem bark extract of Psychotria djumaensis led to the isolation of ten known pentacyclic triterpenoids among which one lupane-, three oleanane-, and six ursane-types. The structures of the isolated compounds were established by means of spectroscopic methods and by comparison with previously reported data. The isolated compounds were tested against five strains of bacteria, and the cytotoxicity against the human cervix carcinoma KB-3-1 cell was evaluated. The isolates exhibited weak antibacterial activity against the five strains. The cytotoxic activity exhibited by 3β,19α-dihydroxyurs-12-en-28-oic acid (5) (IC50 5.9 µM) was about three times more significant than that of the reference [(+) griseofulvin, IC50 17-21 µM].

Perceptions paysannes sur les services écosystémiques d’approvisionnement, la vulnérabilité et les stratégies de conservation de Diospyros mespiliformis Hochst en zone soudanienne du Tchad

Diospyros mespiliformis Hochst. est une espèce d’arbre à usage multiple des forêts tropicales sèches qui est encore exploitée à l’état sauvage et dont les pratiques sylviculturales ne sont pas documentées. La présente étude avait pour but d’appréhender les perceptions paysannes sur l’importance socio-économique, le niveau de vulnérabilité et la pratique de la culture de cette espèce dans la zone soudanienne du Tchad. L’approche méthodologique a consisté en des enquêtes réalisées auprès de 350 personnes réparties dans 10 villages, ainsi que des observations de terrain. Les résultats ont montré que D. mespiliformis est bien connu des populations locales (100 % des enquêtés) qui en font usage dans six catégories d’usage, avec un large consensus au niveau des utilisations médicinales (Cs = 0,96), alimentaires (Cs = 0,33), dans les constructions (Cs = 0,26) et comme bois d’énergie (Cs = 0,24). Par contre le consensus est resté faible pour l’utilisation dans l’artisanat (Cs = - 0,76) et comme bois d’œuvre (Cs = - 0,83). Selon 80,2 % des répondants, les revenus tirés de l’exploitation de cette ressource contribuent significativement à l’amélioration du bien-être des ménages. En dehors de la cueillette et du ramassage des fruits, toutes les autres méthodes de récolte citées par les répondants (écorçage, prélèvement des racines, effeuillage et abatage) sont destructives, mais seulement 17,7 % des répondants en sont conscients. Une tendance régressive de la dynamique du peuplement de l’espèce est perçue par la majorité (52 %) des répondants. Selon 83,5 % des enquêtés, les habitudes en matière de culture de cette espèce sont rares voire inexistantes, à cause des difficultés de germination des graines, de la rareté des graines et des conditions climatiques défavorables à la réussite du drageonnage. Les répondants dans la quasi-totalité (99 %) se sont déclarés prêts à adopter la pratique de la culture de la plante si les contraintes de régénération sont levées. Les résultats de cette étude indiquent clairement que D. mespiliformis serait une espèce propice à la domestication participative pour l’intensification du système agroforestier dans la zone soudanienne du Tchad. Diospyros mespiliformis Hochst. is a multipurpose tree species from tropical dry forests that is still exploited in the wild and whose silvicultural practices are not documented. The aim of this study was to understand the peasants’ perceptions on the socio-economic importance, the level of vulnerability and the cultivation practice of this species in the Sudanese zone of Chad. The methodological approach consisted of surveys carried out among 350 people in 10 villages, as well as field observations. The results showed that D. mespiliformis is well known to local populations (100% of respondents) who use it in six categories of use, with a broad consensus for use in medicine (Cs = 0.96), food (Cs = 0.33), constructions (Cs = 0.26) and as fuelwood (Cs = 0.24). On the other hand, the consensus remained weak for use in crafts (Cs = - 0.76) and as lumber (Cs = - 0.83). According to 80.2 % of respondents, income from the exploitation of this resource significantly contributes to improving household well-being. Apart from picking and collecting fruit, all other harvesting methods cited by respondents (debarking, root picking, leaf stripping and felling) are destructive, but only 17.7 % of respondents are aware of this. A regressive trend in the population dynamics of the species is perceived by the majority (52 %) of respondents. According to 83.5 % of respondents, the cultivation habits of this species are rare or even non-existent, because of poor seed germination, the scarcity of seeds and climatic conditions unfavorable to the success of suckering. Almost all respondents (99 %) declared themselves ready to adopt the practice of growing the plant if the regeneration constraints are lifted. The results of this study clearly indicate that D. mespiliformis would be an interesting species for participatory domestication for the intensification of the agro-forestry system in the Sudanese zone of Chad.

