In vivo and in vitro evidence of protective effects of a natural flavone on rat myocardial ischemia-reperfusion and hypoxia-reoxygenation injuries.

In the present study, we for the first time explored the protective effect of LOB (Chrysoeriol 7-O-[β-D-glucuronopyranosyl-(1→2)-O-β-D-glucuronopyranoside]) on myocardial ischemia-reperfusion (I/R) injury in a rat model and on hypoxia-reoxygenation (H/R) injury in a rat myocardium cell line. An I/R rat model and an H/R rat myocardium cell model were established. The animal and H9C2 (2-1) rat myocardium cells were pretreated with increasing doses of LOB before the I/R or H/R injury. Malondialdehyde (MDA), lactate dehydrogenase (LDH), interleukin 6 (IL-6), and the caspase 3 activity were measured. Pretreatment with LOB dose dependently reduced the elevated plasma levels of LDH and IL-6 and myocardium MDA level induced by the I/R injury in the rat model, and the elevated culture medium LDH, cell MDA levels, and caspase 3 activity induced by the H/R injury in the cell model were also reduced. Both in vivo and in vitro data showed that high-dose LOB (20 mg/kg or 10 μmol/L) had stronger protective effects than the positive control drug verapamil. In conclusion, our study for the first time provided both in vivo and in vitro evidence that LOB exerted significant cardioprotective effects on myocardial I/R injury in rats, suggesting that LOB could be a potential therapeutic agent for myocardial I/R injury.