Purpose: The potential cardio-protective property of germinated brown rice (GBR) has been revealed by ameliorating risk factors related to cardiovascular diseases. This study hypothesized that the combination of GBR and cardioplegic solution could protect the cardiomyocytes exposed to simulated ischemic reperfusion injury in vitro study and preserve cardiac function during cardiopulmonary bypass surgery in animal models.
Methods: Primary porcine cardiomyocytes were isolated and experimented cell viability against simulated ischemic reperfusion injury. In a cardiac surgical animal model, six pigs were randomly assigned to receive the two types of cardioplegic solution: i) St. Thomas cardioplegic solution (20 cc/kg); and ii) St. Thomas cardioplegic solution plus GBR (1 mg/kg). During open-heart surgery, the aorta was cross-clamped for 20 minutes, followed by reperfusion for 1 hour. Cardiopulmonary bypass parameters were recorded until the end of the procedure. Furthermore, hemodynamic parameters and arterial blood gas characteristics of animals among groups were monitored at different time points, including baseline before cardiopulmonary bypass (T1), during cardiopulmonary bypass (T2), during aortic clamp on (T3), and aortic clamp off (T4).
Results: Primarily, GBR cotreatment with cardioplegic solution essentially resulted in the improvement of cell viability in primary porcine cardiomyocytes against simulated ischemic reperfusion induction. The findings from cardiac surgery demonstrated that mean arterial pressure and heart rate are constantly stable in cardioplegic solution combined with the GBR group, while the trend of potassium and lactase concentration was decreased in the animals receiving GBR group. Consistently, all parameters from arterial blood gas showed better outcomes in animals receiving GBR; however, there were no statistically significant differences between groups, except hepatic enzymes.
Conclusion: Therefore, GBR might exert cardio-protective effects against ischemic reperfusion injury in the porcine cardiac surgery model due to anti-inflammatory response. These protective actions of GBR may explain the benefits gained from applying GBR products as a possible therapeutic supplement on cardiac diseases.