Related Experiment Video
Updated: Aug 14, 2025

Author Spotlight: Advancements in Understanding and Combatting Shigella Infections
Published on: February 9, 2024
Asiatic acid inhibits intracellular Shigella flexneri growth by inducing antimicrobial peptide gene expression
Priyanka Maitra1, Priyanka Basak1, Keinosuke Okamoto2
1Division of Biochemistry, National Institute of Cholera and Enteric Diseases, Kolkata 700010, India.
Aims:
A rapid rise in resistance to conventional antibiotics for Shigella spp. has created a problem in treating shigellosis. Hence, there is an urgent need for new and non-conventional anti-bacterial agents. The aim of this study is to show how Asiatic acid, a plant-derived compound, inhibits the intracellular growth of Shigella flexneri.
Methods And Results:
Shigella flexneri sensitive and resistant strains were used for checking antimicrobial activity of Asiatic acid by gentamicin protection assay. Asiatic acid inhibited the intracellular growth of all strains. Gene expression analysis showed antimicrobial peptide (AMP) up-regulation by Asiatic acid in intestinal cells. Further western blot analysis showed that ERK, p38, and JNK are activated by Asiatic acid. ELISA was performed to check IL-8, IL-6, and cathelicidin secretion. The antibacterial effect of Asiatic acid was further verified in an in vivo mouse model.
Conclusions:
The reason behind the antibacterial activities of Asiatic acid is probably over-expression of antimicrobial peptide genes. Besides, direct antimicrobial activities, antimicrobial peptides also carry immunomodulatory activities. Here, Asiatic acid increased IL-6 and IL-8 secretion to induce inflammation. Overall, Asiatic acid up-regulates antimicrobial peptide gene expression and inhibits intracellular S. flexneri growth. Moreover, Asiatic acid reduced bacterial growth and recovered intestinal tissue damages in in vivo mice model.
Related Concept Videos
Gene Regulation in Microbial Communities: Quorum Sensing
Stringent Response in E. coli
Antimicrobial Proteins
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents

