Abstract

The present study was carried out to develop a new natural product reagent which has antimicrobial and antiviral effect, so we assayed the extract from Korean Arbor vitae (Thuja koraiensis) on antimicrobial and antiviral in vitro. The antimicrobial activity was assayed at two gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis); two gram-negative bacteria (Escherichia coli, Salmonella typhimurium) and the results were measured by the paper disc diffusion assay and minimum inhibitory concentration (MIC). The antiviral activity of T. koraiensis extract was assayed at the Bovine viral diarrhoea (BVD) virus which is a RNA virus replication in Madin-Darby bovine kidney (MDBK) cells and the results were measured by maximum non cytotoxic concentration (MNCC) and maximum non-toxic dose (MNTD). The result of paper disk diffusion assay showed that extract had the high antimicrobial effect at S. aureus strain. The MNCC of extract on MDBK cells was 0.031% and the MNTD of extract was 0.0195% on BVD virus. These results suggested that T. koraiensis extract had antimicrobial and antiviral effect, especially at low concentrations which had a strong antiviral effect at BVD virus. The T. koraiensis extract could also be useful as disinfectant for bacterial. The study of T. koraiensis function perhaps would be the first and more research is needed in the future.

Key words: Thuja koraiensis extract, antimicrobial activity, minimum inhibitory concentration, maximum non cytotoxic concentration, maximum non-toxic dose, antiviral activity.