Microbial infections till date remain a scourge of humanity due to lack of vaccine against some infections, emergence of drug resistant phenotypes, and the resurgence of infections amongst others. Continuous quest for novel therapeutic approaches remains imperative. Here we (i) assessed the effects of extracts/hydrolates of some medicinal plants on pathogenic microorganisms and (ii) evaluated the inhibitory potential of the most active ones in combination with antibiotics. Extract E03 had the highest DZI (25 mm). Extracts E05 and E06 were active against all microorganisms tested. The MICs and MBCs of the methanol extracts ranged from 16.667 × 103  μg/mL to 2 μg/mL and hydrolates from 0.028 to 333333 ppm. Extract E30 had the highest activity especially against S. saprophyticus (MIC of 6 ppm) and E. coli (MIC of 17 ppm). Combination with conventional antibiotics was shown to overcome resistance especially with E30. Analyses of the extracts revealed the presence of alkaloids, flavonoids, triterpenes, steroids, phenols, and saponins. These results justify the use of these plants in traditional medicine and the practice of supplementing decoctions/concoctions with conventional antibiotics. Nauclea pobeguinii (E30), the most active and synergistic of all these extracts, and some hydrolates with antimicrobial activity need further exploration for the development of novel antimicrobials.

Objective: Changing forest composition and structure caused by selective logging may affect forest phenology either alone or in combination with other environmental factors. The present study aims to analyze the phenological pattern of some exploitable timber tree species in two forest types. Methodology and Results: Eleven economically important tree species were selected for monitoring at three DBH size classes using the crown density method originally devised by Koelmeyer (1959). Quantitative monthly data were collected from September 2011 to December 2014 for the timing, duration and frequency of flowering, and fruiting. A total of 58 individuals were observed in both forest types. There was a significant difference between forest types and species for flowering (p≤0.001) and fruiting (p≤0.001). However, there was no significant difference in flowering and fruiting between individuals of the same species in both forest types. Flowering occurred during the light wet season and fruiting during the heavy wet season to ensure the availability of seeds to germinate into seedlings. Conclusions and application of findings: Phenology was mainly constrained by the biotic determinants of phenology. However while the determinants of phenology are intact in the unlogged forest types, they are destabilized by selective logging causing an alteration in plant species. Thus, activities that are specifically designed to enrich selectively logged sites are necessary in order to promote the natural regeneration of timber species after selective logging.

Citrus farming is currently a main sector in Africa in general, particularly in the sub-Saharan region. Citrus farming in Cameroon has been expanding since the cocoa crisis and thanks to its financial and economic benefits. The research aim was to evaluate the parasitism of Loranthaceae on citrus trees in the Mongo department. Direct observations were made in the canopy of 796 citrus trees in seven arrondissements, and included species identification, and the Loranthaceae species growing on their foliage. Alive and dead tufts were numbered to estimate parasitism density and mortality rate. Five species of Loranthaceae identified on six citrus species. Tapinanthus predominated with three species, T. bangwensis T. preussii and Tapinanthus sp. Phragmanthera capitata was the most frequent (75.37%), and T. preussii was scattered (2.33%). The highest mean parasitic density was obtained in T. bangwensis has the higher parasitic density (5.76±5.17 tufts/tree), followed by Helixanthera mannii (5.42±4.13 tufts/tree). The highest rate of parasitism was obtained on C. maxima (89.77%), and the highest natural mortality rate of Loranthaceae was on C. medica (12.5%). Loranthaceae have already greatly expanded in Citrus, it recommended to set up a monitoring system to protect the yields.

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To assess the antibacterial and cytotoxic properties of stem-barks of Feretia apodanthera and Erythrophleum ivorense extracts from powdered stem-barks of Feretia apodanthera and Erythrophleum ivorense were prepared following standard techniques of marceration, filtration and evaporation. Antibacterial activity was assayed against five pathogenic bacteria strains by the well-diffusion and broth microdilution methods. Cytotoxicity was measured by acute toxicity test on female albino rats and confirmed by cell viability assay using 3T3 cell lines. Phytochemical analysis was performed following standard techniques. The aqueous/alkaloid extracts of Feretia apodanthera and the ethanol extract of Erythrophleum ivorense were active against the five pathogenic bacteria strains tested (diameter zone of inhibition (DZI) ranging from 5.1 to 17.8mm). The Feretia apodanthera extracts were the most active against Staphylococcus aureus (DZI 17.1-17.8mm). The MIC and MBC of the extracts of both plants ranged from 0.094mg/ml to 48mg/ml and 0.047mg/ml to 48mg/ml respectively. Extracts of Feretia. apodanthera at 5000mg/Kg had no effect on the behavioural properties of rats and no death was observed. Incubation with 3T3 cell lines did not produce any cell toxicity up to 20mM and 5mM respectively for the aqueous extract and the alkaloid fraction. Incubation with higher concentrations produced cell death with IC50 of 39.41 ± 0.95mM and 38.45 ± 1.64mM respectively. Phytochemical analysis revealed the presence of various constituents. The results show for the first time that stem-bark extracts of F. apodanthera and E. ivorense possess antibacterial activities against common human pathogenic bacteria and the low/lack of toxicity as demonstrated with the F. apodanthera extracts justify and confirm their safe ethnomedical uses.

Aromatic plants are one of the components of Cameroonian medicinal flora that seem to be an alternative to fight against the Covid-19 disease. The present study aims to establish chemical characterization of some aromatic plant organs used in the Douala IV sub-division during the COVID-19 pandemic. A semi-structured survey was carried out between September and December 2020 in order to identify aromatic plants used for health diseases during the Covid-19 pandemic. Due to their ethnobotanical index the selected plants were screened chemically through staining and precipitation methods to determine different bioactive compounds. Thirty-one (31) plant species belonging to 17 families were recorded with the dominated by Lamiaceae and Zingiberaceae being the dominant families and Ocimum gratissimum as the most cited species (28.57%) in the composition of recipes. Leaves (50.80%) were the most used organs to prepare the decoctions (33.33%) administered to patients orally. These plants were used in the treatment of 51 ailments diseases, notably malaria, cough and typhoid fever with 22, 21 and 12 citations respectively. Informant Consensus Factors (ICF) showed a relatively high agreement (0.75) for the use of species against respiratory diseases. Zingiber officinale, Citrus limon and Cymbopogon citratus had a good performance (Ip = 3) against cough, typhoid and malaria respectively. Extracts of aromatic plant organs were rich in alkaloids and phenolic compounds. These aromatic species showed their ability to treat respiratory and other infectious diseases, and could be an alternative to fight against Covid-19. Keywords: Aromatic plants; Bioactive compounds; Douala IV; Drug recipes; Ethnobotanical index.