Potentialities of Dandelion (Taraxacum Mongolicum Hand.-Mazz.) Flower Extracts on Gastric Protection against Helicobacter Pylori and Characterization of its Bioactive Constituents.

OBJECTIVES: Dandelion has been shown to exert anti-inflammatory and anti-bacterial effects. Our study aimed to identify the effect and mechanism of dandelion flower extracts on H. pylori-induced gastritis and screen for novel antimicrobial substances. METHODS: Anti-H. pylori activities of water extracts(WEDF) and ethanol extracts (EEDF) of dandelion flowers were performed with disk diffusion method assay, MIC, and MBC. The H. pylori-induced model was constructed to examine the gastroprotective of EEDF using RUT, pathological analysis, and ELISA. RESULTS: EEDF exhibited better anti- H. pylori and urease inhibition activities than WEDF. In vivo studies, EEDF can reduce the adhesion of H. pylori to the gastric mucosa, alleviate gastric damage, and concurrently reduce the levels of TNF-α and IL-6 in gastric tissues. The six phenolic compounds showed urease inhibition effect (IC50: 2.99±0.15 to 66.08±6.46 mmol/mL). Among them, chlorogenic acid, caffeic acid, and luteolin also had anti-H. pylori activity (MIC: 64-256 µg/mL). CONCLUSION: EEDF exhibited anti-H. pylori, gastroprotective and anti-inflammatory effects. Chicoric acid and luteolin may be the main active compounds of dandelion flowers to exert anti-H. pylori, and worthy of further investigation.

Gastroprotective action of the extract of Corydalis yanhusuo in Helicobacter pylori infection and its bioactive component, dehydrocorydaline.

ETHNOPHARMACOLOGICAL RELEVANCE: Helicobacter pylori (H. pylori) infection is a frequent chronic infection. Persistent infection is the strongest risk factor for developing gastric complications leading to gastric cancer. The antibiotic resistance of current anti-H. pylori drugs lead to the search for novel candidates from medicinal plants. Traditionally, Corydalis yanhusuo (Y.H. Chou & Chun C.Hsu) W.T. Wang ex Z.Y. Su & C.Y. Wu (Papaveraceae) has been used for the treatment of digestive system diseases in China. So, it's essential to explore and confirm the anti-H. pylori activity of C. yanhusuo and characterize the pharmacologically active compounds. AIM OF THE STUDY: This study aims to evaluate the efficacy of C. yanhusuo as complementary or alternative modes of treatment against H. pylori-related diseases and ascertain the active substances of C. yanhusuo to develop non-toxic, natural, and inexpensive products. MATERIALS AND METHODS: C. yanhusuo was subjected to solid-liquid extraction with water (WECY), ethanol EECY), and chloroform (CECY). The extracts were screened by agar diffusion assay, the minimum inhibitory concentrations (MIC), the minimum bactericidal (MBC) for their in vitro antimicrobial activity, and by Berthelot reaction for urease inhibition. To assess the in vivo action, H. pylori-induced C57BL/6 mice were used to detect RUT biopsy, perform visual and histopathological analyses and evaluate IgG expression. Furthermore, we compared the anti-H. pylori activities of major alkaloids in CECY to identify the bioactive constituents. RESULTS: Among the three C. yanhusuo extracts, CECY showed the maximum in vitro antibacterial activity. Administration of CECY significantly inhibited the survival of H. pylori colonized in the gastric mucosa and alleviated gastric damage along with a reduction in the expression levels of IgG in H. pylori-infected mice. Berberine and dehydrocorydaline exhibited obvious anti-H. pylori activity with MIC of 25 and 12.5 µg/mL, respectively. CONCLUSION: C. yanhusuo extracts showed anti-H. pylori activity in different degrees. Among them, CECY showed significant anti-H. pylori, gastroprotective and anti-inflammatory activities in vivo and in vitro. Dehydrocorydalmine, an active alkaloid compound isolated from C. yanhusuo, warranted further investigation for its potential anti-H. pylori activity.