Steroidal alkaloids as multi-target therapeutics for the treatment of endometriosis

Endometriosis is a chronic inflammatory disease characterised by ectopic endometrial tissue, progressive fibrosis and chronic pain, with a pathogenesis that goes beyond oestrogen dependence. The central question this review seeks to answer is: are steroidal alkaloids - nitrogenous plant-derived steroids with a unique structure - a mechanistically sensible, non-hormonal alternative that can simultaneously target the inflammatory, fibrotic and epigenetic drivers of endometriotic lesion persistence, while preserving fertility and avoiding systemic hormonal suppression? A growing body of evidence points to non-hormonal molecular networks including immune dysregulation, angiogenesis, and resistance to apoptosis as drivers of lesion persistence. These molecular disturbances are associated with treatment resistance and limit the long-term efficacy of hormone-based therapies. This review synthesises recent mechanistic advances that describe the non-hormonal signalling pathways that maintain endometriotic lesions, with a specific emphasis on NF-κB-mediated sterile inflammation, inflammasome activation, PI3K/Akt/mTOR-dependent survival signalling, Hedgehog-driven fibrosis and epigenetic repression of progesterone receptor expression. Steroidal alkaloids are critically reviewed as multitarget modulators suppressing inflammatory signalling, inhibiting invasive and fibrotic remodelling, and restoring apoptotic sensitivity in this pathophysiological context, without direct systemic oestrogen deprivation. Structural determinants of steroidal alkaloid activity, including glycosylation status, nitrogen topology and configuration of the steroidal scaffold, are discussed in the context of pathway selectivity, pharmacokinetics and toxicity. Preclinical in vitro and in vivo evidence is critically reviewed in the context of key translational limitations such as bioavailability constraints, narrow therapeutic index and teratogenic risk from developmental pathway inhibition. This review highlights steroidal alkaloids as a mechanistically rational, non-hormonal approach to target lesion persistence and fibrosis in endometriosis, integrating molecular, pharmacological and structural insights, and outlines the major hurdles that must be overcome for clinical translation. The main objective of this review is to address a specific unanswered question: can steroidal alkaloids with their multitarget pharmacology offer a biologically coherent, non-hormonal strategy for the treatment of endometriosis that goes beyond oestrogen deprivation to target the molecular machinery of lesion survival, fibrosis and immune dysregulation. This question is addressed by reviewing the nonhormonal signalling networks that support ectopic lesions, the structural and pharmacokinetic properties of steroidal alkaloids that are relevant to these pathways, and the translational challenges that need to be addressed for clinical translation.