TABLE 1.

The population, intervention, comparison, outcome, study design (PICOS) criteria.

Criteria	Selection criteria
Population	Adults (aged ≥18 years)
Intervention	Saffron/Crocin supplement
Comparison	Placebo or no intervention
Outcome	Clinical changes in serum concentrations of oxidative stress biomarkers including TAC, TOS, CAT, MDA, NO, GSH, PAB, SOD, GPx, and isoprostanes
Study design	Randomized controlled trials

CAT, catalase activity; GPx, glutathione peroxidase activity; GSH, glutathione; MDA, malondialdehyde; NO, nitric oxide; PAB, pro-oxidant/antioxidant balance; SOD, superoxide dismutase; TAC, total antioxidant capacity; TOS, total oxidant status.