Screening of synergistic interactions of epigallocatechin-3-gallate with antiangiogenic and antitumor compounds

Evaluation of the Antioxidant Interactions Between Green Tea Polyphenols and Nonsteroidal Anti-inflammatory Drugs

Introduction:

The antioxidant interactions between the commonly used pharmaceuticals (diclofenac, ibuprofen and naproxen) and green tea polyphenols were evaluated.

Methods:

The antioxidant properties of the mixtures were evaluated by a scavenging effect on the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical.

Results:

The mixtures contained green tea extract and each drug exhibited lower antioxidant activity than the mathematical sum of the results obtained for individual components showing antagonistic effect. The results were obtained using isobolographic analysis and interaction factors also suggested the antagonistic type of interaction. Only when the concentration of the green tea infusion was relatively high (in comparison to the drug), an additive effect could be concluded.

Conclusion:

The high concentration of green tea infusion in comparison to the drug should be used in developing the new formulations as it can help in the therapy due to their antioxidant properties.

In Silico Investigation of the Anti-Tumor Mechanisms of Epigallocatechin-3-Gallate

The EGCG, an important component of polyphenol in green tea, is well known due to its numerous health benefits. We employed the reverse docking method for the identification of the putative targets of EGCG in the anti-tumor target protein database and these targets were further uploaded to public databases in order to understand the underlying pharmacological mechanisms and search for novel EGCG-associated targets. Similarly, the pharmacological linkage between tumor-related proteins and EGCG was manually constructed in order to provide greater insight into the molecular mechanisms through a systematic integration with applicable bioinformatics. The results indicated that the anti-tumor mechanisms of EGCG may involve 12 signaling transduction pathways and 33 vital target proteins. Moreover, we also discovered four novel putative target proteins of EGCG, including IKBKB, KRAS, WEE1 and NTRK1, which are significantly related to tumorigenesis. In conclusion, this work may provide a useful perspective that will improve our understanding of the pharmacological mechanism of EGCG and identify novel potential therapeutic targets.