Isosteviol-mediated cardioprotection: relationship between mitochondrial preservation and Protein Kinase B (AKT) activation

DEBORA ELIZABET VÉLEZ; ROMINA HERMANN; VICTORIA MESTRE CORDERO; LUCIA SÁNCHEZ; MARÍA GABRIELA MARINA PRENDES; JULIETA MOURGLIA; MARÍA DE LAS MERCEDES FERNÁNDEZ PAZOS

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencias; 2022

Sociedad Argentina de Investigación Clínica y Sociedad Argentina de Fisiología

Isosteviol (I) is a stevioside derivative, obtained from the leaves of Stevia rebaudiana bertoni. Recently, several studies have attributed cardioprotective properties to this compound, however, its underlying mechanisms remain to be elucidated. Since mitochondrial dysfunction plays a key role in ischemia-reperfusion (IR) injury, we aimed to investigate the effects of acute preischemic administration of I (5µM) and its relationship with the activation of Akt on several mitochondrial parameters from Langendorff-perfused rat hearts subjected to IR. Hearts from female Wistar rats (200-250g) fed ad libitum were used. Wortmannin (W,100nM), a PI3K/Akt inhibitor was added 15 min before ischemia and 5 min before I. Mitochondrial ultrastructure was analyzed by electron microscopy and mitochondrial isolated function was evaluated by the rate of ATP synthesis, O2consumption, membrane potential (ΔΨ) and respiratory complexes I-III, II-III and IV activities. Calcium retention capacity (CRC) was also measured. Western blot was used to study Akt activation profile, considering the ratio p-Akt/total-Akt. ANOVA n=6. At the end of reperfusion, results showed an increase in the rate of mitochondrial ATP synthesis in I group (C 66.4±6.5; CW 56.5±6.1; I 81.0±6.9*; IW 79.6±6.9 nmol/min/mg protein; *p