RESUMEN
<p><b>OBJECTIVE</b>To observe the antioxidant effects of water extract of Carthamus tinctorius on ox-LDL induced injury in rat cardiac microvascular endothelial cell and detecting oxygen derived free radicals (OFR) to explore the antioxidant mechanisms.</p><p><b>METHOD</b>By using the third generation of rat cardiac microvascular endothelial cells (rCMEC), the protection of water extract of C. tinctorius was investigated after ox-LDL (100 mg x L(-1) induced damage. The supernatant was collected for detecting lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), xanthine oxidase (XOD), glutathione peroxidase (GSH-Px), nitric oxide (NO), nitric oxide synthase (NOS) activity, and cell suspension was collected for detecting reactive oxygen species (ROS) by electron spin resonance (ESR).</p><p><b>RESULT</b>Water extract of C. tinctorius increased the rCMEC survival rate, reduced LDH, MDA and XOD levels, and improved SOD, GSH-Px and NOS activity, while in the cell suspension ROS signal decreased significantly.</p><p><b>CONCLUSION</b>Water extract of C. tinctorius has antioxidation. The mechanisms are likely related with scavenging of free radicals, enhancing its clearance, enhancing endogenous antioxidant activity.</p>