In an interesting study performed by Erel and Neselioglu (2014), the authors cited that the formed disulfide bonds under oxidation stress can again be reduced to thiol groups. they called this phenomenon " the dynamic thiol-disulfide homeostasis".

The principle of the assay the authors used was the reduction of the dynamic disulfide bonds (–S–S–) in the sample (glutathione, 2-mercaptoethanol, and albumin) to functional thiol groups (–SH) by NaBH4.

The use of NaBH4 (source of hydrogen molecular in aqueous medium) as a reducing agent increased the levels of plasma -SH in patients without affecting the structural disulfide bonds.

Source:

Article A Novel and Automated Assay for Thiol/Disulphide Homeostasis.

Some key points from the previously cited paper of Erel and Neselioglu (2014) are shown in the attached figures.

Referred following article

https://onlinelibrary.wiley.com/doi/abs/10.1002/ange.201310249

Devidas Bhagat thank you for your answer. However, the referred paper entitled "Mechanistic Insights into the Interface‐Directed Transformation of Thiols into Disulfides and Molecular Hydrogen by Visible‐Light Irradiation of Quantum Dots" explains a procedure for synthesizing disulfides from thiols. However, our goal is opposite i.e. formation SH group from S-S by using molecular hydrogen.

Duried Alwazeer

Sodium borohydride is very toxic if swallowed and affects fertility. We faced the problem of disulfide bond cleavage when studying activators of devulcanization of rubber of automobile tires. The same problem was investigated for the search for X-ray inhibitors. Among them, you can find less toxic.