GC-MS/FID analysis, antibacterial activity and modes of action of essential oils from three Aframomum species found in Cameroon against foodborne pathogenic bacteria

Background: The current study examined the chemical profile and in vitro antibacterial activity of essential oils (EOs) extracted from Aframomum danielli (leaves and seeds), Aframomum chlamydentum (leaves), and Aframomum melegueta (leaves) against foodborne pathogenic bacteria. Methods: The hydro-distillation technique using a Clevenger-type apparatus was used to extract EOs, whereas the Gas Chromatography-Mass Spectrometry (GC-MS) and GC coupled to Flame Ionization Detector (GC-FID) allowed the chemical characterization of oil constituents. The broth micro-dilution method was applied for the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Besides, some modes of action were studied on the cell membrane integrity and biofilm formation of Salmonella typhi. Results: The major compounds identified from EOs of A. danielli seeds were eucalyptol (48.707%), limonene (11.368%), beta pinene (10.342-10.335%), and alpha terpineol (8.785-9.049%), whereas EOs from A. danielli leaves were dominated by sabinene (42.87%), beta pinene, (11.22%), caryophyllene (7.84%), terpinen-4-ol (5.68%), linalool (3.48%) and gamma terpinene (2.02%). Major volatile markers from EOs of A. chlamydentum leaves comprised beta pinene (49.72%), caryophyllene (10.62%), alpha pinene (6.21%) and linalool (2.96%), while those of EOs from A. melegueta included beta pinene (37.15%), caryophyllene (17.64%), caryophyllene oxide (8.72%) and alpha pinene (8.26%). This study is the first to report on the chemical constituents of EOs from A. chlamydentum. Test oils displayed significant antibacterial activity with the MIC ranging from 0.0625 to 0.5% (v/v). EOs from A. melegueta (leaves) appeared to be the most active, acting against all tested bacteria. All EOs identified displayed bactericidal effects against Citrobacter freundii, a bacterium known to cause a broad range of infections associated with a higher rate of in-hospital mortality. The EOs from A. melegueta may act through perturbation of cell membrane integrity and permeability as well as the inhibition of bacterial biofilm formation. Conclusion: Our findings suggest the possible application of essential oils in agricultural food products for the control of bacterial diseases.

Effect of varying the concentration of sulphuric acid and ammonium hydroxide on the release of cellulose from isolated cell wall component of corn cob

The scarcity and high price associated with fossil fuel has urged countries to research resources for alternative energy sources. Biofuels like bioethanol produced from lignocellulosic biomass (corn cob) were considered potential alternative. Cellulose composition from isolated cell wall material of corn cobs was investigated under two different pre-treatments using H2SO4 and NH4OH at varying concentrations of 5%, 10%, 20%, 30% and 40%. Cell wall not treated acted as control. Colorimetric anthrone-assay followed by absorbance reading at 625nm revealed that glucose is present in reasonable amount in corn cob. The analysis of variance (ANOVA) indicated significant differences among pre-treated compared to untreated (Control) corn cob samples at p≤0.05. Acid pre-treatment showed better glucose yield compared to alkali pre-treatment with results revealing 20% (19.37µg/ml) H2SO4 to be the optimal concentration producing highest glucose yield. The study reveals the potential of corn cob as a lignocellulosic feed stock for biofuel production.

