Abstract
There is no drug for cataracts, a leading cause of blindness. However, L-cysteine reportedly mitigates cataractogenesis, in vitro and in vivo. Here, we sought to standardize a new method for screening cataractogenesis and assess the effect of hydrogen sulfide (H2S) on cataractogenesis. Bovine lenses were cultured in DMEM with AA (positive control) or compounds [L-cysteine, diallyl trisulfide (DATS) and GYY 4137 (GYY)] in presence or absence of hydrogen peroxide (H2O2). Lens light transmittance and optical clarity were assessed and confirmed with biochemical assays. One-way Analysis of variance (ANOVA) and two-Way ANOVA with p<0.05 were considered significant. Cultured lenses showed opacity (p<0.0001) after 120 hours and was accelerated by H2O2 (50mM). Lenticular for total glutathione content (GSH) [46.08%, 82.56%] and total superoxide dismutase (SOD) activity [42.02%, 86.59%] decreased (p<0.0001) in untreated and H2O2- treated lenses respectively. AA (10 mM) attenuated time-dependent loss of lens transparency (p<0.0001) for 24 hours; while AA (3 mM) attenuated H2O2-induced opacity (p<0.0001) up to 120 hours. L-cysteine (10-6 M & 10-5 M), DATS (10-7 M & 10-6 M) and GYY (10-7 M & 10-6 M) mitigated (p<0.0001) loss of lens transparency up to 120 hours superior to AA (10 mM). L-cysteine (10-6 M), DATS (10-6 M) and GYY (10-7 M) reversed (p<0.0001) time-dependent decrease in GSH content and SOD activity by [76.58%, 7.42%], [69.9%, 3.32%] and [80.52%, 19.31%], respectively after 120 hours. Increased (p<0.01) cytotoxicity of 17.16% was noted for DATS (10-6 M) after 24 hours of incubation. L-cysteine (10-6 M to 10-4 M) & DATS (10-6 M & 10-4 M) reversed H2O2-induced opacity up to 120 hours greater than AA (3 mM). L-cysteine (10-4 M), DATS (10-4 M) and GYY (10-7M) reversed (p<0.0001) H2O2-induced decrease in GSH content and SOD activity by [74.67%, 161.1%], [121.48%, 109.78%] and [158.51%, 194.89%] respectively, after 120 hours. H2O2-induced bovine lens epithelial cells cytotoxicity was mitigated (p<0.0001) by 27.7% (L-cysteine [10-4 M]), 33.88% (DATS [10-4 M]) and 36.19% (GYY [10-7M]) after 24 hours. Measurement of cultured lens transmittance is a viable method for screening cataractogenesis. H2S protected lenses from time-dependent and H2O2-induced opacity, possibly due to its antioxidant property.