18139
Cytotoxic activities of these saponins were evaluated against five human tumor cell lines ( HCT - 8 , Bel - 7402 , BGC - 823 , A549 , and A2780 ) by using the MTT in vitro assay .
 saponins, MTT
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 saponins, MTT