Influence of indole acetic acid on antioxidant levels and enzyme activities of glucose metabolism in rat liver

Abstract

Indole acetic acid (IAA) is an auxin and can be synthesized in animals. This compound is metabolized in vitro by peroxidase, producing reactive oxygen species. The toxic effect of indole acetic acid in leukocytes is associated with peroxidase activities and these processes have been implicated in activation of glucose and glutamine metabolism. However, studies in vitro have shown that IAA, in absence of peroxidase, is an antioxidant almost as high in potency as those of other indolic compounds. The purpose of this study was to investigate the possible involvement of a toxic effect of indole acetic acid in the liver, as evidenced by oxidative stress and enzyme activities of the glucose pathway. The animals received IAA by subcutaneous or gavage administration in a phosphate buffered saline (the control group received only the phosphate buffered saline). The other groups received IAA at concentrations of 1 mg, 18 mg and 40 mg per kg of body mass per day. Treatments with 18 mg and 40 mg IAA decreased the activity of catalase by both subcutaneous (30% and 26%) or gavage administration (19% and 28%), respectively. A similar effect was observed on the activity of glutathione peroxidase of animals exposed to 18 mg and 40 mg IAA: A decrease of 34% and 29%, respectively, for subcutaneous administration and a decrease of 29% and 25%, respectively, for gavage administration. However, in neither source of administration did the acid alter superoxide dismutase, glutathione reductase and myeloperoxidase activities. Another alteration was observed in respect of reduced glutathione content in this organ. The lipid peroxidation level showed a significant decrease with subcutaneous (30%, 29% and 24%) and gavage administration (25%, 26% and 24%) using 1 mg, 18 mg and 40 mg of IAA, respectively compared with the control. The reduced glutathione content and catalase activity in the plasma were not altered by either of the two methods of administration. In addition to these findings, after subcutaneous or gavage administration of IAA, the activities of hepatic enzymes of glucose metabolism were not affected (glucokinase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase and citrate synthase). Evidence is presented herein that IAA did not have a pro-oxidant effect in the liver as deduced from a reduction of catalase and glutathione peroxidase activities, a decrease of lipid peroxidation content and no alteration of the pool of reduced glutathione. The effects of IAA were independent of the way of administration.

Protective action of indole‐3‐acetic acid on induced hepatocarcinoma in mice

“…Recent studies shown that orally or subcutaneous IAA has no toxic action on rats leukocytes measured by analyzing the DNA integrity, membrane integrity, and enzyme activities. [12][13][14] However, the genotoxic carcinogen DEN induced extensive DNA damage 42 in accordance with the present study. Moreover, IAA was partially efficient in providing protection to DENinduction of DNA fragmentation; similarly, guarana has a protective effect against DEN-induced DNA damage in mouse liver.…”

“…11 Recent studies have shown that oral or subcutaneous administration of IAA can promote a possible beneficial effect by increasing the phagocytic capacity of rat neutrophils. 12,13 This auxin administration does not have a deleterious effect on leukocytes and liver of rats 14 and the IAA does not have an effect on metabolic enzyme activities in mice kidneys. 15 The prevention of several diseases by many natural substances has been associated with the antioxidant action of these compounds upon depletion of reactive oxygen species (ROS).…”

Effect of indole‐3‐acetic acid administration by gavage and by subcutaneous injection on rat leukocytes

“…19 Recent studies have shown that subcutaneous IAA promotes an increase in phagocytic capacity, is accompanied by alteration in hydrogen peroxide production in neutrophils, but does not show a pro-oxidant effect in leukocytes 20 or liver. 21 The information above led us to study the effect of IAA administered subcutaneously and by gavage to rats at low doses (equal to or less than 40 mg of IAA per kg of body mass) on neutrophil functions and cell death of neutrophils and lymphocytes. This study was undertaken to investigate the possible utilization of indole acetic acid as a diet supplement for animals.…”

Metabolite of tryptophan promoting changes in EEG signal and the oxidative status of the brain

“…The presence of peroxidase IAA acts as a prooxidant substance and generates oxidative stress by an increased formation of reactive oxygen species (ROS) . However, studies have showed that oral or subcutaneous administration of IAA increased the phagocytic capacity of neutrophil and do not have deleterious effect of rat livers and mice kidneys . Moreover, IAA showed potent antioxidant effects and warned the mice livers against hepatocarcinoma induced by N‐nitrosodietilamina (DEN) .…”