Tchuenguem Fohouo Fernand-Nestor

The anthelmintic activity of the ethanolic and aqueous extracts of Foumban propolis and PROMAX-C was evaluated in vitro, on the nematode parasite of cattle Onchocerca ochengi. The objective of this study was to find an alternative of synthetic anthelmintic to fight human and animal onchocerciasis. Increasing concentrations of ethanolic and aqueous extracts of propolis and PROMAX-C were prepared in RPMI 1640 culture medium for O. ochengi incubation. Dimethylsulfoxide of 0.5 % concentration was the negative control and the positive control was ivermectin. The anthelmintic activity was assessed every 24 and 48 hours and expressed as mortality rate. Acute oral toxicity was assessed in Mus musculus for 14 days and subacute toxicity was assessed in males and females of Ratus norvegicus for 28 days. Quantification of polyphenols, tannins and flavonoids was performed with a spectrophotometer using gallic acid and rutin as standards. The LC50 value was 52.50 ± 0.04 µg/mL for PROMAX-C, while those of the ethanolic and aqueous extracts were 75.50 ± 0.92 and 261.44 ± 18.98 µg/mL, respectively after 48 hours. The test with ivermectin showed a high efficacy on O. ochengi nematodes with a LC50 value of 100.05 ± 0.35 µg/mL. The ethanolic extract of propolis did not show signs of toxicity on mice. During subacute toxicity, the relative organ weights (kidney, liver, lung, spleen and heart) taken from the rats at the end of treatment did not change significantly. Biochemical showed a decrease in AST and ALT in both sexes at all doses. Thus, the consumption of propolis and PROMAX-C is recommended to fight against onchocerciasis.

To evaluate the apicultural value of Annona senegalensis and the impact of Apis mellifera on fruit and seed yields of this Annonaceae at Dang, its foraging and pollinating activities were studied, from March to June in 2017 and 2020. Observations were carried out on 540 flowers divided in four treatments: 120 flowers accessible to all insects; 120 flowers bagged to avoid all visits; 200 flowers protected then uncovered during anthesis, to allow only Ap. mellifera visits; 100 flowers bagged then uncovered and rebagged without the visit of insects or any other organism. Workers daily rhythm of activity, their foraging behavior on flowers and their pollination efficiency were evaluated. Results showed that, honeybee foraged on An. senegalensis flowers throughout its whole blooming period. This bee intensely and exclusively harvested pollen. The greatest number of workers foraging simultaneously was 3 per flower and 340 per 1000 flowers. The mean foraging speed for each studied year was 3 flowers/min. Through its pollination efficiency on An. senegalensis, Ap. mellifera increased the fruiting rate by 26.19%, the mean number of seeds per fruit by 16.33% and the percentage of normal seeds by 22.41%. Hence, the installation of Ap. mellifera hive close to An. senegalensis plantations is recommended for increase beebread production as a hive product, and to improve fruit and seed yields of this plant.