Table 1.

IC50 values of TPE and TPB in free radical scavenging experiments.

Substance	IC50 (μ g/mL)
	DPPH•	ABTS•+	OH•
TPE	3.15 ± 0.02 **	58.71 ± 1.88 **	36.79 ± 2.44 **
TPB	3.48 ± 0.16 **	76.77 ± 1.67	253.16 ± 19.37 **
VC	5.52 ± 0.18	76.36 ± 2.33	2904 ± 97.97

Data are expressed as mean ± SD; ** p < 0.01 vs. VC; TPE and TPB, vitamin C equivalent antioxidant capacity. TPB: polyphenols of T. chebula n-butanol extract; TPE: polyphenols of T. chebula ethyl acetate extract; VC: vitamin C.