Crocus sativus L. stigmas and byproducts: qualitative fingerprint, antioxidant potentials and enzyme inhibitory activities

Saffron (Crocus sativus L.) has been previously reported to be active as a protective agent in multiple experimental models of oxidative stress, inflammation and cancer. These findings refer to the protective effects of stigmas, not byproducts such as tepals and anthers. In this context, the aims of the present work were to characterize the phytochemical profile of saffron stigmas (CST) and high quality byproducts (tepals + anthers - CTA) extracts. Additionally, we studied the antioxidant and chelating effects of CST and CTA extracts by preliminary in vitro assay. The antioxidant activity was further investigated through the evaluation of reactive oxygen species (ROS) levels and lactate dehydrogenase (LDH) activity on mouse myoblast (C2C12) and human colon cancer (HCT116) cell lines. Additionally, we evaluated CST and CTA extract treatment on cholinesterases, α-glucosidase and α-amylase activity, in vitro. Finally, we studied the effects of CST extract on malondialdehyde (MDA) level in rat colon specimens challenged with E. coli lipopolysaccharide (LPS). We observed that water CST extracts are rich in phenolic content, whereas for CTA the olive oil was the elective extraction solvent. As expected, water CST extracts were the most effective in reducing hydrogen peroxide-induced oxidative stress in both cell lines and in vitro assays. Furthermore, both CST and CTA water extracts reduced the LDH activity in HCT116 cells challenged with hydrogen peroxide and LPS-induced MDA levels in rat colon specimens. Concluding, the present findings showed protective effects exerted by CST and CTA extracts in in vitro and ex vivo models of inflammation and oxidative stress.