Garlic-lemon-agaran blends as natural antioxidant candidates for nutraceutical applications

Oxidative stress plays a central role in the onset and progression of chronic diseases, highlighting the need for safe and effective antioxidant strategies. Garlic (Allium sativum) and lemon (Citrus limon) are recognized sources of bioactive compounds; however, their direct use is limited by bioavailability and adverse effects. Marine polysaccharides, such as agarans from Gracilaria birdiae, represent promising matrices to modulate and enhance redox-related properties. In this study, blended formulations combining aqueous garlic-lemon extract (LG) with a sulfated agaran extracted from Gracilaria birdiae (SPGB) were developed and characterized. Redox behavior and antioxidant-related properties of blends were evaluated using in vitro assays, while physicochemical properties and biocompatibility were assessed through cytotoxicity tests and Danio rerio embryo toxicity. The LG:SPGB (3:1) blend exhibited the highest overall reducing capacity and metal-chelating performance, surpassing the garlic-lemon extract alone, while demonstrating improved stability and reduced cytotoxic effects. Notably, the use of agaran enabled the preservation of redox versatility with reduced garlic-lemon extract content, minimizing potential adverse effects associated with higher extract concentrations. Overall, these findings support the potential application of garlic-lemon-agaran blends as biocompatible antioxidant systems for nutraceutical and pharmaceutical use.