title: Effects of Schisandra chinensis extract on the relaxation of isolated human prostate tissue and smooth muscle cell.
abstract: BACKGROUND
  Schisandra chinensis has been commonly used as a traditional herbal medicine to treat various diseases including body weakness, dysentery, impotence, enuresis and frequent urination in many countries including Korea, China and Russia. Benign prostate hyperplasia is a common disease for the elderly men and it induces lower urinary tract symptoms which hinder general activity and quality of life. We evaluated the therapeutic potential of Schisandra chinensis extract (SCE) in benign prostate hyperplasia using human prostate tissue.
  
  
  METHODS
  Schisandra chinensis fruit was collected and extracted with ethanol. Human prostate tissues were obtained from 14 prostate cancer patients. Macroscopically normal tissue was excised from the transition zone and the periurethral regions. Isolated prostate tissue strips were mounted in an organ-bath system, and the relaxation effect of SCE was evaluated by cumulative addition to prostate strips pre-contracted with 10(-5)M norepinephrine. The effect of tamsulosin was compared, and the additive effect was evaluated. Electrophysiological studies using cultured human prostate smooth muscle cells (HPrSMC) were conducted.
  
  
  RESULTS
  Cumulative dosing of SCE induced concentration-dependent relaxation in contracted prostate tissue (n=18, P<0.05). Simultaneous dosing of SCE and tamsulosin showed an additive relaxation effect. The relaxation effect of SCE was abolished by inhibition of K+ channels by pre-treatment with tetraethylammonium. In HPrSMC, extracellular application of 100 μg/mL SCE significantly increased outward currents, and this effect was significantly attenuated by treatment with 100 nM Iberiotoxin.
  
  
  CONCLUSIONS
  SCE showed a dose dependent relaxation effect on human prostate tissue as well as an additive effect with tamsulosin. The relaxation effects of SCE on HPrSMC were, in part, due to the activation of K+ channels.
authors.affiliation: Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Department of Urology, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: Seol Ho
authors.initials: SH
authors.lastname: Choo
authors.affiliation: Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hyun Hwan
authors.initials: HH
authors.lastname: Sung
authors.affiliation: Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Mee Ree
authors.initials: MR
authors.lastname: Chae
authors.affiliation: Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Su Jeong
authors.initials: SJ
authors.lastname: Kang
authors.affiliation: Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Deok Hyun
authors.initials: DH
authors.lastname: Han
authors.affiliation: Department of Urology, Chonbuk National University School of Medicine, Jeonju-si, Republic of Korea.
authors.forename: Jong Kwan
authors.initials: JK
authors.lastname: Park
authors.affiliation: Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Insuk
authors.initials: I
authors.lastname: So
authors.affiliation: Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: drswlee@skku.edu.
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Lee
mesh_terms: D000368:Aged; D005638:Fruit / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D009126:Muscle Relaxation / Q000187:drug effects*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects*; D008517:Phytotherapy / Q000379:methods; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011467:Prostate / Q000187:drug effects*; D011788:Quality of Life; D032141:Schisandra / Q000737:chemistry*
chemical_list: D010936:Plant Extracts
keywords: Prostate; Schisandra chinensis; Smooth muscle; Tamsulosin