A Combination Therapy of Urolithin A+EGCG Has Stronger Protective Effects than Single Drug Urolithin A in a Humanized Amyloid Beta Knockin Mice for Late-Onset Alzheimer’s Disease

Abstract

In the current study, for the first time, we study mitophagy enhancer urolithin A and a combination of urolithin A+green tea extract EGCG against human Aβ peptide-induced mitochondrial and synaptic, dendritic, inflammatory toxicities and behavioral changes in humanized homozygous amyloid beta knockin (hAbKI) mice of late-onset Alzheimer’s disease (AD). Our findings reveal significantly increased positive effects of urolithin A and a combination treatment of urolithin A+EGCG in hAbKI mice for phenotypic behavioral changes including motor coordination, locomotion/exploratory activity, spatial learning and working memory. mRNA and protein levels of mitochondrial fusion, synaptic, mitophagy and autophagy genes were upregulated, and mitochondrial fission genes are downregulated in urolithin A and combine treatment in hAbKI mice; however, the effect is stronger in combined treatment. Immunofluorescence analysis of hippocampal brain sections shows similar findings of mRNA and protein levels. Mitochondrial dysfunction is significantly reduced in both treatment groups, but a stronger reduction is observed in combined treatment. Dendritic spines and lengths are significantly increased in both treatment groups, but the effect is stronger in combined treatment. The fragmented number of mitochondria is reduced, and mitochondrial length is increased, and mitophagosomal formations are increased in both the groups, but the effect is stronger in the combined treatment. The levels of amyloid beta (Aβ) 40 and Aβ42 are reduced in both treatments, however, the reduction is higher for combined treatment. These observations suggest that urolithin A is protective against human Aβ peptide-induced toxicities; however, combined treatment of urolithin A+EGCG is effective and stronger, indicating that combined therapy is promising to treat late-onset AD patients.

Urolithin A improves Alzheimer’s disease cognition and restores mitophagy and lysosomal functions

“…UA increased muscle strength and physical performance in a 6 min walk test in elderly humans after four months of supplementation [80]. Other studies reported that UA improved motor activity in the rotarod test and increased total distance traveled and average speed in the open field test in young C57BL/6J mice [81] and in 3xTg AD mice [82]. However, we noted that UA decreased the distance travelled by 3xTgAD mice in the open field test (Fig.…”

Relationship between Dietary Polyphenols and Gut Microbiota: New Clues to Improve Cognitive Disorders, Mood Disorders and Circadian Rhythms

“…Ellagic acid regulated intestinal microbiota through increasing Lactobacillus species and decreasing Escherichia coli levels [ 103 ], enhanced the immune response by modulating different signalling pathways and increasing the intestinal mucosal barrier function via activating Zonula occludens-1 and Occludin proteins, which are implicated in the tight junction structure of enterocytes and intestinal permeability [ 104 ]. Following polyphenol treatment, mitochondrial dysfunction and the levels of some neuroinflammatory biomarkers were reduced in mouse brains, and dendritic spines and lengths were significantly increased [ 105 ]. Moreover, in the hippocampus, the Nrf2/HO-1 pathway was activated, and the levels of IL-1β, IL-6 and TNF-α were reduced [ 106 ].…”

Methods to Study Mitochondria: Techniques Used to Study the Effects of Age‐Related Diseases Including Alzheimer's

“…Since the early 21 st century, we have also been able to measure the bioenergetics of mitochondria in cells treated with pharmacological drugs by using a Seahorse XFe96 Flux Analyzer (Gu et al., 2021; Kshirsagar, Sawant, Morton, Reddy, & Reddy, 2021a; Luz, Smith, Rooney, & Meyer, 2015). In our lab, we have used the following pharmacological drugs as mitophagy enhancers: urolithinA, actionin, tomatidine, and nicotinamide riboside (Kshirsagar et al., 2022; Kshirsagar, Sawant, Morton, Reddy, & Reddy, 2021b). There are three main limitations to measuring mitochondrial respiration using the Seahorse bioanalyzer: the cost is high, a single assay can only use four injectable compounds, and drug injection may lead to inaccurate/misleading data by interfering with sensor fluorescence or the plastic plate (Horan, Pichaud, & Ballard, 2012).…”