Description of Freshwater Fish Traditional Smoking in the Western Region, Cameroon

Western Cameroon is one of the regions most in needs of innovative and healthy solutions for freshwater fish conservation. This study aimed at evaluating the socio-economical characteristics of fish smokers and technical factors on the species smoked in the Noun Division. A total of 91 fish smokers were chosen. The socio-economic data were on age, gender, religion, number of dependents, marital status, ethnic group, education level, economic activities, smoking goals and workforce. The results of this study showed that fish smoking is practiced mainly by women (70%) which is common in Sub Sahara Africa small scale fish sector. The smokers are aged from 20 to 50 years (80%), married (92.2%) and taking care of a family of 1 to 10 persons (80%). These smokers are Muslim (74%), belonging to the Bamoun ethnic group (81%). They were also involved in other activities: agriculture (29%) and trade (1%). About 67% of the sampled smokers’ population had an experience of more than 10 years in the domain. The Purpose of smoking was largely sales (97%) and subsistence (3%). Nile tilapia (Oreochromis niloticus) was the most smoked species (36%), followed by African catfish (Clarias gariepinus) with a proportion of 32%. The average quantity of fresh fish smoked was 110 kg/day/smoker, with Oreochromis niloticus being more produced (60±4.74 kg/day/smoker). With regard to the smoking techniques used, hygiene measures were poorly respected. The major constraints revealed by the survey were that freshwater’s traditional fish smoking activities in Noun Division are influenced by gender, economic and cultural background. There is a lack of technical support material and financial means. Any implications for future investigations on health and food safety will be suitable for fresh fish smokers and the entire consumers.

Study on the local know-how of the use of beef hides in western Cameroon meals

The current study was conducted in four localities in the West region of Cameroon from May to September 2019, to know the pre-treatments made on given to beef hides before their use in different dishes, as well as the ingredients used in the preparation of pepper soup beef hides through household surveys. A total of 307 housewives were surveyed interviewed. The data was collected using a questionnaire and further analyzed using Sphinx Plus2 V5 software. Results showed that 54.6 to 71% participants consumed beef hides monthly. More than 50% participants purchased their beef hides at the butchery at a price varying between XAF 1,000 for 1Kg of uncleaned smoked beef hides and XAF 3,000 for 2Kg of clean smoked beef hides. The results also showed that there were five main stages in the preparation of beef hides and housewives had a greater preference of beef hides from the head and buttocks. The pre-cooking of beef hides was done between 180 and 240 minutes, with a quantity of water varying between 4 and 5 liters for 1 to 2Kg of beef hides, on the wood fire. “Eru” and “Yellow achu sauce” were cited as the main sauces in which beef hides were used at 95.40% and 85% respectively. Besides, more than 70% of housewives used a maximum of five ingredients for the preparation of pepper soup beef hides. Our findings revealed, interesting insights on the steps and ingredients used when preparing pepper soup beef hides that will be of great importance in the development of better formulation for pepper soup beef hides preparation

Impact de l’activité de butinage de Dactylurina staudingeri Gribodo (Hymenoptera: Apidae) sur la pollinisation et les rendements de Cajanus cajan (L.) Millspaugh (Fabaceae) à Dang (Ngaoundéré, Cameroun)

