The aim of the present study was to investigate the protective effects and underlying mechanisms of Garcinia xanthochymus, a perennial medicinal plant native to Yunnan, China, against HO-induced oxidative damage in rat pheochromacytoma PC12 cells. Preincubation of PC12 cells with fruit EtOAc fraction (fruit-EFr., 12.5-50 µmol·L) of G. xanthochymus for 24 h prior to HO exposure markedly improved cell viability and increased the activities of antioxidant enzymes (superoxide dismutase, catalase, and heme oxygenase-1 [HO-1]), prevented lactate dehydrogenase release and lipid peroxidation malondialdehyde production, attenuated the decrease of matrix metalloproteinases (MMP), and scavenged reactive oxygen species (ROS). Fruit-EFr. also reduced BAX and cytochrome C expression and improved BCL-2 expression, thereby decreasing the ratio of BAX to BCL-2. Fruit-EFr. activated the nuclear translocation of NRF2 to increase HO-1 and induced the phosphorylation of AKT. Its cytoprotective effect was abolished by LY294002, a specific inhibitor of PI3K. Taken together, the above findings suggested that fruit-EFr.of G. xanthochymus could enhance cellular antioxidant defense capacity, at least in part, through upregulating HO-1 expression and activating the PI3K/AKT pathway and that it could suppress HO-induced oxidative damage via PI3K/AKT and NRF2/HO-1 signaling pathways.
Animals ; Antioxidants ; metabolism ; pharmacology ; Apoptosis ; drug effects ; Biological Transport ; Cell Survival ; Cytochromes c ; metabolism ; Fruit ; Garcinia ; Heme Oxygenase-1 ; metabolism ; Hydrogen Peroxide ; NF-E2-Related Factor 2 ; metabolism ; Oxidative Stress ; drug effects ; PC12 Cells ; Phosphatidylinositol 3-Kinase ; metabolism ; Phosphatidylinositol 3-Kinases ; Phosphorylation ; Plant Extracts ; pharmacology ; Protective Agents ; pharmacology ; Proto-Oncogene Proteins c-akt ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Signal Transduction ; bcl-2-Associated X Protein ; metabolism