Uncovering the pharmacological foundation of NLXT through an ischemic stroke rat model combined with UHPLC-QTOF/MS techniques.

Abstract

Nao-Luo-Xin-Tong (NLXT) is a traditional Chinese medicine (TCM) for treating cerebral ischemic stroke (CIS). However, the specific active ingredients and the functional mechanisms remain unclear. Herein, we employed specific pathogen-free (SPF) male Sprague Dawley (SD) rats to establish an ischemic stroke model, and a reliable LC-MS approach for effectively separating and characterizing substances in the bloodstream and brain was utilized. Thirteen prototypes were identified in rat serum by the ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) approach. Four of these components were also detected in the brain tissue of stroke rats. More importantly, five metabolites were discovered, labeled M, M, M, M, and M. Among these, the possible prototype components for four metabolites were inferred to be Safflor Yellow A (M), Calycosin (M), Formononetin (M), and Sedanolide (M). Meanwhile, mechanistic studies indicated that NLXT effectively repaired neuronal and Nissl body structures in rats with Qi deficiency and blood stasis induced by Middle cerebral artery occlusion and reperfusion (MCAO/R). The findings suggest that NLXT may reduce TNF-α protein expression, thereby benefiting stroke rats through neuronal structure repair.