Les investigations ont été faites sur les fleurs de Cajanus cajan en vue d’estimer l’impact de l’activité de Dactylurina staudingeri sur la pollinisation, la production en gousses et en graines à Dang, en 2016 et 2017. Pour chacune de ces années, 540 boutons floraux ont été étiquetés sur 120 plantes réparties en quatre traitements: 120 fleurs laissées en libre pollinisation, 120 fleurs protégées des insectes, 200 fleurs protégées, puis découvertes, visitées exclusivement par D. staudingeri et de nouveau protégées et 100 fleurs protégées, découvertes et à nouveau protégées, sans visite d’insectes ou de tout autre organisme. Le taux de fructification, le nombre moyen de graines par gousse et le pourcentage de graines normales ont été comparés entre ces traitements. Sur 33 espèces d’insectes recensées, D. staudingeri était majoritaire avec 12,19% de 6037 visites. Cette abeille prélevait fortement le nectar et récoltait faiblement le pollen au niveau des fleurs de C. cajan. La vitesse moyenne de butinage était de 7,14 fleurs/min. Via l’efficacité pollinisatrice d’une visite florale, D. staudingeri a augmenté le taux de fructification de 14,71%, le nombre moyen de graines par gousse de 35,29% et le pourcentage de graines normales de 17,31%. La conservation des colonies de D. staudingeri à proximité des exploitations de C. cajan est recommandée pour assurer la hausse des rendements de cette culture et favoriser une bonne pratique de la méliponiculture dans la région.Abstract Investigations were made on the flowers of Cajanus cajan in order to estimate the impact of the activity of Dactylurina staudingeri on pollination and yields at Dang, in 2016 and 2017. For each of these years, 540 flowers buds labeled on 120 plants were divided into four treatments: 120 open-pollinated flowers, 120 bagged flowers, 200 flowers protected, then unbagged, exclusively visited once by D. staudingeri and rebagged, and 100 flowers bagged, unbagged and rebagged without insect or any other organism visit. The fruiting rate, the mean number of seeds per pod and the percentage of normal seeds were compared between these treatments. Among 33 insect species recorded, D. staudingeri was prominent with 12.19% of 6037 visits. This bee harvested intensely nectar and collected slightly pollen from C. cajan flowers. The mean foraging speed was 7.14 flowers/min. Through the pollinating efficiency of a single flower visit, D. staudingeri increased the fruiting rate by 14.71%, the mean number of seeds per pod by 35.29% and the percentage of normal seeds by 17.31%. The conservation of D. staudingeri colonies close to C. cajan farms is recommended to improve yields of the crop and to promote the good meliponiculture in the region.

Integrated Soil Fertility Management Options for Maize Production and Sustainability in the Western Highlands of Cameroon

Background: Continuous cultivation without fertilizer application and soil erosion are responsible for plant nutrient depletion and yield decline of major food crops in Sub-Saharan Africa.Methods: Nutrient status of Calliandra calothyrsus, Leucaena leucocephala, Acacia angustissima and Cassia spectabilis were characterized. Field experiments were conducted over two years in the Western Highlands of Cameroon to evaluate the effects of the application of leaf biomass of agroforestry tree species and mineral fertilizers on maize yield performance. The residual effects on soil physicochemical properties were also investigated for umbric Cambisols of Babungo and ustic Oxisols of Bansoa. Ten treatments encompassing; sole leaf biomass of Calliandra calothyrsus, Leucaena leucocephala, Acacia angustissima and Cassia spectabilis, leaf biomasses combined with NPK fertilizer, sole NPK fertilizer and absolute control were laid in a randomized complete block design and replicated three times. Data were subjected to analysis of variance and the Duncan Test (p < 0.05) used for mean separation.Results: All the species characterized had nitrogen, polyphenol and lignin contents greater than 2.5 %, 5 % and 15 % respectively. Significant differences (p < 0.05) were observed among treatments on maize growth, productivity parameters and soil chemical properties for both soil types. The highest maize grain yields were recorded in plots amended with 1 t/ha of biomass of Calliandra calothyrsus or Leucaena leucocephala as well as1.5 t/ha of biomass of Acacia angustissima and Cassia spectabilis plus mineral fertilizer (50 N+ 37.5 P2O5 + 45 K2O) on both soils compared to other treatments.on umbric Cambisols and ustic Oxisols respectively. The residual effects of treatments on soil chemical properties showed severe nutrient depletion in control plots and those amended with sole inorganic fertilizer.Conclusions: Combined application of agroforestry tree biomass and inorganic fertilizers remains an appropriate technology to enhance maize yield and sustain production of resource-limited farmers of acid tropical soils..