Exploring the ‘cold/hot’ properties of traditional Chinese medicine by cell temperature measurement

CONTEXT: It is common sense that chewing a mint leaf can cause a cooling feeling, while chewing ginger root will produce a burning feeling. In Traditional Chinese Medicine (TCM), this phenomenon is referred to as ‘cold/hot’ properties of herbs. Herein, it is reported that TCM with different “cold/hot” properties have different effects on the variation of cells. OBJECTIVE: To explore the intrinsic ‘cold/hot’ properties of TCM from the perspective of cellular and molecular biology. MATERIALS AND METHODS: A375 cells were selected using Cancer Cell Line Encyclopaedia (CCLE) analysis and western blots. Hypaconitine and baicalin were selected by structural similarity analysis from 56 and 140 compounds, respectively. A wireless thermometry system was used to measure cellular temperature change induced by different compounds. Alteration of intracellular calcium influx was investigated by means of calcium imaging. RESULTS: The IC(50) values of GSK1016790A, HC067047, hypaconitine, and baicalin for A375 cells are 8.363 nM, 816.4 μM, 286.4 μM and 29.84 μM, respectively. And, 8 μM hypaconitine induced obvious calcium influx while 8 μM baicalin inhibited calcium influx induced by TRPV4 activation. Cellular temperature elevated significantly when treated with GSK1016790A or hypaconitine, while the results were reversed when cells were treated with HC067047 or baicalin. DISCUSSION AND CONCLUSIONS: The changes in cellular temperature are speculated to be caused by the alteration of intracellular calcium influx mediated by TRPV4. In addition, the ‘cold/hot’ properties of compounds in TCM can be classified by using cellular temperature detection.