Premature ovarian failure (POF) is the ovarian function loss, leading to amenorrhea among females of childbearing age before 40 years old (Cai et al., 2022; Jiao et al., 2018). It is characterized by the abnormally increased gonadotropin level and the decreased estrogen level (Webber et al., 2016; Xiu et al., 2023), and most often leads to the loss of fertility in women of childbearing age (Xiu et al., 2023). As revealed by a longitudinal cohort study recruiting 1858 female participants born during 1928–1932, the prevalence of POF is 1% of all women (Coulam et al., 1986). In a recent investigation, the worldwide occurrence of POF is estimated to be 3.7% (Golezar et al., 2019). Besides, POF shows a growing prevalence, and is a very important issue for women who wish to have children. Therefore, in the current lack of reliable treatment methods for POF, it is crucial to develop a new POF treatment method. While the exact cause of POF remains uncertain in the majority of cases, some potential molecular pathways may involve enhancing programmed cell death in granulosa cells (GCs) and hindering follicle maturation and irregularity in follicle activation, which result in the impairment or reduction of ovarian follicles (Jin et al., 2012). As one of the programmed cell death patterns, apoptosis is closely linked with POF (Takahashi et al., 2021), particularly in the course of chemotherapy (Morita and Tilly, 1999). Cyclophosphamide (CYC) chemotherapy induces significant GC apoptosis (Amsterdam et al., 2003; Hurwitz and Adashi, 1992), which leads to ovarian follicular atresia by reducing sex hormone contents produced via the non-resting GSs (Zhao et al., 2010).

Oxidative stress, mainly attributed to the imbalance between the excessive reactive oxygen species (ROS) production and insufficient antioxidant defense mechanisms, is considered as the main factor leading to apoptosis of GCs (Agarwal et al., 2003). The active metabolites of CYC impede DNA synthesis and disrupt the antioxidant defense mechanisms in the ovaries, thereby inducing the excessive production of malondialdehyde (MDA) (Helsby et al., 2019), an important biomarker for oxidative stress and an indicator of oxidative injury (Newsholme et al., 2016).

Traditional Chinese medicine has long been used by the Chinese people to enhance female fertility (Cai et al., 2021), and compounds isolated from herbal medicine have been found to positively affect follicular atresia caused by cell apoptosis (Lin et al., 2017). Danggdui Shaoyao San (DSS), one of the popular TCM prescriptions, is comprised by six Chinese herbs and has been applied clinically for gynecologic diseases for centuries (Hua et al., 2008; Lee et al., 2016; Li et al., 2022). Research have found that DSS exerted estrogenic effects (Wang et al., 2023), indicating a therapeutic property of DSS in POF. In addition, studies have also found that DSS exerts anti-apoptotic effects through activating PINK1-Parkin-dependent mitophagy pathway (Song et al., 2021), and mitigates oxidative stress by regulating redox balance and lipid peroxidation (Lan et al., 2012). However, more investigations should be conducted for determining whether DSS inhibits pathological processes such as apoptosis and oxidative stress in the context of POF, and exploring the underlying molecular mechanisms.

Silent information regulator 1 (SIRT1) exerts an essential effect on diverse folliculogenesis stages through influencing various processes like senescence, inflammation, circadian rhythm, apoptosis, and mitochondrial biogenesis among others in the NAD+-dependent histone deacetylase Sirtuin family (Liu et al., 2020). According to relevant reports, SIRT1 is involved in multiple aspects of follicle development, including the energy equilibrium, mitochondrial generation, chromatin structure modification, and protection from oxidative stress (Tatone et al., 2015, 2018). The inhibition of SIRT1 can decrease ovarian reserve (Guo et al., 2022), which implicates that SIRT1 is involved in the regulation of POF.

It has been observed that p53, a transcription factor, undergoes multiple post-translational modifications for its functional mediation (Nagpal and Yuan, 2021). As suggested by recent evidence, SIRT1 deacetylates the Lys382 residue at the C-terminal of p53 under different physiological conditions (Xu et al., 2011, Xu et al., 2011). This deacetylation process promotes the ubiquitination of p53 mediated by murine double minute 2 (Xiao et al., 2022), thereby inhibiting the p53-induced apoptosis (Rahman and Islam, 2011). Besides, p53 is reported to participate in regulating GCs apoptosis (Sun et al., 2019), and POF development (Xiong et al., 2017).

This study aimed to investigate the roles and mechanisms of DSS in inhibiting apoptosis and oxidative stress in CYC-induced POF. Hence, to assess the effects of DSS on preventing apoptosis and oxidative stress while promoting ovary structure and function in vivo, CYC was intraperitoneally injected in mice to develop the POF mouse model. Additionally, the protective properties of DSS in human GCs (KGN cells) were evaluated in vitro. Furthermore, the possible underlying mechanisms were explored.