13533
Arsenite - induced ROS generation and COX - 2 expression were significantly attenuated by treatment with melatonin ( a ROS scavenger ) , but enhanced by DL - buthionine - ( S , R ) - sulfoximine ( BSO , an inhibitor of gamma - glutamylcysteine synthetase ( gamma - GCS ) resulting in lower GSH and increased ROS levels ) .
 Chemical: Arsenite; Chemical: melatonin; Chemical: DL - buthionine - ( S , R ) - sulfoximine; Chemical: BSO; Chemical: gamma - glutamylcysteine; Chemical: GSH
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Arsenite; Chemical: melatonin; Chemical: DL - buthionine - ( S , R ) - sulfoximine; Chemical: BSO; Chemical: gamma - glutamylcysteine; Chemical: GSH