23876
Our results show that cell growth and DNA synthesis were inhibited , and the cell cycle was arrested at the G0 / G1 phase in a dose - dependent manner in cells treated with beta - ionone ( 25 , 50 , 100 and 200 mu mol / L ) for 24 h .
 beta - ionone
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 beta - ionone