Chemical composition and biological activity of Capparis spinosa L. from Lipari Island

Several plants belonging to the genus Capparis are the focus of growing interest due to their singular nutritional and medicinal properties. In the present study, flower bud samples from C. spinosa L. (Lipari Island, Italy) were subjected to decoction, Soxhlet, and microwave extraction techniques and the individual extracts investigated to better characterize the phytochemical and antioxidant profiles of the plant. Total phenolic and flavonoid amounts, phenolic composition, radical scavenging as well as reductive and metal chelating properties were determinated by well-established chemical and analytical procedures. Furthermore, cholinesterase inhibitory effects were evaluated by Ellman's method. Fatty acid percentage and essential oil composition were also detected by GC and GC–MS techniques respectively. Rutin was found to be the major component in the studied extracts. The Soxhlet extract exhibited the strongest radical scavenging and reductive activities as compared to the other extracts, most probably due to the highest concentration of phenolics, especially rutin. The best cholinesterase inhibitory effect was observed in the microwave extract. Palmitic acid was the most abundant fatty acid in the studied oil, whereas docosane was the major volatile compound in the essential oil. Present data corroborate the multipurpose potential of C. spinosa for designing bio-based drug formulations or functional applications.