Deoxyshikonin: a promising lead drug grass against drug resistance or sensitivity to Helicobacter pylori in an acidic environment

Abstract

Helicobacter pylori (H. pylori) is closely associated with the diseases such as gastric sinusitis, peptic ulcers, and gastric adenocarcinoma. Its drug resistance is very severe, and new antibiotics are urgently needed. Nine comfrey compounds were screened by antimicrobial susceptibility testing, among which deoxyshikonin had the best inhibitory effect, with a minimum inhibitory concentration (MIC) of 0.5-1 µg/mL. In addition, deoxyshikonin also has a good antibacterial effect in an acidic environment, it is highly safe, and H. pylori does not readily develop drug resistance. Through in vivo experiments, it was proven that deoxyshikonin (7 mg/kg) had a beneficial therapeutic effect on acute gastritis in mice infected with the multidrug-resistant H. pylori BS001 strain. After treatment with desoxyshikonin, colonization of H. pylori in the gastric mucosa of mice was significantly reduced, gastric mucosal damage was repaired, inflammatory factors were reduced, and the treatment effect was better than that of standard triple therapy. Therefore, deoxyshikonin is a promising lead drug to solve the difficulty of drug resistance in H. pylori, and its antibacterial mechanism may be to destroy the biofilm and cause an oxidation reaction.

Keywords: Helicobacter pylori; acidic environment; deoxyshikonin; inhibitory action; lead drug.

Fig 1

Chemical structure of nine components of Radix lithospermi. (A) Lithospermic acid; (B) cyanoside; (C) β-acetoxyisovaleryl akanin; (D) β,β-dimethylacryloyl shikonin; (E) β,β-dimethylacryloyl akanin; (F) shikonin; (G) isobutyryl shikonin; (H) acetylshikonin; (I) deoxyshikonin.

Fig 2

Antimicrobial activity of deoxyshikonin. (A) The minimum inhibitory concentration (MIC) of deoxyshikonin; (B) the minimum bactericidal concentration (MBC) of deoxyshikonin.

Fig 3

Safety of deoxyshikonin in vivo. (A) Cytotoxicity of deoxyshikonin to GES-1 cells; (B) dosage response mortality curves of deoxyshikonin; (C) effects of deoxyshikonin on the organs of mice; (D) effects of deoxyshikonin on the weights of mice.

Fig 4

Antibacterial activity of deoxyshikonin in vivo. (A) Colonization of H. pylori in mice with acute gastritis after treatment with deoxyshikonin; (B) repair of gastric mucosa of mice with acute gastritis after treatment with deoxyshikonin (10×).

Fig 5

Deoxyshikonin inhibits the growth of H. pylori biofilms and movement of flagella and enhances the permeability of cell membranes as well as oxidation. (A) Morphological and structural damage caused by H. pylori; (B) the effect of deoxyshikonin on H. pylori biofilm detected using Alamar staining; (C) the effect of deoxyshikonin on the H. pylori biofilm detected using a confocal microscope after staining with SYTO9; (D) the effect of deoxyshikonin on the H. pylori biofilm detected quantitatively after I/SYTO9 staining; (E) the effect of deoxyshikonin on the H. pylori biofilm detected through crystal violet staining; (F) the osmotic damage of the membrane of H. pylori cells caused by deoxyshikonin; (G) the oxidation effect of deoxyshikonin on H. pylori as detected quantitatively; (H) the oxidation effect of deoxyshikonin on H. pylori detected using fluorescence staining; (I) the suspension drop method to observe the inhibitory effect of deoxyshikonin on the movement of H. pylori (40 x); (J) detection of the inhibitory effect of deoxyshikonin on H.pylori flagella by soft agar assay.

Fig 6

Acid resistance testing for deoxyshikonin and detection of H. pylori resistance. (A) MBC of deoxyshikonin at pH = 3.0; (B) MBC of deoxyshikonin at pH = 5.0; (C) MBC of deoxyshikonin at pH = 7.0; (D) detection of drug resistance of H. pylori to deoxyshikonin and metronidazole.

Fig 7

Diversity of intestinal flora in mice treated with deoxyshikonin. (A) Chao, observed species, PD whole tree, and Shannon indices reflect the α-diversity; (B) principal component analysis (PCA) to evaluate the intestinal flora β-diversity; (C) weighted analysis to evaluate intestinal microflora β-diversity; (D) unweighted analysis and evaluation of intestinal flora β-diversity.