title: In vitro effects of aqueous extracts of Astragalus membranaceus and Scutellaria baicalensis GEORGI on Toxoplasma gondii.
abstract: Toxoplasma gondii is a parasite that infects animals and humans worldwide. The standard treatment for toxoplasmosis is limiting due to toxic adverse effects, thus there is a need to identify new drugs that are less toxic. Both Astragalus membranaceus and Scutellaria baicalensis GEORGI are popular traditional Chinese herbs widely used for the treatment of various inflammatory diseases in Asia, and we have previously demonstrated that water extracts of A. membranaceus (AmE) and S. baicalensis GEORGI (SbE) have good efficacy in controlling T. gondii replication in mouse models. This study was designed to further evaluate their effects against developing tachyzoites of the RH strain of T. gondii in HeLa cell cultures. AmE, SbE, and TMP-SMX (trimethoprim-sulfamethoxazole) were added into the wells containing both HeLa cells and replicating T. gondii of green fluorescent protein (GFP)-expressing RH tachyzoites. The proliferation and morphous of the tachyzoites were observed, the fluorescence intensity expressed as the fluorescence gray scale value was measured, and the living tachyzoites were counted at different culture times after treatment. The results showed that, compared to untreated controls, parasites treated with either AmE or SbE had significantly decreased intracellular replication at 72, 96, and 120 h after treatment (P < 0.01); while compared to either AmE- or SbE-treated groups, SMX-treated groups had even significantly decreased replication (only a few living parasites were detected) at the above times (P < 0.01). Our data demonstrated that both AmE and SbE had remarkable in vitro activities against T. gondii.
authors.affiliation: Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, Guangdong, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yang
authors.forename: Bo
authors.initials: B
authors.lastname: Huang
authors.forename: Jianping
authors.initials: J
authors.lastname: Chen
authors.forename: Shiguang
authors.initials: S
authors.lastname: Huang
authors.forename: Huanqin
authors.initials: H
authors.lastname: Zheng
authors.forename: Zhao-Rong
authors.initials: ZR
authors.lastname: Lun
authors.forename: Jilong
authors.initials: J
authors.lastname: Shen
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Fangli
authors.initials: F
authors.lastname: Lu
mesh_terms: D000981:Antiprotozoal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D027885:Astragalus propinquus / Q000737:chemistry*; D004847:Epithelial Cells / Q000469:parasitology; D006367:HeLa Cells; D006801:Humans; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D031364:Scutellaria baicalensis / Q000737:chemistry*; D013997:Time Factors; D014122:Toxoplasma / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000981:Antiprotozoal Agents; D010936:Plant Extracts