Abstract:

Objective To explore the effects of Parnassia palustris Linn extracts on Helicobacter pylori （Hp） eradication and gastric mucosa， and to clarify its antibacterial and anti-inflammatory mechanisms in vitro and in vivo. Methods The six-week old male Kunming mice were randomly divided into blank control group， normal saline group， Hp group， triple group， quadruple group， Parnassia palustris Linn group， triple + Parnassia palustris Linn group， and quadruple + Parnassia palustris Linn group. The minimal inhibitory concentration （MIC） of Parnassia palustris Linn extracts on Hp SS1 standard strains in vitro and the expression levels of Hp colonization- and adhesion-related gene mRNA were detected by real-time fluorescence quantitative （RT-qPCR） method. Animal experiments were used to evaluate the eradication rate of Hp by different methods， and enzyme linked immunosorbent assay（ELISA） method was used to detect the serum levels of inflammatory factors such as interleukin-2 （IL-2）， interleukin-8 （IL-8） and tumor necrosis factor alpha （TNF-α） of the mice in various groups. Rapid urease test （RUT） was used to detect the infection rate of Hp in stomach tissue， HE staining and transmission electron microscope were used to detect the pathomorphology and ultrastructures of stomach tissue. Results The MIC of Parnassia palustris Linn was 10 g·L^－1.The RT-qPCR results showed that compared with Hp group，the expression levels of Bab A， Cag A and Vac A mRNA in Parnassia palustris Linn group were decreased （P<0.05 or P<0.01）.The immunohistochemistry results showed that the part of gastric mucosa had erosion and ulcers，obvious bleeding and conggestion，and positive Hp infection of the mice in Hp group； the symptoms of gastric mucosal bleeding and ulcers in Parnassia palustris Linn group were improved， and Hp infection was mostly negative.The Rut results showed that compared with Hp group，the infection rate of Hp of the mice in Parnassia palustris Linn group was decreased（P<0.05），and the infection rates of the mice in triple group and quadruple group were decreased（P<0.05）；compared with Parnassia palustris Linn group，the eradication rates of Hp of the mice in triple group and quadruple group had no significant differences（P>0.05）； compared with triple group or quadruple group， the eradication rates of Hp of the mice in triple+Parnassia palustris Linn group and quadruple+Parnassia palustric Linn group were increased（P<0.01）. The gastric mucosa was apparently repaired， and the structures of mitochondria and microvilli of gastric mucosal epithelial cells were intact of the mice in triple+Parnassia palustris Linn group and quadruple+Parnassia palustris Linn group.Compared with Hp group，the levels of IL-2 in serum of the mice in triple， quadruple，Parnassia palustris Linn， triple+Parnassia palustris Linn and quadruple+Parnassia palustris Linn groups were increased（P<0.05）， and the levels of serum IL-8 and TNF-α were decreased（P<0.05 or P<0.01）. Conclusion Parnassia palustris Linn extracts can effectively eradicate Hp and protect gastric mucosa， and its mechanism is related to decreasing the levels of IL-2，IL-8 and TNF-α and protecting the integrity of structures of gastric mucosa subcellular organelle after Hp infection.

Key words: Parnassia palustris Linn, Helicobacter pylori, Colonization, Eradication rate, Transmission electron microscope, Inflammatory factors