Dietary Iron Concentration May Influence Aging Process by Altering Oxidative Stress in Tissues of Adult Rats

Abstract

Iron is an essential element. However, in its free form, iron participates in redox-reactions, leading to the production of free radicals that increase oxidative stress and the risk of damaging processes. Living organisms have an efficient mechanism that regulates iron absorption according to their iron content to protect against oxidative damage. The effects of restricted and enriched-iron diets on oxidative stress and aging biomarkers were investigated. Adult Wistar rats were fed diets containing 10, 35 or 350 mg/kg iron (adult restricted-iron, adult control-iron and adult enriched-iron groups, respectively) for 78 days. Rats aged two months were included as a young control group. Young control group showed higher hemoglobin and hematocrit values, lower levels of iron and lower levels of MDA or carbonyl in the major studied tissues than the adult control group. Restricted-iron diet reduced iron concentrations in skeletal muscle and oxidative damage in the majority of tissues and also increased weight loss. Enriched-iron diet increased hematocrit values, serum iron, gamma-glutamyl transferase, iron concentrations and oxidative stress in the majority of tissues. As expected, young rats showed higher mRNA levels of heart and hepatic L-Ferritin (Ftl) and kidneys SMP30 as well as lower mRNA levels of hepatic Hamp and interleukin-1 beta (Il1b) and also lower levels of liver protein ferritin. Restricted-iron adult rats showed an increase in heart Ftl mRNA and the enriched-iron adult rats showed an increase in liver nuclear factor erythroid derived 2 like 2 (Nfe2l2) and Il1b mRNAs and in gut divalent metal transporter-1 mRNA (Slc11a2) relative to the control adult group. These results suggest that iron supplementation in adult rats may accelerate aging process by increasing oxidative stress while iron restriction may retards it. However, iron restriction may also impair other physiological processes that are not associated with aging.

Effects of long-term exposures to low iron and branched-chain amino acid containing diets on aging skeletal muscle of Fisher 344 × Brown Norway rats

“…In particular, aged animals fed 2×BCAA exhibited a lower iron status in skeletal muscle. Similar to previous findings (D’Antona et al 2010; Arruda et al 2013), LI and 2×BCAA diets did not alter body mass of old rats, and muscle mass values were not changed by the dietary treatments.…”

“…Based on previous reports that LI (Otogawa et al 2008; Naito et al 2011; Arruda et al 2013) and BCAA (Iwasa et al 2013; Korenaga et al 2015) diets decrease tissue iron status in various iron overload conditions, we examined whether LI and/or 2×BCAA diets would alter the muscle iron status. The main effect of 2×BCAA diets on non-heme iron concentration level of the aged plantaris approached statistical significance ( P = 0.059; Fig.…”

“…The LI diets minimized background iron (≤ 6 mg iron/kg; ~6 ppm) by the use of microcrystalline cellulose and an iron deficient mineral mix. Since adult rats require ~35 mg iron/kg diet (i.e., 35 ppm) (Reeves et al 1993; Arruda et al 2013) the regular iron diets contained 36–46 mg iron/kg. Total body mass and food consumption were measured weekly.…”

“…Previous studies showed the effectiveness of LI-containing diets in attenuating iron accumulation in liver (Otogawa et al 2008) and heart (Naito et al 2011) disease models that feature the pathological condition of iron overload. Additionally, recent work showed that a long-term (i.e., 12 weeks) LI diet reduced iron accumulation in skeletal muscle of adult rats (Arruda et al 2013). Thus, prolonged administration of a LI-containing diet could be an effective strategy to reduce skeletal muscle iron levels and attenuate sarcopenia.…”

Magnetic Properties of Iron Oxides in the Human Globus pallidus

“…Accumulation of iron in basal ganglia is probably associated with neuronal death leading to Alzheimer disease, Parkinson disease, epilepsy, Huntington disease, dementia with Lewy bodies, and multiple sclerosis [4][5][6][7][8]. It was reported that iron participates in redox reactions, and catalyzes the formation of reactive oxygen species responsible for oxidative stress and damaging processes [9][10][11].…”