Polyphenols as natural antioxidants in cosmetics applications.

Background: Currently, there is a great interest in cosmetics prepared on natural resources bases and this may restrict the use of synthetic substances. Plants play a relevant role as a source of biologically active natural products with cosmetic and dermatological importance. According to this context, polyphenolic extracts are highlighted because they have proven antioxidant, anti-inflammatory, anti-aging, antimicrobial, and supporting activity in solar photoprotection.

Aims: The purpose this study were reviewed at reporting the antioxidant activity of phenolic compounds, mainly applied to dermatological therapy, and highlighting the action mechanisms and structure-activity relationship.

Methodology: In September 2017, we performed a literature search in PubMed and Scielo for scientific researches, antioxidant studies, and systemic reviews. The search terms we used were "PHYTOCOSMETICS" AND "ANTIOXIDANT ACTIVITY" OR "PHENOLIC COMPOUNDS" (from 2000). As inclusion criteria were used relevant original articles, scientific research in the area of interest, and crucial reference articles. Exclusion criteria were: duplicate publications, non-relevant articles and not published in English.

Results: The potential cosmetic application of phenolic compounds as natural antioxidants has been attributed to the chemical structure of these compounds, which to interfere in different phases of the oxidation mechanism.

Conclusion: The use of phenolic extracts emerges as a viable alternative for cosmetic application, ensuring a commitment to sustainability. However, it is of crucial importance to evaluate the toxicity risks of raw materials and finished products.