摘要：
The objective of this study was to explore the immunomodulatory effects of betulinic acid (BA) extracted from the bark of white birch on mice. Female mice were orally administered BA for 14 days in doses of 0, 0.25, 0.5, and 1 mg/kg body weight. We found that BA significantly enhanced the thymus and spleen indices, and stimulated lymphocyte proliferation induced by Concanavalin A and lipopolysaccharide as shown by MTT assay. Flow cytometry revealed that BA increased the percentage of CD4(+) cells in thymus as well as the percentage of CD19(+) and the ratios of CD4(+)/CD8(+) in spleen. BA increased the number of plaque-forming cell and macrophage phagocytic activity as indicated by a neutral red dye uptake assay, and the peritoneal macrophages levels of TNF-alpha were also increased. In contrast, serum levels of IgG and IgM and serum concentrations of IL-2 and IL-6 were significantly decreased in BA-treated mice compared to the control as assayed by haemagglutination tests and ELISA, respectively. Taken together, these results suggest that BA enhances mouse cellular immunity, humoral immunity, and activity of macrophages. Thus, BA is a potential immune stimulator and may strengthen the immune response of its host.
作者机构：
[Zeng, D. L.; Liu, W.; Wang, K. Z.; Liu, Y.] Hunan Agr Univ, Coll Vet Med, Changsha 410128, Hunan, Peoples R China.;[Zhu, X. Q.] CAAS, Lanzhou Vet Res Inst, State Key Lab Vet Etiol Biol, Key Lab Vet Parasitol Gansu Prov, Lanzhou 730046, Gansu, Peoples R China.;[Zhao, G. H.] NW A&F Univ, Coll Vet Med, Yangling 712100, Shaanxi Prov, Peoples R China.;[Tan, M. Y.] Ctr Qual Quarantine Livestock Poultry & Aquacultu, Changsha 410006, Hunan, Peoples R China.;[Zhao, G. H.; Lin, R. Q.; Zhu, X. Q.; Yuan, Z. G.] S China Agr Univ, Coll Vet Med, Guangzhou 510642, Guangdong, Peoples R China.
通讯机构：
[Zhu, X. Q.] C;CAAS, Lanzhou Vet Res Inst, State Key Lab Vet Etiol Biol, Key Lab Vet Parasitol Gansu Prov, Lanzhou 730046, Gansu, Peoples R China.
摘要：
The prevalence of spargana infection in frogs (Rana nigromaculata) was investigated in China's central Hunan Province, from March 2007 to October 2009. 59 of 292 (20.2%) wild-caught frogs were found to be infected with plerocercoids (spargana) of the genus Spirometra. Spargana were recovered from the skeletal muscle of the hind limb. The infection rate ranged from 4.5% to 27.4%, and the infection intensity was 1-15 spargana per frog. To identify the species identity of the collected spargana, a portion of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene was amplified, sequenced, and analyzed. Sequence variations for cox1 among all the examined spargana were 0.0-3.1%, with 14 variable sites being identified in sequences obtained (3.1%, 14/446), representing 6 different cox1 sequences. Phylogenetic analysis showed that all the spargana isolates in Hunan province represented Spirometra erinaceieuropaei. This is the first report of S. erinaceieuropaei infection in frogs in Hunan province, China. (C) 2010 Elsevier B.V. All rights reserved.
