Xylopine Induces Oxidative Stress and Causes G₂/M Phase Arrest, Triggering Caspase-Mediated Apoptosis by p53-Independent Pathway in HCT116 Cells

Table 1

Cytotoxic activity of xylopine (XYL).

Cells	Histological type	IC50 in μM
		DOX	OXA	XYL
Cancer cells
MCF7	Human breast carcinoma	1.1	5.9	12.0
		0.3–3.5	3.5–9.9	6.1–23.6
HCT116	Human colon carcinoma	0.1	4.1	6.4
		0.04–0.11	2.7–6.4	5.1–8.2
HepG2	Human hepatocellular carcinoma	0.1	1.0	9.4
		0.04–0.11	0.2-3.9	6.0–14.8
SCC9	Human oral squamous cell carcinoma	0.5	N.d.	26.6
		0.4–0.7		21.9–32.1
HSC3	Human oral squamous cell carcinoma	0.3	3.3	15.7
		0.2–0.4	1.4–7.8	10.2–24.3
HL-60	Human promyelocytic leukemia	0.3	0.4	18.5
		0.3–0.4	0.1–3.8	16.0–21.3
K562	Human chronic myelogenous leukemia	0.3	0.9	7.8
		0.2–0.5	0.1–9.7	6.1–9.9
B16-F10	Murine melanoma	0.03	0.1	9.6
		0.02–0.07	0.03–1.3	8.0–11.4
Noncancer cells
MRC5	Human lung fibroblast	1.5	1.5	24.1
		1.2–2.0	0.9–2.8	20.8–28.3
PBMC	Human peripheral blood mononuclear cells	5.2	14.9	18.3
		2.4–11.4	8.9–24.8	11.0–29.0

Data are presented as IC₅₀ values in μM and their respective 95% confidence interval obtained by nonlinear regression from at the least three independent experiments performed in duplicate and measured by alamarBlue assay after 72 h incubation. Doxorubicin (DOX) and oxaliplatin (OXA) were used as positive controls. N.d.: not determined.