Plant Polyphenols and Oxidative Metabolites of the Herbal Alkenylbenzene Methyleugenol Suppress Histone Deacetylase Activity in Human Colon Carcinoma Cells

Table 1

Cytotoxic properties of the test compounds in HT29 cells.

Compound	IC50-value [𝜇M]
	24 h	48 h	72 h
EGCG	n.d.^a, b	n.d.^a, b	40 ± 6^c
GEN	n.d.^a, b	>100^b	~50^d
CGA	n.d.^a, b	n.d.^a, b	205 ± 53^c
ME	n.d.^a	n.d.^a	n.d.^a
1′-OH-ME	n.d.^a	n.d.^a	n.d.^a
3′-OXO-MIE	n.d.^a	>100	100 ± 14
MEE	n.d.^a	>100	>100

^aNo cytotoxicity up to the highest concentration implemented in the testing; ^bdata was performed in the presence of catalase (100 U/mL) to avoid hydrogen peroxide formation; ^cwithout catalase; previously reported by Kern et al. [32]; ^dpreviously reported by Yu et al. [33].