Fermented Protaetia brevitarsis Larvae Improves Neurotoxicity in Chronic Ethanol-Induced-Dementia Mice via Suppressing AKT and NF-κB Signaling Pathway

Abstract

This study was investigated to examine the neuroprotective effect of fermented Protaetia brevitarsis larvae (FPB) in ethanol-induced-dementia mice. Consumption of FPB by mice resulted in improved memory dysfunction in the Y-maze, passive avoidance, and Morris water maze tests. FPB significantly decreased oxidative stress by regulating levels of malondialdehyde (MDA), superoxide dismutase (SOD), and reduced glutathione (GSH) in brain tissues. In addition, FPB restored cerebral mitochondrial dysfunction by modulating levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and ATP. In addition, FPB enhanced the cholinergic system via the regulation of acetylcholine (ACh) content, acetylcholinesterase (AChE) activity, and expressions of AChE and choline acetyltransferase (ChAT) in brain tissues. FPB ameliorated neuronal apoptosis through modulation of the protein kinase B (AKT)/B-cell lymphoma (BCL)-2 signaling pathway. Also, FPB improved inflammation response by down-regulating the toll-like receptor (TLR)-4/nuclear factor (NF)-κB pathway. Additionally, FPB ameliorated synaptic plasticity via the increase of the expressions of synaptophysin (SYP), postsynaptic density protein (PSD)-95, and growth-associated protein (GAP)-43. Treatment with FPB also reinforced the blood-brain barrier by increasing tight junctions including zonula occludens (ZO)-1, occludin, and claudin-1. In conclusion, these results show that FPB can improve cognitive impairment via AKT/NF-κB pathways in ethanol-induced-dementia mice.

Keywords: alcoholic dementia; cognitive function; edible insects; neuroinflammation; synaptic plasticity.

Figure 1

Cytoprotective effect of fermented Protaetia brevitarsis larvae (FPB) in ethanol and H₂O₂-induced cell viability (a,b) and oxidative stress level (c,d) in HT22 cells. Data were represented as mean ± SD (n = 5). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).

Figure 2

Effect of fermented Protaetia brevitarsis larvae (FPB) on behavioral disorder in ethanol-induced-dementia mice. Number of arm entries (a), alternation behavior (b), and 3D image of path tracking (c) in Y-maze test. Latency during habituation (d) and step-through latency (e) in passive avoidance test. Hidden platform test (f), probe test (g), and swimming pattern visualization image on probe test (h) in Morris water maze test. Data were represented as mean ± SD (n = 7). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).

Figure 3

Effect of fermented Protaetia brevitarsis larvae (FPB) on antioxidant parameters in ethanol-induced-dementia mice. Malondialdehyde (MDA) production (a), reduced glutathione (GSH) (b), and superoxide dismutase (SOD) level (c) in brain tissues. Data were represented as mean ± SD (n = 5). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).

Figure 4

Effect of fermented Protaetia brevitarsis larvae (FPB) on cholinergic system in ethanol-induced-dementia mice. ACh content (a) and AChE activity (b) in brain tissues. Western blot band images (c) and the expression levels of AChE (d) and ChAT (e) in brain tissues. Data were represented as mean ± SD (ex-vivo, n = 5; Western blot, n = 3). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).

Figure 5

Effect of fermented Protaetia brevitarsis larvae (FPB) on mitochondrial function in ethanol-induced-dementia mice. Mitochondrial reactive oxygen species (ROS) production (a), mitochondrial membrane potential (MMP) (b), and mitochondrial ATP content (c) in brain tissues. Data were represented as mean ± SD (n = 5). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).

Figure 6

Effect of fermented Protaetia brevitarsis larvae (FPB) on neurocytotoxicity in ethanol-induced-dementia mice. Western blot band images (a), relative expression levels of p-AKT (b), p-GSK-3β (c), BCL-2 (d), BAX (e), BAX/BCL-2 ratio (f), and Caspase-3 (g) in brain tissues. Data were represented as mean ± SD (n = 3). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).

Figure 7

Effect of fermented Protaetia brevitarsis larvae (FPB) on neuroinflammation in ethanol-induced-dementia mice. Western blot band images (a), relative expression levels of TLR-4 (b), p-IκB-α (c), p-NF-κB (d), TNF-α (e), and IL-1β (f) in brain tissues. Data were represented as mean ± SD (n = 3). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).

Figure 8

Effect of fermented Protaetia brevitarsis larvae (FPB) on synaptic protein markers in ethanol-induced-dementia mice. Western blot band images (a), relative expression levels of SYP (b), GAP-43 (c), and PSD-95 (d) in brain tissues. Data were represented as mean ± SD (n = 3). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).

Figure 9

Effect of fermented Protaetia brevitarsis larvae (FPB) on blood–brain barrier (BBB) function in ethanol-induced-dementia mice. Western blot band images (a), relative expression levels of ZO-1 (b), occludin (c), and claudin-1 (d) in brain tissues. Data were represented as mean ± SD (n = 3). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).

Figure 9

Effect of fermented Protaetia brevitarsis larvae (FPB) on blood–brain barrier (BBB) function in ethanol-induced-dementia mice. Western blot band images (a), relative expression levels of ZO-1 (b), occludin (c), and claudin-1 (d) in brain tissues. Data were represented as mean ± SD (n = 3). Values with different superscripts on the bar graph indicate statistical differences (p < 0.05).