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.

This study examined the efficacy of natural ingredient formulated herbal medicine as feed additives against coccidiosis in broiler chicken. Medicinal herbs used in this study were Artemisia annua, Pulsatilla chinensis, Clematis chinensis and Scutellaria baicalensis. Two week old chicks were administered with 1% ingredient formulated herbal medicine. Observations of the efficacy were confirmed by examining the lesion score, histopathological appearance of cecum, shedding of fecal oocyst and production index in farm. S. baicalensis of the most effective substance were analyzed by UPLC. The results are as follows; among various types of Chinese medicine, the most efficacious ingredient was found to be pure bicalein. The major index substance is bicalein and 13 μg/ml per gram was found. Feeding of chickens with S. baicalensis induced the coccidiostat effect and reduced the fecal shedding of E. tenella oocyst by 14%. Experimental results on a farm, feed conversion ratio and weight gain and production rate in the group with natural ingredient formulated additives than in control group increased. The rate of weight gain (%) in each experimental group showed 108% and 126% increase while the mortality rate was 1.4% lower than the control group. The investigation showed that the most efficacious ingredient was found to be S. baicalensis among herbal medicine products for coccidiostats. However, as it was found in the farm experiment that pure S. baicalensis alone is economically unviable. The additives with cocktailed of efficacious ingredient are suggested to be implemented for effective protection against coccidiosis.

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