Bioactive constituents from seeds of Annona Senegalensis Persoon (Annonaceae)

Phytochemical and bioactive potentials of African Annonaceae species

This review aims to gather available information on the medicinal, nutritional, and bioactive profiles of Annonaceae species in the African continent, sponsoring their use worldwide and mainly in African communities, where access to food and medicines for basic health care is scarce. >60 medicinal taxa were compiled, belonging to 22 genera, namely Annickia, Annona, Anonidium, Artabotrys, Cleistochlamys, Cleistopholis, Dennettia, Duguetia, Greenwayodendron, Hexalobus, Isolona, Lettowianthus, Monanthotaxis, Monodora, Neostenanthera, Polyceratocarpus, Sphaerocoryne, Uvaria, Uvariastrum, Uvariodendron, Uvariopsis and Xylopia; the most diverse and economically important genera were the genera Annona, Uvaria and Xylopia with 7 species each. Annonaceae species hold a valuable nutritional profile, rich in proteins, fibers, and minerals, being also good sources of a wide range of bioactive compounds of high biological relevance. These compounds are especially important in developing countries, where most of these species are available for direct use as food and/or medicines by the most deprived populations.

Health-promoting foods and food crops of West-Africa origin: The bioactive compounds and immunomodulating potential

The rural communities of the sub-Sahara regions in Africa are rich in diverse indigenous culinary knowledge and foods, food crops, and condiments such as roots/tubers, cereal, legumes/pulses, locust beans, and green leafy vegetables. These food crops are rich in micronutrients and phytochemicals, which have the potentials to address hidden hunger as well as promote health when consumed. Some examples of these are fermented foods such as ogi and plants such as Vernonia amygdalina (bitter leaf), Zingiber officinales (garlic), Hibiscus sabdariffa (Roselle), and condiments. Food crops from West Africa contain numerous bioactive substances such as saponins, alkaloids, tannins, phenolics, flavonoids, and monoterpenoid chemicals among others. These bioresources have proven biological and pharmacological activities due to diverse mechanisms of action such as immunomodulatory, anti-inflammatory, antipyretic, and antioxidant activities which made them suitable as candidates for nutraceuticals and pharma foods. This review seeks to explore the different processes such as fermentation applied during food preparation and food crops of West-African origin with health-promoting benefits. The different bioactive compounds present in such food or food crops are discussed extensively as well as the diverse application, especially regarding respiratory diseases. PRACTICAL APPLICATIONS: The plants and herbs summarized here are more easily accessible and affordable by therapists and others having a passion for promising medicinal properties of African-origin plants.The mechanisms and unique metabolic potentials of African food crops discussed in this article will promote their applicability as a template molecule for novel drug discoveries in treatment strategies for emerging diseases. This compilation of antiviral plants will help clinicians and researchers bring new preventive strategies in combating COVID-19 like viral diseases, ultimately saving millions of affected people.

Antibiofilm, antiquorum sensing and antioxidant activity of secondary metabolites from seeds of Annona senegalensis, Persoon

The increasing resistance of bacteria to antibiotics has motivated the interest in potent natural compounds capable of disrupting bacterial cell-to-cell communication. Column chromatography of seed extract of Annona senegalensis afforded N-cerotoyltryptamine (1), asimicin (2) and ent-19-carbomethoxykauran-17-oic acid (3). The compounds were tested for their antimicrobial, antibiofilm, and anti-quorum sensing activities. The minimum inhibitory concentrations (MIC) values ranged from 50 μg/mL to 100 μg/mL for C. albicans ATCC 10239 and S. aureus ATCC 25923 E. coli ATCC 25922, C. violaceum CV026 and C. violaceum CV12472. All the compounds inhibited biofilm formations of all microorganisms tested in various percentages at MIC and MIC/2. Compound 2 also exhibited the highest antibiofilm activity against C. albicans (yeast) and E. coli with percentage inhibitions ranging from 6.3 ± 4.1 (MIC/4) to 37.9 ± 4.5 (MIC) for C. albicans and from 18.8 ± 1.1 (MIC/4) to 43.2 ± 0.5 (MIC) for E. coli. Compound 1, however, showed highest biofilm inhibition on S. aureus as the percentage inhibition varied from 26.7 ± 3.6 (MIC/4) to 43.8 ± 2.1 (MIC). Compound 2 showed highest percentage violacein inhibition on C. violaceum CV12472 ranging from 10.2 ± 0.5 (MIC/8), 65.76 ± 1.3 (MIC/2) and 100 (MIC). Compound 1 and 3 had percentage violacein formation inhibitions on C. violaceum CV12472 ranging from 9.66 ± 1.1 (MIC/4) to 100 (MIC), and from 17.4 ± 2.4 (MIC/4) to 100 (MIC), respectively. Swimming and swarming motility of P. aeruginosa PA01 strain was evaluated at three concentrations of 50, 75 and 100 μg/mL. The compounds inhibited the P. aeruginosa swimming and swarming motility at the three tested concentrations (50, 75 and 100 μg/ml) in a dose-dependent manner. The extents of inhibition of motility migration was relatively higher in the swimming model than in the swarming model for all compounds. Compound 1 exhibited the highest percentage inhibition of motility of 41.50 ± 3.5 and 39.73 ± 1.5 in swimming model and swarming model respectively at 100 μg/ml. Compound 3 showed the lowest percentage inhibition of 30.36 ± 2.0 and 23.50 ± 2.5 in swimming and swarming respectively at 100 μg/ml. At the lowest tested concentration of 50 μg/ml, it was compound 2 showing the highest inhibition of motility of 17.49 ± 0.5 and 14.29 ± 1.0 in swimming and swarming respectively. Compound 1 showed highest quorum sensing (QS) activity with QS inhibition zone of 20.0 ± 1.5 mm at MIC and 11.0 ± 1.0 mm at MIC/8 while compound 2 had the highest antimicrobial (AM) zone diameter amongst the compounds at MIC. Compound 3 was the QS inhibitory sample and did not show any QS inhibition at MIC/8 while showing its highest QS inhibition zone of 13.0 ± 1.6 mm at MIC. For antioxidant assays, no sample showed better activity than the standards. Compound 2 had highest activity with IC₅₀ values of 87.79 ± 2.70 and 42.77 ± 1.53 μg/mL in DPPH and β-carotene-linoleic acid assay respectively and was more active (IC₅₀ of 97.69 ± 1.40 μg/mL) than standard quercetin (IC₅₀ 250.09 ± 0.87 μg/mL) in metal chelation assay.