The Intraspecific Variation And Quality Evaluation Of Centella Asiatica

Herba Centellae is the dried whole plant of Centella asiatica (L.) Urban belonging to the Apiaceae family. It has traditionally been used as an antipyretic, diuretic according to Pharmacopoeia of PRC. Modern research found that C. asiatica could stimulate the wound healing, improve memory, anti-tumor, antidepressant, and so on. C. asiatica was also extensively investigated in Thailand, India, etc. In China, C. asiatica distributed widely just presented as one species. However, the previous research found that the intraspecific variation of C. asiatica was obvious. There is also unable quality control of this crude drug in China. C. asiatica is in great need in clinic, so the confusion of species and irregular quality will surely bring adverse effect to its application. The main contents of our study are as following four aspects:1 Study on phenotypic diversity of C. asiatica1.1 Samples of 14 populations of wild C. asiatica were collected from 11 provinces and municipalities of China, 14 of which were cultivated in the same place in school of pharmacy, second military medical university, Shanghai, China.1.2 The samples of 14 populations with 20 major characteristic were analyzed by quantitative taxonomy method and cluster analysis was undertaken by SPSS. All the samples were classified to four groups, as the same result as our direct certification by traits. The samples from Guizhou, Fujian provinces showed great difference from others, which was worth being further studied.2 Study on chemical diversity of C. asiaticaStudies on chemical fingerprint of C. asiatica were performed by HPLC-DAD. The HPLC data showed considerable variation of chemical constituents among the C. asiatica populations. The hierarchical clustering analysis (HCA) further revealed that 14 different populations were classified to four major groups based on their chemotype variation, which were absolutely consistent with four chemotypes divided intuitively based on HPLC fingerprint.3 Study on activity difference of key rate-limiting enzyme of C. asiaticaResearch on activity of squalene synthase (SQS), amyrin synthase (AS), cycloartenol synthase (CS) from different populations was completed by RT-PCR semi-quantitative analysis. The electrophoresis data suggested that OD value of SQS, AS of C. asiatica possessed positive correlation with corresponding contents of major chemical composition based on HPLC quantitative determination.4 Study on genetic diversity of C. asiaticaGenetic diversity of C. asiatica populations from China were investigated using inter-simple sequence repeat (ISSR) makers. 14 natural populations were analyzed to evaluate genetic diversity. The overall genetic diversity of C. asiatica populations in China was moderate (H=0.218). The AMOVA data and UPGMA dendrogram showed considerable genetic differentiation of the populations. Such characteristics of C. asiatica are likely attributed to its sexual or asexual reproduction and limited gene flow.5 Correlation of genetic variation and chemical diversity in C. asiaticaThe study found that groupings of cluster analysis about genetic variation and chemical diversity in C. asiatica were not completely consistent. The result suggested that the intraspecific variation was related to geographical environment, not obvious relevance to genetic background. However, the combination of genetic variation and chemical diversity in C. asiatica could provide scientific basis for selecting elite germplasm and establishing GAP base.