Volatile Oil From Acorus Gramineus Rhizoma Synergizes with Crebanine to Alleviate Oxidative Stress and Endoplasmic Reticulum Stress in Myocardial Ischemia-Reperfusion Injury by Suppressing GRP78-PERK/ATF6-CHOP and MAPK-NF-κB-TNF-α Signaling Pathways.

Purpose: To investigate the synergistic protective effects and underlying mechanisms of combining Acorus gramineus rhizoma volatile oil (VOA), known for its "Cardiotropic-channel-directing" properties, with Crebanine (Cre) in MIRI.

Patients and methods: An MIRI model was established in Sprague-Dawley rats to evaluate the synergistic cardioprotective effects of VOA combined with Cre. Myocardial injury was assessed by measuring the infarct size, apoptotic cardiomyocytes, myocardial injury biomarkers, and histopathological changes. Proinflammatory mediators and oxidative stress markers and results of Western blotting were analyzed to determine the underlying cardioprotective mechanisms of Cre and VOA. In addition, metabolomic analysis was conducted to identify alterations in relevant metabolic pathways.

Results: Cre and VOA alleviated MIRI in rats by reducing infarct size, lowering the levels of myocardial injury biomarkers (Lactate dehydrogenase (LDH), cardiac troponin I (cTnI), creatine kinase (CK), and creatine kinase-myocardial band (CK-MB)), and ameliorating histopathological damage. Mechanistically, Cre and VOA attenuated oxidative stress by enhancing the activity of the antioxidant enzyme superoxide dismutase (SOD) and suppressing the expression of the oxidative stress marker malondialdehyde (MDA). In addition, they downregulated proinflammatory cytokines (interleukin-6 (IL-6) and interleukin-1β (IL-1β)) by inhibiting the MAPK/NF-κB/TNF-α signaling pathway. They mitigated endoplasmic reticulum (ER) stress and apoptosis by modulating the GRP78-PERK/ATF6-CHOP pathway. Metabolomic analysis identified 13 potential biomarkers, and glutamic, pantothenic, and oleic acids were the key metabolites. The glycine, serine, and threonine metabolism pathway, glutathione metabolism, the pentose phosphate pathway, and the biosynthesis of unsaturated fatty acids were the most relevant metabolic pathways involved in the cardioprotective effects of Cre and VOA.

Conclusion: Cre and VOA may alleviate MIRI by modulating energy metabolism and suppressing apoptosis and inflammatory responses triggered by oxidative and ER stress. This effect is mediated by GRP78-PERK/ATF6-CHOP and MAPK-NF-κB-TNF-α signaling pathways. Moreover, the volatile oil of Acorus tatarinowii significantly enhanced the cardioprotective effects of Cre against ischemia-reperfusion injury.