S-allyl cysteine and alliin enhance catalase activity and prevent aggregation to counter oxidative stress in alzheimer’s disease

Sep 30, 2026

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Oxidative stress drives Alzheimer’s disease (AD) and is linked to reduced catalase activity, with catalase implicated in harmful amyloid-β protein aggregates in brain plaques. This study evaluates two garlic-derived organosulfur compounds, S-allyl cysteine (SAC) and alliin, for catalase effects. Both compounds increase catalase activity in a concentration-dependent manner by stabilizing structure and improving thermodynamic stability. Molecular docking and simulation show allosteric binding that promotes structural compaction and reduces amyloid-like aggregation propensity, suggesting therapeutic potential for lowering disease progression.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages16

Reading Time40 min

AccessFree to download

Background

Oxidative stress and Alzheimer’s disease

Role of catalase

Study Focus

Compounds: SAC and alliin

Findings

Catalase activity enhancement

Allosteric binding and stability

Reduction of aggregation

[www. nature.com/scientificreports](www. nature.com/scientificreports) OPEN S-allyl cysteine and alliin enhance catalase activity and prevent aggregation to counter oxidative stress in alzheimer’s disease Seemasundari Yumlembam2, Kuldeep Singh1, Akshita Gupta1, Priya Adhikarimayum2, Anju Kumari1, Kananbala Sarangthem2􀀍 & Laishram Rajendrakumar Singh1􀀍 Oxidative stress is a key driver of Alzheimer’s disease (AD), often linked to reduced activity of catalase, a major antioxidant enzyme. In AD, catalase is not only less active but also found as part of harmful protein aggregates with amyloid-β in brain plaques. Finding safe molecules that can boost catalase activity and stop it from aggregating could, therefore, offer a new strategy to lower disease progression. In this study, we examined two natural organosulfur compounds from garlic—S-allyl cysteine (SAC) andAlliin—for their effects on catalase. We found that both compounds significantly increased catalase activity in a concentration-dependent manner by stabilizing its structure and enhancing its thermodynamic stability. Furthermore, Molecular docking and Simulation studies revealed that SAC andAlliin bind at an allosteric site, promoting structural compaction and enhancing stability. Importantly, these compounds also reduced the tendency of catalase to form amyloid-like aggregates, a feature directly relevant toAD pathology. Our findings provide new mechanistic insights into how SAC and Alliin act on catalase—both stabilizing the enzyme and resulting in an increase in its activity along with lowering its aggregation propensity. This suggests that SAC andAlliin may serve as promising, natural candidates for therapeutic intervention in Alzheimer’s disease. Keywords Oxidative stress, Alzheimer’s disease, Organosulfurs, Protein stability, Antioxidant, Toxic inclusion Alzheimer’s disease is a progressive neurological disorder that causes memory loss, confusion and changes in a person’s behaviour1,2. It primarily affects older adults and is the most common form of dementia3,4. The pathophysiology of AD is characterized by the accumulation of extracellular amyloid-β (Aβ) aggregates and intracellular neurofibrillary tangles of hyperphosphorylated Tau protein in the brain leading to the mitochondrial dysfunction that results in an increased oxidative stress5–8. The increase in oxidative stress is considered to be an early event in AD pathology9, 10 as it contributes to membrane damage, cytoskeleton alteration and cell death11. Therefore, it is believed that increased production of ROS may act as an important mediator of synaptic loss and eventual progression of disease pathology12. Cells have various safety mechanisms comprising of various enzymatic and non-enzymatic antioxidant systems to maintain ROS concentrations below thresholds that would otherwise induce cellular toxicity. These antioxidant systems play a critical role in neutralizing free radicals and their antecedents, preventing their formation, and sequestering metal ions that catalyse oxidative reactions13, 14. These antioxidant enzymes include, catalase, peroxiredoxin, superoxide dismutase, glutathione peroxidasesand thioredoxin and other non-enzymatic molecules are vitamin A, C,E, flavonoids, carotenoids, glutathione, polyamines, polyphenols, bilirubin etc15–17. Among these enzymatic antioxidants, catalase stands as one of the most crucial enzyme, due to its exceptionally high catalytic efficiency among other antioxidant enzymes13. Indeed, a single catalase enzyme is capable of decomposing millions of hydrogen peroxide (H₂O₂) molecules into water and oxygen each second. The remarkable turnover rate of the enzyme highlight its critical function in maintaining cellular homeostasis by mitigating oxidative damage13, 18 .Catalase deficiency has been reported tobe associated with peroxisomal AD, primary reason is believed to be because of its peroxisomal localisation or its interaction with inhibitor brain metabolit

FAQs

Why is catalase important in Alzheimer’s disease?

Catalase is a key antioxidant enzyme, and oxidative stress in AD is associated with reduced catalase activity. Catalase can also colocalize with senile plaques and participate in amyloid-β–related harmful aggregation processes.

What do S-allyl cysteine (SAC) and alliin do to catalase?

Both SAC and alliin significantly increase catalase activity in a concentration-dependent manner. They stabilize the enzyme’s structure and enhance thermodynamic stability.

How do SAC and alliin affect catalase aggregation and amyloid-related pathology?

The compounds reduce catalase’s tendency to form amyloid-like aggregates. Docking and simulation indicate binding at an allosteric site that promotes structural compaction, which supports stability and lower aggregation propensity.

Sep 30, 2026

Upload by Oliver