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Pu-erh tea is produced in China and known to possess medicinal properties. The anticancer and antiangiogenesis effects of fermented Pu-erh tea on HT-29 colon cancer cells and human umbilical vein endothelial cells, respectively, were examined. Two kinds of unfermented and fermented Pu-erh tea (Seven-son tea cake Pu-erh tea and Xiaguan bowl tea [X]) and green tea were used. An MTT assay showed fermented Pu-erh tea X (85% inhibition) possessed more potent anticancer activities than unfermented Pu-erh tea X (67% inhibition) and green tea (53% inhibition) (P < 0.05). Moreover, fermented Pu-erh tea X increased the number of apoptotic bodies determined through DAPI staining and flow cytometric analysis. Fermented Pu-erh tea X induced apoptosis indicated by increased expression of Bax, caspase-9, and caspase-3 messenger RNA and decreased expression of Bcl-2. Fermented Pu-erh tea X also had an anti-inflammation effect, shown in decreased expression of nuclear factor-κB-p65, inducible nitric oxide synthase, COX-2 messenger RNA and increased expression of IκB-α. Further, fermented Pu-erh teas showed stronger antiangiogenesis effects than the 2 other types of tea. After fermentation, the concentrations of gallic acid, resorcylic acid, quercetin, and kaempferol in Pu-erh tea were increased. These results collectively indicated that fermented and unfermented Pu-erh teas possess stronger anticancer and antiangiogenesis effects than green tea. Furthermore, fermented Pu-erh tea showed stronger functional activities than unfermented Pu-erh tea.

Theasaponin E₁ (TSE₁) has been suggested to have higher biological activity than other saponins present in tea seed. Saponins have recently been considered as a potential chemotherapeutic agent for treating cancer. We examined the anti-angiogenic and anti-obesity properties of TSE₁ contributing to anti-cancer efficacy. Treating with a 10 μg/mL concentration of TSE₁ completely inhibited tube formation in human umbilical vein endothelial cells (HUVECs). TSE₁ showed toxicity toward cancer cells and inhibited in vivo growth of the tumor. The vascular endothelial growth factor (VEGF) receptor complex was suppressed, leading to the inhibition of protein kinase B (Akt) expression and down-regulation of nuclear factor-kappa B (NF-kB) activation. The differentiating 3T3-L₁ cells treated with TSE₁ had decreased lipid droplet formation measured by Oil Red O staining. Reduced weight was measured in mice fed with a TSE₁ plus high-fat diet. The results taken together, and particularly the NF-kB inhibition, suggest that TSE₁ may have multi-target action for treating cancer as a novel chemotherapeutic agent.

The anti-cancer activity of saponins and phenolic compounds present in green tea was previously reported. However, the immunomodulatory and adjuvanticity activity of tea saponin has never been studied. In this study, we investigated the immunomodulatory effect of tea saponin in T-lymphocytes and EL4 cells via regulation of cytokine response and mitogen-activated protein kinases (MAPK) signaling pathway. Quantitative analysis of mRNA expression level of cytokines were performed by reverse transcription polymerase chain reaction following stimulation with tea saponin, ovalbumin (OVA) alone or tea saponin in combination with OVA. Tea saponin inhibited the proliferation of EL4 cells measured in a dose-dependent manner. No cytotoxicity effect of tea saponin was detected in T-lymphocytes; rather, tea saponin enhanced the proliferation of T-lymphocytes. Tea saponin with OVA increased the expression of interleukin (IL)-1, IL-2, IL-12, interferon-γ and tumor necrosis factor (TNF)-α and decreased the expression level of IL-10 and IL-8 in T-lymphocytes. Furthermore, tea saponin, in the presence of OVA, downregulated the MAPK signaling pathway via inhibition of IL-4, IL-8 and nuclear factor kappaB (NF-κB) in EL4 cells. Th1 cytokines enhancer and Th2 cytokines and NF-κB inhibitor, tea saponin can markedly inhibit the proliferation and invasiveness of T-lymphoma (EL4) cells, possibly due to TNF-α- and NF-κB-mediated regulation of MAPK signaling pathway.

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