Antibacterial and Immuno-modulatory Activity of Ethanol Extracts from Lespedeza sp during Helicobacter pylori Infections

Abstract

Chemical therapeutics targeted against H pylon may lead to host toxicity and pathogen eradication failures In this study, ethanolic extracts from five Lespedeza sp plants were shown to inhibit the gastric-pathogen H pylori and to modulate cytokine production Disc agar diffusion assays showed that Lespedeza sp ethanol extracts possess potent ant-H pylori activity Among the five plant extracts, the extracts from L cyrtobotrya demonstrated the highest anti-H pylon effect The growth inhibitory effect against H pylori was initiated after six h of treatment with plant extracts and the effect remained for a continuous period of 48 h Incubation of the gastric cells infected with H pylon with 1 25 to 50 mg/mL of Lespedeza sp plant extracts resulted in a reduction of the production of cytokine IL-8 The plant ethanol extracts generally had little influence on AGS cell viability, indicating their safety for the treatment of bacterial infections Three active fractions of L cyrtobotrya also demonstrated similar anti-H pylon and immuno-modulatory effects Taken together, these results provide evidence that Lespedeza sp plant extracts might be potential sources of new host friendly anti-H pylori agents