In Vitro Inhibition of Cholera Toxin Production in Vibrio cholerae by Methanol Extract of Sweet Fennel Seeds and Its Components

• Published in: Japanese Journal of Infectious Diseases Vol. 69; no. 5; pp. 384 - 389
• Main Authors: Chatterjee, Shruti, Zahid, M. Shamim Hasan, Awasthi, Sharda Prasad, Chowdhury, Nityananda, Asakura, Masahiro, Hinenoya, Atsushi, Ramamurthy, T., Iwaoka, Emiko, Aoki, Shunji, Yamasaki, Shinji
• Format: Journal Article
• Language: English
• Published: Japan National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee 2016
• Subjects: 4-allylanisole; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - metabolism; cholera toxin; Cholera Toxin - antagonists & inhibitors; Cholera Toxin - biosynthesis; Foeniculum - chemistry; Foeniculum vulgare; Gene Expression - drug effects; Methanol; Microbial Viability - drug effects; Plant Extracts - isolation & purification; Plant Extracts - metabolism; Seeds - chemistry; Solvents; sweet fennel seed; trans-anethole; Vibrio cholerae; Vibrio cholerae - drug effects; Vibrio cholerae - genetics
• ISSN: 1344-6304; 1884-2836
• DOI: 10.7883/yoken.JJID.2015.421

A newly emerged Vibrio cholerae O1 El Tor variant strain with multidrug resistance is considered a threat to public health. Recent strategies to suppress virulence factors production instead of bacterial growth may lead to less selective pressure for the emergence of resistant strains. The use of spices and their active constituents as the inhibitory agents against cholera toxin (CT) production in V. cholerae may be an alternative approach to treat cholera. In this study, we examined the potential of sweet fennel seed (Foeniculum vulgare Miller var. dulce) methanol extract to inhibit CT production in V. cholerae without affecting viability. The methanol extract of sweet fennel seeds significantly inhibited CT production in various V. cholerae strains, regardless of serogroup or biotype. Interestingly, trans-anethole and 4-allylanisole, essential oil components of sweet fennel seeds, also demonstrated similar effects. Here, we report that sub-bactericidal concentrations of sweet fennel seed methanol extract and its major components can drastically inhibit CT production in various V. cholerae strains.