In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes

• Published in: Brazilian journal of microbiology 2014-01, Vol.45 (1), p.209-214
• Main Authors: Kubiça, Thaís F, Alves, Sydney H, Weiblen, Rudi, Lovato, Luciane T
• Format: Article
• Language: English
• Subjects: Antimicrobial agents; Antiviral Agents - isolation & purification; Antiviral Agents - pharmacology; Antiviral Agents - toxicity; Cattle; Cell Survival - drug effects; Colorimetry - methods; Diarrhea; Inhibitory Concentration 50; Microbial Sensitivity Tests; MICROBIOLOGY; Monoterpenes - isolation & purification; Monoterpenes - pharmacology; Monoterpenes - toxicity; Ocimum basilicum - chemistry; Oils, Volatile - isolation & purification; Oils, Volatile - pharmacology; Oils, Volatile - toxicity; Pestivirus - drug effects; Pestivirus - growth & development; Phytochemicals; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; Plant Extracts - toxicity; Research Paper; Tetrazolium Salts - metabolism; Thiazoles - metabolism; Viral infections; Viral Plaque Assay; Virus Inactivation
• ISSN: 1517-8382; 1678-4405; 1678-4405
• DOI: 10.1590/S1517-83822014005000030

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL(-1)) and 1,8-cineole (CC50 = 2996.10 μg mL(-1)) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle.