Xiao-Jie-An Capsule Alleviates Uterine Fibroids by Modulating Oestrogen–Progesterone Balance and Reducing Inflammatory Response

Uterine fibroids (UF) are benign tumours composed of smooth muscle cells and fibrous connective tissue. UF are common among women aged 30–50 years and often present with symptoms such as anaemia, pelvic pain and bladder dysfunction. Xiao-Jie-An Capsule (XJA), a traditional Chinese medicine formula, has been clinically used to treat UF. However, the underlying mechanisms of its efficacy remain unclear. The aim of this study was to determine the therapeutic effect of XJA and related mechanisms in a UF rat model. The experimental results showed that XJA significantly alleviated abnormalities in uterine morphology, tissue structure and purulent discharge in the UF rats. XJA also reduced serum oestrogen and progesterone in UF rats. Moreover, XJA decreased blood pro-inflammatory factors in UF rats by modulating the TLR4/NF-κB pathway. Western blotting and immunohistochemistry analyses revealed that XJA decreased the expression of Bcl-2, PCNA and Ki67 while increasing the expression of Bax, indicating its role in inhibiting cell proliferation and promoting apoptosis. Additionally, XJA exhibited immunomodulation in UF rats. In summary, our study suggests that XJA alleviates UF by multiple targets and mechanisms, such as restoring the oestrogen–progesterone balance, reducing inflammation, inhibiting cell proliferation, inducing apoptosis and regulating immune function.