Fig. 2

Exposure to Glycyrrhizin reduces intracellular H. pylori growth in AGS cells. a–c Infection with H. pylori SS1 strain (MOI 100) was performed in cells for 4 h and further exposed to glycyrrhizin (GLZ) (200 µM) for 4 h. a Immunoblotting was performed for quantification of autophagy-associated marker proteins (LC3B-II and LAMP1). Beta-actin was used as a loading control. Densitometry analyses are represented graphically. One-way ANOVA was performed. b Confocal microscopy showed LC3B puncta (green) in H. pylori (HP) infected & H. pylori + glycyrrhizin (HP + GLZ) treated cells, LC3B puncta formation was quantified and change in the mean fluorescence intensity was measured and graphically plotted. Scale bar: 5 μm. c Live cell imaging of LAMP1 under confocal microscopy showed GFP-LAMP1 puncta formation. Fold change in the mean fluorescence intensity of GFP-LAMP1 was calculated, unpaired t-test was performed and graphically represented Scale bar: 10 μm. d, e Cells were incubated with H. pylori SS1 strain (MOI 100) for 4 h followed by gentamicin treatment to kill extracellular bacteria. Finally, cells were treated with glycyrrhizin GLZ (200 µM) at two different time points for 4 h and 18 h d Intracellular H. pylori DNA (16SrDNA) was determined by real-time PCR. GAPDH was used as the internal control. e Cells were lysed and plated on BHIA plates with serial dilutions, for 4–5 days for counting colonies and CFU/ml was graphically represented. f Infection with H. pylori resistant strain [OT-14(3)] (MOI 100) for 4 h was performed in gastric cells followed by glycyrrhizin GLZ (200 µM) treatment for 4 h and CFU/ml was graphically represented. Graph were represented as mean ± SEM (n = 3); Unpaired t-test was done and significance was calculated; *p < 0.05, **p < 0.01 and ***p < 0.001