Inhibitory effect of essential oils obtained from plants grown in Colombia on yellow fever virus replication <it>in vitro</it>

• Main Authors: Martínez Jairo R, Ocazionez Raquel E, Meneses Rocío, Stashenko Elena E
• Format: Article
• Language: English
• Published: BMC 2009-03-01
• Series: Annals of Clinical Microbiology and Antimicrobials
• Online Access: http://www.ann-clinmicrob.com/content/8/1/8

<p>Abstract</p> <p>Background</p> <p>An antiviral drug is needed for the treatment of patients suffering from yellow fever. Several compounds present in plants can inactive <it>in vitro </it>a wide spectrum of animal viruses.</p> <p>Aim</p> <p>In the present study the inhibitory effect of essential oils of <it>Lippia alba, Lippia origanoides, Oreganum vulgare </it>and <it>Artemisia vulgaris </it>on yellow fever virus (YFV) replication was investigated.</p> <p>Methods</p> <p>The cytotoxicity (CC₅₀) on Vero cells was evaluated by the MTT reduction method. The minimum concentration of the essential oil that inhibited virus titer by more than 50% (MIC) was determined by virus yield reduction assay. YFV was incubated 24 h at 4°C with essential oil before adsorption on Vero cell, and viral replication was carried out in the absence or presence of essential oil. Vero cells were exposed to essential oil 24 h at 37°C before the adsorption of untreated-virus.</p> <p>Results</p> <p>The CC₅₀values were less than 100 μg/mL and the MIC values were 3.7 and 11.1 μg/mL. The CC₅₀/MIC ratio was of 22.9, 26.4, 26.5 and 8.8 for <it>L. alba, L origanoides, O. vulgare and A. vulgaris</it>, respectively. The presence of essential oil in the culture medium enhances the antiviral effect: <it>L. origanoides </it>oil at 11.1 μg/mLproduced a 100% reduction of virus yield, and the same result was observed with <it>L. alba, O. vulgare </it>and <it>A. vulgaris </it>oils at100 μg/mL. No reduction of virus yield was observed when Vero cells were treated with essential oil before the adsorption of untreated-virus.</p> <p>Conclusion</p> <p>The essential oils evaluated in the study showed antiviral activities against YFV. The mode of action seems to be direct virus inactivation.</p>