Methionine restriction vs CR

[Guest guest]

Hi All, "In summary, the results of the present study strongly support the possibility that the reduced intake of dietary methionine is the dietary factor responsible for the decrease in mitROS generation and oxidative stress and around half of the increase in maximum longevity that take place in [C]R." The below paper is pdf-availed.Caro P, Gómez J, López- M, Sánchez I, Naudí A, Jove M, Pamplona R, Barja G.Forty percent and eighty percent methionine restriction decrease mitochondrial ROS generation and oxidative stress in rat liver.Biogerontology. 2008 Feb 19; [Epub ahead of print]PMID: 18283555AbstractDietary restriction (DR) lowers mitochondrial reactive oxygen species (ROS) generation and oxidative damage and increases maximum longevity in rodents. Protein restriction (PR) or methionine restriction (MetR), but not lipid or carbohydrate restriction, also cause those kinds of changes.

However, previous experiments of MetR were performed only at 80% MetR, and substituting dietary methionine with glutamate in the diet.In order to clarify if MetR can be responsible for the lowered ROS production and oxidative stress induced by standard (40%) DR, Wistar rats were subjected to 40% or 80% MetR without changing other dietary components.It was found that both 40% and 80% MetR decrease mitochondrial ROS generation and percent free radical leak in rat liver mitochondria, similarly to what has been previously observed in 40% PR and 40% DR. The concentration of complexes I and III, apoptosis inducing factor, oxidative damage to mitochondrial DNA, five different markers of protein oxidation, glycoxidation or lipoxidation and fatty acid unsaturation were also lowered.The results show that 40% isocaloric MetR is enough to decrease ROS production and oxidative stress in rat liver. This suggests that the lowered intake of methionine is

responsible for the decrease in oxidative stress observed in DR.Keywords Mitochondria - Caloric restriction - Aging - Oxygen radicals - Longevity - Protein damage - Fatty acids - Respiratory complexes ++++++++++++++++++++++++ Table 4 Fatty acid composition of liver mitochondria from control, 40% and 80% methionine restricted rats.=========================================== Control 40% MetR 80% MetR===========================================14:0 0.41±0.03 0.34±0.04 0.39±0.0316:0 16.36±0.24 16.22±0.26 15.43±0.23a**,b*16:1n-7 0.70±0.04 0.69±0.06 0.43±0.03a***,b***18:0 20.20±0.41 20.06±0.46 22.07±0.43a**,b**18:1n-9 7.78±0.30 7.61±0.31 6.78±0.35a*18:2n-6 15.85±0.23 17.82±0.45a** 19.84±0.48a***,b**18:3n-3 0.25±0.02 0.17±0.01a** 0.20±0.01a*20:3n-6 0.18±0.01 0.19±0.01 0.14±0.007b*20:4n-6 32.07±0.17 30.38±0.15a***

27.73±0.46a***,b***22:4n-6 1.55±0.10 1.71±0.14 1.99±0.13a*22:5n-6 0.45±0.02 0.50±0.02 0.50±0.0322:5n-3 0.32±0.02 0.44±0.02a** 0.37±0.0222:6n-3 3.82±0.10 3.82±0.14 4.09±0.08ACL 18.53±0.01 18.51±0.01 18.50±0.01SFA 36.98±0.51 36.63±0.62 37.90±0.55UFA 63.01±0.51 63.36±0.62 62.09±0.55MUFA 8.49±0.31 8.31±0.36 7.21±0.38a*,b*PUFA 54.51±0.25 55.05±0.42 54.88±0.53PUFAn-6 50.11±0.25 50.62±0.49 50.21±0.52PUFAn-3 4.40±0.10 4.43±0.15 4.66±0.08DBI 202.85±1.26 201.12±1.15 195.77±1.61a**,b**PI 186.71±1.14 183.43±1.22 177.61±1.83a***,b**=========================================== Values are mean±SE from 10 different animals and are expressed as mol % ACL acyl chain length, SFA saturated fatty acids, UFA unsaturated fatty acids, MUFA monounsaturated fatty acids, PUFA polyunsaturated fatty acids, DBI double bond index, PI peroxidizability index a Represents significant differences

compared to controls, brepresents significant differences between 40% and 80% MetR groups; * P < 0.05, ** P < 0.01, *** P < 0.001

Be a better friend, newshound, and know-it-all with Mobile. Try it now.