Oregano And Thyme Oil Especially Useful in the prevention of fungi growth. Many herbs, vegetables, and fruits contain significant quantities (1% of more of dry weight) of fatty compounds called essential oils.
Most of these essential plant oils have a strong fragrance and/or taste and are often used as fragrances, cosmetics, or as herb-like flavors in foods. Many of the essential oils provide much of the flavor in herbs like thyme and mint. Some of these essential oils also have strong anti-fungal properties as well.
A Czech Republic study tested the efficacy of 20 essential plant oils against 4 types of common indoor fungi (molds) including Alternaria alternata, Stachybotrys chartarum, Cladosporium cladosporoides, and Aspergillus niger. Growth of the 4 fungi were tested in petri plates containing low concentrations of one of the 20 essential oils. The two most effective anti-fungal essential oils were obtained from Origanum vulgare (oregano) and Thymus vulgaris (thyme). Both the oregano and thyme essential oils completely inhibited growth of all 4 fungi at concentrations of 0.014% or less. Other highly effective anti-fungal essential oils were obtained from Coriandrum sativum (coriander), Ocimum citriodorum (basil), Carum carvi (caraway), and Pimenta racemosa (bay). The essential oils from the following plants were also effective against all 4 fungi, except for Aspergillus niger- the most resistant species; Citrus aurantium (bitter orange), Lavandula angustifolia (lavender), Mentha arvensis and pulegium (mint), and Salvia sclerea (clary).
Many of these essential oils are effective against fungal at concentrations at or below those of synthetic fungicides such as azoles used in agricultural and medicine. Moreover, these essential oils often have significantly less adverse side effects to plants, animals, and people than most synthetic antifungal fungicides/drugs. The use of essential oils offer great promise in controlling fungi growth on agricultural crops, on stored foods, and in indoor environments. In the future, essential oils may perhaps be used to prevent and treat human fungal diseases.