Nitric Oxide: Probably the in Vivo Mediator of the Bisulfite’s Effects

The use of bisulfite in food and beverage preservation, as well as in commercial goods and phar- maceuticals as antimicrobial agents is well known, but not very much is reported on its action in vivo. It has been stressed that its action is connected to the presence of NO, and the only reported/ hypothesized evidence concerns the possible interaction with GSNO (S-nitrosoglutathione), an NO releaser. In this light, we investigated the interaction between GSNO and the bisulfite in an aqueous medium at pH = 6.4; actually, a positive effect of the sulfite was evidenced. i.e., the S-ni- trosoglutathione becomes a more efficient NO-releaser. But, the nitrite is the real pool of NO in vi- vo, therefore we investigate its interaction with the bisulfite in an aqueous acidic solution at pH = 6.4; this time, a definitely efficient and abundant NO release, 3.61 times higher compared to the GSNO, has been evidenced. Therefore, these results allow hypothesizing a fundamental role of NO in the bisulfite’s action in vivo, or most probably the bisulfite acts simply as cofactor of NO-re- leasers.