Contribution of the Glucosinolate Fraction to the Overall Antioxidant Potential, Cytoprotection against Oxidative Insult and Antimicrobial Activity of Mill. Leaves Extract.

Background: Mill. (Brassicaceae) is commonly utilized as an ingredient in salads and also as a folk remedy to treat various diseases.

Objective: The objective of this study was to establish the contribution of the glucosinolate (GLS) fraction to the overall antioxidant, cytoprotection against oxidative insult and antimicrobial properties of the hydro-alcoholic extract of leaves from Sicily (Italy), characterized phytochemically.

Materials And Methods: The antioxidant activity was evaluated by different systems. The cytoprotective effect against hydrogen peroxide (HO)-induced oxidative stress was tested in human peripheral blood mononuclear cells (PBMCs). The antimicrobial potential against bacteria and fungi was assayed by standard methods.

Results: extract exhibited both radical scavenging (50% inhibitory concentration [IC] 1.04 ± 0.04 mg/mL) and ferrous ions-chelating activity (IC 0.327 ± 0.0032 mg/mL) and mild reducing power; the GLS fraction showed chelating ability only (IC 0.225 ± 0.009 mg/mL). In the experimental model of HO-induced oxidative stress in human PBMCs, a significant cytoprotective effect and a suppression of reactive oxygen species production by both extract and GLS fraction were observed ( < 0.001). extract displayed moderate antimicrobial activity against Gram-positive bacteria, and was the most sensitive strain (minimum inhibitory concentration 0.125 mg/mL), whereas the GLS fraction was not active.

Conclusion: GLSs are not involved in the primary antioxidant activity of leaf extract but they are, almost in part, responsible for its ferrous ion-chelating properties. Iron-chelating compounds in extract may protect cells under conditions of oxidative stress, and GLSs might play a chief role in this effect.

Summary: Mill. leaf extract exhibited antioxidant activity in different systems, whereas the glucosinolate (GLS) fraction showed Fe-chelating ability onlyA significant cytoprotective effect and a suppression of intracellular reactive oxygen species production by both extract and GLS fraction were observed in human peripheral blood mononuclear cells extract displayed moderate antimicrobial activity against Gram-positive bacteria, whereas the GLS fraction was not active. GLS: Glucosinolate; HO: Hydrogen peroxide; PBMCs: Peripheral blood mononuclear cells; IC: 50% inhibitory concentration; MIC: Minimum inhibitory concentration.