In Vitro Evaluation of the Protective Efficacy of Crocus sativus L. Waste for the Sustainable Development of Bioactive Phytocomplexes.

Saffron, branded as Repron®, is effective in slowing the progression of several neurodegenerative diseases. Its production, however, requires specific cultivation techniques and procedures that, together with low yields, make it expensive. To address this challenge, hydroponic cultivation has been adopted. Previous studies have shown that hydroponically cultivated saffron and Repron® share comparable chemical compositions and neuroprotective effects under oxidative stress conditions. In this study, we evaluated the protective properties of extracts derived from Crocus sativus L. waste, compared with those of saffron derived from stigmas. Human retinal pigment epithelium (ARPE-19) cells were pre-treated with extracts of various plant waste fractions before being subjected to three stress conditions: H2O2-induced oxidative stress (500 μM, 3 h), lipopolysaccharide (LPS; 0.25 mg/mL, 24 h), and hyperglycemia (25 mM glucose, 96 h). Saffron Repron® served as a positive control. The results revealed that the extract derived from C. sativus waste had superior protective effects against oxidative stress and inflammation by preserving the state of the mitochondria and tight junctions (ZO-1); conversely, the tepal extract alone was more effective under hyperglycemic conditions by also modulating acrolein levels. These results suggest that different plant fractions contain bioactive compounds with specific protective actions, which together lead to increased cell survival.