UVA-Photoactivated Riboflavin Treatment of Vaginal Cells Derived from Pelvic Organ Prolapse Cases

Abstract

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.

Can UVA-light-activated riboflavin-induced collagen crosslinking be transferred from ophthalmology to spine surgery? A feasibility study on bovine intervertebral disc

“…The reduction of cell viability after UVA treatment and their increment after RF treatment, has been already demonstrated by Schultz et al in vaginal connective tissue cells [ 28 ]. Schultz et al tried to clarify viability, apoptosis and necrosis of vaginal cells treated by RF and UVA-based photopolymerization in order to strengthen vaginal tissues at risk of prolapse.…”

“…To achieve this goal, vaginal cells were exposed to different concentrations of RF (0.1 and 10%) and control medium, followed by UVA irradiation (3 mW/cm 2 ). They showed that RF attenuated UVA-related phototoxicity and damage by inhibiting necrosis [ 28 ].…”

Does the chemistry of fungal pigments demand the existence of photoactivated defense strategies in basidiomycetes?

“…In addition, riboflavin (7) and synthetic derivatives are photoactive, as shown by their ability to produce singlet oxygen under irradiation [63]. Nevertheless, photoprotective properties were also demonstrated for riboflavin [64], thus riboflavin's phototoxicity seems strongly concentration and irradiation dependent. Riboflavin (7) can be isolated from several higher fungi [65], as for example from Calocybe chrysenteron [66] or Russula xerampelina (η = 12.6% DW) [67].…”