Antimicrobial Activity of the Essential Oil Isolated from Pistacia lentiscus Leaves Against Helicobacter pylori Algerian Clinical Isolates

Helicobacter pylori (H. pylori) infection plays a crucial role in the pathogenesis of gastritis, peptic ulcer, and gastric cancer. The current treatment for the eradication of H. pylori is unwieldy as relapses may occur. As H. pylori continues to resist the present antibiotic treatments, we are challenged in attempting to find alternative treatment methods; one treatment method may be the utilization of extracted oils from plants such as Pistascia lentiscus (P. lentiscus) leaves which are widely used in Mediterranean folk medicine to treat various infectious diseases, including stomach-associated diseases. Thus, this study aimed to evaluate the anti-H. pylori activity of Pistacia lentiscus essential oil (PLEO) obtained from leaves by hydro-distillation and analyzed by gas chromatography coupled to a mass spectrometry (GC-MS). H. pylori strains were isolated from Algerians symptomatic patients' gastric biopsies and characterized for their susceptibility to PLEO using both disc diffusion and agar dilution methods. Results revealed 65 components of PLEO dominated by monoterpenes, principally were alpha-pinene (15.47%), limonene (14.7%) and beta-myrcene (9.93%). Twenty two H. pylori strains were isolated and their antibiotic characterization revealed that 18.18% of the tested isolates were resistant to at least two of the three antibiotics belonging to the main groups of antibiotics used in therapy to eradicate H. pylori. In contrast, PLEO showed anti-H. pylori activity against all the tested strains (100%). The inhibition diameters (32 mm, 26.66 mm, 19.67 and 12.33 for the pure and diluted oil to 1/2, 1/4 and 1/8) and minimum inhibitory concentration (1/5000, v/v) affirm the strong antimicrobial activity of PLEO against H. pylori.