Dietary supplementation of lutein reduces colon carcinogenesis in DMH-treated rats by modulating K-ras, PKB, and ß-catenin proteins.

In colon cancer, disturbances have been detected in genes coding for proteins involved in cellular proliferation, such as K-ras, ß-catenin, extracellular signal-regulated kinases (ERKs), and the protein kinase B (PKB). Although carotenoids such as lutein have an important role to prevent and treat some types of cancer, there are very few studies about the effect of lutein against colon cancer and its activity at the molecular level. Therefore, the aim of this study was to evaluate the chemoprotective activity of lutein against colon cancer induced by dimethylhydrazine (DMH). The results showed a significant increase in protein expression for K-ras and ß-catenin in tumors of DMH-treated rats. Simultaneously, we detected changes in the phosphorylation state of ERK1/2 and PKB in DMH-treated animals. Lutein given in the diet (0.002%), before (prevention) and after (treatment) DMH administration, diminished the number of tumors by 55% and 32%, respectively. Moreover, lutein significantly decreased in tumors the expression of K-ras (25%) and ß-catenin (28%) and the amount of pPKB (32%), during the prevention, and 39%, 26%, and 26% during the treatment stage, respectively. This study demonstrates the chemoprotective effect of lutein against colon cancer by modulating the proliferative activity of K-ras, PKB, and ß-catenin proteins.

Physicochemical, nutritional and antioxidant properties of tempeh flour from common bean ( Phaseolus vulgaris L.).

The effects of solid state fermentation (SSF) on physicochemical, nutritional and antioxidant properties of common bean flour were studied. SSF increased protein content (21.7%) and decreased lipids (-38.4%), carbohydrates (-3.5%) and phytic acid (-58.3%). Fermented (tempeh) flour showed higher dispersability, lower water solubility index and pH than unfermented flour. Fermentation also increased an average of 0.21 g/100 g protein, six of the essential amino acids (EAAs), including total sulfur (Met + Cys), the limiting EAAs in unfermented flour (score = 0.91); Lys and Trp decreased 0.21 and 0.09 g/100 g protein, respectively. SSF improved the in vitro protein digestibility and the calculated protein efficiency ratio. Tempeh flour had 2.2-fold more phenolics than the bean flour and exhibited antiradical activity (43%) and antioxidant activity (38%) correlated with total phenolics content. Common bean tempeh flour may be considered for the fortification of widely consumed legume-based food products and also for the prevention of pathologies associated with oxidative stress.