{"id":151103,"date":"2025-11-24T23:54:08","date_gmt":"2025-11-24T23:54:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/151103\/"},"modified":"2025-11-24T23:54:08","modified_gmt":"2025-11-24T23:54:08","slug":"arginine-slows-amyloid-buildup-and-improves-brain-outcomes-in-alzheimers-disease-models","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/151103\/","title":{"rendered":"Arginine slows amyloid buildup and improves brain outcomes in Alzheimer\u2019s disease models"},"content":{"rendered":"

New preclinical evidence shows that oral arginine reduces toxic amyloid structures and eases behavioral impairments in Alzheimer\u2019s models, highlighting a potential therapeutic path that now requires careful human dose and safety evaluation.<\/p>\n

\"Study:<\/a><\/p>\n

Study: Oral administration of arginine suppresses A\u03b2 pathology in animal models of Alzheimer’s disease<\/a>. Image Credit: Kateryna Kon \/ Shutterstock<\/p>\n

A recent study published in the journal\u00a0Neurochemistry International<\/a> showed that arginine suppresses amyloid beta (A\u03b2) pathology in preclinical Alzheimer\u2019s disease (AD) models. AD is the most common dementia, affecting more than 50 million individuals worldwide. The aggregation of A\u03b2 peptides into fibrils and oligomers is likely the upstream event in the pathogenesis of AD. While various therapies have been developed targeting A\u03b2, they have limited efficacy<\/a>, adverse effects, and high costs. As such, safe and cost-effective orally administered therapeutic approaches to inhibit A\u03b2 aggregation are needed.<\/p>\n

Rationale for Testing Arginine as an Anti-Aggregation Agent<\/p>\n

Previously, the authors showed that arginine suppresses the aggregation of polyglutamine (PolyQ) proteins, exerting therapeutic effects in preclinical models of PolyQ diseases. Moreover, oral arginine administration was found to improve patients with spinocerebellar ataxia type 6, a PolyQ disease. Given that arginine is a chaperone that inhibits protein misfolding and aggregation, the authors hypothesized that it might suppress the aggregation of A\u03b2.<\/p>\n

In Vitro Assays Demonstrate Strong Inhibition of A\u03b2 Aggregation<\/p>\n

In the present study, researchers investigated whether arginine suppresses the aggregation of A\u03b2 in preclinical models of AD. First, they examined the suppression of A\u03b2 aggregation in vitro and incubated A\u03b242 peptides in the presence of varying concentrations of arginine. The aggregation of A\u03b242 peptides was determined by Thioflavin T (ThT) fluorescence intensity.<\/p>\n

The team observed that co-incubation of\u00a0A\u03b242 and arginine substantially reduced ThT fluorescence intensity in a dose-dependent manner, decreasing A\u03b242 aggregation by 80% at 1 mM arginine. Electron microscopy showed that fibrils were shortened, and biochemical analyses indicated reduced insoluble A\u03b242 fractions with unchanged soluble A\u03b242 levels, consistent with reduced fibrillar aggregation.<\/p>\n

\"Arginine<\/p>\n

Arginine suppresses A\u03b242 aggregation\u00a0in vitro. (A) Effect of arginine on A\u03b242 aggregation\u00a0in vitro. The incubation of A\u03b242 peptide (5\u00a0\u03bcM) at 37\u00a0\u00b0C resulted in an increase in Thioflavin T (ThT) fluorescence after a short lag phase, which eventually reached a plateau. (B) Bar graph showing the ratio of A\u03b242 aggregation in the presence of arginine at 24\u00a0h. (C) EM images of A\u03b242 amyloid fibrils. Scale bars, 100\u00a0nm (left images) and 40\u00a0nm (right images). The panel on the right is a magnified image of the boxed region in the left panel. Statistical analysis in (B) was performed to assess differences from the control group (A\u03b242 without arginine) by one-way ANOVA followed by the Dunnett’s multiple comparisons test. \u2217\u2217p\u00a0<\u00a00.01, \u2217\u2217\u2217p\u00a0<\u00a00.001, \u2217\u2217\u2217\u2217p\u00a0<\u00a00.0001.<\/p>\n

