Scutellarin Attenuates Oxidative Glutamate Toxicity in PC12 Cells

Abstract

The present study investigated the protective effects of the antioxidant scutellarin against oxidative toxicity induced by glutamate in PC12 cells. Vitamin E, a classical antioxidant was employed as a comparative agent. Incubation of PC12 cells with 10 mM glutamate resulted in significant cytotoxity as evaluated by the MTT and lactate dehydrogenase (LDH) assays, decreases of GSSG reductase activity, disturbance of the cell redox state as indicated by the GSH/GSSG ratio, and accumulation of intracellular reactive oxygen species (ROS) and lipid peroxidation products. Scutellarin at 0.1, 1 and 10 μM significantly protected against the cytoxicity and production of ROS and lipid peroxidation induced by glutamate. Scutellarin did not prevent the reduction of cellular GSH levels, but it up-regulated GSSG reductase activity, thus preventing an increase in cellular GSSG levels, and concomitantly improved the cell redox status. Our data also show that the protective effects of scutellarin against glutamate-induced oxidative toxicity are more potent than that of vitamin E. These results demonstrate that scutellarin can protect PC12 cells from oxidative glutamate toxicity by scavenging ROS, inhibiting lipid peroxidation and improving the cell redox status, and may reduce the cellular damage in pathological conditions associated with excessive glutamate release.

Abbreviations

MTT:3-(4,5-dimethythiazole-2-yl)-2,5-diphenyl-tetrazo-lium bromide

LDH:lactate dehydrogenase

ROS:reactive oxygen species

GSH:reduced glutathione

GSSG:oxidized glutathione

TBARS:thiobarbituric acid-reactive substance

DCFH-DA:6-carboxy-2′,7′-dichloroflurescin diacetate

Vit E:vitamin E

Key Words

Scutellarin - flavone glycoside - PC12 cells - oxidative glutamate toxicity - reactive oxygen species - glutathione - lipid peroxidation - Erigeron breviscapus - Compositae

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