Saffron (Crocus sativus L.) Flowers: a good source of Crocin & Kaempferol.

Crocus sativus L. is an autumn-flowering geophyte extensively cultivated in countries such as Italy, Spain, Greece, Turkey, Iran and India. The only part used of the whole plant is its dried stigmas which have been used as a valuable spice and traditional medicine for centuries; the other parts of the flowers are normally wasted. Recently, attention was paid to the identification of natural antioxidants from the petals. The antioxidant activities were mainly attributed to carotenoid and flavonoid compounds, kaempferol and crocins. These bioactive compounds have important biological activities including prevention of heart and vascular disease, oocyte prevention and cancer. Crocins are glycosides of the carotenoid crocetin which is known to inhibit nucleic acid synthesis and cell proliferation. Numerous reports have shown that kaempferol and/or its glycosides induce cell death in a variety of cancer cells from different tissues. The antioxidants were extracted using aqueous alcohol followed by flash column chromatography purification, and analysed using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) by comparison with authentic standards. Crocin and kaempferol were further characterised by infrared (IR), mass spectroscopy (MS), nuclear magnetic resonance (1H & 13C NMR). Kaempferol was assayed for toxicity towards MCF-7 breast cancer cell lines and multi-drug resistant MDA-MB468 breast cancer cell lines and MCF10A a normal breast cell line. In addition to their antitumor activity, in vitro biological assays have been exerted in order to assess the cardiovascular effects of the compounds. The cardiac activity assays, on guinea-pig left and right atria, as well as their relaxant activity on guinea-pig vascular (aorta) and nonvascular (ileum) smooth muscle were studied. The presence of very high amounts of antioxidants, notably of kaempferol, in saffron petals makes that we should considered them an important resource rather than a waste product.