Table 1.

PICO search strategy.

Framework item	Description
Population	Diabetic patients and animals (mice and/or rats) with periodontitis
Intervention	Systemic administration of various polyphenols and its derivates for at least 28 days
Comparison	Systemic administration of placebo solution for at least 28 days
Outcome	Polyphenol supplementation demonstrates several positive effects, including improvement in clinical periodontal parameters, reduction in the expression and levels of inflammatory mediators, and effective control of hyperglycaemia in both patients and mice and/or rats with DM, as compared to the control group

PICO: Population, Intervention, Comparison, and Outcome.