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In contrast , cells exposed to Cu exhibited adaptive increases in reduced glutathione ( GSH ) content and the activities of anti - hydroxyl radical ( AHR ) , glutathione peroxidase ( GPx ) , glutathione - S - transferase ( GST ) and glutathione reductase ( GR ) .
 Cu, reduced glutathione, GSH, glutathione, glutathione, S, glutathione
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Cu, reduced glutathione, GSH, glutathione, glutathione, S, glutathione