Fig. 6: Antioxidant vitamin C suppresses endometriosis progression in vivo by inducing BARD1 and BRCA1 expression.

a Schematic diagram of mouse model of endometriosis. Mice received intraperitoneal (IP) transplantation of uterine tissue from syngeneic donor mice and were then treated with phosphate-buffered saline (PBS) or vitamin C via intraperitoneal injection (IPIVC) every other day or administered oral intake vitamin C solution (OIVC) every day. All mice were supplied with 200 mg/kg 17β-estradiol every other day. After 4 weeks, endometriotic cysts were excised to harvest the extent of endometriosis. b Upper panel shows scatter plot of lesion volumes from PBS, OIVC and IPIVC mice. Lesion sizes were significantly smaller in IPIVC mice than in PBS and OIVC mice, with the smallest cyst volume in IPIVC mice (n = 11). *P < 0.05 versus PBS, ^#P < 0.05 versus OIVC, one-way ANOVA with LSD for multiple comparisons. Lower panel shows representative visible lesions within the peritoneal cavity of PBS mouse, OIVC mouse and IPIVC mouse. c Expression of HIF-1α, 8-OHdG, BARD1 and BRCA1 in stromal cells (left panel) and glandular cells (right panel) from lesions in PBS, OIVC or IPIVC mice by H-score (y-axis) (n = 11). *P < 0.05, PBS versus OIVC; ^#P < 0.05, PBS versus IPIVC; ^$P < 0.05, OIVC versus IPIVC; one-way ANOVA with LSD for multiple comparisons; the expression of BARD1 and BRCA1 increased in stromal cells and glandular cells of OIVC and IPIVC mice compared with PBS mice (n = 11, *P < 0.05, PBS versus OIVC, ^#P < 0.05, PBS versus IPIVC, ^$P < 0.05, OIVC versus IPIVC, one-way ANOVA with LSD for multiple comparisons). d Immunohistochemistry photomicrographs of HIF-1α, 8-OHdG, BARD1 and BRCA1 expressions in lesions from PBS, OIVC or IPIVC mice by H-score (y-axis). Scale bar = 100 μm for ×100 images. Scale bar = 50 μm for ×400 images