Arginine Reduces Amyloid Deposition in Drosophila AD Models<\/p>\n

Next, the researchers examined in vivo suppression of A\u03b2 aggregation in a Drosophila AD model carrying the A\u03b242 transgene with the E22G Arctic mutation<\/a> (A\u03b242arc). A\u03b242arc expression in the compound eyes led to abnormal deposition in larval eye discs and shrinkage of adult eyes due to A\u03b2 toxicity. However, oral arginine administration substantially decreased A\u03b242 deposition and suppressed eye shrinkage in a dose-dependent manner.<\/p>\n

Mouse Studies Show Reduced Amyloid Deposition and Plaque Burden<\/p>\n

The team further evaluated arginine in App knock-in mice carrying Arctic, Beyreuther, or Iberian, and Swedish mutations (AppNL-G-F mice), which develop age-dependent A\u03b2 deposition and behavioral abnormalities. The mice received 6% arginine orally from 5 weeks of age. Body weight did not differ between treated AppNL-G-F, untreated AppNL-G-F, or wildtype mice.<\/p>\n

At six months, immunohistochemistry showed reduced A\u03b2 deposition throughout the brain in arginine-treated AppNL-G-F mice. Quantitative analyses demonstrated fewer and smaller plaques in both the hippocampus and cortex. At nine months, arginine-treated mice showed only a weak overall reduction in hippocampal plaque area but maintained markedly fewer dense-core plaques, suggesting delayed or suppressed A\u03b2 aggregation.<\/p>\n

Behavioral Improvements in Y-Maze Performance<\/p>\n

AppNL-G-F mice typically demonstrate behavioral abnormalities in the Y-maze test, including fewer arm entries and reduced total distance traveled. These deficits appeared at both six and nine months of age. Arginine-treated AppNL-G-F mice exhibited substantial improvements in arm entries and total distance at nine months, with only mild improvement seen at six months. The authors noted large variability in Y-maze data, which may obscure early treatment effects.<\/p>\n

Anti-Inflammatory Effects Observed in AD Mouse Models<\/p>\n

Finally, the researchers examined the downstream neurotoxic events associated with A\u03b2 accumulation, focusing on inflammatory cytokines. Arginine treatment in wildtype mice did not affect cytokine production. In contrast, AppNL-G-F mice treated with arginine showed substantial reductions in IL-1\u03b2, IL-6, and tumor necrosis factor, indicating that arginine mitigates A\u03b2-driven neuroinflammation.<\/p>\n

Arginine Shows Preclinical Promise but Requires Human Safety Evaluation<\/p>\n

Taken together, the study demonstrated that arginine suppresses A\u03b2 aggregation both in vitro and in vivo. Oral arginine administration suppressed A\u03b2 pathology and ameliorated A\u03b2-mediated toxicity in different animal AD models.<\/p>\n

The findings provide preclinical evidence that arginine is a disease-modifying candidate drug for AD treatment. However, the authors emphasized that these findings are limited to animal models with familial Arctic (E22G) mutations, which do not capture key features of human sporadic AD, such as tau pathology or neuronal loss.<\/p>\n

Additionally, the mouse dose (6 percent in drinking water) corresponds to a human-equivalent dose approximately twice the maximum currently approved for other clinical indications, underscoring the need for safety and dose-finding studies. Future research must determine therapeutic effects, safety, dose\u2013response relationships, and the translational feasibility of arginine for human A\u03b2 pathology.<\/p>\n","protected":false},"excerpt":{"rendered":"New preclinical evidence shows that oral arginine reduces toxic amyloid structures and eases behavioral impairments in Alzheimer\u2019s models,…\n","protected":false},"author":2,"featured_media":151104,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[32888,164,5303,9937,27351,29999,163,85,11589,28049,46,13867,10744,9435,16764],"class_list":["post-151103","post","type-post","status-publish","format-standard","has-post-thumbnail","category-health","tag-arginine","tag-brain","tag-dementia","tag-efficacy","tag-eye","tag-fluorescence","tag-health","tag-il","tag-in-vitro","tag-in-vivo","tag-israel","tag-oral","tag-pathology","tag-peptides","tag-preclinical"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/151103","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=151103"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/151103\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/151104"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=151103"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=151103"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=151103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}