Functionality of oak (Quercus spp.) parts and possible prospects for their usage: a review

Abstract

Oaks (Quercus spp.) are perennial, widespread throughout the Northern Hemisphere trees of whose certain parts can have a positive impact on human health and other areas like food, cosmetics. At these times, Quercus species are becoming reliable objects for fundamental studies due to the biological activities of their various parts (bark, leaves and acorns). It is known that the properties of Quercus bark have been used in ancient traditional medicine to treat human burns, infections, and gastrointestinal diseases [1]. Nowadays, studies show that oak bark extracts can be used as an antifungal agent and as a potential medicament against certain cancer types [2]. In addition, studies show that some species show antidiabetic activity and can cause improvement in energy, fatigue, and stress levels [3]. Oak fruits – acorns have a lot of potential in the field of pharmacy, as many studies demonstrate antioxidant and antibacterial activities of various Quercus species, as well as anti-inflammatory, antifungal or antiviral activities. Even more promising results are being achieved in area of antiproliferative activity; the suppression effect of acorns extract in cancer cells proliferation through induction of early apoptosis was determined [4]. Furthermore, studies have assessed acorns influence on anti-obesity effect: acorns extracts can reduce lipids droplet size and gradual gathering of hepatic lipids [5]. Oak leaves, like other oak parts, have bioactive components that provides them basic properties, such as: antioxidant, antibacterial, antifungal and anti-inflammatory activities [6, 7]. More studies currently underway on the various medical uses of Quercus spp. leaves and their potential with feasibility in finding new applications for treatments. In general, extracts obtained from different parts of the Quercus spp. are rich in phenolic compounds like tannins.[...]