Biological properties of Elaeagnus rhamnoides (L.) A. Nelson twig and leaf extracts.

Sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson, SBT) is a valuable plant because of its medical and therapeutic potential. Different bioactive compounds in SBT berries are of special interest to various researchers. However, not only sea buckthorn berries, but also leaves of this plant (both fresh and dried) contain a lot of nutrients and bioactive compounds, including phenolic compounds. The present study was carried out in order to investigate antioxidant and anticoagulant properties of sea buckthorn twig and leaf extracts (0.5-50 μg/mL) by using various in vitro models. Moreover, the aim of present experiments was to compare the biological activity of SBT leaf extract and SBT twig extract with selected berry extracts (a rich source of phenolic compounds): SBT berry extract (flavonoids being the dominant components), a commercial extract from the berries of Aronia melanocarpa (Aronox®), and a grape seed extract.We determined the effect of plant extracts on the oxidative stress using selected markers of this process, i.e. the level of carbonyl groups in proteins. Additionally, we analysed the potential mechanism of modulation of hemostatic properties of human plasma (using selected coagulation times).

SBT twig and leaf extracts were observed to exhibit an antioxidant activity against two strong biological oxidants: hydrogen peroxide (H₂O₂) and H₂O₂/Fe (the donor of hydroxyl radicals), which induced human plasma lipid peroxidation and protein carbonylation. Both extracts also showed anticoagulant properties.

Our present results have demonstrated that extracts from different parts of SBT, especially berries and twigs, in comparison to well-known berries (aronia and grape), may also be viewed as a good source of active substances - antioxidants for pharmacological or cosmetic applications. Moreover, it is very important from an economic point of view to know that there is a possibility of obtaining phenolic compounds not only from the berries or leaves, but also from twigs, which constitute a production waste.