Short-Term Hesperidin Pretreatment Attenuates Rat Myocardial Ischemia/Reperfusion Injury by Inhibiting High Mobility Group Box 1 Protein Expression via the PI3K/Akt Pathway.

BACKGROUND/AIMS: Hesperidin pretreatment has been shown to protect against myocardial ischemia/reperfusion (I/R) injury, but the underlying mechanism is poorly understood. This study aimed to investigate the cardioprotective effects of a 3-day hesperidin pretreatment on I/R injury and to further explore whether its mechanism of action was associated with the inhibition of high mobility group box 1 protein (HMGB1) expression via the PI3K/Akt pathway.

METHODS: In a fixed-dose study, hematoxylin and eosin staining and myocardial enzyme measurements were used to determine the optimal dose of hesperidin that elicited the best cardioprotective effects against I/R injury. Furthermore, rats were pretreated with 200 mg/kg hesperidin, and infarct size and the levels of myocardial enzymes, apoptosis, inflammatory and oxidative indices, and HMGB1 and p-Akt expression were measured.

RESULTS: Our results indicated that while different 3-day hesperidin pretreatment doses promoted histopathological changes and reduced myocardial enzymes induced by I/R the optimal dose was 200 mg/kg. Moreover, the 200 mg/kg hesperidin pretreatment not only significantly decreased the infarct size as well as myocardial enzyme levels but also inhibited myocardial apoptosis, the inflammatory response and oxidative stress. Additionally, hesperidin downregulated HMGB1 expression and upregulated p-Akt expression in the myocardium. LY294002, a specific PI3K inhibitor, partially reversed the decreased HMGB1 expression, increased p-Akt expression induced by hesperidin and abolished the anti-apoptotic, anti-inflammatory and anti-oxidative effects of hesperidin.

CONCLUSION: These findings suggest that short-term pretreatment with hesperidin protects against myocardial I/R injury by suppressing myocardial apoptosis, the inflammatory response and oxidative stress via PI3K/Akt pathway activation and HMGB1 inhibition.