title: Saponin inhibits hepatitis C virus propagation by up-regulating suppressor of cytokine signaling 2.
abstract: Saponins are a group of naturally occurring plant glycosides which possess a wide range of pharmacological properties, including anti-tumorigenic and antiviral activities. To investigate whether saponin has anti-hepatitis C virus (HCV) activity, we examined the effect of saponin on HCV replication. HCV replication was efficiently inhibited at a concentration of 10 µg/ml of saponin in cell culture grown HCV (HCVcc)-infected cells. Inhibitory effect of saponin on HCV replication was verified by quantitative real-time PCR, reporter assay, and immunoblot analysis. In addition, saponin potentiated IFN-α-induced anti-HCV activity. Moreover, saponin exerted antiviral activity even in IFN-α resistant mutant HCVcc-infected cells. To investigate how cellular genes were regulated by saponin, we performed microarray analysis using HCVcc-infected cells. We demonstrated that suppressor of cytokine signaling 2 (SOCS2) protein level was distinctively increased by saponin, which in turn resulted in inhibition of HCV replication. We further showed that silencing of SOCS2 resurrected HCV replication and overexpression of SOCS2 suppressed HCV replication. These data imply that saponin inhibits HCV replication via SOCS2 signaling pathway. These findings suggest that saponin may be a potent therapeutic agent for HCV patients.
authors: National Research Laboratory of Hepatitis C Virus, Ilsong Institute of Life Science, Hallym University, Anyang, Korea.
authors: Jihye
authors: J
authors: Lee
authors: Seri
authors: S
authors: Lim
authors: Sang-Min
authors: SM
authors: Kang
authors: Saehong
authors: S
authors: Min
authors: Kidong
authors: K
authors: Son
authors: Han Sol
authors: HS
authors: Lee
authors: Eun Mee
authors: EM
authors: Park
authors: Huong T T
authors: HT
authors: Ngo
authors: Huong T L
authors: HT
authors: Tran
authors: Yun-Sook
authors: YS
authors: Lim
authors: Soon B
authors: SB
authors: Hwang
mesh_terms: D045744:Cell Line, Tumor; D016174:Hepacivirus / Q000187:drug effects*; D006801:Humans; D015151:Immunoblotting; D034741:RNA, Small Interfering; D012503:Saponins / Q000494:pharmacology*; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D034741:RNA, Small Interfering; C106643:SOCS2 protein, human; D012503:Saponins; D050826:Suppressor of Cytokine Signaling Proteins