Biological Profiles of Quercus cerris, Quercus dalechampii, and Quercus robur Bark Extracts: A Characterization Study

Adrian Nisca; Sanziana Sisea; Nastaca Alina Coman; Mihai Babota; Oleg Frumuzachi; Corneliu Tanase

doi:10.2478/amma-2024-0003

Adrian Nisca Doctoral School of Medicine and Pharmacy, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Târgu Mures, 38 Gheorghe Marinescu Street, 540139 Târgu Mures, Romania
Sanziana Sisea Department of Pharmaceutical Botany, Faculty of Pharmacy, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Târgu Mures, 38 Gheorghe Marinescu Street, 540139 Târgu Mures, Romania
Nastaca Alina Coman Doctoral School of Medicine and Pharmacy, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Târgu Mures, 38 Gheorghe Marinescu Street, 540139 Târgu Mures, Romania
Mihai Babota Department of Pharmaceutical Botany, Faculty of Pharmacy, “Iuliu Hatieganu” University of Medicine and Pharmacy, Gheorghe Marinescu Street 23, 400337 Cluj-Napoca, Romania
Oleg Frumuzachi Department of Pharmaceutical Botany, Faculty of Pharmacy, “Iuliu Hațieganu” University of Medicine and Pharmacy, 23 Gheorghe Marinescu Street, 400337 Cluj-Napoca, Romania
Corneliu Tanase Department of Pharmaceutical Botany, Faculty of Pharmacy, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Târgu Mures, 38 Gheorghe Marinescu Street, 540139 Târgu Mures, Romania

DOI: https://doi.org/10.2478/amma-2024-0003

Keywords: Quercus; antioxidant; oak; polyphenols; tyrosinase

Abstract

Objective: The main objective of the present study was to characterize the extracts obtained from the bark of three oak species in order to assess their use in potential cosmetic products.

Methods: The extracts were obtained from the oak barks (periderm and rhytidome) using an ultrasonic probe. The total polyphenolic content was assessed afterwards, using the Folin–Ciocâlteu method, while the antioxidant capacity was determined using methods based on the neutralization of the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl radicals. For the assessment of the tyrosinase inhibitory effect, a protocol using L–DOPA as the substrate of the enzyme was used.

Results: The extracts presented high levels of polyphenolic compounds, Q. cerris having the highest content. Because of the high concentration of the extracts in polyphenolic compounds, they revealed a great reducing capacity against both radicals, but unfortunately the tyrosinase inhibitory effect was very weak when compared to the positive control.

Conclusions: The extracts may have beneficial effects when used in cosmetic products because of the antioxidant effects, but more studies must be conducted for the determination of the main phytochemical compounds comprised in the extracts and their correlation to the biological effects.