Repurposing levomilnacipran to attenuate premature ovarian insufficiency induced by cyclophosphamide in female Wistar albino rats through modulation of TLR4/p38-MAPK/NF-κB p65, caspase-3-driven apoptosis, and Klotho protein expression.

Aim: This study aims to explore the mitigative impact of levomilnacipran (LVM) against cyclophosphamide (CPA)-induced premature ovarian insufficiency by targeting TLR4/p38 MAPK/NF-κB p65, and klotho expression.

Methods: Rats were allocated into five groups as follows: control, LVM, CPA, CPA + LVM, and CPA + TRI. Serum hormones and histopathological examination were performed. To assess oxidative stress, ovarian MDA, GSH, and SOD were evaluated. The ovarian contents of caspase-3 and inflammatory markers were assessed using the ELISA method. The expression of ovarian NF-κB p65 was examined using an immunohistochemical technique. RT-qPCR was used to measure Bax and Bcl-2 mRNA expression. Utilizing a Western blot, the TLR4, p38 MAPK, α-Klotho, and cleaved caspase-3 levels were estimated. The estrous cycle was also monitored.

Findings: LVM attenuated CPA-induced ovarian toxicity by regulating hormones and alleviating histopathological aberrations. It also raised SOD and GSH levels and lowered MDA's ovarian content. Moreover, Bcl-2 levels were raised, Bax and caspase-3 expression levels were reduced, and IL-18, IL-1β, and TNF-α levels were all reduced. LVM-induced ovarian protection by diminishing TLR4/p38 MAPK/NF-κB p65 expression and boosting the protein levels of α-Klotho.

Significance: LVM mitigated POI caused by CPA by downregulating TLR4/p38 MAPK/NF-κB p65, enhancing the α-Klotho level and attenuating caspase-3 derived apoptosis.