Objective This study investigates the phenolic and flavonoid content, antimicrobial susceptibility, and cytotoxic effects of Vaccinium corymbosum L. fruit extracts at different ripening stages to determine their potential bioactive properties. Methods Extracts were analyzed for phenolic and flavonoid content, antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, and Klebsiella pneumoniae, and cytotoxicity using MTT assays. Apoptotic effects were examined through AO staining, and high-performance thin-layer chromatography (HPTLC) was employed to profile bioactive compounds. Results Pale green fruit extracts exhibited the highest phenolic and flavonoid concentrations, showing significant antimicrobial activity and time-dependent bactericidal effects against tested bacterial strains. Cytotoxic assays revealed superior anticancer activity of the pale green extract, with AO staining indicating apoptosis induction. HPTLC confirmed the presence of phenolic and terpenoid–steroid compounds across ripening stages. Conclusion The pale green fruit extract demonstrates strong antibacterial and anticancer properties, underscoring the importance of ripening stages in bioactive compound profiles. Further preclinical studies are recommended to validate therapeutic applications, and HPTLC fingerprinting offers a reliable tool for blueberry authentication.
