Antioxidant dietary intervention is considered a potential strategy in delaying age-related dysfunctions. In this study of 56 days, we assessed the antioxidant effects of walnut kernel (WK) and walnut septum extract (WSE) in a D-galactose (D-gal)-induced aging model and in a naturally aged rat model. Young Wistar rats, treated with D-gal (1200 mg/week), and old rats received daily WK or WSE added to the feed. After 8 weeks, blood, liver, and brain samples were collected and hematological, biochemical, oxidative stress biomarkers, histological, and immunohistochemical analyses were performed. Moreover, acetylcholinesterase activity was investigated in brain homogenates. The outcomes demonstrated significant improvement in cellular antioxidant activity and/or decrease of reactive oxygen species, advanced glycation end products, nitric oxide, malondialdehyde, or increase of glutathione after WK or WSE intake in both models. Additionally, WSE showed hypoglycemic effect, and both WK and WSE lowered acetylcholinesterase activity. Both diets could protect neurons against the induced senescence and could reverse the pathological conditions in the physiological aged brain. Thus, dietary supplementation with WK or WSE can maintain the liver and brain health and reduce the risk of age-related diseases, as well as delaying the onset of aging processes.

Biomarkers of metabolic syndrome and inflammation are pathophysiological predictors and factors of senescence and age-related diseases. Recent evidence showed that particular diet components, such as walnuts rich in antioxidant bioactive compounds and with a balanced lipid profile, could have positive outcomes on human health. A systematic search in PubMed, EMBASE, Cochrane Library, Scopus, and ClinicalTrials.gov databases was performed to retrieve randomized controlled trials published from the beginning of each database through November 2021, reporting on the outcomes of walnut consumption over 22 metabolic syndrome and inflammatory markers in middle-aged and older adults. The search strategy rendered 17 studies in the final selection, including 11 crossover and 6 parallel trials. The study revealed that walnut-enriched diets had statistically significant decreasing effects for triglyceride, total cholesterol, and LDL cholesterol concentrations on some inflammatory markers and presented no consequences on anthropometric and glycemic parameters. Although further studies and better-designed ones are needed to strengthen these findings, the results emphasize the benefits of including walnuts in the dietary plans of this age group.

In the last few decades, scientific evidence has stressed the importance of plants in the prevention and/or supportive treatment of a plethora of diseases, many of them chronic, age-associated disorders. Juglans regia L. is a traditional plant that has been integrated into traditional medicine since ancient times. Due to the presence of biologically active compounds, walnut was used in the treatment of various maladies. Recently, investigations have focused on the walnut by-products and waste products, with research on their valuable constituents and active properties. Among these secondary products, walnut septum was analyzed in several studies, its phytochemical profile described, and some of the biological activities examined. However, compared to other walnut by-products, no comprehensive review to gather all the pertinent scientific knowledge was found in the literature. Therefore, the aim of this study was to critically assess the information furnished by peer-reviewed articles regarding the walnut septum chemical composition and the related biological activities, including antioxidant activities, anti-inflammatory effects, antimicrobial properties, antidiabetic activities, anti-tumor properties, and anti-aging potential. In conclusion, as these preclinical studies showed that walnut septum metabolites were responsible for a wide range of preventive and therapeutic uses, further research should confirm the beneficial outcomes in clinical trials.

Walnuts (Juglans regia L.) are an important source of ellagitannins. They have been linked to positive effects on many pathologies, including cardiovascular disorders, neurodegenerative syndromes, and cancer. The limited bioavailability of ellagitannins prevents them from reaching significant circulatory levels, despite their antioxidant, anti-inflammatory, and chemopreventive properties. Urolithins are ellagitannin gut microbiota-derived metabolites. They have better intestinal absorption and may be responsible for the biological activities of ellagitannins. Recent evidence showed that walnut ellagitannins and their metabolites, urolithins, could have positive outcomes for human health. This study aims to synthesize the current literature on the antioxidant activity and mechanistic pathways involved in the therapeutic potential of walnut ellagitannins and their metabolites. In the eligible selected studies (n = 31), glansreginin A, pedunculagin, and casuarictin were the most prevalent ellagitannins in walnuts. A total of 15 urolithins, their glucuronides, and sulfate metabolites have been identified in urine, blood, feces, breast milk, and prostate tissue in analyzed samples. Urolithins A and B were associated with antioxidant, anti-inflammatory, cardioprotective, neuroprotective, anticarcinogenic, and anti-aging activities, both in preclinical and clinical studies. Despite the promising results, further well-designed studies are necessary to fully elucidate the mechanisms and confirm the therapeutic potential of these compounds in human health.

This study explores the bioactive potential of young shoots from blackcurrant, European blueberry, and mountain cranberry, widely employed in gemmotherapy and phytotherapy, as rich sources of antioxidants, antimicrobial agents, and anti-inflammatory components. The primary aims of this study were to enhance the extraction conditions for bioactive compounds from blackcurrant young shoots using Modde software for experimental design, to conduct a comprehensive phytochemical analysis of blackcurrant, European blueberry, and mountain cranberry young shoot extracts through LC–MS analysis, and to evaluate the in vitro biological activities of these optimized extracts. The experimental design comprised multiple variables: extraction techniques, solvent type, extraction time, apparent pH, and the solvent-to-vegetal product ratio. The responses included total phenolic content, total flavonoid content, condensed tannin content, and total antioxidant activity determined through the DPPH assay. Furthermore, the antioxidant potential of the extracts was validated through in vitro cell culture experiments, in addition to the cytotoxicity assessments conducted on both normal and cancer cell lines. Extracts obtained through Ultra-Turrax extraction using 70% acetone displayed high levels of polyphenolic compounds and enhanced antioxidant potential, regardless of young shoots origin. LC–MS analysis revealed the predominant occurrence of chlorogenic acid, hyperoside, and isoquercitrin in all examined samples. The optimized extracts also displayed significant biological potential when evaluated in vitro on cell lines. These results provide valuable insights into the potent bioactive components present in these young shoot extracts, paving the way for further exploration in therapeutic applications.

Background: Epidemiological research has shown that regular walnut (from Juglans regia L.) consumption is associated with a reduced risk of cardiovascular disease (CVD), potentially attributable to their antioxidant and anti-inflammatory properties. The vascular cellular adhesion molecule-1 (VCAM-1), a protein upregulated in CVD, has been previously examined in relation to walnut consumption. However, the clinical findings regarding the effects of walnuts on endothelial function among middle-aged individuals susceptible to metabolic syndrome (MetS) remain inconclusive. Objective: This study examined the effects of daily walnut consumption over a four-week period on cardiometabolic parameters (lipid and glycemic profiles, as well as soluble VCAM-1 levels) and anthropometric measurements in middle-aged individuals with at least one altered MetS parameter and no medication. Methods: In a randomized controlled cross-over trial, 22 eligible Caucasian participants (48.81 ± 4.3 years) were selected and randomly assigned to receive either 45 g of walnuts per day or no walnuts within a controlled diet. There were two 28-day intervention periods, with a one-month washout period in between. Clinical and biochemical evaluations were conducted at the beginning and end of each intervention period. Results: A total of 20 participants completed the intervention and were analyzed, with walnuts being well tolerated. A significant decrease in waist circumference (p = 0.049) and a slight change in fasting blood glucose (p = 0.089) were noted following walnut intake. Conclusions: Short-term (4 weeks) dietary supplementation with walnuts resulted in a statistically significant reduction in waist circumference while not impacting the overall health status of participants. Longer-term studies are necessary to investigate the benefits of daily walnut consumption and its impact on the onset and development of MetS in this age group.