Study on the mechanism of anti-MIRI action of total flavones of Fructus Chorspondiatis by PET/CT imaging

Background To investigate anti myocardial ischemia/reperfusion injury (MIRI) action of total flavones of Fructus Chorspondiatis (TFFC) in rats by 13N-ammonia micro PET/CT imaging, etc. Methods Male Sprague-Dawley rats were randomly divided into 6 groups. Micro PET/CT imaging was performed before and after modeling to calculate the volume (VOI) and SUVmean of myocardial ischemic area. The oxidative stress index [(superoxide dismutase (SOD), malondialdehyde (MDA)] and the marker enzymes [creatine kinase (CK), lactate dehydrogenase (LDH)] of myocardial injury were detected. The pathological changes of myocardial were observed via HE staining. A MIRI model of rat cardiomyocytes in vitro was established, the damage and apoptosis of myocardial cells in each group were observed, and the apoptosis rate of cardiomyocytes was detected. Results The imaging viscosities of the imaging agents were observed at 24 and 48 h in each group. The VOI of 24 h imaging was (6.33±2.02), (6.01±1.56) and (3.32±0.86) mm3, respectively. The VOI of 48 h imaging was (3.31±1.33), (2.61±1.01) and (1.32±0.58) mm3. The 72 h imaging medium and high dose group recovered, while the low dose group still saw sparseness with (1.26±0.68) mm3 VOI. The ischemic (SUVmean) gradually increased with time. Metabolism gradually recovered (F=121.82, 450.82, 435.75, P<0.05). The three doses of TFFC can eliminate free radicals and reduce the damage of myocardial injury. Amongst them, the high-dose group had a better effect on SOD, and the middle-dose group had a better effect on MDA and LDH. The low-dose group affected CK, and a significant difference was observed compared with the control group (P<0.05). After administration, the morphology of myocardial cells in each dose group was improved to some extent. Nuclear pyknosis, rupture, the apoptosis rate, etc. were significantly reduced, the number of cells increased. The high dose group showed the most obvious improvement. Conclusions The PET/CT imaging method can detect non-invasive, in vivo and dynamic MIRI, and can accurately evaluate the protective effect of traditional Mongolian medicine TFFC on MIRI. The Anti-MIRI of TFFC can scavenge free radicals, reduce oxidative stress damage, inhibit apoptosis, affect the activity of related enzymes.