Phytochemical screening and antimicrobial activity of Corymbia torelliana (Myrtaceae) bark extracts

Infectious diseases represent a real public health problem. They are widespread in several regions of the world, particularly in developing countries. Opportunistic pathogens from fungal, bacterial and parasitic infections are the main causes. The aim of this study is to scientifically validate the therapeutic properties attributed to the bark of Corymbia torelliana (Myrtaceae), a plant used in the treatment of various infections in Côte d'Ivoire. It consisted of carrying out a phytochemical screening and assessing the antimicrobial activity of aqueous (EAq), hexanolic (Ehex) and ethanolic (Eeth) extracts of the plant bark on Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Trichophyton rubum and Aspergillus fumigatus. After the extractions had been carried out, phytochemical analysis of the three extracts revealed the presence of gall tannins, sterols/terpenes, polyphenols, saponosides, flavonoids and quinones, and a total absence of catechic tannins and alkaloids. The assessment of the antimicrobial activity of Corymbia torelliana bark extracts showed that the plant has bacteriostatic activity for all three extracts on all the bacterial strains tested, namely Escherichia coli (MBC=32mg/mL), Enterobacter cloacae (MBC>32mg/mL) and Enterobacter aerogenes (MBC>32mg/mL). Similarly, the hexanic extract showed fungicidal activity on Trichophyton rubum (MBC=50mg/mL) and Aspergillus fimugatus (MBC=25mg/mL) compared to the other two extracts.