Identification of the Natural Steroid Sapogenin Diosgenin as a Direct Dual-Specific RORα/γ Inverse Agonist

Abstract

The steroid sapogenin diosgenin is a well-known natural product with a plethora of described pharmacological activities including the amelioration of T helper 17 (Th17)-driven pathologies. However, the exact underlying mode of action of diosgenin leading to a dampened Th17 response is still largely unknown and specific molecular targets have yet to be identified. Here, we show that diosgenin acts as a direct ligand and inverse agonist of the nuclear receptor retinoic acid receptor (RAR)-related orphan receptor (ROR)α and RORγ, which are key transcription factors involved in Th17 cell differentiation and metabolism. IC50 values determined by luciferase reporter gene assays, employing constructs for either RORγ-Gal4 fusion proteins or full length receptors, were in the low micromolar range at around 2 µM. To highlight the functional consequences of this RORα/γ inverse agonism, we determined gene expression levels of important ROR target genes, i.e., IL-17A and glucose-6-phosphatase, in relevant cellular in vitro models of Jurkat T and HepG2 cells, respectively, by RT-qPCR (reverse transcription quantitative PCR). Thereby, it was shown that diosgenin leads to a dose-dependent decrease in target gene expressions consistent with its potent cellular ROR inverse agonistic activity. Additionally, in silico dockings of diosgenin to the ROR ligand-binding domain were performed to determine the underlying binding mode. Taken together, our results establish diosgenin as a novel, direct and dual-selective RORα/γ inverse agonist. This finding establishes a direct molecular target for diosgenin for the first time, which can further explain reported amendments in Th17-driven diseases by this compound.

Novel Therapeutic Potential of Retinoid-Related Orphan Receptor α in Cardiovascular Diseases

“…Additionally, Nobiletin is a natural compound that directly binds to and activates RORα, modulating circadian rhythms and showing robust in vivo efficacies to combat clock-associated pathophysiologies and age-related decline [ 59 ]. One latest study confirmed that diosgenin acted as a direct ligand and inverse agonist of RORα, which is a key transcription factor involved in Th17 cell differentiation and metabolism [ 60 ]. Another group underscored the screening of a large combinatorial library of 1,5-disubstituted acylated 2-amino-4,5-dihydroimidazoles using a demonstrated synthetic and screening approach and the utility of the positional scanning libraries strategy for the rapid identification of a novel class of RORα inhibitors.…”

Effects of natural products on skin inflammation caused by abnormal hormones secreted by the adrenal gland

“…Diosgenin ( Figure 1E ) is a natural steroidal sapogenin ( Schwarz et al, 2022 ). Diosgenin is found in Dioscorea alata L., Smilax china L., and Trigonella foenum-graecum L. ( Jesus et al, 2016 ).…”

Recent Advances in the Discovery of Novel Drugs on Natural Molecules

“…TAN was already recognized in herbal medicine for its anti-inflammatory, antioxidant, and vascular endothelial cell-protective properties. Likewise, Schwarz et al [ 31 ] investigated the mode of action of the steroid sapogenin diosgenin, previously identified in the Chinese plant Dioscoreae rhizoma, in dampening the autoimmune inflammatory response in T helper 17 (Th17)-driven pathologies. By combining methodological approaches including gene expression analysis and in silico analyses, the authors revealed diosgenin as an inverse agonist of the key transcription factors leading to Th17 cell differentiation and metabolism.…”