The Effect Of18β-glycyrrhetinic Acid On The Ultrastructure Of Nasal Mucosa Cilia In Rat Models Of Allergic Rhinitis And On The Liver Of Normal Rats

Part one:The Effect of18β-glycyrrhetinic Acid on the Ultrastructure of Nasal Mucosa Cilia in Rat Models of Allergic RhinitisObjective:To investigate the ultrastructure changes of nasal mucosa cilia in rat models of allergic rhinitis (AR), and the effect of18β-glycyrrhetinic acid on that.Materials and Methods:96Wistar rats were randomly divided into4groups as normal group, model group, loratadine group and glycyrrhetinic acid group. AR models were established by ovalbumin-induction, and then each group was administrated with different drugs respectively. After2weeks,4weeks,6weeks, and10weeks, the behavioral changes and the ultrastructure of nasal mucosa cilia observed with electron microscope and transmission electron microscope were compared to each group.Results:Model group showed typical AR symptoms, and cilia in the top layer of the nasal mucosa were disordered, lodging, sticky, integrated and even some lost, the cilia membrane was broken, and the microtubules of cilia decreased or disappeared. Furthermore, small and abnormal cilia were observed, while mucous blanket upon cilia was thicker and contained neutrophil, monocytes, eosinophil and other inflammatory cells. With persistent allergen exposure, the morphological changes of nasal cilia in rats of model group aggravated gradually, meanwhile the AR symptoms relieved gradually in both glycyrrhetinic acid group and loratadine group, and the morphological damages of nasal mucosa recovered gradually that cilia were regular and their density was similar to that of normal group, small cilia decreased and the thicker mucous blanket upon cilia disappeared.Conclusion:Ultrastructure changes of nasal mucosa cilia in rat models of AR processed gradually due to persistent exposure to allergen. And18β-glycyrrhetinic acid is effective to relieve or even reverse the pathomorphological changes of nasal mucosa cilia in rat models of AR. Part two:The Influence of Long-term Intragastric Administration with18β-glycyrrhetinic Acid on Hepatic Function and Hepatic Morphology of RatObjective:To investigate the influence of long-term intragastric administration with18β-glycyrrhetinic acid(18β-GA) on hepatic function and hepatic morphology of rat.Materials and Methods:120Wistar rats were randomly divided into4groups as normal group, low-dose group, mid-dose group and high-dose group. Each group was administrated with respective dose of18β-GA by gavage. At the end of the6th,14th,22nd,30th week of administration and the4th week of withdrawal, the hepatic function was detected and hepatic morphology was observed by HE dyeing.Results:At the different observation points mentioned above, the serum transaminase, albumin, total bilirubin and alkaline phosphatase in each GA group (low-dose, mid-dose and high-dose) showed no significant differences compared with normal group. Serum total protein and globulin in low-dose group, mid-dose group and high-dose group were lower than normal group at the30th week of administration and the4th week of withdrawal (p<0.05), while there was no statistical difference among the three dose groups. During the long-term administration, the morphology of liver in each group showed integrity hepatic lobules, well-arranged hepatic cord and hepatic cells radiated from central veins, thus no obvious morphological changes were found in all the four groups.Conclusion:Long-term intragastric administration with18β-GA showed no significant influence on hepatic function and hepatic morphology of rat, but a long-term medication may decrease serum globulin level due to the immunosuppressive effect of18β-GA.