A Review of the Traditional Uses, Medicinal Properties and Phytochemistry of Centaurea benedicta L.

Centaurea benedicta L. is an annual herbaceous plant which belongs to the Asteraceae family. It is native to the Mediterranean region and western Asia and is commonly known as blessed thistle, holy thistle, St Benedict’s thistle or spotted thistle. Traditionally, it has been used to treat bubonic plague and possesses diuretic, galactagogue, liver-strengthening and wound healing properties. Recent research studies have investigated its anticancer, antiinflammatory, antioxidant and other therapeutic properties. Several studies have also reported its antimicrobial activity against a range of bacterial pathogens. However, most of these studies were preliminary and only tested relatively high concentrations of the extracts. Additionally, most studies screened a limited number of pathogens. Cnicin is the main chemical compound present in C. benedicta and it has been widely investigated. However, few other compounds from this plant have been identified and/or investigated, and further phytochemical studies are warranted. Interestingly, pure cnicin has good anticancer activity, whilst the crude extracts lack cytotoxic properties. Phytochemical analyses of C. benedicta extracts reveal the presence of multiple flavonoids, tannins, terpenoids and lactones, although few specific phytochemicals within these phytochemical classes have been identified. A limited number of research studies have determined the toxicity profile of C. benedicta in order to evaluate its safety for human use. Substantially more detailed studies are required to rigorously investigate the therapeutic properties and phytochemistry of C. benedicta, which may ultimately lead to the development of new plant-based therapeutic medicines.