# Sea Buckthorn Leaves as a Potential Source of Antioxidant Substances
###### Abstract
Due to the interesting nutrient profiling of SBT products, several authors have investigated its effect on the final quality of different animal products. SBT leaves and other by-products can be used to feed livestock (both ruminant and monogastric animals), with a stimulatory effect on growth and performance [17; 18; 19; 20; 21]. Meat products enriched with nutrients, such as polyunsaturated fatty acids and antioxidants, are gaining much more interest among consumers. It has been reported that SBT leaves contributes positively to the nutritional quality and lipid oxidative stability of chicken breast and thigh meat [22]. For example, broiler production efficiency is quite high per se, because the growth and development of a broiler to its full potential does not take much longer than one month. However, different and more natural strategies are needed to achieve the same or higher levels of production efficiency, plainly because of the increasing consumer awareness of feeding products. [PERSON] et al. [18] compared three different diets in the growing and finishing stages of broiler chicks with a conventional diet, with one including rapeseeds and grape meal and the others including flaxseed meal and SBT meal. It showed that broilers who were fed a diet with SBT and flaxseed meals showed significantly higher concentrations of polyunsaturated fatty acids family n-3 when compared to the control or the group fed with rapeseeds and grape meal. Sea buckthorn pomace (SBT_P) is an industrial by-product rich in a variety of functional compounds, but it has not yet been effectively used. Therefore, [PERSON] et al. [23] concluded that SBT_P could improve the production, immune function, and antioxidant status of weaned piglets and that the appropriate level of SBP supplementation is from 1.0% to 2.0%  
A study by [PERSON] et al. [24] investigated the effect of sea buckthorn pomace (SBT_P) supplementation in the diet of growing German Landrace pigs on fatty acids in the blood and hypothalamus, on peripheral immune parameters and mRNA expression of the corticotropin-releasing hormone, and on the mineralocorticoid receptor and glucocorticoid receptor in the hypothalamus and spleen. The fatty acid profiles in the blood plasma were significantly affected by SBT_P supplementation at a C18:2n-6 and n-6/n-3 PUFA ratio compared with the control group. And the authors pointed out that effects derived from supplementation with a rich source of n-3 fatty acids (such as SBT_P) might be more appreciable on stressful situations. Sea buckthorn leaves are a rich source of phytochemicals, such as phenolic compounds (including polyphenols and flavonoids), polysaccharides, carotenoids, and saponins [25; 26; 27]. Therefore, SBT leaves have various beneficial effects, like antioxidant, hepato-protective, immunomododulatory, antistress, cardioprotective, and antidiabetic actions [13; 28; 29; 30; 31; 32]. In this regard, sea buckthorn leaves are a potential ingredient because of their nutritional and medical components that are beneficial to human and animal health. Modern research is needed for better utilization of this species for food/fodder and for their pharmaceutical potential. Nowadays, traditionally grown plants are the centre of attention, and the demand for their production is increasing due to the strategy of inhibiting or delaying diseases using a natural diet [33]. Young branches with leaves are a by-product after the mechanical harvesting of sea buckthorn berries [33; 34]. Current research on this plant is very important and can lead to the emergence of new avenues of its utilization, including food/feed and pharmaceutical potential [35]. The potential for the production and sustainable harvest of edible and other useful parts of this plant can also boost the local economy for farmers. However, literature reports on the profiles of many bioactive components of the leaves of SBT are still very limited. The necessity to characterize secondary metabolites and nutrients also results from previous reports on SBT [36; 37; 38].