Concordance between cardio-protective effect on isoproterenol-induced acute myocardial ischemia and phenolic content of different extracts of Curcuma aromatica

Context: A classic traditional Chinese medicine Curcuma aromatica Salisb. (Zingiberaceae) has been reported to have favourable effects on the cardiovascular system. Objective: To research the cardio-protective effect of different C. aromatica hydroalcoholic extracts on isoproterenol (ISO)-induced acute myocardial ischemia (AMI) in rats. The total phenols in different extracts were detected simultaneously. Materials and methods: The rhizomes of C. aromatica dry powder were refluxed with 30%, 50%, 70% and 90% hydroalcoholic solvents to obtain different extracts. Rats were pretreated with four C. aromatica extracts (150 mg/kg/day, i.g.) for 9 days and then given ISO (30 mg/kg/day, s.c.) for 2 consecutive days, respectively. Heart rate, ST-segment, T-wave and serum levels of CK-MB, LDH, TAC, SOD, NO and MDA were measured. Total phenols of the different extracts were determined using the Folin-Ciocalteu assay. Results: Pretreatment with C. aromatica significantly decreased the elevated levels of serum specific cardiac injury biomarkers (CK-MB and LDH), the serum level of MDA, the ST-segment and T-wave. In addition, C. aromatica increased the heart rate, as well as the levels of TAC, SOD and NO, compared to ISO-induced controls. The total phenols in the 70% extract were higher than in the other extracts reaching 5.629 ± 0.037 mg/g, crude drug. Discussion and conclusion: Curcuma aromatica hydroalcoholic extracts exhibited remarkable cardio-protective effects against AMI in rats. The 70% extracts showed the strongest bioactivity. These results indicate that ethanol concentration in preparation of extracts of C. aromatica plays an important role in the protective effect against AMI.