Mangifera indica Bark Essential Oil: Chemical Composition and Biological Activities in Comparison with Aqueous and Ethanol Extracts

Ethnobotanic surveys have revealed the use of Mangifera indica L. (Anacardiaceae) bark for the treatment of infectious diarrhea. The essential oil of M. indica bark is described for the first time for its chemical composition, radical scavenging activity (DPPH method) and antimicrobial properties. The total phenols content of its water and ethanol bark extracts as well as their radical scavenging and antimicrobial properties were also evaluated. Four commercial plant extracts were also studied for a comparison purpose. The antimicrobial activities were measured for all samples against three Gram (-): Escherichia coli, Salmonella enteritidis, Shigella and two Gram (+): Staphylococcus aureus and Bacillus cereus bacteria. The M. indica bark essential oil was characterized by the association of two major sesquiterpenes: (E)-β-caryophyllene (60.3%) and α-humulene (36.7%). It presented the lowest ratio of concentration to inhibition zone diameter on all the strains. The aqueous and ethanol extracts of M. indica bark were characterized by high contents of total phenols compounds and high radical scavenging activity compared to the essential oil. Finally, the interesting combination of the antibacterial and antiradical activities of the aqueous M. indica bark extract justifies the traditional use of this plant part in decoction form for the treatment of diarrheal infections.