Dalbergia odorifera Essential oil protects against myocardial ischemia through upregulating nrf2 and inhibiting caspase signaling pathways in isoproterenol-induced rats

Objective: Dalbergia odorifera has long been used as a Chinese herbal medicine for the treatment of cardiovascular and cerebrovascular diseases. This study aimed to determine the potential myocardial protective effect and possible mechanism of action of D. odorifera essential oil (DOEO). Materials and Methods: The essential oil of D. odorifera was extracted by hydrodistillation. The cardioprotective effects of DOEO were examined by histopathological observation, myocardial enzyme detection, peroxidation, anti-oxidant level detection, and related protein expression. The compounds in the blood were identified by gas chromatography–mass spectrometry. Results: These results showed that DOEO had significant myocardial cell protection, with IC50 values ranging from 17.64 to 24.78 μg/mL in vitro. Compared to the myocardial ischemia group, the DOEO pretreatment groups had lower levels of myocardial injury, creatinine kinase, lactate dehydrogenase, alanine transaminase, aspartate transaminase, hydrogen peroxide, and nitric oxide, and higher levels of glutathione and superoxide dismutase. In addition, DOEO pretreatment significantly increased Na+-K+-ATPase and Ca2+-ATPase levels. Moreover, immunohistochemical experiments showed that DOEO remarkably increased the protein levels of NF-E2-related nuclear factor 2 (Nrf2) and heme oxygenase-1 (HO-1) and reduced the expression of apoptotic caspases, including caspase 3 and caspase 9. The main components of the blood were transnerolidol and nerolidol oxide. Overall, the study showed that DOEO displayed myocardial protection by upregulating the NF-E2-related nuclear factor- antioxidant response element (Nrf2-ARE) and caspase pathways. DOEO has a therapeutic effect on MI by inhibiting the oxidant and apoptotic effects. Conclusions: D. odorifera may be a potential candidate drug for treating myocardial ischemic injury.