Anxiolytic effects of γ-oryzanol in chronically- stressed mice are related to monoamine levels in the brain.
Study Goal
The researchers aimed to investigate the anxiolytic effect of Gamma Oryzanol (GORZ) during chronic restraint stress and explore its potential molecular mechanisms.
Results Summary
0.5% GORZ partially prevented stress-induced weight loss, improved behavioral parameters in stress tests, and enhanced levels of certain neurotransmitters in the amygdala, suggesting anxiolytic effects under chronic stress.
Population
5-week-old male ICR mice
Effective Dosage
0.5% in standard diet
Duration
20 consecutive days
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
0.5% γ-oryzanol (GORZ) in the mouse standard diet | decrease | stress-induced reduction of body weight gain | male ICR mice subjected to chronic restraint stress treatment (CRST) | - | partially blocked | #1 |
0.5% γ-oryzanol (GORZ) in the mouse standard diet | increase | main behavioral parameters (in OFT and EPM tests) | male ICR mice subjected to chronic restraint stress treatment (CRST) | - | significantly improve | #2 |
chronic restraint stress treatment (CRST) | decrease | body weights | male ICR mice | - | significantly lower | #3 |
chronic restraint stress treatment (CRST) | increase | serum corticosterone (CORT) levels | male ICR mice | - | significant increase | #4 |
0.5% γ-oryzanol (GORZ) in the mouse standard diet | no change | CRST-induced increase in serum CORT levels | male ICR mice subjected to chronic restraint stress treatment (CRST) | - | almost unaffected | #5 |
0.5% γ-oryzanol (GORZ) in the mouse standard diet | increase | 5-HIAA levels in the amygdala | male ICR mice after chronic restraint stress treatment (CRST) | - | enhancement | #6 |
0.5% γ-oryzanol (GORZ) in the mouse standard diet | increase | NE levels in the amygdala | male ICR mice after chronic restraint stress treatment (CRST) | - | enhancement | #7 |
AIMS: The present study was aimed to investigate the anxiolytic effect of γ-oryzanol (GORZ) during chronic restraint stress treatment (CRST), which is a well-documented model of stress-related disorders, like anxiety, and its potential molecular mechanisms. MATERIALS AND METHODS: In this experiment, 5-week-old male ICR mice were used and the concentration of GORZ was fixed at 0.5% in the mouse standard diet (14% casein, AIN 93 M). Mice were immobilized daily for 3 h from ZT 2.5 to 5.5 (ZT0 was designated as light-on time) for 20 consecutive days, followed by behavioral testing, including the open field test (OFT) and elevated plus maze (EPM) test. The concentration of serum corticosterone (CORT) was measured. In addition, the expression of central monoamine neurotransmitters with their metabolites in the hippocampus, cerebral cortex, and amygdala of the brain were examined. KEY FINDINGS: 0.5% GORZ partially blocked stress-induced reduction of body weight gain while stressed mice had significantly lower body weights during the entire experimental period. Further, 0.5% GORZ treatment could significantly improve the main behavioral parameters even in CRST situations. The significant increase in serum CORT levels indicated CRST-induced stress, which was almost unaffected by 0.5% GORZ treatment. Moreover, 0.5% GORZ also supported the anxiolytic mechanism with enhancement of 5-HIAA and NE levels in the amygdala of brain after CRST. SIGNIFICANCE: Taken together, our studies suggested that 0.5% GORZ is a potential therapeutic drug candidate against anxiety under chronic stress conditions.