Phytochemical study and determination of biological activities of Quercus spp. different extracts

Abstract

Quercus spp or oak, belonging to the fagaceae family, is an important tree in the Algerian forest, but its biological properties and interest in phytotherapy are little known. In order to contribute to the improvement of the Algerian flora, The objective of this study was to prepare alcoholic and aqueous extracts of both oak leaves and fruits using two different extraction methods. The phytoconstituents present in the oak extracts were then detected and spectrophotometrically measured, with a focus on secondary metabolites such as polyphenols and flavonoids. Finally, the biological activities of the extracts were evaluated. Extraction by maceration and ultrasound was carried out using 2 solvents of different polarities (ethanol, distilled water). A quantitative analysis was carried out to determine the polyphenols contained in the extracts using the Folin Ciocalteu reagent, as well as the flavonoids present in the extracts using the aluminium chloride (AlCl3) method. The results of the various assays show that the highest content of phenolic compounds was obtained in the leaf extracts. In terms of flavonoid content, the aqueous acorn extract had the highest flavonoid content. Phytochemical screening of Quercus acorn and leaf extracts revealed the presence of tannins, gall tannins, catechetic tannins, saponins, favonoids, polyphenols, terpenes and carbohydrates. The results of the DPPH test demonstrated that Quercus extracts exhibited significant antioxidant activity. As the in vitro investigation indicated that the extracts, when subjected to the protein denaturation method and haemolysis test, exhibited good anti-inflammatory properties. This study has demonstrated that the ethanolic and aqueous extracts of this plant have the potential to act as a potent antioxidant and anti-inflammatory agent, with significant biological and therapeutic implications.