Glutamine Is a Superior Protector Against Lead-Induced Hepatotoxicity in Rats via Antioxidant, Anti-inflammatory, and Chelating Properties.

Lead acetate-motivated oxidative stress can affect all organ systems, particularly the liver. Glutamine (Gln) has both antioxidant and chelating properties. Therefore, we investigated for the first time the effect of Gln on the biochemical and histopathological alternations in a rat model of lead toxicity. Thirty-two rats were divided into four groups (eight rats in each): untreated normal, lead poisoning, and two similar groups receiving Gln (0.1% in drinking water for 4 weeks). To induce lead poisoning, rats received 50 mg/L lead acetate in drinking water for 4 weeks. Oxidative stress indices (total glutathione, the ratio of reduced glutathione to oxidized glutathione, advanced protein oxidation products, malondialdehyde, and ferric ion reducing power) and inflammatory markers (hepatic nuclear factor-kβ expression, interleukin 1β level, and myeloperoxidase activity) were measured. Furthermore, biochemical markers of hepatotoxicity (alanine transaminase, aspartate transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase, total bilirubin, total protein, albumin, and globulins) were measured. Histopathological examination evaluated lead-induced liver damage. The treatment compensated lead-induced biochemical and histopathological alternations in rat liver. Furthermore, it decreased lead acetate level, the NF-kβ gene expression, oxidative stress, and inflammatory markers. Moreover, the treatment elevated total glutathione and reduced glutathione in the sera and liver homogenates of treated groups (p < 0.001). Glutamine could protect the liver against lead intoxication via antioxidant, anti-inflammatory, and chelating properties. In addition, its downregulating effect on the hepatic NF-kβ signaling pathway confirms its hepatoprotective activity.