Green tea catechins in combination with irinotecan attenuates tumorigenesis and treatment-associated toxicity in an inflammation-associated colon cancer mice model

Natural Polyphenols for Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a prevalent and serious gastrointestinal malignancy with high mortality and morbidity. Chemoprevention refers to a newly emerged strategy that uses drugs with chemopreventive properties to promote antioxidation, regulate cancer cell cycle, suppress proliferation, and induce cellular apoptosis, so as to improve cancer treatment outcomes. Natural polyphenols are currently recognized as a class of chemopreventive agents that have shown remarkable anticarcinogenic properties. Numerous in vitro and in vivo studies have elucidated the anti-CRC mechanisms of natural polyphenols, such as regulation of various molecular and signaling pathways. Natural polyphenols are also reportedly capable of modulating the gut microbiota and cancer stem cells (CSCs) to suppress tumor formation and progression. Combined use of different natural polyphenols is recommended due to their low bioavailability and instability, and combination treatment can exert synergistical effects, reduce side effects, and avoid drug resistance in CRC treatment. In summary, the application of polyphenols in the chemoprevention and treatment of CRC is promising. Further clinical evaluation of their effectiveness is warranted and anticipated.

Anticarcinogenic potentials of tea catechins

Catechins are a cluster of polyphenolic bioactive components in green tea. Anticarcinogenic effects of tea catechins have been reported since the 1980s, but it has been controversial. The present paper reviews the advances in studies on the anticarcinogenic activities of tea and catechins, including epidemiological evidence and anticarcinogenic mechanism. Tea catechins showed antagonistic effects on many cancers, such as gynecological cancers, digestive tract cancers, incident glioma, liver and gallbladder cancers, lung cancer, etc. The mechanism underlying the anticarcinogenic effects of catechins involves in inhibiting the proliferation and growth of cancer cells, scavenging free radicals, suppressing metastasis of cancer cells, improving immunity, interacting with other anticancer drugs, and regulating signaling pathways. The inconsistent results and their causes are also discussed in this paper.

Epigallocatechin-3-gallate inhibits the formation of neutrophil extracellular traps and suppresses the migration and invasion of colon cancer cells by regulating STAT3/CXCL8 pathway

Colon cancer is a common malignant tumor of the digestive tract. Tea catechin exerts anti-tumor effects in colon cancer. This work aimed to determine the functions of epigallocatechin-3-gallate (EGCG), one of the main active components of Tea catechins, in the progression of colon cancer. In this work, enzyme-linked immune-sorbent assay, quantitative real-time PCR and western blotting was utilized to examine the levels of IL-1β, TNF-α, STAT3, p-STAT3 and CXCL8 in colon cancer patients and healthy controls. Compared with healthy controls, the levels of IL-1β and TNF-α were significantly increased in the peripheral blood of colon cancer patients, and the expression of STAT3, p-STAT3 and CXCL8 was elevated in the neutrophils derived from colon cancer patients. Moreover, neutrophils were treated with phorbol ester (PMA) or DNase I to induce or impede the formation of neutrophil extracellular traps (NETs). Both STAT3 overexpression and PMA treatment promoted the expression of CXCL8, myeloperoxidase (MPO) and citrullinated histone H3 (H3Cit) in the colon cancer-derived neutrophils, indicating that STAT3 overexpression facilitated the formation of NETs. STAT3 deficiency suppressed the formation of NETs, which consistent with the results of DNase I treatment. Transwell assay was utilized to detect the migration and invasion of colon cancer cell line SW480. EGCG treatment suppressed the formation of NETs and the expression of STAT3 and CXCL8 in the colon cancer-derived neutrophils, and then inhibited the migration and invasion of SW480 cells. In conclusion, this work demonstrated that EGCG inhibited the formation of NETs and subsequent suppressed the migration and invasion of colon cancer cells by regulating STAT3/CXCL8 signalling pathway. Thus, this study suggests that EGCG may become a potential drug for colon cancer therapy.