Salvia sahendica protects against apoptosis by interfering intrinsic pathway and reducing caspase-mediated PARP activation in vitro and in vivo

Abstract

Oxidative stress, an imbalance in prooxidant and antioxidant levels, has been implicated to play a crucial role in the pathogenesis of a number of diseases including neurodegenerative disorders, such as Alzheimer disease. Salvia is the largest genus of the family of “Laminaceae”, commonly referred to as “sage” with a multitude of biological activities including antioxidant, and anti-apoptotic effects. NGF- differentiated PC12 Cells were treated with 10, 25, 50 and 100 μg/ml of Salvia sahendica, followed by adding H2O2 (150 μM). The extent of apoptosis was assessed by acridine orange/ethidium bromide staining. Levels of Bax, Bcl2, Cytochrome C, Caspase-3, PARP, Calpain, Caspase-12 were determined by western blot analysis. To confirm effects of S. sahendica, rats oral administrated by S. sahendica, (2%, w/v) then Aß solutions were injected to the CA1 region and apoptotic factors were determined. In this study we indicated that oxidative stress resulting from H2O2 can be inhibited by S. sahendica in a dose-dependent manner in in vitro. In addition, in vivo data revealed the neuroprotective effects of S. sahendica in Aß-injected rats. S. sahendica showed a strong protective effects against H2O2 and Aß -induced endoplasmic reticulum (ER) and mitochondrial-dependent apoptotic cell death. It promoted Bcl-2 expression, while blocked Bax expression, inhibited Cytochrome C releasing, caspase-3 activation and subsequently PARP cleavage. H2O2 and Aß caused the increase in the intracellular calcium level, and activation of calcium-dependent calpain which leads to cleavage of caspase-12. While S. sahendica markedly attenuated the change of these factors. As oxidative stress is a critical event in the pathogenesis of neurodegenerative diseases, having neuroprotective effects implies the possibility of using S. sahendica as a candidate for treating neurodegenerative diseases like AD.