Essential Oils for the Prevention and Treatment of Human Opportunistic Fungal Diseases

Abstract

Human infectious diseases have significantly increased during the past decade, especially among immunocompromised patients. As high as 10% of hospital acquired systemic infections are caused by fungi. Among animal and human pathogens, the dermatomycetes group is the main cause of dermatomycoses, which are chronic but not life threatening infections that bring about considerable morbidity. Under certain circumstances Candida spp. commensals (ie, C. albicans and some non-albicans species) can become pathogenic, which causes amucous membrane infection to turn into a life-threatening systemic disease, particularly in patients with a weakened immune system. In addition to increased resistance of human pathogens to current commercial drugs, conventional treatments have many adverse side effects, thus drugs may become insufficient for treatment and this presents a serious medical problem. Hence, the development of more effective and less toxic antifungal agents, including natural products, is vitally important. Due to their biologically active secondary metabolites, many plants have been traditionally used in ethnomedicine for their therapeutic antifungal potential, with some recent experimental compounds proven to be promising. Essential oils and/or their individual constituents play an important role as potential therapeutic agents. The main advantage is their lipophilic nature, which allows the compounds to easily penetrate the plasma membrane, in addition to the ability to cure opportunistic fungal diseases without harmful effects on human and animal tissues. With growing interest in the use of essential oils in the pharmaceutical industry, systematic examination of their preventive and therapeutic properties has become increasingly important. This paper reviews the antifungal efficacy of essential oils belonging to various plant families for the prevention and treatment of common opportunistic diseases in humans (i.e., dermatomycosis and candidosis), specifically those infections caused by fungi with primary entry routes through skin and mucosa.