A potential application of dietary soy protein, aminoguanidine and L‐carnitine as anti‐oxidants in an animal model of simulated microgravity.

Abstract

The objective of the current study was to determine the effect of antioxidants in rats under simulated microgravity induced by hind‐limb suspension (HLS). Methods: A NASA validated model was used with five groups of rats. L‐carnitine and aminoguanidine were used in the drinking water in rats on Purina chow. A separate group was maintained on a soybean diet. Group 1 was hindlimb loaded control; Group 2 was hindlimb unloaded control, Group 3 was hindlimb unloaded on L‐carnitine (LC), Group 4 was hindlimb unloaded on aminoguanidine (AG), and Group 5 was hindlimb unloaded on 9.6% soybean protein diet. The animals were primed and suspended for fourteen days (total 21 days). At term, the animals were sacrificed. Tissues from brain, heart, lung, liver, stomach, pancreas, small intestine, kidney and testes were harvested. Harvested tissues were extracted for measurements of malondialdehyde (MDA) and glutathione levels. Results: MDA levels in tissues were elevated by suspension (p < 0.05). MDA levels were lower (p< 0.05) in the animals on LC, AG, and the soybean diet, when compared to the hindlimb unloaded control group. Glutathione levels varied between the tissues. Conclusions: Results suggest that LC, AG, and a soybean diet decrease peroxide formation, while tail suspension increases it. Data indicate that LC, AG, and a soybean diet may have a protective role in the reduction of lipid peroxidation damage produced by stress.