6-Shogaol protects against isoproterenol-induced cardiac injury in rats through attenutating oxidative stress, inflammation, apoptosis and activating nuclear respiratory factor-2/heme oxygenase-1 signaling pathway.

The current study investigated the preventive effect of 6-Shogaol on isoproterenol hydrochloride (ISO)-induced myocardial cardiac injury. 6-Shogaol (50 mg/kg b.w.) was administered for 14 days at pretreatment and ISO-induction (85 mg/kg b.w.) for the last two days (13th and 14th days) by subcutaneous injection. Cardiac markers in serum like creatine kinase (CK), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), cardiac troponins T (cTn T) and I (cTn I) increased in ISO-induced rats. Moreover, lipid peroxidative markers like thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were raised, and the activities/level of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and reduced glutathione (GSH) were diminished in ISO-treated heart tissue. In addition, inflammatory and nuclear respiratory factor (Nrf)-2 signalling molecules were upregulated in ISO-induced ischemic rats. 6-Shogaol pretreatment decreased the activities of cardiac and lipid peroxidative markers and enhanced the antioxidant status in ISO-induced cardiac injury rats. Further, 6-Shogaol pretreatment inhibited serum inflammatory markers: tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), nuclear factor-kappaB (NF-κB), Nrf-2 molecule and heme oxygenase (HO)-1 in ISO-induced cardial damage rats. We noticed the effect of 6-Shogaol inhibited pro-apoptotic genes like B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), Fas, caspase-3, -8, -9, cytochrome C, and inflammatory genes and increased Bcl-2 expression in ISO-treated rats. The cardioprotective activity of 6-Shogaol in rats with ISO-induced myocardial damage may be due to its ability to reduce oxidative stress, inflammation, and apoptosis, perhaps via the Nrf-2/HO-1 signalling pathway.