Ellagic acid reduces hepatic lipid contents through regulation of SIRT1 and AMPK in old rats

Exploring the molecular mechanisms underlying neuroprotective effect of ellagic acid in okadaic acid-induced Alzheimer's phenotype

Pomegranate polyphenol ellagic acid has medicinal potential in neurodegenerative disorders. The advantageous effect of this polyphenol in improving cognition in okadaic acid (OA)-instigated murine model with unraveling some modes of its action was assessed. Rats received ICV okadaic acid (OA) and post-treated with oral ellagic acid for 3 weeks (25 and 100 mg/kg/day). Cognition was analyzed in behavioral tasks besides assessment of oxidative, apoptotic, and inflammatory factors in addition to hippocampal histochemical analysis. Ellagic acid at a dose of 100 mg/kg properly attenuated cognitive abnormalities in novel object recognition (NOR), Y maze, and Barnes maze tests. Additionally, ellagic acid diminished hippocampal changes of malondialdehyde (MDA), protein carbonyl, reactive oxygen species (ROS), glutathione (GSH), glutathione peroxidase, superoxide dismutase (SOD), apoptotic factors caspases 1 and 3, tumor necrosis factor α (TNFα), and acetylcholinesterase (AChE) and beta secretase 1 (BACE 1) besides reversal of AMP-activated protein kinase (AMPK) and hyperphosphorylated tau (p-tau). Moreover, lower glial fibrillary acidic protein (GFAP) and less injury of hippocampal CA1 pyramidal neurons were observed upon ellagic acid. To conclude, neuroprotective potential of ellagic acid was shown which is somewhat attributable to its reversal of oxidative, apoptotic, and neuroinflammatory events in addition to proper regulation of AMPK and p-tau.

Dietary Polyphenols as Anti-Aging Agents: Targeting the Hallmarks of Aging

Background: Aging is a natural biological process influenced by multiple factors and is a significant contributor to various chronic diseases. Slowing down the aging process and extending health span have been pursuits of the scientific field. Methods: Examination of the effects of dietary polyphenols on hallmarks of aging such as genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, disabled macroautophagy, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, chronic inflammation, and dysbiosis. Results: Polyphenols, abundant in nature, exhibit numerous biological activities, including antioxidant effects, free radical scavenging, neuroprotection, and anti-aging properties. These compounds are generally safe and effective in potentially slowing aging and preventing age-related disorders. Conclusions: The review encourages the development of novel therapeutic strategies using dietary polyphenols to create holistic anti-aging therapies and nutritional supplements.

Effects of Ellagic Acid on Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis

Background

Abnormal glucose and lipid metabolism (GALM) serve as both a cause and an inducer for the development of the disease. Improvement and treatment of GALM are an important stage to prevent the occurrence and development of the disease. However, current clinical treatment for GALM is limited. Ellagic acid (EA), a common polyphenol present in foods, has been shown to improve abnormalities in GALM observed in patients suffering from metabolic diseases.

Objective

This study used a meta-analysis method to systematically assess the effects of EA on GALM.

Method

As of November 8, 2023, a comprehensive search was conducted across 5 databases, namely, PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar to identify randomized controlled trials (RCTs) in which EA served as the primary intervention for diseases related to GALM. The risk of bias within the included studies was assessed according to the Cochrane Handbook. All statistical analyzes were performed using RevMan 5.4 software.

Results

In this study, a total of 482 articles were retrieved, resulting in the inclusion of 10 RCTs in the meta-analysis. The results showed that EA could reduce fasting blood glucose (FBG) (p = 0.008), increase insulin secretion (p = 0.01), improve insulin resistance index (HOMA-IR) (p = 0.003), decrease triglyceride (TG) (p = 0.004), and reduce cholesterol (Chol) (p = 0.04) and low-density lipoprotein (LDL-c) (p = 0.0004). EA had no significant effect on waist circumference (WC), body weight (BW), body mass index (BMI), 2 hours after prandial blood glucose (2 h-PG), total cholesterol (TC), and high-density lipoprotein (HDL-c).

Conclusions

The effect of improvement in glucose and lipids of EA was closely related to the dose and the intervention time. EA can improve GALM caused by diseases. To corroborate the findings of this study and improve the reliability of the results, EA is imperative to refine the research methodology and increase the sample size in future investigations.

A mechanistic exploration of the metabolome of African mango seeds and its potential to alleviate cognitive impairment induced by high-fat/high-carbohydrate diets: Involvement of PI3K/AKT/GSK-3β/CREB, PERK/CHOP/Bcl-2, and AMPK/SIRT-1/mTOR Axes

ETHNOPHARMACOLOGICAL RELEVANCE

Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill., also known as "African mango" or "bush mango", belonging to family Irvingiaceae, has been mostly used as food and traditional medicine for weight loss and to enhance the health.

AIM OF THE STUDY

The overconsumption of high-fat and high-carbohydrate (HFHC) food induces oxidative stress, leading to neurological and cognitive dysfunction. Consequently, there is an immediate need for effective treatment. Hence, this study explored the efficacy of orlistat, metformin, and I. gabonensis seeds' total aqueous extract (IG SAE) in addressing HFHC-induced cognitive impairment by mitigating oxidative stress and their underlying mechanistic pathways.

MATERIALS AND METHODS

Initially, the secondary metabolite profile of IG SAE is determined using high-performance liquid chromatography coupled with a mass detector (UHPLC/MS). The in vivo study involves two phases: an established model phase with control (10 rats on a standard diet) and HFHC diet group (50 rats) for 3 months. In the study phase, HFHC is divided into 5 groups. The first subgroup receives HFHC diet only, while the remaining groups each receive HFHC diet with either Orlistat, metformin, or IG SAE at doses of 100 mg/kg and 200 mg/kg, respectively, for 28 days.

RESULTS

More than 150 phytoconstituents were characterized for the first holistic approach onto IG metabolome. Characterization of IG SAE revealed that tannins dominate metabolites in the plant. Total phenolics and flavonoids were estimated to standardize our extract (77.12 ± 7.09 μg Gallic acid equivalent/mg extract and 8.039 ± 0.53 μg Rutin equivalent/mg extract, respectively). Orlistat, metformin, and IG SAE successfully reduced the body weight, blood glucose level, lipid profile, oxidative stress and neurotransmitters levels leading to improved behavioral functions as well as histological alternation. Also, IG SAE halted inflammation, apoptosis, and endoplasmic reticulum stress, together with promoting autophagy, via modulation of PI3K/AKT/GSK-3β/CREB, PERK/CHOP/Bcl-2 and AMPK/SIRT-1/m-TOR pathways.

CONCLUSION

Metformin, orlistat, and IG SAE offer a promising multi-target therapy to mitigate HFHC diet-induced oxidative stress, addressing cognitive function. This involves diverse molecular mechanisms, particularly the modulation of inflammation, ER stress, and both PI3K/AKT/GSK-3β/CREB and AMPK/SIRT-1/m-TOR pathways. Furthermore, the higher dose of IG SAE demonstrated effects comparable to orlistat and metformin across most studied parameters.