Table 3.

Combination index values of 1,3,6-trihydroxy-4,5,7-trichloroxanthone (TTX)–doxorubicin calculated using CompuSyn (ComboSyn, Inc, Paramus, NJ).

Concentration		Doxorubicin (µM)
		3.179	6.358	9.537	12.716
TTX (µM)	1.993	0.073*	0.181†	0.159†	0.258†
	3.986	0.072*	0.124†	0.166†	0.175†
	5.981	0.078*	0.121†	0.285†	0.135†
	7.974	0.057*	0.091*	0.166†	0.069*

^⁎Combination index values <0.1 indicate very strong synergism.

^†Combination index values 0.1 to 0.3 indicate strong synergism.⁸