Phytochemical Profiling, Antioxidant Potential and Antibacterial Activity of Fagraea fragrans Roxb. Flower Extract Against Antibiotic-Resistant Bacteria

Background and Objective: Fagraea fragrans Roxb. is a medicinal plant traditionally used in herbal medicine; however, information regarding the phytochemical composition and antibacterial activity of its flower extract against antibiotic-resistant bacteria remains limited. This study aimed to investigate the phytochemical constituents, antioxidant capacity and antibacterial activity of F. fragrans Roxb. flower ethanol extract against selected antibiotic-resistant bacterial strains. Materials and Methods: Qualitative phytochemical screening was performed to identify major bioactive compounds in the ethanol extract. Antioxidant activity was assessed using the DPPH radical scavenging assay, while antibacterial activity against clinically important antibiotic-resistant bacteria was evaluated by agar disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Data (mean±SD, n = 3) were analyzed by one-way ANOVA with Duncan's test using SPSS v20 (p<0.05). Results: Phytochemical analysis revealed the presence of phenolics, flavonoids, alkaloids and terpenoids in the ethanol extract. The extract demonstrated considerable antioxidant activity with strong DPPH radical scavenging capacity. Antibacterial assays showed inhibitory activity against Acinetobacter baumannii, Burkholderia pseudomallei, carbapenem-resistant Enterobacteriaceae (CRE), multidrug-resistant Klebsiella pneumoniae (MDR-K) and Proteus mirabilis, with inhibition zone diameters ranging from 7 to 11 mm. The lowest MIC value was observed against A. baumannii (1.95 mg/mL), while the lowest MBC value was detected against B. pseudomallei (31.25 mg/mL). No detectable antibacterial activity was observed against Enterococcus faecalis and colistin-resistant Pseudomonas aeruginosa. Conclusion: The new findings demonstrated that F. fragrans Roxb. flower extract possesses promising phytochemical constituents with antioxidant and antibacterial properties. The extract may serve as a potential natural source of bioactive compounds for herbal medicine and future antimicrobial applications against antibiotic-resistant bacteria.