Protective effect of Cordyceps militaris against hydrogen peroxide-induced oxidative stress in vitro.

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Citation abstract

BACKGROUND/OBJECTIVES: Excessive production of reactive oxygen species (ROS) such as hydroxyl (·OH), nitric oxide (NO), and hydrogen peroxide (H 2 O 2 ) is reported to induce oxidative stress. ROS generated by oxidative stress can potentially damage glial cells in the nervous system. Cordyceps militaris (CM), a kind of natural herb widely found in East Asia. In this study, we investigated the free radical scavenging activity of the CM extract and its neuroprotective effects in H 2 O 2 -induced C6 glial cells.

MATERIALS/METHODS: The ethanol extract of CM (100-1,000 µg/mL) was used to measure DPPH, ·OH, and NO radical scavenging activities. In addition, hydrogen peroxide (H 2 O 2 )-induced C6 glial cells were treated with CM at 0.5-2.5 µg/mL for measurement of cell viability, ROS production, and protein expression resulting from oxidative stress.

RESULTS: The CM extract showed high scavenging activities against DPPH, ·OH, and NO radicals at concentration of 1,000 µg/mL. Treatment of CM with H 2 O 2 -induced oxidative stress in C6 glial cells significantly increased cell viability, and decreased ROS production. Cyclooxygenase-2 and inducible nitric oxide synthase protein expression was down-regulated in CM-treated groups. In addition, the protein expression level of phospho-p38 mitogen-activated protein kinase (p-p38 MAPK), phospho-c-Jun N-terminal kinase (p-JNK), and phospho-extracellular regulated protein kinases (p-ERK) in H 2 O 2 -induced C6 glial cells was down-regulated upon CM administration.

CONCLUSION: CM exhibited radical scavenging activity and protective effect against H 2 O 2 as indicated by the increased cell viability, decreased ROS production, down-regulation of inflammation-related proteins as well as p-p38, p-JNK, and p-ERK protein levels. Therefore, we suggest that CM could play the protective role from oxidative stress in glial cells.