Non-food crop Rosa caninaL leaf and twig extracts as a source of nutrients and bioactive compounds

It is important to search for new sources of bioactive, natural compounds because customers pay more attention to food quality. Fruits and berries from horticultural plants are known to be good sources of agents beneficial for human well-being and could serve as natural preservatives in the food industry. However, more recent research indicates that other plant organs can also be rich in nutrients. Our study focused on characterizing an unexplored source: leaf and twig extracts from Rosa canina. The chemical composition of these extracts was analyzed and their in vitro activity measured. HPLC analysis of the content of phenolics, vitamins and amino acids revealed that the leaf and twig extracts are rich in bioactive compounds with potent antioxidant properties. The greatest differences between bioactive phenolic compounds in leaf and twig extracts related mainly to p-coumaric acid, myricetin, ellagic acid, cyanidin, procyanidin and quercetin, whereas salicylic acid levels were similar in both types of extract. Interactions with human serum albumin were investigated and some conformational changes in protein structure were observed. Further analysis (lipid peroxidation, protein carbonylation, thiol group oxidation, DPPH inhibition and ROS inhibition) confirmed that both leaf and twig extracts exhibited antioxidant and antiradical scavenging activities. Cytotoxicity and hemotoxicity assays confirmed very low toxicity in the extracts over the range of concentrations tested. Our results indicate that both extracts could serve as non-toxic sources of bioactive compounds with antiradical properties.