Quality markers based on biological activity: A new strategy for the quality control of traditional Chinese medicine

The quality and quality evaluation system of traditional Chinese medicine (TCM) are crucial in the safety and effectiveness assessment of TCM. However, they are also the major bottlenecks that restrict the quality control of TCM. Given the nature of Chinese medicine and the limitations of science and technology, the quality evaluation of TCM involves a few difficulties. Therefore, scholars have conducted considerable amount of research on this topic and obtained promising results. Biological potency and biomarkers have been used to evaluate the quality of TCM. Previous studies provided new strategies and methods to establish a system on quality evaluation.This review aims to provide a new strategy for the quality control of Chinese herbal medicine by combining biological potency and biomarkers based on biological effects.We reviewed the quality evaluation system of Chinese herbal medicine, focusing on quality markers (Q-markers) based on biological effects and the application of these markers in the quality evaluation of Chinese herbal medicine. We also reviewed the factors affecting quality, the difficulties related to the quality evaluation system and the attempt of researchers to improve the quality control of TCM.We propose Q-biomarkers by integration of biological potency and biomarkers to evaluate the quality of TCM. The quality markers provided us significant insights in the process of definition. We further optimised the concept of Q-markers and summarised their definition and properties (including quantification, specificity and related to biological response) in accordance with the requirement of the quality evaluation of TCM.We propose the use of Q-biomarkers in vivo related to specific diseases as a new strategy for the quality evaluation of Chinese herbal medicine. The quality evaluation system of Q-biomarkers would provide a new perspective to standardise and globalise TCM.