Application of 18β-glycyrrhetinic acid Fluorescent probes in cell imaging

TL;DR

Researchers developed fluorescent probes to study how 18β-GA reduces inflammation in macrophages, finding that it likely acts on cytoplasmic proteins.

Contribution

Designed and tested fluorescent probes to identify the subcellular targets of 18β-GA in anti-inflammatory processes.

Findings

Modifying C-3 hydroxyl and C-30 carboxyl groups improved 18β-GA's anti-inflammatory activity.

Two fluorescent probes (Ia and IIc) showed similar anti-inflammatory effects to 18β-GA on key inflammatory factors.

Fluorescence signals from the probes were localized in the cytoplasm, suggesting cytoplasmic protein targets.

Abstract

Fluorescently labelled small molecule probes (fluorescent probes) play an important role in cell imaging and are often used in combination with light-affinity probes to determine the subcellular localisation of target proteins. To investigate the target proteins of 18β-glycyrrhetinic acid (18β-GA), which regulates the macrophage inflammatory response, we designed and synthesised three types of fluorescent probes. We analysed its structure-activity relationship by evaluating the biological activity and screening for fluorescent probes with high activity. Our results showed that modifying C-3 hydroxyl and C-30 carboxyl groups enhanced the anti-inflammatory activity of 18β-GA, and found that two preferred probes had similar effects on LPS-induced, inflammation-related factor release (IL-1β, TNF-α, IL-6, HDAC8, P-STAT3, and SOCS3) to those of 18β-GA. Fluorescence signals of the preferred probes Ia and IIc were observed in the cytoplasm. The above results indicated that the anti-inflammatory site of 18β-GA may be located in proteins in the cytoplasm, which would provide useful information for research on the anti-inflammatory targets of 18β-GA.

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