ABSTRACT
Objective To establish the in vivo models of adriamycin(ADR)-induced cardiotoxicity in rabbits, investigate the protective effect of oxymatrine (OMT) on ADR-induced cardiotoxicity, and explore the possible mechanism. Methods Twenty-six rabbits were randomly divided into ADR group (n=8, 2 mg/kg ADR), OMT group (n=5, 10 mg/kg OMT), ADR + OMT group (n=8, 10 mg/kg OMT was injected 30 min before ADR injection) and saline group (n=5, same quantity of normal saline), and rabbits in each group were infused with medicine or normal saline through ear marginal vein once a week for 8 weeks. The apoptosis of myocardial cells was detected by TUNEL methods, and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) was determined. Results After treatment, the body weight of ADR group was significantly lower than that of the other groups(P < 0.05), the activity of SOD and GSH-Px significantly decreased and the apoptosis index (AI) was significantly higher than that of the other groups(P <0.01). There were similar while minor changes in ADR + OMT group. There was no significant adverse effects in OMT group. Conclusion OMT protects heart from adriamycin-induced injury in rabbits, which may relate to the decrease in level of antioxidant and apoptosis of myocardial cells.
ABSTRACT
The dialysis method was employed to load adriamycin into the micelles formed by temperature and pH sensitive polyhistidine-co-DL-lactide-co-glycolide-polyethylene glycol poly DL-lactide-co-glycolide-co-histidine (OLH-b-PLGA-b-PEG-b-PLGA-b-OLH). The critical micelle concentration (CMC) of the copolymer was measured with pyrene fluorescent probe method under different temperatures. The entrapment rate and drug-loading rate were determined with dialysis method. The diameter, morphology and surface potential of the copolymer micelles were investigated by corresponding instruments, respectively. The release behavior of adriamycin from copolymer micelles and the pH sensitivity were studied. The CMC of the copolymers ranged from 0.022 4 to 0.001 7 microg x mL(-1). The entrapment rate and drug-loading rate were 92.8% and 15.7%, respectively. The micelles have a mean diameter of (61.7 +/- 13.4) nm, and zeta potential was -9.88 mV. The in vitro adriamycin release rate increased with the pH dropping from 7.4 to 5.0. The results indicated that the CMC of the copolymers decreased as the raising of temperature, drug release behavior from the micelles possessed clearly pH sensitivity, and the copolymers may have a potential in targeted delivery system for anticancer drugs.