Antifungal Effect of Essential Oils against Fusarium Keratitis Isolates

Abstract

The present study was carried out to investigate the antifungal effects of Cinnamomum zeylanicum, Citrus limon, Juniperus communis, Eucalyptus citriodora, Gaultheria procumbens, Melaleuca alternifolia, Origanum majorana, Salvia sclarea, and Thymus vulgaris essential oils against Fusarium species, the most common etiologic agents of filamentous fungal keratitis in South India. C. zeylanicum essential oil showed strong anti-Fusarium activity, whereas all the other tested essential oils proved to be less effective. The main component of C. zeylanicum essential oil, trans-cinnamaldehyde, was also tested and showed a similar effect as the oil. The in vitro interaction between trans-cinnamaldehyde and natamycin, the first-line therapeutic agent of Fusarium keratitis, was also investigated; an enhanced fungal growth inhibition was observed when these agents were applied in combination. Light and fluorescent microscopic observations revealed that C. zeylanicum essential oil/trans-cinnamaldehyde reduces the cellular metabolism and inhibits the conidia germination. Furthermore, necrotic events were significantly more frequent in the presence of these two compounds. According to our results, C. zeylanicum essential oil/trans-cinnamaldehyde provides a promising basis to develop a novel strategy for the treatment of Fusarium keratitis.

In vitro efficacy of essential oils and extracts of Schinus molle L. against Ctenocephalides felis felis.

“…Assays with Saccharomyces cerevisiae yeast cells in the presence of the essential oils obtained from fruit and leaves did not show toxicity levels near the LD 50 found in our study. This seems confusing given the strong antifungal activity of essential oils, such as of Cinnamomum zeylanicum on the pathogenic filamentous fungus Fusarium keratitis (Homa et al 2015), or of Melaleuca alternifolia on the fungus Botrytis cinerea (Yu et al 2015).…”

Essential Oils and Their Natural Active Compounds Presenting Antifungal Properties

“…In addition, some of its compounds could have anti-cancer activities [49]. A study on the effect of Cinnamomum verum essential oil on Fusarium strains responsible for keratitis in humans was conducted and showed an efficacy at a concentration between 31.25 and 500 μg/mL, depending on the strain studied [50].…”

In vitro effect of seven essential oils on the reproduction of the cattle tick Rhipicephalus microplus

“…The Pelargonium graveolens essential oil has been used due to its hypoglycemic and antioxidant [12] properties, and exhibits also antifungal and insecticidal activities against Rhizoctonia solani and Rhysopertha dominica, respectively [13]. The use of Citrus aurantium essential oil by Homa et al [14] revealed the antifungal activity against different isolates of Fusarium keratitis, antibacterial activity against Vibrio species [15], as well as insecticidal activity against Aedes aegypti and Anopheles dirus [16]. As mentioned above, there are many properties of these essential oils, but there are only few studies on their acaricidal effects despite the great interest on finding alternative control methods.…”