Mechanism(s) of Toxic Action of Zn²⁺ and Selenite: A Study on AS-30D Hepatoma Cells and Isolated Mitochondria

Table 4

Time-dependent effects of high concentrations of Zn²⁺ and selenite on ROS formation by AS-30D cells measured by flow cytometry using DCFH₂-DA as ROS-sensitive probe.

Medium	Time	DCF fluorescence (arbitrary units)
		Control	50 𝜇M Se	250 𝜇M Zn	500 𝜇M Zn
PBS	50 min	32.8±6.3	90.9±3.1 *	38.5±2.2	29.2±9.5
RPMI	3 h	21.1±1.1	75.6±2.5 *	31.6±1.5 *	32.1±1.8 *
	24 h	25.8±4.3	4.2±0.8 *	12.0±1.0 *	n.d.
	48 h	21.7±4.7	7.3±0.7 *	11.8±0.5 *	n.d.

The overall ROS production is shown as the geometric mean (±SE, 𝑛 = 3) of total green fluorescence of the oxidation product of DCFH₂. *𝑃 < 0.05 compared to untreated control; for other details, see Section 2; n.d., not determined.