To research the therapeutic effects of Modified Guishen Wan (归肾丸化裁) on rat model of polycystic ovary syndrome (PCOS) by regulating Toll-like receptor 4 (TLR4) /nuclear factor-κB (NF-κB) signaling pathway, particularly its impact on ovarian function, serum hormone levels and inflammatory factor expression.

Forty 8-week-old SPF female SD rats with normal estrous cycle were randomly divided into four groups (n＝10) : normal group, model group, Modified Guishen Wan group and positive drug group (metformin). Except for the normal group, the other groups were administered letrozole via gavage for 21 consecutive days to establish the PCOS model. The Modified Guishen Wan group and the positive drug group received the corresponding treatments for 21 days. After the experiment, the estrous cycle, ovarian index, serum sex hormone levels, serum inflammatory factor levels, the mRNA levels of inflammation-related genes in ovarian tissue and protein expression were detected to evaluate the efficacy of the Modified Guishen Wan.

The estrous cycle of the normal group was 3-5 days/cycle. After 21 days of modeling, the estrous cycles of the other groups became disordered, with an average of 5-8 days/cycle, mostly in the interphase or prophase, and some lacked a complete estrous cycle, indicating ovarian damage. After 3 weeks of gavage treatment, the estrous cycles of the positive group and the Modified Guishen Wan group recovered. Compared with that of the normal group, the ovarian index of the model group significantly increased (P<0.01). Compared with that of the model group, the ovarian index of the rats of the Modified Guishen Wan group and the positive drug group significantly decreased (P<0.01), approaching the normal group levels. The ovarian tissue of the model group showed multiple cystic changes, with reduced or absent corpora lutea. In contrast, the Modified Guishen Wan group and the positive drug group had fewer cystic and atretic follicles, and the granulosa cell layer structure tended to be normal. The levels of testosterone (T) and luteinizing hormone (LH) in the model group were significantly higher (P<0.01, P<0.05), while follicle-stimulating hormone (FSH) levels were significantly lower (P<0.05). The Modified Guishen Wan group and the positive drug group could significantly reduce the levels of T and LH (P<0.05), and the Modified Guishen Wan group and the positive drug group could also significantly increase the FSH levels (P<0.05). Compared with those of the normal group, the serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1 β (IL-1β) in the model group were significantly elevated (P<0.001). Compared with the model group, both the Modified Guishen Wan and the positive drug could significantly reduce the serum levels of TNF-α, IL-6 and IL-1β in PCOS rats (P<0.01 and P<0.05). Compared with those of the normal group, the mRNA levels of IL-6, IL-1β, TNF-α and TLR4 in the ovarian tissue of the model group were significantly increased (P<0.05, P<0.01). The Modified Guishen Wan group had significantly lower levels of IL-6, IL-1β and TLR4 mRNA compared to the model group (P<0.05), with a trend toward lower TNF-αmRNA levels (P＝0.188). Compared with the normal group, the protein expression of TLR4 in the ovarian tissue of the model group was significantly increased (P<0.05), and the phosphorylation levels of NF-κB p65 and IκBα were significantly elevated (P<0.05). The Modified Guishen Wan group had significantly lower TLR4 protein levels (P<0.05) and significantly reduced phosphorylation levels of NF-κB p65 and IκBα (P<0.05).

The Modified Guishen Wan may improve reproductive dysfunction and ovarian inflammation in PCOS rats by inhibiting the activation of the TLR4/NF-κB signaling pathway and reducing the production of inflammatory factors, providing new insights and theoretical basis for the clinical treatment of PCOS.