Abstract
Background. Helicobacter pylori are the principal causative factor in the etiological factors of chronic, active, or type B gastritis; peptic and duodenal ulcers; stomach carcinoma; and epithelial tissue lymphoid malignancies. It infects more than half of the population worldwide. To reduce H. pylori production, pharmacological therapy of H. pylori diseases typically involves using threefold treatment methods. However, as a result of such therapy, antimicrobial resistance is commonly developed. Alternative therapeutics for H. pylori diseases are thus of particular interest. Methods. Thyme essential oils (EOs) obtained from T. caramanicus Jalas plants in Iran were tested for antibacterial activity against H. pylori obtained from 320 poultry specimens in this investigation. Antibacterial activity was measured using inhibition zones, minimum inhibitory concentrations (MICs), and minimum bactericidal concentrations (MBCs). The impact of T. caramanicus Jalas essential oils on H. pylori isolate cagA, vacA, and babA2 gene expression was evaluated using a quantitative real‐time PCR method (p < 0.05). Results. The chemical content of these EOs varied significantly according to chromatographic examination. Thymol, carvacrol, and terpinene‐4‐ol are the most abundant components in these EOs. H. pylori was recognized as a Helicobacter species with a 175‐bp PCR product of 16S rRNA in 20/20 (100%). According to PCR results, all 20 (100%) isolates belonged to H. pylori. The EOs inhibited H. pylori in a dose‐dependent manner, with T. caramanicus Jalas being the most effective, followed by pterygium EOs in decreasing order. At 8 mg/mL of T. caramanicus Jalas EOs, IZs against H. pylori were 27.4 ± 0.42 mm, and at 8 mg/mL of pterygium, IZs against H. pylori were 1 ± 0.02. T. caramanicus Jalas essential oils were used to treat all bacteria, and the findings showed that T. caramanicus Jalas had a substantial inhibitory impact on the expression of cagA, vacA, and babA2 virulence‐related genes (p < 0.05). Conclusions. In a dose‐dependent manner, the EOs of T. caramanicus Jalas EO demonstrated a high degree of antimicrobial property against H. pylori bacteria. The most efficient EOs were those from T. caramanicus Jalas with relative concentrations of thymol and carvacrol, followed by the coumarin‐dominated pterygium EO with reduced antibacterial activity.