Abstract
Helicobacter pylori causes gastritis, peptic ulcers and gastric cancer and affects more than half of the world's population. Although this infection can have serious consequences, no novel cure or remedy have been discovered, the present therapy still relies on a variety of known antibiotics and anti-secretory agents. In the present study, the potential effect of combinations between methanolic extracts of four Algerian medicinal plants, garlic (Allium sativum), red onion (Allium cepa), cumin (Cuminum cyminum L.) and fenugreek (T. foenum-graecum L.), with different strains of lactic acid bacteria against H. pylori, was investigated. Similarly, the in vivo antibacterial effect of fenugreek extract combined with Bifidobacterium breve on H. pylori colonization potential to confirm the enhanced effect of the mixture was explored. Helicobacter pylori was inhibited by all combined mixtures of extracts and probiotics with varying results. The highest anti-H. pylori activities were found in fenugreek/B. breve, cumin/B. breve, garlic/B. breve and onion/B. breve combinations with inhibition diameters of 29, 26, 23 and 25 mm, respectively. Preliminary studies on the effect of probiotics against H. pylori revealed that the inhibition was due to lactic acid and bacteriocins and it was also related to the presence of phenolic compounds in the studied plants, such as gallic acid, caffeic acid, quercetin and vanillic acid. Fenugreek extract was found to inhibit the growth of H. pylori in a concentration-dependent manner. When H. pylori-infected rats were administered B. breve, the infection rate of H. pylori was significantly reduced, while the combination of B. breve and fenugreek extract effectively inhibited H. pylori. In addition, the B. breve and fenugreek extract mixture significantly reduced gastritis in H. pylori-infected rats. These results suggest that this complex mixture may be an alternative to treating diseases caused by H. pylori infection.