Potential mechanisms underlying the protective effects of lily bulbs extract and characteristic ingredients against LPS-induced inflammation in HaCaT cells

Abstract

Lily bulbs are a type of food raw material, but they are less studied as a cosmetic raw material. This study explored the specific components with such inhibitory effects in lily bulbs, to provide a basis for developing functional cosmetic ingredients with skin-soothing properties.

High-performance liquid chromatography (HPLC) analysis revealed that the lily bulbs extract (LBE) contains specific components regaloside A, regaloside B, and regaloside C at 2.506 mg/g, 1.405 mg/g, and 0.621 mg/g, respectively. Furthermore, network pharmacology analysis showed that these three components acted on key inflammation-related targets such as tumor necrosis factor-alpha (TNF-α), matrix metalloproteinase 2 (MMP2), estrogen receptor 1 (ESR1), AKT (Protein Kinase B) serine/threonine kinase 1 (AKT1), toll-like receptor 4 (TLR4), and heat shock protein 90-alpha (HSP90AA1), to regulate signaling pathways, including Pathways in cancer, TNF signaling pathway, Inflammatory mediator regulation of TRP (Transient Receptor Potential) channels, for anti-inflammation. Among them, these components exhibited binding energies of −25.02 kJ/mol, −22.63 kJ/mol, and −22.13 kJ/mol, respectively, with TNF-α. Notably, molecular docking studies demonstrated that, compared to regaloside B and regaloside C, regaloside A bound more closely to key anti-inflammatory targets, including TNF-α, AKT1, TLR4, HSP90AA1, albumin (ALB), and matrix metalloproteinase 9 (MMP9).

This study pioneered the use of lipopolysaccharide (LPS) to induce HaCaT cells to construct an inflammation model. Additionally, the real-time quantitative polymerase chain reaction (RT-qPCR) analysis of regaloside A at 25 μg/mL, 50 μg/mL, and 100 μg/mL revealed a negative correlation between expression levels and sample concentrations, with a 61% reduction in interleukin 6 (IL-6) relative mRNA expression and a 60% reduction in inducible nitric oxide synthase (iNOS) relative mRNA expression in the model group at 100 μg/mL.

These findings indicated that regaloside A was superior to LBE in its anti-inflammatory effect on human skin cells. Combined with findings from molecular docking studies, regaloside A was identified as a functional cosmetic ingredient with skin-soothing properties, offering significant potential for further development.