Fermentation enhances the biological activity of Allium cepa bulb extracts.
In this study, we compared the analytical fingerprint and bioactivity of three onion extracts, including an aqueous, a methanol, and a fermented aqueous extract. The extracts were characterized by HPLC-DAD, LC-MS, and GC-MS analyses. The antibacterial, antigenotoxic, and antiproliferative activity of these extracts was assessed by means of agar disk diffusion, bacterial growth kinetics, a comet assay, cell cycle distribution analysis, and cell viability testing. Both the aqueous and methanolic extracts showed a typical flavonol-fingerprint as assessed by HPLC measurements and showed little to no bioactivity. The fermented aqueous extract, which lacks the usual onion flavonoid profile, was found to be the most active in all of the assays. This finding indicates that metabolites of onion compounds, generated by lactic acid fermentation, may be more active than their precursor substances.
Institute for Pharmaceutical Sciences, Department of Pharmaceutical Biology and Biotechnology, Albert-Ludwig-University Freiburg, Freiburg, Germany.
Agnès
A
Millet
Evelyn
E
Lamy
Daniel
D
Jonas
Florian
F
Stintzing
Volker
V
Mersch-Sundermann
Irmgard
I
Merfort
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016587:Antimutagenic Agents / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D005285:Fermentation; D005419:Flavonoids / Q000032:analysis; D019344:Lactic Acid / Q000378:metabolism; D000432:Methanol; D019697:Onions / Q000737:chemistry*; D010936:Plant Extracts / Q000378:metabolism* / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry*; D014867:Water
D000900:Anti-Bacterial Agents; D016587:Antimutagenic Agents; D000972:Antineoplastic Agents, Phytogenic; D005419:Flavonoids; D010936:Plant Extracts; D014867:Water; D019344:Lactic Acid; D000432:Methanol