Phycocyanin relieves myocardial ischemia-reperfusion injury in rats by inhibiting oxidative stress

Purpose: To investigate the effect of phycocyanin on myocardial ischemia-reperfusion injury, and possible mechanisms involved.
 Methods: Twenty-four Sprague-Dawley (SD) rats were randomly divided into Sham group (only threading without ligation), IRI (myocardial injury group) (phycocyanin pretreatment + group). The heart was harvested cardiomyocytes isolated. Colorimetry used to determine contents cardiomyocyte serum creatine phospho-MB (CK-MB), lactate dehydrogenase (LDH) malondialdehyde (MDA), activities total antioxidant capacity (T-AOC), catalase (CAT), glutathione (GSH), superoxide dismutase (SOD) other related oxidative stress indicators. Furthermore, apoptosis evaluated using TUNEL staining. Protein levels cardiac factor E2 2 (Nrf2), heme oxygenase-1 (HO-1), human NADPH 1 (NQO1) nuclear factor-κB (NF-κB) by Western blot immunohistochemistry.
 Results: Compared with group, CK-MB, LDH, MAD ROS in treated significantly decreased (p < 0.05), but SOD, GSH, CAT, T-AOC tissues enhanced 0.05). Moreover, pathological changes tissue reduced. In addition, expression Nrf2, HO-1 NQO-1 up-regulated after pretreatment, while NF-κB down-regulated 0.05).
 Conclusion: Phycocyanin improves anti-oxidative via activation Nrf2 signaling pathway, also protects from reducing inflammatory response inhibition pathway.