Table 3.

Antioxidant activities of the extracts of O. stamineus leaves obtained by supercritical CO₂.

Assaysa	IC50 valuesd of the samples in μg/mL
	A1	A2	A3	B1	B2	B3	C1	C2	C3	AA
ABTSb	ND	1150	ND	ND	91.7∗	ND	218	ND	117	6.5∗∗
DPPHc	>200	>200	>200	136	42.8∗	164	168	56.1∗∗	198	5.8∗∗

^aMicrotiter 96-well plate was used to assess the concentrations (12.5, 25, 50, 100, and 200 μg/mL) of test samples. Methanol was used as blank. ABTS or DPPH was used as negative control. Ascorbic acid (AA) was used as reference standard.

^bAbsorbance for ABTS was measured at 734 nm.

^cAbsorbance for DPPH was measured at 517 nm.

^dUsing linear regression curves the median inhibitory concentrations (IC₅₀) were calculated. The results are expressed as mean ± SD (n = 6); ∗P < 0.05; ∗∗P < 0.01.