Protection of flavonoids from Smilax china L. rhizome on phenol mucilage-induced pelvic inflammation in rats by attenuating inflammation and fibrosis

Pelvic inflammatory disease (PID), an infection and inflammation disorder of the upper genital tract, results in infertility in approximately 20% of cases. No antibiotic that can alleviate the sequelae of PID has been identified. Smilax china L. rhizome (SCR), which are widely used in functional food and folk medicine, exhibit multiple pharmacological activities, such as anti-inflammatory, antioxidant and antitumour activities. In this study, the flavonoids of SCR (FSCR) were purified and analysed by UPLC-PDA-MS. The therapeutic effects of FSCR in a rat PID model were evaluated. FSCR-treated PID rats exhibited significantly decreased inflammation, ameliorated fibrosis, and enhanced production of matrix metalloproteinase (MMP)-2 and MMP-9 in uteri. Moreover, the phosphorylation of ERK1/2 and Smad2/3 was markedly inhibited by FSCR. These results indicate that FSCR exhibits robust anti-inflammatory and anti-fibrosis effects, possibly via inhibition of the ERK1/2 and TGF-β-Smad2/3 signalling pathways, and may be an effective candidate natural medicine for PID treatment.