Chemical characterization, antioxidant and antimutagenic evaluations of pigmented corn.

In order to identify pigmented corn with nutraceutical potential, the secondary metabolite content, the antioxidant capacity and antimutagenic activity of red, and blue corn were analyzed. The ranges of total phenolic, flavonoid and anthocyanin contents of the corn samples were from 69.4 to 212.8 mg gallic ac. equiv./100 g DW, 0.07 to 12.19 mg (+) catechin eq./100 g DW and 3.89 to 34.17 mg cyanidin-3-O-glucoside eq./100 g DW, respectively. The phenolic extracts demonstrated the highest antioxidant capacity evaluated by the ABTS assay displaying values from 2.06 to 7.34 mmol Trolox/100 g DW. None of the extracts was toxic to the tested bacteria strains TA98 and TA100. For TA98 tester strain, percentage inhibition values against AFB1 mutagenicity from 61 to 93, and 38 to 75 for flavonoid and anthocyanin extracts were obtained. The total phenol and anthocyanin contents correlate with the observed antioxidant capacity. The most biological active corn samples were the blue color while the least actives were the red ones. The results show that the studied blue corn samples are good sources of antioxidant and antimutagenic compounds, which could use to develop products that contribute to human health.

Antioxidant, antimutagenic, and antidiabetic activities of edible leaves from Cnidoscolus chayamansa Mc. Vaugh.

UNLABELLED: The methanolic extract of Cnidoscolus chayamansa leaves from Mexico was screened for antioxidant and antimutagenic properties by the DPPH, ABTS, iron chelating, and Kado microsuspension assays, respectively. The hypoglycemic effect was also studied. Total phenolic and flavonoid contents as well as HPLC identification and quantification of protocatechuic acid and rutin were also carried out. The C. chayamansa leaves extract contained 71.3 +/- 1.7 mg gallic acid equivalent/g extract and 42.6 +/- 3.7 mg (+)-catechin equivalent/g extract of total phenols and flavonoids, respectively. Concentrations of 0.242 +/- 0.001 mg/g and 2.00 +/- 0.097 mg/g were found for protocatechuic acid and rutine, respectively. The extract was capable of scavenging DPPH and ABTS(+) radicals in a concentration dependent manner. The extract was not toxic to TA100 and TA98 strains at the concentrations tested; moreover, the extract at a concentration of 1000 microg inhibited 24% and 39% the mutagenicity induced by 4-nitro-O-phenylenediamine and sodium azide, respectively. An acute hypoglycemic effect in diabetic rats was observed. PRACTICAL APPLICATION: C. chayamansa has been proposed as an herbal medicine to treat diabetes; however, the reported results are not conclusive and further studies need to be performed. Despite this fact, chaya leaves can be commercialized as tea in a dried presentation since the dried leaves conserve high polyphenol contents.

PI3K and ERK 1-2 regulate early stages during head regeneration in hydra.

Different signaling systems coordinate and regulate the development of a multicellular organism. In hydra, the canonical Wnt pathway and the signal transduction pathways mediated by PKC and Src regulate early stages of head formation. In this paper, we present evidence for the participation of a third pathway, the PI3K-PKB pathway, involved in this process. The data presented here are consistent with the participation of ERK 1-2 as a point of convergence for the transduction pathways mediated by PKC, Src and PI3K for the regulation of the regeneration of the head in hydra. The specific developmental point regulated by them appears to be the commitment of tissue at the apical end of the regenerate to form the head organizer.

High levels of palmitic acid lead to insulin resistance due to changes in the level of phosphorylation of the insulin receptor and insulin receptor substrate-1.

Insulin resistance is defined as the decrease in the glucose disposal in response to insulin by the target tissues. High concentrations of nonesterified fatty acids (NEFA) in plasma have been implicated with many insulin resistance states. We evaluated several aspects of the insulin resistance induced by palmitic acid in rats and found that after treatment with 0.09 g/kg of palmitic acid there is a delay in the curve of tolerance to glucose. We measured the changes in protein phosphorylation in samples from abdominus rectus muscle and there was a decrease of 64 and 75% in the levels of phosphorylation in tyrosine of the insulin receptor and insulin receptor substrate-1, respectively. This diminution in the tyrosine phosphorylation is consistent with a decrease in the main pathway known to be activated after insulin treatment, the mitogen activated protein kinases (MAPKs). If the animals were treated with inhibitors of PKC, like sphingosine, there was a prevention of the effect of palmitic acid determined at the level of tyrosine phosphorylation. According with this result, we found an increase in the phosphorylations in serine of the insulin receptor after the treatment with palmitate. These results suggest that PKC has a role as negative regulator (by phosphorylation in serine) of the insulin receptors activation in the insulin resistance induced by palmitic acid.