title: Stevioside inhibits inflammation and apoptosis by regulating TLR2 and TLR2-related proteins in S. aureus-infected mouse mammary epithelial cells.
abstract: Stevioside is a natural sweetener that is commonly used in traditional medicine and as a food additive. The object of this study was to investigate the anti-inflammatory and anti-apoptosis function of stevioside and the possible molecular mechanisms for such activity in Staphylococcus aureus (S. aureus)-infected mouse mammary epithelial cells (MMECs). The cells were treated with varying doses of stevioside before infection with S. aureus. The live/dead cells were detected by immunofluorescence microscopy. The pro-inflammatory cytokines were determined by ELISA. The mRNA of TLR2 and proteins related to NF-κB, MAPK and apoptosis were analyzed by q-PCR. The relative protein expression levels were determined by Western blot. The results indicated that stevioside inhibited the mRNA and protein expression of TNF-α, IL-6 and IL-1β dose-dependently in S. aureus-stimulated MMECs. Stevioside suppressed the S. aureus-induced expression of TLR2 and proteins of the NF-κB and MAPK pathways as well as apoptosis. The mRNA levels of IκBα, p38, ERK, JNK, p65, caspase-3 and Bax were not influenced by the stevioside treatment. Stevioside exerts anti-inflammatory and anti-apoptotic properties by inhibiting the release of cytokines and the activation of TLR2 and proteins of the NF-κB and MAPK signaling pathways, as well as caspase-3 and Bax.
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, People's Republic of China.
authors: Tiancheng
authors: T
authors: Wang
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, People's Republic of China.
authors: Xiaojing
authors: X
authors: Song
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, People's Republic of China.
authors: Zecai
authors: Z
authors: Zhang
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, People's Republic of China.
authors: Mengyao
authors: M
authors: Guo
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, People's Republic of China.
authors: Haichao
authors: H
authors: Jiang
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, People's Republic of China.
authors: Wei
authors: W
authors: Wang
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, People's Republic of China.
authors: Yongguo
authors: Y
authors: Cao
authors: College of Animal Science and Technology, Qingdao Agriculture University, Qingdao, Shandong Province 266109, People's Republic of China. Electronic address: lqzhu@qau.edu.cn.
authors: Lianqin
authors: L
authors: Zhu
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, People's Republic of China. Electronic address: zhangns@jlu.edu.cn.
authors: Naisheng
authors: N
authors: Zhang
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D017209:Apoptosis / Q000187:drug effects; D045786:Diterpenes, Kaurane / Q000008:administration & dosage*; D004848:Epithelium / Q000187:drug effects* / Q000473:pathology; D005260:Female; D005960:Glucosides / Q000008:administration & dosage*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D042361:Mammary Glands, Human / Q000473:pathology; D008807:Mice, Inbred BALB C; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology*; D051195:Toll-Like Receptor 2 / Q000276:immunology*
chemical_list: D000893:Anti-Inflammatory Agents; D045786:Diterpenes, Kaurane; D005960:Glucosides; D018836:Inflammation Mediators; D016328:NF-kappa B; C493486:Tlr2 protein, mouse; D051195:Toll-Like Receptor 2; C012043:stevioside; D020928:Mitogen-Activated Protein Kinases
keywords: Anti-apoptosis; Anti-inflammatory; Mouse mammary epithelial cells; Staphylococcus aureus; Stevioside; TLR2