Laser Microdissection Analysis: Linking morphology and biochemistry to assess the quality of Chinese medicinal materials

Various specifications or grades of some Chinese medicinal materials (CMMs) can be found in the markets. Different grades have different quality; generally, higher grade means higher quality. These various specifications or grades of CMMs are mainly determined according to the traditional experiences, and are mostly based on morphological features. However, many modern researches have demonstrated that not all the traditional experiences as to the classification of various grades of CMMs actually distinguish relative quality. Different growing environments, cultivation techniques and/or processing methods can greatly influence morphological features as well as chemical components of CMMs. Thus, the classification and quality evaluation of various commercial specifications of CMMs according to morphological features has drawn popular concern, and need to be validated by modern analytical methods for each CMM. As we know, evaluating the quality of various specifications or grades of CMMs by morphological features is a convenient, quick and practical method compared with other methods that mostly depend on modern instruments. Morphological features are linked to chemical components of CMMs, but in what way and to what extent? In this study, a systematical investigation will be carried out to answer these questions. First, information about traditional experiences regarding the quality evaluation of CMMs by morphological features will be acquired from historical documents. Then CMM samples will be acquired from herbal markets. Different cells and tissue regions of CMMs will be separated by means of laser microdissection and their metabolite profiling will be analysed by ultra high performance liquid chromatograph (UPLC) with mass spectrometry. The results can correlate active components and morphological features of CMMs; this relationship will be helpful in classifying the CMMs in terms of specifications or grades as well as in evaluating their quality relatively by morphology. In addition, the relationship will be further validated by determining the contents of active components in various specifications or grades of CMMs by UPLC. The results will enable us to assess, scientifically, whether traditional experiences accurately indicate pharmaceutical quality. Moreover, these results should enable medicinal vendors and consumers relatively evaluate the quality of various commercial specifications or grades of CMMs by themselves.