OBJECTIVETo study the mechanism that mediates the therapeutic effect of the bioactive fraction of Baqia (Smilax china) on chronic pelvic inflammatory disease (CPID).

METHODSSeventy rats were randomized into CPID model group, sham-operated group, normal control group, Jingangteng capsule group, and high-, medium-, and low-dose Baqia groups. Rat models of CPID were established by inducing chemical burns of the uterus and corresponding treatments were administered. After 14 days of treatment, the rat uterus was observed for swelling and inhibition rate, and the expressions of tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4) in the uterine tissues were determined using enzyme-linked immunosorbent assay.

RESULTSThe bioactive fraction of Baqia at the 3 doses obviously reduced the inflammatory cells in the endometrium, promoted epithelial cell proliferation, and ameliorated congestion and edema of the serosa. High and medium doses of Baqia bioactive fraction significantly decreased uterus swelling rate of the rats (P<0.01). All the 3 doses of the Baqia bioactive fraction obviously decreased uterine TNF-α content (P<0.01) and significantly increased uterine IL-4 expression level (P<0.05), and IL-4 up-regulation was especially obvious in high and medium dose groups (P<0.01).

CONCLUSIONBaqia bioactive fraction can ameliorate uterine swelling, lower uterine TNF-α and increase IL-4 expressions in rats with CPID, which may be a pharmacological mechanism underlying its therapeutic effect on CPID and cervical adhesion.