Isolation of Abscisic Acid from Korean Acacia Honey with Anti-Helicobacter pylori Activity

BACKGROUND: Helicobacter pylori (H. pylori) is linked to the development of the majority of peptic ulcers and some types of gastric cancers, and its antibiotic resistance is currently found worldwide. OBJECTIVE: This study is aimed at evaluating the anti-H. pylori activity of Korean acacia honey and isolating the related active components using organic solvents. MATERIAL AND METHODS: The crude acacia honey was extracted with n-hexane, dichloromethane, ethyl acetate (EtOAc), and n-butanol. The EtOAc extract was subjected to octadecyl-silica chromatography. The extracts and fractions were then examined for anti-H. pylori activity using the agar well diffusion method. The antimicrobial activity of abscisic acid against H. pylori was investigated by determining the minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), and by performing a time-kill assay. RESULTS: Abscisic acid related to the botanical origins of acacia honey from Korea has been analyzed using ultra-performance liquid chromatography. The MICs and MBCs of abscisic acid were 2.7 ± 1.3 and 6.9 ± 1.9 μg/mL, respectively. The bactericidal activity of abscisic acid (at 10.8 μg/mL corresponding to 4 × MIC) killed the organism within 36–72 h. These results suggest that abscisic acid isolated from Korean acacia honey has antibacterial activity against H. pylori. CONCLUSION: Abscisic acid isolated from Korean acacia honey can be therapeutic and may be further exploited as a potential lead candidate for the development of treatments for H. pylori-induced infections. SUMMARY: The crude acacia honey was extracted with n-hexane, dichloromethane, EtOAc, and n-butanol. The EtOAc extract yielded eight fractions and four subfractions were subsequently obtained chromatographically. Abscisic acid was isolated from one subfraction. All the solvent extracts and fractions showed antibacterial activity against H. pylori. Abscisic acid exhibited antibacterial activity against H. pylori. Abbreviations used: MeOH: Methanol; EtOAc: Ethyl acetate; TSB: Trypticase soy broth; MIC: Minimum inhibitory concentration; MBC: Minimum bactericidal concentration; CFU: Colony-forming units; UPLC: Ultra-performance liquid chromatography; DAD: Diode array detector; UV: Ultraviolet; ODS: Octadecyl-silica; MS: Mass spectrometry; SE: Standard error.