Improvement effect and mechanism of Baicao fuyanqing suppository on bacterial vaginitis in rats / 中国药房

ABSTRACT

OBJECTIVE To explore the improvement effect and potential mechanism of Baicao fuyanqing suppository on bacterial vaginitis （BV） in rats. METHODS The female SD rats were randomly divided into normal group， model group， metronidazole group （positive control， 0.03 g/kg）， Baicao fuyanqing suppository low-dose， medium-dose and high-dose groups （0.18， 0.36， 0.72 g/kg）， with 8 rats in each group. Except for the normal group， the rats in other groups were injected subcutaneously with 0.2 g of Estradiol benzoate injection+20 μL of Escherichia coli suspension （2×108～3×108 cfu/mL） through the vaginal opening to establish the BV rat model. Administration groups were given relevant medicine vaginally， while the normal group and the model group were given normal saline， once a day， for 6 consecutive days. Twenty-four hours after the last administration， the vaginal appearance score and vaginal pH were measured for each group of rats. The levels of cytokines [interleukin-1β （IL-1β）， IL-2， IL-13， immunoglobulin A （IgA）] in vaginal lavage fluid were determined. The morphology of the uterus and accessories， and pathological changes in the vaginal tissue were observed. The expressions of Toll-like receptor 2 （TLR2）， TLR4 and nuclear factor-κB （NF-κB） in vaginal tissues were determined. RESULTS Compared with the normal group， the uterus edema， the irregular shape of uterus and accessories， the vaginal mucosa hyperplasia， and the massive desquamation of epithelial cells were observed in the model group， complicating with massive infiltration of inflammatory cells； vaginal opening redness and swelling score and secretion score， vaginal pH， the levels of proinflammatory cytokine IL-1β and IL-2， the protein expressions of TLR2， TLR4 and NF- κB were all increased or up-regulated， while the levels of IgA and anti-inflammatory cytokine IL-13 decreased significantly （P＜0.05 or P＜0.01）. Compared with the model group， varying cn degrees of improvement in uterine and accessories， and vaginal tissue lesions in rats were observed in administration groups， and most of the quantitative indicators mentioned above showed significant improvement （P＜0.05 or P＜0.01）. CONCLUSIONS Baicao fuyanqing suppository has a certain improvement effect on inflammatory symptoms in BV rats， and its mechanism may be related to the inhibition of the TLR/NF-κB signaling pathway.