Antioxidant Potential, Genotoxic Safety, and Metabolomic Profiling of Cladode Extracts from Dactylopius opuntiae-Resistant Opuntia Species

Abstract

Species of the Opuntia genus are widely recognized for their richness in bioactive metabolites and antioxidant potential, particularly in their cladodes. However, despite increasing interest in cochineal-resistant cultivars, their genotoxic safety remains poorly explored. In this study, the phytochemical composition, antioxidant activity, and genotoxic effects of cladode extracts from three Dactylopius opuntiae-resistant Opuntia species (O. ficus-indica, O. robusta, and O. stricta) collected in eastern Morocco were comparatively evaluated. Hydroethanolic extracts were characterized for their biochemical composition and screened for antioxidant activity using DPPH, β-carotene bleaching, FRAP, and total antioxidant capacity assays. An untargeted UHPLC-Orbitrap MS/MS approach was applied to profile secondary metabolites, while genotoxicity was assessed using the comet assay on rat leukocyte DNA. The three species exhibited distinct phytochemical and antioxidant profiles. O. ficus-indica showed the highest total phenolic and flavonoid contents and the strongest radical scavenging and reducing capacities, whereas O. stricta was particularly rich in ascorbic acid and exhibited the highest total antioxidant capacity. Metabolomic analysis revealed a predominance of phenolic acids and flavonoids, with piscidic acid as a major constituent, along with isorhamnetin derivatives and organic acids. Importantly, none of the extracts induced genotoxic effects compared to the negative control, while all differed significantly from the oxidative damage induced by hydrogen peroxide. Overall, these findings demonstrate the phytochemical richness, antioxidant potential, and genotoxic safety of cochineal-resistant Opuntia cladodes, supporting their sustainable valorization in food, nutraceutical, cosmetic, and agricultural applications.