Enhanced Anti-Inflammatory Effects of Rosemary (Salvia rosmarinus) Extracts Modified with Pseudomonas shirazensis Nanoparticles

Rosemary (Salvia rosmarinus) is renowned for its antioxidant, anti-inflammatory, and antihyperglycemic properties, largely attributed to its rich phytochemical profile. This study evaluates the potential of metabolites from Pseudomonas shirazensis NFV3, formulated in silver nanoparticles (AgNPs), to enhance the bioactivity of rosemary extracts in postharvest applications. Rosemary stems were treated with AgNPs coated with bacterial metabolites (NP), bacterial cells, or metabolites (LM), and the extracts’ phytochemical composition and bioactivities were assessed. HPLC and HPLC–MS analyses revealed that the NP treatment induced significant metabolic remodeling, particularly upregulating rosmarinic acid and selected triterpenes (ursolic and betulinic acids), while reducing carnosic acid levels. NP-treated extracts exhibited significantly enhanced inhibition of cyclooxygenase (COX-1 and COX-2), indicating improved anti-inflammatory potential. The α-glucosidase inhibition and antioxidant activity (DPPH assay) of the extracts were not substantially altered, suggesting the selective enhancement of pharmacological functions. These findings demonstrate that nanoparticle-based elicitation selectively remodels secondary metabolism in rosemary, improving extract quality and bioactivity. This strategy offers a novel, sustainable tool for optimizing plant-based therapeutics in the phytopharmaceutical industry.