Fig 1.
a–Scheme: The predator exposure/psychosocial stress model includes two cat exposures over a 45 and 31 day period, combined with daily cage cohort changes. The experimental animals were fed with 2% blueberry diet 15 days ahead of the cat exposure (Total 45 days–blueberry diet pre feeding group) and blueberry diet post feeding group along with first cat exposure (Total 31 days). The Anxiety levels were measured at the baseline and at the end of the stress schedule via Elevated plus maze. b—The role of proinflammatory cytokines and reactive oxygen species in the progression of PTSD.
Fig 2.
a and b: Reactive oxygen species in the prefrontal cortex and Hippocampus: The total reactive oxygen species were significantly elevated in the PTSD group. The elevation was normalized to control group levels with blueberry diet. Statistical analysis was performed using one way ANOVA with repeated measurements followed by Tukey’s multiple comparison test. *p<0.05 Control Vs PTSD, #p<0.05 PTSD Vs BB = PTSD, and $p<0.05 PTSD Vs PTSD + BB. All data are presented as mean ± SEM. P<0.05 compared to control.
Fig 3.
Elevated plus-maze performance: The PTSD group spent significantly less time in the open arms when compared to closed arms, as demonstrated by their reluctance to spend time in the open arms of the elevated plus maze.
There were no differences in the total arm entries between groups. Statistical analysis was performed using one way ANOVA with repeated measurements followed by Tukey’s multiple comparison test. *p<0.05 Control Vs PTSD, #p<0.05 PTSD Vs BB = PTSD, and $p<0.05 PTSD Vs PTSD + BB. All data are presented as mean ± SEM. P<0.05 compared to control.
Fig 4.
a and b: Neurotransmitters quantification: In the PFC and Hippocampus region the NE levels were significantly higher in the PTSD group Vs controls (p<0.05). On the contrary the monoamine 5-HT levels were significantly lower in the PTSD group Vs control. Blueberry enriched diet lowered NE levels and increased 5-HT levels similar as the untreated controls. Statistical analysis was performed using one way ANOVA with repeated measurements followed by Tukey’s multiple comparison test. *p<0.05 Control Vs PTSD, #p<0.05 PTSD Vs BB = PTSD, and $p<0.05 PTSD Vs PTSD + BB. All data are presented as mean ± SEM. P<0.05 compared to control. c and d: Rate-limiting enzymes tyrosine hydroxylase (catecholamines) and tryptophan hydroxylase (5-HT) post stress: Tyrosine hydroxylase elevation in the PFC and hippocampus corroborated the findings of elevated NE levels. The elevation was normalized to control group levels with blueberry diet. The tryptophan hydroxylase levels were downregulated in the PFC and hippocampus. The downregulation was upregulated with blueberry diet. Statistical analysis was performed using one way ANOVA with repeated measurements followed by Tukey’s multiple comparison test. *p<0.05 Control Vs PTSD, #p<0.05 PTSD Vs BB = PTSD, and $p<0.05 PTSD Vs PTSD + BB. All data are presented as mean ± SEM. P<0.05 compared to control.
Fig 5.
a: Pro and anti-inflammatory Marker Protein: The prefrontal cortex of the PTSD group showed elevated levels (p<0.05) of IL-1b, IL18, TLR4 and HMGB1. In contrast, the level of anti-inflammatory protein IL-4 were lower (p < 0.05) in the PTSD group. Blueberry enriched diet shows the significant reduction in the levels of proinflammatory cytokines (IL-1b, IL-18) in addition to TLR4 and HMGB1. Statistical analysis was performed using one way ANOVA with repeated measurements followed by Tukey’s multiple comparison test. *p<0.05 Control Vs PTSD, #p<0.05 PTSD Vs BB = PTSD, and $p<0.05 PTSD Vs PTSD + BB. All data are presented as mean ± SEM. P<0.05 compared to control. b: Pro and anti-inflammatory Marker Protein: The Hippocampus of the PTSD group showed elevated levels (p<0.05) of IL-1b, IL18, TLR4 and HMGB1. In contrast, the level of anti-inflammatory protein IL-4 were lower (p < 0.05) in the PTSD group. Blueberry enriched diet shows the significant reduction in the levels of proinflammatory cytokines (IL-1b, IL-18) in addition to TLR4 and HMGB1. Statistical analysis was performed using one way ANOVA with repeated measurements followed by Tukey’s multiple comparison test. *p<0.05 Control Vs PTSD, #p<0.05 PTSD Vs BB = PTSD, and $p<0.05 PTSD Vs PTSD + BB. All data are presented as mean ± SEM. P<0.05 compared to control.
Fig 6.
a: RT-PCR mRNA: The prefrontal cortex region of the PTSD group showed elevated levels (p<0.05) of IL-1b, IL-18, TLR4 and HMGB1. In contrast, the level of anti-inflammatory protein IL-4 were lower (p<0.05) in the PTSD group. Blueberry enriched diet shows the significant reduction in the levels of inflammatory markers. Statistical analysis was performed using one way ANOVA with repeated measurements followed by Tukey’s multiple comparison test. *p<0.05 Control Vs PTSD, #p<0.05 PTSD Vs BB = PTSD, and $p<0.05 PTSD Vs PTSD + BB. All data are presented as mean ± SEM. P<0.05 compared to control. b: RT-PCR mRNA: The Hippocampus region of the PTSD group showed elevated levels (p<0.05) of IL-1b, IL-18, TLR4 and HMGB1. In contrast, the level of anti-inflammatory protein IL-4 were lower (p<0.05) in the PTSD group. Blueberry enriched diet shows the significant reduction in the levels of inflammatory markers. Statistical analysis was performed using one way ANOVA with repeated measurements followed by Tukey’s multiple comparison test. *p<0.05 Control Vs PTSD, #p<0.05 PTSD Vs BB = PTSD, and $p<0.05 PTSD Vs PTSD + BB. All data are presented as mean ± SEM. P<0.05 compared to control.