NovelN-acyl dehydroalanine derivatives as antioxidants: Studies on rat liver lipid peroxidation levels and DPPH free radical scavenging activity

The influence of feeding purple wheat with higher content of anthocyanins on antioxidant status and selected enzyme activity of animals

The influence of anthocyanins on antioxidant activity and liver function was measured in three different animal species (rats, chickens and fish). Purple Konini wheat with the total anthocyanin content (TAC) of 41.70 mg/kg was fed to the experimental groups of animals (rats n = 32; chickens n = 32; fish n = 20). The same numbers of animals (control groups) were fed common wheat with TAC of 24.95 mg/kg. At the end of the experiment, the animals were killed and blood and liver tissues were taken for biochemical analyses. The liver enzyme activities were measured in blood. Antioxidant activity in the liver tissue was measured using the DPPH (2,2-diphenyl-1-picrylhydrazyl test), FR (Free Radicals method), FRAP (Ferric Reducing Antioxidant Power method), and ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) test. Significantly higher values (P< 0.05) measured by the DPPH and FR methods were determined in the liver from rats fed Konini wheat. The chickens fed Konini wheat showed significantly different values using DPPH, FR and ABTS methods. No significant differences were found in hepatopancreases of fish. Animals fed Konini wheat showed a tendency to lower liver enzyme activities in general, but a significant difference was found only in gamma-glutamyl transferase activity in the chicken’s blood. Our results suggest that feeding a higher content of anthocyanins can improve the antioxidant activity and function of the liver tissue.

Synthesis and comparison of antioxidant properties of indole-based melatonin analogue indole amino Acid derivatives

Increased levels of reactive oxygen species attributed to oxidative stress have been found to be responsible for the development of some vital diseases such as cardiovascular, neurodegenerative and autoimmune diseases. Recently, it was observed that melatonin is a highly important antioxidant, and melatonin analogues are under investigation to find out improved antioxidant activity. In this study, 14 melatonin -based analogue indole amino acid and N-protected amino acid derivatives were synthesized and elucidated spectrometrically. To investigate the antioxidant activity of the synthesized compounds and to compare with melatonin, butylhydroxytoluene and vitamin E, lipid peroxidation inhibition and 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activities were tested. The results indicated that the synthesized new indole amino acid derivatives have similar activities to melatonin in 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity assay but more potent activities in lipid peroxidation inhibition assay.

Chronic administration of melatonin reduces cerebral injury biomarkers in SAMP8

Certain effects of melatonin on senescence were investigated. The experimental model used was 10-month-old senescence-accelerated mouse prone 8 (SAMP8). The mice in the experiment were administered melatonin (10 mg/kg) from the age of 1 month. Results showed that chronic administration of melatonin decreased cell loss in the cerebral cortex and reduced oxidative damage in protein and lipids. There are several studies suggesting that the activation of the cdk5/p35 pathway at its cleavage to cdk5/p25 may play a role in hyperphosphorylation of tau during aging and neurodegenerative diseases. Melatonin not only reduced the cerebral aging disturbances, but also prevented tau hyperphosphorylation present in the experimental model used in this study. Melatonin reduced cdk5 expression, as well as the cleavage of p35 to p25. The other tau kinase studied, GSK3beta, showed a reduction in this activity in comparison with SAMP8 nontreated SAMP8. These data indicate that melatonin possesses neuroprotective properties against cerebral damage gated to senescence. Moreover, these data suggest that the cdk5/GSKbeta signaling cascade has a potential role as a target for neurodegenerative diseases related to aging.