title: Modulation effect of Smilax glabra flavonoids on ryanodine receptor mediated intracellular Ca2+ release in cardiomyoblast cells.
abstract: BACKGROUND
  Smilax glabra rhizome, a plant material from Liliaceae family, is a widely used traditional Chinese medicine for anti-cardiac hypertrophy treatment. We have previously found that Smilax glabra flavonoids (SGF) exerted such anti-cardiac hypertrophy activity. However, the mechanism of this activity of SGF has not been clarified yet.
  
  
  METHODS
  This study was aimed to investigate the inhibitory role of SGF on intracellular Ca(2+) release in rat cardiomyoblast cells (H9C2). Intracellular Ca(2+) release was determined by Ca(2+) indicator fluorescence (fluo 4-AM) in H9C2 cell line.
  
  
  RESULTS
  SGF at concentrations of 0.25, 0.5, 1.0mg/ml significantly inhibited the phenylephrine or angiotensin II induced intracellular Ca(2+) release in a dose-dependent manner. Furthermore, SGF could also inhibit ryanodine receptor (RyR) agonist caffeine induced Ca(2+) release and phenylephrine (PE)-induced Ca(2+) release under the condition in which inositol trisphosphate (IP3) receptors were blocked with 2-Aminoethoxydiphenyl borate (2-APB). Nevertheless, SGF had no impact on PE-induced Ca(2+) release under the condition in which RyRs were blocked with tetracaine.
  
  
  CONCLUSIONS
  Our results suggest that the protective effects of SGF are mediated via targeting inhibition of RyR mediated intracellular Ca(2+) release.
authors: Experimental Animal Research Center, Zhejiang Chinese Medical University, Hangzhou 310053, China.
authors: Qiyang
authors: Q
authors: Shou
authors: Shuizhen
authors: S
authors: Pan
authors: Jue
authors: J
authors: Tu
authors: Jianping
authors: J
authors: Jiang
authors: Yun
authors: Y
authors: Ling
authors: Yueqin
authors: Y
authors: Cai
authors: Minli
authors: M
authors: Chen
authors: Dejun
authors: D
authors: Wang
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects*; D002460:Cell Line; D005419:Flavonoids / Q000494:pharmacology*; D032386:Myoblasts, Cardiac / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D032281:Smilax
chemical_list: D005419:Flavonoids; D019837:Ryanodine Receptor Calcium Release Channel
keywords: 2-APB; 2-Aminoethoxydiphenyl borate; ANP; Ang II; Angiotensin II; CICR; Ca(2+)-induced Ca(2+) release; ER; FCS; HBSS; Hanks balanced salt solution; IP3; IP3R; Inositol 1,4,5-trisphosphate receptors; Intracellular Ca(2+) release; PE; RyR; RyR2; Ryanodine receptors; SGF; SR; Smilax glabra flavonoids; atrial natriuretic peptide; endoplasmic reticulum; fetal calf serum; flavonoids of Smilax glabra; inositol trisphosphate; inositol trisphosphate receptor; phenylephrine; ryanodine receptor; ryanodine receptor 2; sarcoplasmic reticulum