Modulation of Colitis-associated Colon Tumorigenesis by Baicalein and Betaine

Abstract

In this review, we will summarize the current understanding of modulation of colitis-associated colon tumorigenesis by two natural products, baicalein and betaine, which have anti-inflammatory activities. Baicalein and betaine have been shown to provide various health benefits to organism in many ways. Baicalein is a phenolic flavonoid derived originally from the root of Scutellaria baicalensis Georgi. From ancient times, baicalein has widely been used in oriental medicines as an anti-inflammatory and anti-cancer therapy. Betaine, trimethylglycine, is an essential biochemical molecule of the methionine/homocysteine cycle and is synthesized by conversion of choline. Betaine is an important human nutrient obtained from various foods including sugar beet and lycium. Betaine has provided various health benefits including disease prevention. However, the action mechanisms of their activity remain poorly understood. Recent studies reported the effects of baicalein and betaine on cytotoxicity against colon cancer cells and chemically induced colitis-associated colon tumorigenesis in mice. Administrations of baicalein and betaine containing diets significantly inhibited the incidence of tumors and hyperplasia with down-regulation of inflammation. Therefore, baicalein and betaine might be applicable to the prevention of inflammation-associated colon carcinogenesis.

Keywords: Azoxymethane/dextran sodium sulfate model; Baicalein; Betaine; Colon cancer; Inflammatory bowel disease.

Figure 1.

Structures of baicalein and betaine.

Figure 2.

Modulation of colitis-associated colon tumorigenesis by baicalein and betaine. Baicalein and betaine suppressed colon tumor formations by inhibiting nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS), interleukin (IL)-6 and tumor necrosis factor (TNF)-α during azoxymethane/dextran sodium sulfate (AOM/DSS)-induced inflammation-associated colon tumorigenesis. MMP, matrix metalloproteinase; PPAR, peroxisome proliferator-activated receptor.