title: Effects of Thai piperaceae plant extracts on Neospora caninum infection.
abstract: Neosporosis has a worldwide distribution and causes economic losses in farming, particularly by increasing the risk of abortion in cattle. This study investigated the effects of Thai piperaceae (Piper betle, P. nigrum, and P. sarmentosum) extracts on Neospora caninum infections in vitro and in vivo. In an in vitro parasite growth assay based on the green fluorescent protein (GFP) signal, P. betle was the most effective extract at inhibiting parasite growth in human foreskin fibroblast cells (IC50of GFP-expressing N. caninum parasites, 22.1μg/ml). The P. betle extract, at 25μg per ml, inhibited parasite invasion into host cells. Furthermore, in two independent experiments, treating N. caninum-infected mice with the P. betle extract for 7days post-infection increased their survival. In trial one, the anti-N. caninum effects of the P. betle extract reduced the mouse clinical scores for 30days post-infection (dpi). The survival rate of the mice treated with 400mg/kg was 100% compared with 66.6% for those treated with 100mg/kg and the non-treated controls. In trial two, treating the infected mice with the P. betle extract increased their survival at 50dpi. All mice in the non-treatment group died; however, the survival rates of the 400mg/kg-treated and 100mg/kg-treated mice were 83.3% and 33.3%, respectively. Also, a trend towards a reduced parasite burden was noted in the brains of the P. betle extract-treated mice, compared with the control mice. Therefore P. betle extract has potential as a medicinal plant for treating neosporosis.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan. Electronic address: arpron.lee@mahidol.ac.th.
authors.forename: Arpron
authors.initials: A
authors.lastname: Leesombun
authors.affiliation: Department of Preclinical and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, 999 Phutthamonthon Sai 4 Road Salaya, Phutthamonthon, Nakhon Pathom 73170, Thailand. Electronic address: sookruetai.boo@mahidol.ac.th.
authors.forename: Sookruetai
authors.initials: S
authors.lastname: Boonmasawai
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan. Electronic address: nisikawa@obihiro.ac.jp.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Nishikawa
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan; D001921:Brain / Q000469:parasitology; D003048:Coccidiosis / Q000188:drug therapy* / Q000453:epidemiology / Q000469:parasitology; D005260:Female; D005347:Fibroblasts / Q000469:parasitology; D049452:Green Fluorescent Proteins; D006801:Humans; D051379:Mice; D018688:Neospora / Q000187:drug effects* / Q000254:growth & development; D059208:Parasite Load; D008517:Phytotherapy; D031721:Piper betle / Q000737:chemistry*; D010936:Plant Extracts / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D013785:Thailand / Q000453:epidemiology
chemical_list: D000913:Antibodies, Protozoan; D010936:Plant Extracts; D049452:Green Fluorescent Proteins
keywords: Ethanol extract; Neospora caninum; Neosporosis; Piper betle; Piper nigrum; Piper sarmentosum