Transcriptome and metabolome reveal the accumulation of secondary metabolites in different varieties of Cinnamomum longepaniculatum.

BACKGROUND: Cinnamomum longepaniculatum (Gamble) N. Chao ex H. W. Li, whose leaves produce essential oils, is a traditional Chinese medicine and economically important tree species. In our study, two C. longepaniculatum varieties that have significantly different essential oil contents and leaf phenotypes were selected as the materials to investigate secondary metabolism. RESULT: The essential oil content and leaf phenotypes were different between the two varieties. When the results of both transcriptome and metabolomic analyses were combined, it was found that the differences were related to phenylalanine metabolic pathways, particularly the metabolism of flavonoids and terpenoids. The transcriptome results based on KEGG pathway enrichment analysis showed that pathways involving phenylpropanoids, tryptophan biosynthesis and terpenoids significantly differed between the two varieties; 11 DEGs (2 upregulated and 9 downregulated) were associated with the biosynthesis of other secondary metabolites, and 12 DEGs (2 upregulated and 10 downregulated) were related to the metabolism of terpenoids and polyketides. Through further analysis of the leaves, we detected 196 metabolites in C. longepaniculatum. The abundance of 49 (26 downregulated and 23 upregulated) metabolites differed between the two varieties, which is likely related to the differences in the accumulation of these metabolites. We identified 12 flavonoids, 8 terpenoids and 8 alkaloids and identified 4 kinds of PMFs from the leaves of C. longepaniculatum. CONCLUSIONS: The combined results of transcriptome and metabolomic analyses revealed a strong correlation between metabolite contents and gene expression. We speculate that light leads to differences in the secondary metabolism and phenotypes of leaves of different varieties of C. longepaniculatum. This research provides data for secondary metabolite studies and lays a solid foundation for breeding ideal C. longepaniculatum plants.

Extraction and antioxidant activity of flavonoids of Morus nigra.

Morus nigra has a long history of medicinal use in Chinese medicine, but the study on it is limited, the flavonoids are one of the main biological active substances. In this study, the Morus nigra flavonoids were extracted by ultrasonic and antioxidant activities both in vitro and in vivo were measured. The results showed that hydroxyl radicals clearance rate and superoxide radical anion clearance rate in vitro increased with the concentration of the total flavonoids in the range of 0-1.05 mg/mL and the maximum clearance rate was 80.33% and 87.69%, respectively. After mice were treated with flavonoids, the content of malonaldehyde (MDA) in serum and liver decreased; the activities of superoxide dismutase (SOD) in serum and liver, catalase (CAT) in liver and glutathione peroxidase (GSH-PX) in blood and liver increased; Langhans cells increased in spleen. These results revealed that the Morus nigra flavonoids possessed strong antioxidant activity.

γ-terpineol inhibits cell growth and induces apoptosis in human liver cancer BEL-7402 cells in vitro.

To investigate the effect of γ-terpineol on cell proliferation and apoptosis of human hepatoma BEL-7402 cells to elucidate its molecular mechanism. Here, BEL-7402 cells were treated with various concentrations (40, 80, 160, 320 and 640 µg/ml) of γ-terpineol for 48 h, cell proliferation was determined by 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromides (MTT) assay. Cell colony inhibition was determined by soft agar assay. Apoptosis and possible molecular mechanisms were evaluated by morphological observation, flow cytometry analysis, and DNA fragmentation assay. The γ-terpineol significantly suppressed BEL-7402 cell proliferation in a dose-dependent manner. Characteristic morphological and biochemical changes associated with apoptosis such as cells shrinkage, deformation and vacuolization of mitochondria, nuclear chromatin condensation and fragmentation, formation of apoptotic bodies were observed after BEL-7402 cells treated with γ-terpineol for 24 h and 48 h. Cell cycle were displayed by flow cytometry analysis, the γ-terpineol treatment resulted in accumulation of cells at G1 or S phase and a blockade of cell proliferation compared to control group. Treating BEL-7402 cells with 320 µg/ml of γ-terpineol for 36 h and 48 h, a typical apoptotic "DNA ladder" was observed using DNA fragmentation assay. The present study demonstrated that possible anti-cancer mechanism of γ-terpineol on human hematomas cells is through inducing cell apoptosis to suppress tumor cell growth.

Anti-inflammatory activity of leaf essential oil from Cinnamomum longepaniculatum (Gamble) N. Chao.

The anti-inflammatory activity of the essential oil from C. longepaniculatum was evaluated by three experimental models including the dimethyl benzene-induced ear edema in mice, the carrageenan-induced paw edema in rat and the acetic acid-induced vascular permeability in mice. The influence of the essential oil on histological changes and prostaglandin E2 (PGE2), histamine and 5-hydroxytryptamine (5-HT) production associated with carrageenan-induced rat paw edema was also investigated. The essential oil (0.5, 0.25, 0.13 ml/kg b.w.) showed significantly inhibition of inflammation along with a dose-dependent manner in the three experimental models. The anti-inflammatory activity of essential oil was occurred both in early and late phase and peaked at 4 h after carrageenan injection. The essential oil resulted in a dose dependent reduction of the paw thickness, connective tissue injury and the infiltration of inflammatory cell. The essential oil also significantly reduced the production of PGE2, histamine and 5-HT in the exudates of edema paw induced by carrageenan. Both the essential oil and indomethacin resulted relative lower percentage inhibition of histamine and 5-HT than that of PGE2 at 4 h after carrageenan injection.

The expression and imprinting status of insulin-like growth factor 2 gene in colorectal cancer / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the imprinting status and expression level of insulin-like growth factor 2 (IGF2) gene in colorectal cancer and to provide a clue for the mechanism of carcinogenesis of colorectal cancer.</p><p><b>METHODS</b>The expression levels of IGF2 in the paired colorectal cancer and adjacent normal tissue were examined and compared by use of semi-quantitative reverse transcription-polymerase chain reaction. The imprinting status of IGF2 was detected by restriction fragment length polymorphism. The relationships between the expression level of IGF2, its imprinting status, and the carcinogenesis of colorectal cancer were analyzed.</p><p><b>RESULTS</b>IGF2 was overexpressed in 82.4% (28/34) of colorectal cancer tissues which was significantly higher than those of the matched normal tissues (P<0.01, t=3.01). 87.5% (14/16) of colorectal cancer showed loss of imprinting(LOI), while 71.4%(10/14) of normal tissues also displayed LOI of IGF2.</p><p><b>CONCLUSION</b>Overexpression of IGF2 was found to play an important role in carcinogenesis of colorectal cancer. LOI of IGF2 may be a prophase manifestation of colorectal cancer.</p>