Green hydrothermal valorization of Rosa damascena Mill. floral waste into functional carbon dots for anti-inflammatory nanomedicine

The industrial production of rose essential oil via steam distillation generates substantial quantities of Rosa damascena floral residues, posing an ecological burden while remaining an underutilized source of bioactive compounds. This study aimed to develop a sustainable valorization strategy by converting such floral wastes into functional carbon dots (rose residue–derived carbon dots, RR-CDs) with potential applications in anti-inflammatory nanotherapeutics. Rose residue–derived carbon dots were synthesized using a simple one-pot hydrothermal method and comprehensively characterized, revealing them to be monodisperse, fluorescent nanoparticles with an average diameter of 3.43 nm and abundant oxygen-containing functional groups. The resulting carbon dots exhibited robust antioxidant properties, including high superoxide dismutase (SOD)-like activity (9252 U/mg) and more than 85 % hydroxyl radical scavenging at 200 μg/mL. In vitro and zebrafish models demonstrated that carbon dots effectively scavenged intracellular reactive oxygen species (ROS), preserved mitochondrial function, and inhibited lipopolysaccharide (LPS)-induced inflammation by suppressing nuclear factor kappa B (NF-κB) activation. In a murine sepsis-induced liver injury model, prophylactic treatment with the carbon dots reduced levels of pro-inflammatory cytokines (tumor necrosis factor-alpha [TNF-α], interleukin-1 beta [IL-1β], interleukin-6 [IL-6]), hepatic enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST]), histopathological damage, and immune cell infiltration, while enhancing glutathione peroxidase (GPx) expression. Notably, high-dose carbon dots demonstrated efficacy comparable to that of dexamethasone, without detectable cytotoxicity or organ toxicity. These findings highlight a circular bioeconomy approach that transforms rose floral waste into high-value nanotherapeutics, offering a sustainable platform for addressing inflammatory diseases. • Industrial rose distillation waste was valorized into functional carbon dots via one-pot hydrothermal synthesis. • Carbon dots exhibit multi-antioxidant capacities surpassing natural enzymes. • Carbon dots inhibit LPS-induced inflammation via NF-κB pathway inhibition. • Carbon dots demonstrate dexamethasone-matched efficacy with superior safety for mitigating sepsis-induced liver injury.