Biological Activity

• DescriptionSpleen tyrosine kinase (Syk) is a cytosolic non-receptor protein tyrosine kinase (PTK) and is mainly expressed in hematopoietic cells. Syk was recognized as a critical element in the B-cell receptor signaling pathway. Syk is also a key component in signal transduction from other immune receptors like Fc receptors and adhesion receptors^[10]. Piceatannol, an anti-inflammatory, immunomodulatory, and anti-proliferative stilbene, is a selective Syk inhibitor, about 10-fold more sensitive than Lyn^[11]. The treatment of human myeloid cells with piceatannol suppressed TNF-induced DNA binding activity of NF-κB. TNF-induced NF-κB activation was also suppressed in lymphocyte and epithelial cells. It also inhibited NF-κB activated by H₂O₂, PMA, LPS, okadaic acid, and ceramide^[12]. In rat ventricular cells, piceatannol (3 - 30 µmol/L) prolonged the action potential durations (APDs) and decreased the maximal rate of upstroke (V_max) without altering Ca²⁺ transients. Piceatannol (1 – 10 µmol/L) exerted antiarrhythmic activity in isolated rat hearts subjected to ischaemia‐reperfusion injury^[13]. Oral piceatannol administration in BALB/c mice with dextran sulfate sodium (DSS)-induced colitis was associated with a remarkable amelioration of the disruption of the colonic architecture, a significant reduction in colonic myeloperoxidase (MPO) activity, and a decrease in production of inflammatory mediators such as nitric oxide (NO), prostaglandin (PG) E2, and pro-inflammatory cytokines^[14]. Piceatannol suppressed the rises in blood glucose levels at early stages and improved the impaired glucose tolerance at late stages in db/db mice^[15].
• Cell Study
• Cell Data

  Cell Lines	Concentration	Assay Type	Time	Activity Description	Data Sources
  human A2780 cells	-	Proliferation assay	2 days	Antiproliferative activity against human A2780 cells after 2 days by Alamar Blue assay, IC50=41 μM	24239390
  human lung mast cells	-	Function assay	-	Inhibition of SYK in human lung mast cells assessed as reduction in anti-IgE-stimulated histamine release, EC50=25 μM	22257213
  mouse 3T3L1 cells	10 to 50 μM	Function assay	48 h	Reduction in triglyceride level in mouse 3T3L1 cells at 10 to 50 uM after 48 hrs	22765896

• Animal Study
  Dose	Rat: 10 mg/kg, 30 mg/kg[7] (i.v.) Mice: 50 mg/kg/day for 2 weeks[8] (i.p.); 1 mg/kg, 5 mg/kg[9] (p.o.)
  Administration	i.v., i.p., p.o.