Anti-senescence Effect Of Natural Active Ingredients A Tetraeptie From Maize (TPM)

Oxidative stress represents an imbalance between the production of reactive oxygen species (ROS) and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. Disturbances in the normal redox state of tissues can cause toxic effects through the production of peroxides and free radicals that damage the components of the cell, including proteins, lipids, and DNA.Extensive studies suggest that ROS, byproducts of cellular respiration, play a role in normal aging by causing random deleterious oxidative damage to a variety of tissue. Resistance to ROS due to high activities of ROS-detoxifying enzymes and/or low intrinsic ROS-production levels characterize commonly long-lived C. elegans mutants and these findings are taken to substantiate the free radical theory of aging. Longevity genes also mediate increased resistance to oxidative stress; long-lived dauer mutants show increased resistance to oxidative stress and up-regulation of antioxidant genes.Maize is a plant whose food value and wide variety of uses make it one of the most important crop grown in the world. With the development of science and technology, as well as the need of using food for health promotion, the understanding of the significance of corn nutrition had constantly advanced for the past century. A tetrapeptide from maize (TPM) is a bioactive peptide. It was prepared via protease hydrolysis of zein catalyzed by alcalase, an alkaline protease, followed by isolation and purification.In this study, we investigated the antiaging effects of TPM in C. elegans and found that TPM could significantly improve the longevity of C. elegans under stress conditions. Our results suggests:In vitro the free radical-scavenging effects of TPM were measured by Pyrogallol self-oxidation, Fenton's reaction and ABTS assay. The results show that TPM has a strong free radical-scavenging effect.In vivo:1. Stress resistance assay To evaluate the potential longevity-extending effect of TPM on wild-type C. elegans N2 under oxidative stress, the worms that had just reached adulthood were pretreated with various concentration of TPM. The results show TPM can extend the lifespan of Caenorhabditis elegans (C. elegans) under heat and oxidative stress.2. Measurement of intracellular ROS in C. elegans Intracellular ROS in C. elegans were measured using molecular probe H2DCF-DA. TPM was also demonstrated to have ROS scavenging ability in C. elegans3. SOD-3∷GFP expression in transgenic C. elegans CF1553 TPM can up-regulate SOD-3∷GFP expression in transgenic C. elegans CF1553.4. the expression of heat shock protein HSP-16.2 in transgenic C. elegans CL2070 TPM can up-regulate the expression of heat shock protein HSP-16.2 in transgenic C. elegans CL20705. Nile red staining of stored fat Nile red staining of stored fat was performed according to Ashrafi et al. (2003). The results show TPM can decrease the fat accumulation in C. elegans.6. Quantitative real-time PCRThe results suggested that TPM might improve the stress resistance of C. elegans and extended life expectancy of the worms through regulating above aging-related genes, such as daf-2,daf-16,sod-3,hsp-16.2,skn-1,ctl-1,ctl- 2These interesting findings highlight the potential of TPM to extend the human average life expectancy by providing protection against environmental stress.