Journal of Research and Development
Open Access

Abstract

Danggui Buxue Tang, a Chinese Herbal Decoction, Induces Nitric Oxide Production in Cultured Endothelial Cells: Probing Calycosin as a Key Player by Chemical Knock-Out Approach

Gong AGW, Lam CTW, Zhang LML, Deng JY, Wang HY, Lin HQ, Dong TTX and Karl WK Tsim

Danggui Buxue Tang (DBT) is a Chinese herbal decoction prescribed for woman menopausal symptoms. The make-up of DBT is Astragali Radix (AR) and Angelicae Sinensis Radx (ASR) at a weight ratio of 5:1. In cultured endothelial cells, application of DBT induced the production of nitric oxide (NO), the phosphorylations of eNOS and Akt, and the mobilization of intracellular calcium. The chemicals within DBT responsible for the effects in endothelial cells however have never been addressed. Here, we developed a chemical knock-out method in a herbal mixture as to determine the role of individual ingredient(s). Calycosin is the most abundant flavonoid in DBT herbal decoction. By HPLC separation, calycosin was removed at over 97% from DBT decoction, which was named as DBTΔcal. Comparing to authentic DBT, the induction of NO production as well as its signaling responses, triggered by DBTΔcal, in cultured endothelial cells were markedly reduced. In contrast, calycosin alone showed no response in the cultures. Our finding showed a synergistic role of calycosin in the herbal mixture.