1,2,3,4,6-Penta-O-galloyl-beta-D-glucose protects rat neuronal cells (Neuro 2A) from hydrogen peroxide-mediated cell death via the induction of heme oxygenase-1.

The root of Paeonia suffruticosa ANDREWS is an important Chinese crude drug used in many traditional prescriptions. 1,2,3,4,6-Penta-O-galloyl-beta-D-glucose (PGG), a major component of this crude drug, has been shown to possess potent anti-oxidant, anti-mutagenic and anti-proliferative effects. In the present study, we examined the effect of PGG on the expression of neuronal heme oxygenase-1 (HO-1), an inducible stress protein that degrades heme to the neuroactive molecule, carbon monoxide and the anti-oxidant, biliverdin. Exposure of Neuro 2A cells to PGG (10-50 microM) resulted in a concentration- and time-dependent induction of HO-1 mRNA, and protein expressions and heme oxygenase activity. Interestingly, pretreatment of the neuronal cells with PGG resulted in enhanced cellular resistance to hydrogen peroxide. This cytoprotective effect was reversed by zinc protoporphyrin IX, an inhibitor of heme oxygenase. This study showed that PGG could protect neuronal cells from oxidative stress via the induction of HO-1 gene expression.