Host: The Japanese Pharmacological Society, The Japanese Society of Clinical Pharmacology
Name : WCP2018 (18th World Congress of Basic and Clinical Pharmacology)
Location : Kyoto
Date : July 01, 2018 - July 06, 2018
Background: Interferon alpha (IFN) therapy can cause depressive symptom which may lead to drug discontinuation. It increases the activity of enzymes that shift tryptophan from serotonin synthesis to its kynurenine pathway metabolism which leads to over production of neurotoxic metabolites, such as quinolinic acid. Soybean contains tryptophan amino acid and has proved antidepressant effects. The aim was evaluating if a tryptophan containing diet can prevent IFN induced depression.
Materials and methods: Male albino mice (25 to 30 g) were used. The immobility time was measured in the forced swimming test (FST), a despair based model used to assess certain depression like phenotypes in mice. Animals were forced to swim for 6 min the immobility time was recorded in the last 4 min. IFN 1600000 IU/kg was injected subcutaneously for 6 consecutive days, during the experiment animals were fed with normal mice chow or soybean diets (30, 40, and 50 percent). Separate groups of animals were treated with fluoxetine 20 mg/kg or tryptophan 300 mg/kg intraperitoneally one hour before the test.
Results: Soybean diets decreased the immobility in the FST that was considerable with 50 percent soybean (26.4 sec vs control 142 sec, p<0.001). IFN increased the immobility time in the FST (192 sec), by administrating 50 percent soybean diet simultaneously immobility was reduced to (54 sec) as parallel to the standard drug fluoxetine (68 sec). Tryptophan injection also had similar results to the soybean diet (38 sec). Other soybean diet concentrations were not able to prevent IFN induced depression response after 6 days. Animals' activity that was measured by the locomotor apparatus was normal.
Conclusion: Our findings showed that the soybean diet could prevent IFN induced depression. Since tryptophan administration had similar results the antidepressant effects of soybean maybe related to its tryptophan content. Probably soybean increases the serotonin yield, while preventing IFN to induce kynurenine pathway metabolism in the brain, this interpretation needs further biochemical evaluations. Finally, soybean diet could be considered as a harmless remedy for patients undergoing IFN treatment against cytokine induced depression.
