Indigodole E from Strobilanthes cusia exhibits anti-IL-17A effect

One new indazole alkaloid, indigodole E (1), was isolated from a traditional Chinese medicine Qing Dai prepared from the aerial parts of Strobilanthes cusia. The structure of 1 was elucidated by NMR, MS, UV, and IR spectra as well as optical rotation. Additionally, compound 1 could obviously inhibit not only IL-17A protein production at concentrations from 1.25 to 2.5 mu g/mL, but also IL-17 gene expression at concentrations from 5.0 to 10.0 mu g/mL without cytotoxicity toward Th17 and Jukat cells, respectively. Overall, indazole analogue 1 could be the anti-IL 17 A contributor of Qing Dai in this investigation.

Automated summary

A new indazole alkaloid, indigodole E (1), was isolated from Qing Dai, a traditional Chinese medicine. Its chemical structure was determined using various spectroscopic techniques. The compound was found to significantly inhibit the production and gene expression of IL-17A without causing cytotoxicity towards specific cells. These findings suggest that indigodole E (1) may contribute to the anti-IL-17A activity of Qing Dai.