α-Lipoic Acid Reduces Ceramide Synthesis and Neuroinflammation in the Hypothalamus of Insulin-Resistant Rats, While in the Cerebral Cortex Diminishes the β-Amyloid Accumulation

Figures & data

Figure 1 Effects of α-lipoic acid (ALA) on brain pro-oxidant enzymes [NADPH oxidase (NOX), (A) xanthine oxidase (XO), (B)], antioxidant status [ferric-reducing antioxidant power (FRAP), (C)], and oxidative stress [total thiols, (D) thiobarbituric acid reactive substances (TBARS), (E)] in the hypothalamus and cerebral cortex of rats fed a control (CD) and high-fat diet (HFD). Values are presented as mean ± SD. Three-way ANOVA followed by post hoc Tukey HSD test was performed. *p < 0.05, **p < 0.005, ***p < 0.0005, ****p < 0.0001.

Figure 2 Effects of α-lipoic acid (ALA) on brain sphingolipid metabolism [sphingosine (SFO), (A) sphinganine (SFA), (B) sphingosine-1-phosphate (S1P), (C) sphinganine-1-phosphate (SFA1P), (D) ceramide (CER), (E) neutral sphingomyelinase (nSMase), Figure 2F] in the hypothalamus and cerebral cortex of rats fed a control (CD) and high-fat diet (HFD). Values are presented as mean ± SD. Three-way ANOVA followed by post hoc Tukey HSD test was performed. *p < 0.05, **p < 0.005, ***p < 0.0005, ****p < 0.0001.

Figure 3 Effects of α-lipoic acid (ALA) on brain pro-inflammatory enzymes [myeloperoxidase (MPO), (A) β-glucuronidase (GLU), (B)] and cytokines [interleukin 1 beta (IL-1β), (C) interleukin 6 (IL-6), (D)] in the hypothalamus and cerebral cortex of rats fed a control (CD) and high-fat diet (HFD). Values are presented as mean ± SD. Three-way ANOVA followed by post hoc Tukey HSD test was performed. *p < 0.05, ** < 0.005, ***p < 0.0005, ****p < 0.0001.

Figure 4 Effects of α-lipoic acid (ALA) brain apoptosis [caspase-3 (CAS-3), (A) caspase-8 (CAS-8), (B)] in the hypothalamus and cerebral cortex of rats fed a control (CD) and high-fat diet (HFD). Values are presented as mean ± SD. Three-way ANOVA followed by post hoc Tukey HSD test was performed. *p < 0.05, **p < 0.005, ***p < 0.0005.

Figure 5 Effects of α-lipoic acid (ALA) on brain metalloproteinases [metalloproteinase-2 (MMP-2), (A) metalloproteinase-9 (MMP-9), (B)] and their ratio [MMP-2/MMP-9 ratio (MMP-2/MMP-9), (C)] in the hypothalamus and cerebral cortex of rats fed a control (CD) and high-fat diet (HFD). Values are presented as mean ± SD. Three-way ANOVA followed by post hoc Tukey HSD test was performed. * p < 0.05, ** p < 0.005.

Figure 6 Effects of α-lipoic acid (ALA) on brain β-amyloid level in the hypothalamus and cerebral cortex of rats fed a control (CD) and high-fat diet (HFD). Values are presented as mean ± SD. Three-way ANOVA followed by post hoc Tukey HSD test was performed. **p < 0.005, ***p < 0.0005, ****p < 0.0001.