GC-MS and UHPLC-QTOFMS-assisted identification of the differential metabolites and metabolic pathways in key tissues of Pogostemon cablin.

Pogostemon cablin is an important aromatic medicinal herb widely used in the pharmaceutical and perfume industries. However, our understanding of the phytochemical compounds and metabolites within P. cablin remains limited. To our knowledge, no integrated studies have hitherto been conducted on the metabolites of the aerial parts of P. cablin. In this study, twenty-three volatile compounds from the aerial parts of P. cablin were identified by GC-MS, predominantly sesquiterpenes. Quantitative analysis showed the highest level of patchouli alcohol in leaves (24.89 mg/g), which was 9.12 and 6.69-fold higher than in stems and flowers. UHPLC-QTOFMS was used to analyze the non-volatile compounds of leaf, stem and flower tissues. The differences in metabolites between flower and leaf tissues were the largest. Based on 112, 77 and 83 differential metabolites between flower-leaf, flower-stem and leaf-stem, three tissue-specific biomarkers of metabolites were identified, and the differential metabolites were enriched in several KEGG pathways. Furthermore, labeling differential metabolites in the primary and secondary metabolic pathways showed that flowers accumulated more lipids and amino acids, including proline, lysine and tryptophan; the leaves accumulated higher levels of terpenoids, vitamins and flavonoids, and stems contained higher levels of carbohydrate compounds. Based on the role of acetyl coenzyme A, the distribution and possible exchange mechanism of metabolites in leaves, stems and flowers of P. cablin were mapped for the first time, laying the groundwork for future research on the metabolites in P. cablin and their regulatory role.

ß-catenin correlates with the progression of colon cancers and berberine inhibits the proliferation of colon cancer cells by regulating the ß-catenin signaling pathway.

INTRODUCTION: Berberine was one of the active components in Chinese herb and exerted tumor suppressive role in cancer progression, but the exact antitumor mechanism is still not clearly clarified. In the present study, bioinformatics analysis was performed on COAD patients from TCGA, HPA database, UALCAN and GEPIA 2 platform. We also explored the role of berberine on progression of human colon cancers in vitro and in vivo and clarified weather the antitumor effects of berberine was mediated by Wnt/beta-catenin pathway. METHODS: Cell viability was determined by MTT assay. The protein levels were tested by western blotting and the distribution of ß-catenin was observed by confocal microscope. RESULTS: The results showed the levels of CTNNB1 mRNA was increased in colon cancer patients than normal controls. The diagnostic value of CTNNB1 was AUC = 0.882 (CI:0.854-0.911) with sensitivity of 1.000 and specificity of 0.777. The promoter methylation level of CTNNB1 in COAD patients was significantly decreased. Moreover, univariate analysis and multivariate analysis results showed the expression of CTNNB1 in COAD patients was associated with T stage (p = 0.010), pathological stage (p = 0.025) and perineural invasion (p = 0.025). Furthermore, the in vitro assay results showed ß-catenin signaling was highly activated in human colon cancer cells and berberine inhibited the cell viability of colon cancer cells in vitro and in vivo in a dose-and time-dependent manner. Moreover, berberine induced the translocation of ß-catenin to cytoplasm from nucleus. CONCLUSION: The levels of CTNNB1 mRNA was increased in colon cancer patients than normal controls. Berberine inhibited the proliferation of colon cancer cells by regulating the beta-catenin signaling pathway.

Global analysis of lysine succinylation in patchouli plant leaves.

Lysine succinylation is a novel, naturally occurring posttranslational modification (PTM) in living organisms. Global lysine succinylation identification has been performed at the proteomic level in various species; however, the study of lysine succinylation in plant species is relatively limited. Patchouli plant (P. cablin (Blanco) Benth., Lamiaceae) is a globally important industrial plant and medicinal herb. In the present study, lysine succinylome analysis was carried out in patchouli plants to determine the potential regulatory role of lysine succinylation in patchouli growth, development, and physiology. The global succinylation sites and proteins in patchouli plants were screened with an immunoprecipitation affinity enrichment technique and advanced mass spectrometry-based proteomics. Several bioinformatic analyses, such as function classification and enrichment, subcellular location predication, metabolic pathway enrichment and protein-protein interaction networking, were conducted to characterize the functions of the identified sites and proteins. In total, 1097 succinylation sites in 493 proteins were detected in patchouli plants, among which 466 succinylation sites in 241 proteins were repeatedly identified within three independent experiments. The functional characterization of these proteins indicated that the tricarboxylic acid (TCA) cycle, oxidative phosphorylation, photosynthesis processes, and amino acid biosynthesis may be regulated by lysine succinylation. In addition, these succinylated proteins showed a wide subcellular location distribution, although the chloroplast and cytoplasm were the top two preferred cellular components. Our study suggested the important role of lysine succinylation in patchouli plant physiology and biology and could serve as a useful reference for succinylation studies in other medicinal plants.

Full-length transcriptome sequencing and methyl jasmonate-induced expression profile analysis of genes related to patchoulol biosynthesis and regulation in Pogostemon cablin.

BACKGROUND: Pogostemon cablin (Blanco) Benth. (Patchouli) is an important aromatic and medicinal plant and widely used in traditional Chinese medicine as well as in the perfume industry. Patchoulol is the primary bioactive component in P. cablin, its biosynthesis has attracted widespread interests. Previous studies have surveyed the putative genes involved in patchoulol biosynthesis using next-generation sequencing method; however, technical limitations generated by short-read sequencing restrict the yield of full-length genes. Additionally, little is known about the expression pattern of genes especially patchoulol biosynthesis related genes in response to methyl jasmonate (MeJA). Our understanding of patchoulol biosynthetic pathway still remained largely incomplete to date. RESULTS: In this study, we analyzed the morphological character and volatile chemical compounds of P. cablin cv. 'Zhanxiang', and 39 volatile chemical components were detected in the patchouli leaf using GC-MS, most of which were sesquiterpenes. Furthermore, high-quality RNA isolated from leaves and stems of P. cablin were used to generate the first full-length transcriptome of P. cablin using PacBio isoform sequencing (Iso-Seq). In total, 9.7 Gb clean data and 82,335 full-length UniTransModels were captured. 102 transcripts were annotated as 16 encoding enzymes involved in patchouli alcohol biosynthesis. Accorded with the uptrend of patchoulol content, the vast majority of genes related to the patchoulol biosynthesis were up-regulated after MeJA treatment, indicating that MeJA led to an increasing synthesis of patchoulol through activating the expression level of genes involved in biosynthesis pathway of patchoulol. Moreover, expression pattern analysis also revealed that transcription factors participated in JA regulation of patchoulol biosynthesis were differentially expressed. CONCLUSIONS: The current study comprehensively reported the morphological specificity, volatile chemical compositions and transcriptome characterization of the Chinese-cultivated P. cablin cv. 'Zhanxiang', these results contribute to our better understanding of the physiological and molecular features of patchouli, especially the molecular mechanism of biosynthesis of patchoulol. Our full-length transcriptome data also provides a valuable genetic resource for further studies in patchouli.