Probiotic Supplementation Facilitates Recovery of 6-OHDA-Induced Motor Deficit via Improving Mitochondrial Function and Energy Metabolism

Abstract

Parkinson's disease (PD) is a neurodegenerative disease associated with progressive impairment of motor and non-motor functions in aging people. Overwhelming evidence indicate that mitochondrial dysfunction is a central factor in PD pathophysiology, which impairs energy metabolism. While, several other studies have shown probiotic supplementations to improve host energy metabolism, alleviate the disease progression, prevent gut microbiota dysbiosis and alter commensal bacterial metabolites. But, whether probiotic and/or prebiotic supplementation can affect energy metabolism and cause the impediment of PD progression remains poorly characterized. Therefore, we investigated 8-weeks supplementation effects of probiotic [Lactobacillus salivarius subsp. salicinius AP-32 (AP-32)], residual medium (RM) obtained from the AP-32 culture medium, and combination of AP-32 and RM (A-RM) on unilateral 6-hydroxydopamine (6-OHDA)-induced PD rats. We found that AP-32, RM and A-RM supplementation induced neuroprotective effects on dopaminergic neurons along with improved motor functions in PD rats. These effects were accompanied by significant increases in mitochondrial activities in the brain and muscle, antioxidative enzymes level in serum, and altered SCFAs profile in fecal samples. Importantly, the AP-32 supplement restored muscle mass along with improved motor function in PD rats, and produced the best results among the supplements. Our results demonstrate that probiotic AP-32 and A-RM supplementations can recover energy metabolism via increasing SCFAs producing and mitochondria function. This restoring of mitochondrial function in the brain and muscles with improved energy metabolism might additionally be potentiated by ROS suppression by the elevated generation of antioxidants, and which finally leads to facilitated recovery of 6-OHDA-induced motor deficit. Taken together, this work demonstrates that probiotic AP-32 supplementation could be a potential candidate for alternate treatment strategy to avert PD progression.

Keywords: 6-hydroxydopamine; Lactobacillus salivarius AP-32; Parkinson’s disease; energy metabolism; mitochondrial function; prebiotic; probiotic.

FIGURE 1

Timeline of the study.

FIGURE 2

Supplementation of AP-32, RM, and A-RM rescued the 6-OHDA-mediated reduction of dopaminergic neurons in the striatum and substantia nigra pars compacta (SNc) after 8-weeks of supplementations. (A) A representative of the immunohistochemical staining for TH (dopaminergic neuron marker) in the striatum. (B) Quantitative analysis of the number of TH-positive cells in the striatum. (C) A representative of the immunohistochemical staining for TH in SNc. (D) Quantitative analysis of the number of TH-positive cells in the SNc. The intensity of the lesioned side was standardized with the non-lesioned side and reported as mean ± SEM (n = 5 rats/group). #p < 0.05 PD group compared to NC group. *p < 0.05 L, AP-32, RM, and A-RM groups compared to PD group. Data were evaluated by one-way ANOVA with Tukey’s post hoc test.

FIGURE 3

Dynamic parameters for gait analysis in 6-OHDA-induced PD rats. (A) Speed started from entering until leaving the walkway. (B) Stride length. (C) Stride frequency. (D) Stance time. (E) Section from original footprints recorded after 8-weeks supplementations; pink, front left; blue, front right; green, hind left; red, hind right. (F) Duty factor. (G) Left pair lag. (H) Left pair gap. (I) Right pair lag. (J) Right pair gap. (K) Intensity sum. All data are expressed as mean ± SEM (n = 5 rats/group). ^#p < 0.05 PD group compared to NC group. *p < 0.05 L, AP-32, RM, and A-RM groups compared to PD group. Data were evaluated by one-way ANOVA with Tukey’s post hoc test.

FIGURE 4

The effect of AP-32, RM, and A-RM on mitochondrial function in the brain and soleus muscle after 8-weeks of supplementation. Mitochondrial function was evaluated by basal mitochondria respiration, oxygen consumption rate (OCR), and basal glycolysis rate, and basal extracellular acidification flux (ECAR). (A,B) The mitochondrial activates in the brain, including striatum and SNc. (C,D) The mitochondrial actives in the soleus muscle. All data are expressed as mean ± SEM (n = 5 rats/group). #p < 0.05 PD group compared to NC group. *p < 0.05 L, AP-32, RM, and A-RM groups compared to PD group. Data were evaluated by one-way ANOVA with Tukey’s post hoc test.

FIGURE 5

Body composition of rats after 8 weeks of treatments. Body composition was evaluated by Dual-Energy X-Ray Absorptiometry (DXA), which includes (A) fat mass, (B) muscle mass, and (C) bone mineral density. All data are expressed as mean ± SEM (n = 5 rats/group). *p < 0.05 compared to PD group. Data were evaluated by one-way ANOVA with Tukey’s post hoc test. ^#p < 0.05 PD group compared to NC group.

FIGURE 6

The effect of AP-32, RM, and ARM on antioxidative enzyme activities in serum. (A) Glutathione peroxidase (GPx) activity, (B) superoxide dismutase (SOD) activity. Data are expressed as mean ± SEM (n = 5 rats/group). #p < 0.05 PD group compared to NC group. *p < 0.05 L, AP-32, RM, and A-RM groups compared to PD group. All data were evaluated by one-way ANOVA with Tukey’s post hoc test.

FIGURE 7

Potential neurorestoration molecular pathway of probiotic in facilitating recovery of motor deficit in unilateral 6-OHDA-induced Parkinson’s disease.