OPTIMIZED COMBINATIONS OF OCIMUM ESSENTIAL OILS INHIBIT GROWTH OF FOUR Candida albicans

Drug combinations against candidiasis and other fungal infections have been considered as alternatives for mono-therapy.However, there are no data available on the combination of essential oils from Ocimum genus.The aim of this work is the optimization of essential oils derived from Cameroon-grown Ocimum against four Candida albicans.The essential oils were extracted by hydrodistillation.The anti-candidal activities were assessed using broth dilution technique and the combinatorial analysis was done using central composite design, the latter being maximised by a multiple response optimization approach.The optimums were tested for their efficiency using the time kill kinetic approach.Linalool (53.34%), 1,8 Cineol (55.32%), γ-Terpinene (24.54%),Eugenol (26.01%) were the major componentsfor Ocimum basilicum, Ocimum canum, Ocimum gratissimum and Ocimum urticaefolium respectively.The most active oil was Ocimum gratissimum followed by Ocimum basilicum and Ocimum urticaefolium, the least active being Ocimum canum.The optimum values were 0.62/0.14mg/mlwith desirability of 96%for the combination of Ocimum basilicum/Ocimum gratissimum and 0.58/0.14mg/mlwith the desirability of 98% for Ocimum urticaefolium/ Ocimum gratissimum.The optimum values of 0.56/0.63mg/mland the desirability of 100%for the combination of Ocimum urticaefolium/ Ocimum basilicum.All these combinations inhibited the growth of the fungal strain for 20 hours.Our research shows that the Ocimum essential oils have an antifungal activity and that this potential is increased when the essential oils are combined.More research is needed to extend this potential to other microbial strains .