Background: In Cameroon, one of the most common childhood illnesses after malaria is diarrhea, which generally has
a bacterial origin. In rural areas, plant utilization is often one of the first ways of treatment though, with no scientific
bases. Therefore, the aim of this work was to evaluate the antibacterial activities of nine essential oils (EOs) of
Cameroonian plants and their combinations against some strains responsible for diarrhea.
Material and Methods: To determine the bacterial species generally involved in childhood diarrheal infections, a
retrospective study was done. The EOs of
Eucalyptus globulus
,
Cymbopogon citratus
,
Xylopia aethiopica
,
Thymus vulgaris
,
Ocimum canum
,
Cananga odorata
,
Citrus medica
,
Citrus paradisi
and
Citrus reticulata
were screened against
the most incriminated bacterial species using the spot-on-agar test and microdilution methods. Some of the EOs with
good antibacterial activity were analyzed by Gas Chromatography and Gas Chromatography/Mass Spectrometry.
According to their composition,
Thymus vulgaris and
Eucalyptus globulus EOs were combined with that of
Cymbopogon citratus using the ratios 2/1; 1/1; 1/2 (w/w) and tested against on bacterial growth.
Results: The retrospective study showed that 10.8% of infant diarrhea was caused by
Escherichia coli
,
Salmonella typhimurium
and
Salmonella paratyphimurium. The Minimum inhibition Concentrations (MIC) of single EOs was
between 0.78 and 25 mg/mL which were observed to be greater than those of their combinations which ranged between
0.195 and 6.52 mg/mL. The active essential oils contained mainly hydrocarbonated and oxygenated monoterpens.
Conclusion: The good antibacterial effects of two
Thymus combinations
Th1 and
Th2 observed on
Salmonella
typhimurium and
Salmonella paratyphimurium suggest their used in aromatherapy to cure bacterial diarrhea.