Kidney cells of canine embryos were separated into single cells using collagenase and dispase. Primary culture was conducted using these cells. To remove fibroblasts, these cells were treated with edetate disodium dihydrate (Na2EDDA), and pure epithelial cells were separated. Recombinant retrovirus particles that manifest teromerase were produced and inoculated into primary culture cells to produce immortalized canine cell strains (JNUCK-1 and JNUCK-2). To examine the characteristics of the produced cell strains, the growth curve, maximum cultured households, and expressed proteins (keratin) were identified. The JNUCK-1 and JNUCK-2 cell lines showed division ability until the 30th generation without growth retardation. JNUCK-1 and JNUCK-2 cell lines clearly expressed telomerase until the 25th generation. The canine distemper virus (CDV) was inoculated into the JNUCK-1 and JNUCK-2 cell lines, as well as in the Madin–Darby canine kidney (MDCK) cell line. The maximum titer of CDV from the JNUCK-1 cell strain was about 200 times higher than that from the MDCK cell strain. However, the JNUCK-2 cell strain produced a lower titer than the MDCK cell strain. We established a new canine kidney epithelial cell line (JNUCK-1) that could produce CDV with high titer.

Toxoplasmosis is an important cause of foodborne, inflammatory, as well as congenital abnormalities. There is an urgent need for safe and effective therapies to eliminate or treat this cosmopolitan infectious disease. A medicinal herbal plant, Meliae fructus, has been used to soothe the liver and kills worms in Chinese medicine. In this study, Meliae fructus ethanol extract was examined and screened for its anti-T. gondii activity. For anti-T. gondii activity screening, in vitro study of Meliae fructus extract using tachyzoit of T. gondii RH strain-infected HeLa cells was performed. Further, in vivo anti-T. gondii study using a mouse infection model was conducted. Safety of herbal compounds was evaluated in SD rats by treatment with Meliae fructus extract for 28 days. As a result, selectivity of Meliae fructus ethanol extract was 5.85, which was higher than sulfadiazine selectivity (2.06). We also performed an in vivo study to evaluate the anti-T. gondii activity of Meliae fructus extract in a mouse model. The inhibition rate of Meliae fructus extract was as high as that of sulfadiazine. These results demonstrate that Meliae fructus can successfully cure T. gondii infection and could be a promising native herb treatment for prevention of T. gondii infection.