Synergic Effects of Curcumin, Licorice, and Endoscopic Photodynamic Therapy Against Helicobacter Pylori by Modulating the NF-Κb Signaling Pathway.

Background: Helicobacter pylori (H. pylori) infection affects nearly half of the global population and is a significant contributor to gastroduodenal conditions, including gastric carcinoma. Research on herbal extracts has highlighted their antibacterial, antioxidant, and anti-inflammatory properties, indicating potential for novel, synergistic therapeutic approaches.

Objective: To assess the synergistic antimicrobial effect of Curcumin, Licorice, and photodynamic therapy (PDT) against the H. pylori infection in a rat model by evaluating the NF-κB signaling pathway.

Materials and methods: Forty male rats (250-300 g) were divided into eight groups as follows: control, rats treated with 600 mg.kg^-1 of Curcumin and 200 mg.kg^-1 of Licorice, H. pylori-infected rats, H. pylori-infected rats treated with 600 mg.kg^-1 of Curcumin, H. pylori-infected rats treated with 200 mg.kg^-1 of Licorice, H. pylori-infected rats treated with 600 mg.kg^-1 of Curcumin and 200 mg.kg^-1 of Licorice, H. pylori-infected rats treated with PDT (based on 3'-sialyllactose [3SL]-conjugated, poly-l-lysine-based photosensitizer [p3SLP]), and H. pylori-infected rats treated with PDT combined with Curcumin and Licorice. The immunohistochemistry test was performed to investigate NF-κB p65 expression in gastric epithelial cells (GECs).

Results: The average H. pylori colonization score was zero for the control and Curcumin + Licorice groups. However, the scores were 1.8, 1.0, 1.2, 0.8, 0.6, and 0.2 for the H. pylori, H. pylori + Curcumin, H. pylori + Licorice, H. pylori + Curcumin and Licorice, PDT alone treatment, and PDT + Curcumin and Licorice groups, respectively. Regarding H. pylori colonization and gastric inflammation scores, the treatment effect of PDT combined with Curcumin and Licorice was significantly greater than that of the other treatments (P<0.05). H. pylori infection significantly increased the NF-κB expression in GECs compared to the control group (20.6%±2.1% vs. 10.1%±2.2%, P=0.035). This expression was significantly reduced in the H. pylori + PDT combined with Curcumin and Licorice (8.8%±1.2%), the H. pylori + Curcumin (15.3%±2.4%), and the H. pylori + Licorice groups (16.4%±2.2%) compared to the H. pylori only group (P <0.05). The administration of Curcumin and Licorice alone did not alter baseline NF-κB expression in GECs (8.3%±1.8%, P=0.120).

Conclusion: Our results demonstrated that combination treatment of PDT with Curcumin and Licorice may exert stronger anti-inflammatory effects by suppressing NF-κB p65 expression in GECs compared to each treatment alone. This combination could serve as a potential treatment option for future studies.