chemical composition, configuration, and molecular weight [3; 4; 5]. Some of the mechanisms of these activities are still under research. The involvement of immune cells, especially macrophages, is suspected in the immunostimulatory effect of polysaccharides. It has been shown that glycan may enhance macrophage functions through stimulation of phagocytosis and an increase in the secretion of cytokines and chemokines. Moreover, it may enhance cytotoxic activity against cancer cells and free oxygen radicals [1].  
Roots of different rose species are a relatively poorly known plant material. Rose roots are used in Chinese herbal medicine to treat enuresis, diarrhoea and redness [6]. They have been also used in folk medicine in the treatment of pain, chronic inflammatory diseases or diabetes [7]. They contain many valuable components representing multiple phytochemical groups. _Rosa laevis_ Michx. and _Rosa zymosa_ Tratt. roots were shown to contain triterpenes (e.g., betulinic acid), triterpen saponins (e.g., kajiichigoside and rosamutin), flavonoids and tannins [6; 8]. In the root of _Rosa acicularis_ Lindl., high levels of polyphenic compounds, e.g., proanthocyanidins, epigallocatechin, catechin, and ellagic acid, were found [9]. The analysis of the root of _Rosa rugosa_ [PERSON] of European origin showed a high content of polyphenols, including a high proportion of phenolic acids (e.g., gallic, and caffe) and tannins. Additionally, a remarkable amount of flavonoids (e.g., quercetin, and isoquercetin) was detected [10]. The phytochemical composition strongly affects the biological activity and therapeutic use of these organs. Tritterponoids from _Rosa laevis_ Michx. roots have been shown to exert anti-inflammatory, antifungal and acetylcholinesterase-inhibiting properties [6]. Extracts from rugosa rose roots possess antifungal, antibacterial, and hyaluronidase inhibitory activity as well as high antioxidant potential [10; 11]. Moreover, teas from rugosa rose roots were found to strongly affect the proliferation of breast (T47D), ovarian (TOV-112D), cervical (HeLa) and lung cancer (A549) cell lines [7].  
Rose polysaccharides are the least studied rose metabolites. Some previous studies revealed the chemopre potential of polysaccharide-rich fractions prepared from rose petals, pseudofruits, leaves, and achenes. The samples were also shown to have radical scavenging, strong hyaluronidase inhibitory and anti-inflammatory activity [12; 13]. However, polysaccharides from rose roots have not been investigated to date. Meanwhile, rose roots can be obtained in industrial amounts after renovation of rose cultivations. One of the most commonly grown rose cultivars is rugosa rose (_Rosa rugosa_ Thunb.; Japanese rose). It is known mostly for its large pseudo-fruits and fragment petals. At present, its roots are rarely used, as they are regarded rather as post-harvest residue and discarded [10]. This is quite surprising and seems to be a waste, considering the value of the ingredients contained in this plant material. Perhaps the knowledge of this issue is insufficiently promoted, or further investigations on the phytochemistry of rose roots and their possible new applications are needed.  
Therefore, the aim of the present study was to determine the composition of the polysaccharide fraction obtained from _R. rugosa_ roots and evaluate its anti-inflammatory, antioxidant, and antiproliferative activity. Since other macromolecules (e.g., proteins or polysaccharide-peptide conjugates) often co-elute with polysaccharides and can be found in the final extract (even despite the de-ballasting stages) we also wanted to examine the presence of proteins and their conjugates in the prepared samples.