## 4 Discussion  
Numerous flavonoids have showcased promising chemoprotective effects on human colon cancer cell lines through multiple molecular and biochemical mechanisms of action [8]. For example, quercetin presents inhibitory effects on the growth and proliferation of several colorectal cancer cells, including Caco-2 cells. Similarly, myricetin has been shown to inhibit proliferation and induce apoptosis in colorectal cancer cells via the modulation of apoptotic and inflammatory pathways [8]. Quercetin-3-O-sophoroside along with other quercetin and kaempfer glycosides have demonstrated cytotoxic activity against P-388 murine leukemia cells [20]. Additionally, isorhannetin glycosides have been shown to induce apoptosis in HT-29 and Caco-2 human colon cancer cells [21]. Saffron leaves are rich in flavonoid C-glycosides such as luteolin-6-C-glucoside (isoorientin) or nigerin-8-C-glucoside (vitexin), which have recently captured the attention of researchers due to their health benefits, including anticancer properties [22]. According to [PERSON] et al. (2016) [23], vitexin inhibits autophagy and thereby induces apoptosis in hepatocellular carcinoma cells by activating the JNK signaling pathway. Conversely, isorientin has been shown to induce apoptosis, decrease invasiveness and downregulate vascular endothelial growth factor in pancreatic cancer cells [24]. An intriguing aspect of flavonoid C-monoglycosides concerning colorectal cancer is their limited absorption by humans, potentially leading to the accumulation of higher concentrations in the colon compared to aglycones or flavonoid O-glycosides, which are more easily absorbed in the gastrointestinal tract [22]. Experimental evidence suggests that iron and other metals may act as carcinogenic factors involved in both the initiation and promotion of cancer. Transition metals like iron catalyze Fenton's reaction to produce reactive oxygen species that contribute to carcinogenesis, so elevated iron levels have been documented in colorectal tumor tissues [25]. This role is particularly relevant in colorectal cancer because of the relatively high concentration of iron in feces, especially in individuals with a diet rich in red meat [8]. To address this issue, several synthetic chelators have been developed to deplete iron levels in cells for antitumor therapies, potentially increasing therapeutic benefits in the management of colorectal cancer. The ability of phenolic compounds to chelate transition metals is well-established, dependent on the presence and arrangement of hydroxyl and carbonyl groups within the molecules. Notably, the phenolic compounds identified in saffron leaves present some of these reactive sites: kaempfer, isorhamnetin and apigenin derivatives have available the 4-carbonyl and 5-hydroxy groups, and quercetin glycosides and isoorientin 4-carbonyl and 5-hydroxy groups as well as the 3\({}^{\prime}\) and 4\({}^{\prime}\) dihydroxy groups. This is consistent with the significant iron- and copper-chelating activities observed in this study. The EC\({}_{50}\) values of SLE for iron and copper chelation activities compare favorably with those of other plant by-products previously studied [14], highlighting the potential of saffron leaves as a source of chelating compounds. Notably, the chelating activity of its phenolic compounds was found to be comparable to that of well-established chelating agents, such as the hydroxybenzoic acid phenol, gallic acid. Several studies have extensively explored the iron- and copper-chelating capabilities of the aglycones present in the major flavonoids identified in saffron leaves, including quercetin, kaempfer, isorhamnetin, luteolin and apigenin. Despite variations observed due to the pH, the preferred binding sites, and the resulting stoichiometry of the formed complexes, all these flavonoids demonstrated metal-chelating activity [26]. Quercetin, one of the most abundant flavonoids in nature, has been extensively studied for its metal-chelating properties.