Protective Action of Hydrogen Sulfide-Releasing Compounds against Oxidative Stress-Induced Cataract Formation in Cultured Bovine Lenses

ABSTRACT

Purpose

The gaseous signalling molecule, hydrogen sulfide (H₂S) has antioxidant, anti-inflammatory and anti-apoptotic properties. Since oxidative stress has been implicated in the pathogenesis of cataracts and lenticular hydrogen peroxide (H₂O₂) is elevated in some cataract patients, the present study investigated the ability of H₂S-releasing compounds to prevent H₂O₂-induced cataract formation in cultured bovine lenses.

Methods

Lenses were cultured in either Dulbecco's Modified Eagle Medium (DMEM; control); H₂O₂ (50 mM); ascorbic acid (AA; 3 mM) (positive control); and the H₂S-releasing compounds (diallyl trisulfide [DATS] or GYY4137) in the presence of H₂O₂ (50 mM). Lens opacity was determined using a plate reader to measure transmittance. Lens glutathione content (GSH), superoxide dismutase (SOD) activity and lactate dehydrogenase (LDH) cytotoxicity were assessed before and after treatment with the H₂S-releasing compounds.

Results

Both DATS (10⁻⁷M – 10⁻⁴M) and GYY4137 (10⁻⁷M – 10⁻⁴M) significantly (p < .001) attenuated H₂O₂ (50 mM)-induced loss in transmittance, with DATS (10⁻⁴M) and GYY4137 (10⁻⁷M) achieving a maximal reversal of opacity by 56.86 ± 0.01% (n = 6) and 8.39 ± 0.11% (n = 6) after 120 hours, respectively. These observations were corroborated by photographic evaluation, where DATS (10⁻⁵M – 10⁻⁴M) and GYY4137 (10⁻⁷M – 10⁻⁵M)-treated lenses had relatively clear grids after 120 hours, compared to H₂O₂ (50 mM)-treated lenses. The H₂O₂ (50 mM)-induced decline in total GSH content and total SOD activity were significantly (p < .001; n = 5) reversed by DATS (10⁻⁴M) and GYY4137 (10⁻⁷M). After 24 hours, DATS (10⁻⁴M) and GYY4137 (10⁻⁷M) significantly (p < .001; n = 4) reduced cytotoxicity of primary bovine lens epithelial cells by 33.88 ± 4.59% and 36.19 ± 10.53%, respectively.

Conclusion

Both H₂S-releasing compounds protected cultured bovine lenses against oxidative stress-induced cataract formation. The slow-releasing H₂S compound, GYY4137 was more potent than DATS in restoring lenticular total GSH content and total SOD activity along with reducing H₂O₂ (50 mM)-induced cytotoxicity

KEYWORDS:

• Cataracts
• lens opacity
• hydrogen peroxide
• hydrogen sulfide
• antioxidants

Acknowledgments

Creighton University, School of Pharmacy and Health professions, Department of Pharmacy Sciences, Pharmaceutical Sciences Graduate Program.

Data availability

The authors confirm that the data supporting the findings of this study are available within the article.

Disclosure statement

No potential conflict of interest was reported by the author(s).