Nitric oxide plays a role in anxiety- and depression-like behaviors induced by sodium metabisulfite intake in rats.
Level 5 - mechanism / opinion, no new human data
Animal experiment with no human clinical data
PubMed 40706911 · doi:10.1016/j.toxlet.2025.07.1411
What was done
Researchers divided 100 male Wistar rats into four groups receiving daily oral gavage for 35 days: distilled water control, or sodium metabisulfite at 25 mg/kg (S25), 100 mg/kg (S100), or 260 mg/kg (S260). Rats from each group were subjected to behavioral testing for anxiety- and depression-like behaviors (n = 15 per group), hippocampal long-term potentiation recordings (n = 5 per group), or long-term depression recordings (n = 5 per group). Hippocampal tissue was subsequently analyzed for nitrite/nitrate, neuronal nitric oxide synthase (nNOS), and inducible nitric oxide synthase (iNOS) levels.
What was found
Sulfite exposure at 100 mg/kg and 260 mg/kg induced anxiety- and depression-like behaviors, impaired long-term potentiation, and facilitated long-term depression in the hippocampus. Hippocampal levels of nitrite/nitrate, nNOS, and iNOS were significantly lower in the S100 and S260 groups compared to the control group. Exact numerical values, test metrics, and p-values were not reported in the abstract.
Why it matters
The study suggests that subchronic exposure to moderate-to-high doses of sulfite food preservatives can alter emotional behavior and impair hippocampal synaptic plasticity, potentially mediated by reduced nitric oxide production.
Limits
This is an animal study conducted solely in male rats, limiting direct translation to human dietary safety and female biology. Electrophysiology subgroup sizes were small (n = 5 per group). The abstract does not report exact numerical data or effect sizes and demonstrates an association rather than direct causal rescue of the nitric oxide pathway.
Cited by
- supports Excess levels of histamine, sulfites, glutamate, and adrenaline are linked to anxiety.