Study on the Effect of Baitouweng Decoction on VVC Mice by Regulating PI3K/AKT-HIF-1α Pathway

OBJECTIVE To explore the mechanism Baitouweng Decoction on mice with vulvovaginal candidiasis (VVC) based on phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)-hypoxia-inducible factor-1α(HIF-1α) pathway.

METHODS Female SPF-grade Kunming mice were injected subcutaneously with estradiol benzoate and vaginally inoculated with Candida albicans suspension to establish a VVC mouse model.The mice with successful modeling were randomly divided into model group, high-, medium-, and low-dose Baitouweng Decoction groups (23.4, 11.7, and 5.85 g·kg^-1), and fluconazole group (0.02 g·kg^-1), with 20 mice in each group.Another 20 mice were injected with estradiol benzoate as control group.Treatment started the day after successful model establishment and continued for 14 days.Two hours after the last administration, the number of neutrophils in vaginal lavage fluid was examined with Papanicolaou stain.The HE staining method was used to observe the morphology of vaginal tissue.ELISA was used to measure the levels of nicotinamide adenine dinucleo-tide phosphate oxidase 2(NOX2), reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA) in the vaginal tissues.The mRNA expression levels of PI3K, AKT and HIF-1α were detected using qPCR.Western blot was employed to evaluate the protein expression of p-PI3K, PI3K, p-AKT, AKT, and HIF-1α in vaginal tissue.

RESULTS Compared to the control group, the model group exhibited a significant increase in neutrophils in vaginal lavage fluid (P < 0.001);the vaginal mucosal layer was severely desquamated and a large number of inflammatory cells infiltrated.Additionally, there was an elevation in NOX2, ROS, and MDA levels in vaginal tissue (P < 0.001), while SOD content decreased (P < 0.001).Furthermore, the mRNA expression of PI3K, AKT and HIF-1α was reduced along with decreased protein expression of p-PI3K/PI3K, p-AKT/AKT, and HIF-1α(P < 0.001).In comparison to the model group, both high-dose and medium-dose groups treated with Baitouweng Decoction demonstrated a significant decrease in neutrophil count in lavage fluid (P < 0.01, P < 0.001);the condition of the vaginal mucosa improved to varying degrees.Moreover, the levels of ROS and MDA in vaginal tissue were reduced (P < 0.05, P < 0.01, P < 0.001), the activity of NOX2 was decreased (P < 0.01, P < 0.001), and the activity of SOD was increased (P < 0.01, P < 0.001).The high-dose group showed that, the mRNA expression of PI3K, AKT, and HIF-1α in vaginal tissue was increased (P < 0.001), the ratios of p-PI3K/PI3K and p-AKT/AKT, and the protein expression of HIF-1α were increased (P < 0.001).

CONCLUSION Baitouweng Decoction has a therapeutic effect on VVC, and its mechanism of action may be related to the PI3K/AKT-HIF-1α signal pathway.