Abstract: OBJECTIVE: To investigate the effect of Sophora flavescens alkaloid(SFA) in gel form on aerobic vaginitis(AV) and the possible mechanism underlying the effects.METHODS: AV rat models were prepared by intravaginal inoculation of Escherichia coli and Staphylococcus aureus. SFA gel and placebo gel were intravaginally administered. In vivo antibacterial effects,vaginal microenvironment, vaginal smears, pathological tissues of vaginas, and retention of gel in the vaginal cavity were investigated.RESULTS: SFA gel had much higher antibacterial effect than placebo gel. SFA gel protected the vaginal mucosa from erosion of bacteria. At the same time,they inhibited the inflammatory responses, exhibiting little leukocytes and parabasal cells. Furthermore, the number of vaginal Lactobacilli remarkably increased following administration of SFA gel.However, the vaginal p H did not recover to thehealthy acidic levels after treatment due to the buffering effect of gel. The gel of a fluorescent agent,Cyanine 7, showed very long retention time in the vaginal cavity, up to more than 24 h, much longer than the solutions.CONCLUSION: The SFA gel is a promising medicine for local treatment of AV with the advantages of anti-bacteria, protection of vaginal mucosa, increase of Lactobacilli, and long retention time in the vaginal cavity.

Key words: Matrine, Escherichia coli, Lactobacillus, Administration, intravaginal, Microenvironment, Staphylococcus aureus