theaflavin-3-3--digallate and epigallocatechin-gallate

The purpose of this study was to clarify the mechanism of the antibacterial action of two high potential and natural food additives, epigallocatechin gallate (EGCg) and theaflavin-3,3'-digallate (TF3), on Clostridium perfringens.. Minimal inhibitory concentrations were determined by the serial dilution method. Afterwards, the cells were treated with 250 or 1000 mg l. It seems that EGCg at a low concentration affected the proteins involved in the septum formation, DNA segregation and cell division. Furthermore, the high concentration of EGCg and TF3 seemed to cause stronger cellular damage to C. perfringens.. These polyphenols are widely distributed in all higher plants especially in tea plants, and people tend to use natural food additives rather than synthetic ones. EGCg and TF3, as natural food additives, can prevent C. perfringens food poisoning along with other potential health benefits.

Topics: Anti-Bacterial Agents; Biflavonoids; Catechin; Clostridium perfringens

Topics: Biflavonoids; Biocatalysis; Catechin; Catechol Oxidase; Cross-Linking Reagents; Enzymes, Immobilized; Equipment Reuse; Ferrosoferric Oxide; Glutaral; Kinetics; Metal Nanoparticles; Plant Proteins; Protein Multimerization; Pyrus; Substrate Specificity

Theaflavin-3, 3'-digallate (TF3) is a black tea polyphenol produced from polymerization and oxidization of the green tea ployphenols epicatechin gallate and (-)-epigallocatechin-3-gallate (EGCG) during fermentation of fresh tea leaves. TF3 has been reported to have anticancer properties. However, the effect of TF3 on tumor angiogenesis and the underlying mechanisms are not clear. In the present study, TF3 was verified to inhibit tumor angiogenesis. Compared with EGCG, TF3 was more potent. TF3 inhibited human ovarian carcinoma OVCAR-3 cell-induced angiogenesis in human umbilical vein endothelial cell model and in chick chorioallantoic membrane model. TF3 reduced tumor angiogenesis by downregulating HIF-1α and VEGF. One of the mechanisms was TF3 inactivated Akt/mTOR/p70S6K/4E-BP1 pathway and Akt/c-Myc pathway. Besides, TF3 suppressed the cleavage of Notch-1, subsequently decreased the expression of c-Myc, HIF-1α and VEGF, and finally the impaired cancer cells induced angiogenesis. Nevertheless, TF3 did not have any influence on the MAPK pathways. Taken together, these findings suggest that TF3 might serve as a potential anti-angiogenic agent for cancer treatment.

Topics: Biflavonoids; Carcinoma; Catechin; Cell Line, Tumor; Female; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Mitogen-Activated Protein Kinase Kinases; Neovascularization, Pathologic; Oncogene Protein v-akt; Ovarian Neoplasms; Proto-Oncogene Proteins c-myc; Receptor, Notch1; Signal Transduction; Vascular Endothelial Growth Factor A

Over the years, several studies have brought evidence suggesting that tea polyphenols, mostly from green tea, may have oral health benefits. Since few data are available concerning the beneficial properties of black tea and its theaflavin derivatives against periodontal disease, the objective of this study was to investigate their antibacterial activity as well as their ability to modulate interleukin-8 and human β-defensin (hBD) secretion in oral epithelial cells. Among the periodontopathogenic bacteria tested, Porphyromonas gingivalis was found to be highly susceptible to the black tea extract and theaflavins. Moreover, our data indicated that the black tea extract, theaflavin and theaflavin-3,3'-digallate can potentiate the antibacterial effect of metronidazole and tetracycline against P. gingivalis. Using lipopolysaccharide-stimulated oral epithelial cells, the black tea extract (100 μg/ml), as well as theaflavin and theaflavin-3,3'-digallate (50 μg/ml) reduced interleukin-8 (IL-8) secretion by 85%, 79%, and 86%, respectively, thus suggesting an anti-inflammatory property. The ability of the black tea extract and its theaflavin derivatives to induce the secretion of the antimicrobial peptides hBD-1, hBD-2 and hBD-4 by oral epithelial cells was then evaluated. Our results showed that the black tea extract as well as theaflavin-3,3'-digallate were able to increase the secretion of the three hBDs. In conclusion, the ability of a black tea extract and theaflavins to exert antibacterial activity against major periodontopathogens, to attenuate the secretion of IL-8, and to induce hBD secretion in oral epithelial cells suggest that these components may have a beneficial effect against periodontal disease.

Topics: beta-Defensins; Biflavonoids; Catechin; Cell Line; Epithelial Cells; Humans; Interleukin-8; Lipopolysaccharides; Microbial Sensitivity Tests; Mouth; Plant Extracts; Porphyromonas gingivalis; Tea