The four major commercial teas, oolong, black, pu-erh, and green teas, have been manufactured in southeast Asia. In this study, we evaluated the growth suppressive and hypolipidemic effect of these four different tea leaves by oral feeding to male Sprague-Dawley rats for 30 weeks. The results showed that the suppression of body weights of tea leaves-fed groups were in the order: oolong tea > pu-erh tea > black tea > green tea. Pu-erh tea and oolong tea could lower the levels of triglyceride more significantly than that of green tea and black tea, but pu-erh tea and green tea were more efficient than oolong tea and black tea in lowering the level of total cholesterol. In lipoprotein, 4% pu-erh tea could increase the level of HDL-C and decrease the level of LDL-C, but other teas simply decrease the levels of both. The activity of antioxidant enzyme SOD is increased in all tea-fed groups as compared to the basal diet-fed group. Finally, relative weight ratios of liver to epididylmal adipose tissue were lower in feeding oolong tea and pu-erh tea groups. On the basis of these findings, it seemed that the fully fermented pu-erh and black tea leaves and partially fermented oolong tea leaves were more effective on their growth suppressive and hypolipidemic effects as compared to the nonfermented green tea leaves.

Propolis is a sticky substance that is collected from plants by honeybees. We previously demonstrated that propolins A, B, C, D, E and F, isolated from Taiwanese propolis (TP), could effectively induce human melanoma cell apoptosis and were strong antioxidant agents. In this study, we evaluated TP for free radical scavenging activity by DPPH (1,2-diphenyl-2-picrylhydrazyl). The phenolic concentrations were quantified by the Folin–Ciocalteu method. The apoptosis trigger activity in human melanoma cells was evaluated. TP contained a higher level of phenolic compounds and showed strong capability to scavenge free radicals. Additionally, TP1g, TP3, TP4 and TP7 exhibited a cytotoxic effect on human melanoma cells, with an IC50 of ∼2.3, 2.0, 3.3 and 3.3 μg/ml, respectively. Flow cytometric analysis for DNA fragmentation indicated that TP1g, TP2, TP3 and TP7 could induce apoptosis in human melanoma cells and there is a marked loss of cells from the G2/M phase of the cell cycle. To address the mechanism of the apoptosis effect of TP, we evaluated its effects on induction of apoptosis-related proteins in human melanoma cells. The levels of procaspase-3 and PARP [poly(ADP-ribose) polymerase] were markedly decreased. Furthermore, propolins A, B, C, D, E and F in TP were determined using HPLC. The results indicate that TP is a rich source of these compounds. The findings suggest that TP induces apoptosis in human melanoma cells due to its high level of propolins.

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Epithelial-to-mesenchymal transition (EMT) is a major process to regulate cell migration and invasion. Inhibition of epidermal growth factor receptor (EGFR)-mediated EMT by tyrosine kinase inhibitors (TKIs) is a strategy to prevent lung cancer invasion. However, drug resistance is emerged and accelerated invasion through other signaling bypassing EGFR after TKIs therapy. c-Met signaling pathway is highly activated in EGFR-mutated lung cancer cells. Targeting c-Met signaling pathway may be a strategy to suppress EGFR-independent migration and invasion for lung cancer therapy. Therefore, we examined the anti-migration and anti-invasion abilities of shikonin, an active compound from Lithospermum erythrorhizon, in highly and ligand-induced c-Met activation lung cancer cells. Our results revealed that cell viability and cell cycle progression did not change under 1 μM of shikoinin treatment in highly c-Met expressive HCC827 lung cancer cells. Endogenous c-Met activation was dose-dependently inhibited and the migration and invasion activity of HCC827 cells were suppressed by shikonin treatment. Induction of E-cadherin expression and inhibition of vimentin, slug, and snail expression by shikonin was through c-Met-mediated PI3K/Akt and ERK signaling suppression. Furthermore, hepatocyte growth factor (HGF)-induced migration, invasion and EMT marker change were reversed by shikonin in low c-Met expressive A549 lung cancer cells. Inhibition of HGF-induced c-Met, PI3K/Akt and MEK/ERK activation were observed in shikonin-treated cells. Co-treatment of PI3K/Akt inhibitor or ERK inhibitor with shikonin enhanced shikonin-reversed HGF-regulated EMT marker expression. Taken together, the results suggested that the anti-migration and anti-invasion activities of shikonin was through c-Met inhibition and following by EMT suppression in lung cancer. J. Cell. Biochem. 118: 4639-4651, 2017. © 2017 Wiley Periodicals, Inc.

Fatty acid synthase (FAS) is a key enzyme of lipogenesis. Overexpression of FAS is dominant in cancer cells and proliferative tissues. The expression of FAS in the livers of rats fed pu-erh tea leaves was significantly suppressed. The gains in body weight, levels of triacylglycerol, and total cholesterol were also suppressed in the tea-treated rats. FAS expression in hepatoma HepG2 cells was suppressed by the extracts of pu-erh tea at both the protein and mRNA levels. FAS expression in HepG2 cells was strongly inhibited by PI3K inhibitor LY294002 and JNK inhibitor II and slightly inhibited by p38 inhibitor SB203580 and MEK inhibitor PD98059, separately. Based on these findings, we suggest that the suppression of FAS in the livers of rats fed pu-erh tea leaves may occur through downregulation of the PI3K/AKt and JNK signaling pathways. The major components of tea that have been demonstrated to be responsible for the antiobesity and hypolipidemic effects are catechins, caffeine, and theanine. The compositions of catechins, caffeine, and theanine varied dramatically in pu-erh, black, oolong, and green teas. The active principles and molecular mechanisms that exerted these biological effects in pu-erh tea deserve future exploration.