Extraordinary Anticancer Effect of Green Tea and Red Light

The anti-cancer activity of green tea, coffee and cocoa extracts on human cervical adenocarcinoma HeLa cells depends on both pro-oxidant and anti-proliferative activities of polyphenols

Thein vitroanti-cervical cancer potency of tested polyphenol extracts is exhibited in the following order: green tea > coffee > cocoa, with only green tea showing both pro-oxidative and anti-proliferative action.

Early transcriptional pattern of angiogenesis induced by EGCG treatment in cervical tumour cells

The major green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) has been shown to exhibit antitumour activities in several tumour models. One of the possible mechanisms by which EGCG can inhibit cancer progression is through the modulation of angiogenesis signalling cascade. The tumour cells’ ability to tightly adhere to endothelium is a very important process in the metastatic process, because once disseminated into the bloodstream the tumour cells must re-establish adhesive connections to endothelium in order to extravasate into the target tissues. In this study, we investigated the anti-angiogenic effects of EGCG treatment (10 μM) on human cervical tumour cells (HeLa) by evaluating the changes in the expression pattern of 84 genes known to be involved in the angiogenesis process. Transcriptional analysis revealed 11 genes to be differentially expressed and was further validated by measuring the induced biological effects. Our results show that EGCG treatment not only leads to the down-regulation of genes involved in the stimulation of proliferation, adhesion and motility as well as invasion processes, but also to the up-regulation of several genes known to have antagonist effects. We observed reduced proliferation rates, adhesion and spreading ability as well as invasiveness of HeLa tumour cells upon treatment, which suggest that EGCG might be an important anti-angiogenic therapeutic approach in cervical cancers.

670 nm laser light and EGCG complementarily reduce amyloid-β aggregates in human neuroblastoma cells: basis for treatment of Alzheimer's disease?

OBJECTIVE

The aim of the present study is to present the results of in vitro experiments with possible relevance in the treatment of Alzheimer's disease (AD).

BACKGROUND DATA

Despite intensive research efforts, there is no treatment for AD. One root cause of AD is the extra- and intracellular deposition of amyloid-beta (Aβ) fibrils in the brain. Recently, it was shown that extracellular Aβ can enter brain cells, resulting in neurotoxicity.

METHODS

After internalization of Aβ(42) into human neuroblastoma (SH-EP) cells, they were irradiated with moderately intense 670-nm laser light (1000 Wm(-2)) and/or treated with epigallocatechin gallate (EGCG).

RESULTS

In irradiated cells, Aβ(42) aggregate amounts were significantly lower than in nonirradiated cells. Likewise, in EGCG-treated cells, Aβ(42) aggregate amounts were significantly lower than in non-EGCG-treated cells. Except for the cells simultaneously laden with Aβ(42) and EGCG, there was a significant increase in cell numbers in response to laser irradiation. EGCG alone had no effect on cell proliferation. Laser irradiation significantly increased ATP levels in Aβ(42)-free cells, when compared to nonirradiated cells. Laser-induced clearance of Aβ(42) aggregates occurred at the expense of cellular ATP.

CONCLUSIONS

Irradiation with moderate levels of 670-nm light and EGCG supplementation complementarily reduces Aβ aggregates in SH-EP cells. Transcranial penetration of moderate levels of red to near-infrared (NIR) light has already been amply exploited in the treatment of patients with acute stroke; the blood-brain barrier (BBB) penetration of EGCG has been demonstrated in animals. We hope that our approach will inspire a practical therapy for AD.

Green tea polyphenol epigallocatechin-3-gallate suppresses melanoma growth by inhibiting inflammasome and IL-1β secretion

Epigallocatechin-3-gallate (EGCG), the major polyphenolic component of green tea, has been demonstrated to possess anti-inflammatory, antioxidant, anti-mutagenic and anti-carcinogenic properties. The anti-melanoma effect of EGCG has been previously suggested, but no clear mechanism of action has been established. In this study, we demonstrated that EGCG inhibits melanoma cell growth at physiological doses (0.1-1 μM). In the search for mechanisms of EGCG-mediated melanoma cell suppression, we found that NF-κB was inhibited, and that reduced NF-κB activity was associated with decreased IL-1β secretion from melanoma cells. Since inflammasomes are involved in IL-1β secretion, we investigated whether IL-1β suppression was mediated by inflammasomes, and found that EGCG treatment led to downregulation of the inflammasome component, NLRP1, and reduced caspase-1 activation. Furthermore, silencing the expression of NLRP1 abolished EGCG-induced inhibition of tumor cell proliferation both in vitro and in vivo, suggesting a key role of inflammasomes in EGCG efficacy. This paper provides a novel mechanism for EGCG-induced melanoma inhibition: inflammasome downregulation→decreased IL-1β secretion→decreased NF-κB activities→decreased cell growth. In addition, it suggests inflammasomes and IL-1β could be potential targets for future melanoma therapeutics.

Pulsed laser light forces cancer cells to absorb anticancer drugs--the role of water in nanomedicine

Anticancer drugs executing their function intracellularly enter cancer cells via diffusive processes. Complementary to these slow processes, cells can be forced to incorporate drugs by convection - a more efficient transport process. Transmembrane convection is induced by moderately intense pulsed laser light (or light emitting diodes) changing the structure of nanoscopic water layers in cells. This is a fundamental difference with the method of photodynamic therapy. In a model system we demonstrate that a total irradiation time of one minute is sufficient to completely inhibit proliferation of cancer cells. Transmembrane convection protects healthy cells from extended chemotherapy exposure, could be exploited to overcome multidrug resistance, and is a promising new tool in a variety of therapies as well as in skin rejuvenation.