RESUMO
BACKGROUND: The pathophysiology of pelvic organ prolapse (POP) involves vaginal collagen degradation. Strengthening collagen by UVA-photoactivated cross-linking has been demonstrated and suggested target applications include the vaginal wall. AIM: To identify UVA irradiation and riboflavin effects on vaginal cells. MATERIALS AND METHODS: Vaginal cells were incubated for 24 h (DMEM/F-12 Ham's media) and were exposed to riboflavin (0, 0.1 and 10%) for 30 min before UVA photoactivation. Percentages of live, apoptotic and necrotic cells were determined by propidium iodide/Hoechst 33342 stains. RESULTS: UVA decreased vaginal cell viability [mean ± standard error of the mean: 26.2 ± 0.5% vs. control (43.9 ± 3.8%)], but riboflavin blocked UVA-induced damage (57.9 ± 2.7 and 56.7 ± 2.1% at 0.1 and 10% riboflavin, respectively). Cells treated with low- and high-dose riboflavin had lower apoptosis (32.9 ± 1.0 and 35.5 ± 0.9%, respectively). Furthermore, riboflavin-treated cells had reduced necrosis (9.3 ± 1.7, 7.8 ± 3.0%) versus UVA-only (32.4 ± 5.5%) or control (17.1 ± 2.8%). Viability was similar for cells from the cervical and hymenal segments. CONCLUSION: The results demonstrated that riboflavin attenuated UVA damage in vaginal cells by inhibiting necrosis. Cervical and hymenal end vaginal cells were equally affected by UVA. UVA phototoxicity was reduced by the presence of riboflavin.
