Afolabi Clement Akinmoladun ^a, Johnson Akintunde Olowe ^a,c, Kayode Komolafe ^a,b,*, Joan Ogundele ^d, Mary Tolulope Olaleye ^a

^a Department of Biochemistry, School of Sciences, The Federal University of Technology, PMB 704, Akure, Nigeria
^b Department of Biochemistry, Faculty of Science, Federal University, PMB 373, Oye-Ekiti, Nigeria
^c Department of Physiology, College of Medicine, University of Lagos, PMB 12003, Lagos, Nigeria
^d Department of Industrial Chemistry, Faculty of Science, Federal University Oye-Ekiti, PMB 373, Oye-Ekiti, Nigeria

 

Protection against cardiomyocyte damage following ischemia/reperfusion (I/R) injury is highly desirable in patients with ischemic heart disease. Hydromethanol extracts of Globimetula cupulata (mistletoe) growing on cocoa (CGCE) and kola nut (KGCE) trees were assessed for antioxidant content and cardioprotective potential against I/R. Graded concentrations (1–50 μg/mL) of CGCE or KGCE were tested on Langendorff-perfused rat hearts to evaluate the effects on the flow rate, heart rate, and force of cardiac contraction, while another set of hearts were subjected to biochemical analyses. Both extracts showed good antioxidant content and activity, but KGCE (EC₅₀: 24.8±1.8 μg/mL) showed higher hydroxyl radical scavenging activity than CGCE (70.2±4.5 μg/mL). Both extracts at 3 μg/mL reversed (p < 0.001) membrane peroxidation and the significant decrease in nitrite level, coronary flow rate, and superoxide dismutase and catalase activity caused by the I/R cycle. It is concluded that G. cupulata protects against ischemia–reperfusion injury in rat hearts via augmenting endogenous antioxidants and significant restoration of altered hemodynamic parameters.

 

Keywords: cardioprotection, Globimetula cupulata, ischemia, reperfusion