Antioxidant Effects of Walnut (Juglans regia L.) Kernel and Walnut Septum Extract in a D-Galactose-Induced Aging Model and in Naturally Aged Rats

Abstract

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.

Antitussive, Antioxidant, and Anti-Inflammatory Effects of a Walnut (Juglans regia L.) Septum Extract Rich in Bioactive Compounds

“…As in other studies [ 35 ], a more plausible explanation would be that reduced ROS concentration is related to the modulation of endogenous antioxidant defense systems. The in vivo antioxidant capacity of WSE was also reported in a D-gal-induced aging model in rats where administration of this extract for 8 weeks statistically decreased the ROS levels in brain and liver tissues [ 36 ]. The results obtained indicate that WSE possess in vitro and in vivo antioxidant potential, thus being in accordance with previously published other studies on walnut-derived extracts [ 37 , 38 ].…”

“…However, it should be noted that changes in NO were mostly reported in asthmatic patients that present eosinophilic inflammation, while no correlation between exhaled NO and other respiratory pathologies characterized by cough were demonstrated [ 49 ]. In a previous study in which we evaluated the anti-aging potential of WSE, no changes in this parameter were observed in liver and brain tissues of naturally aged animals [ 36 ]. Alternatively, these results could be due to the fact that whole lung tissues were used for the assay, and local changes of NO concentration in superficial tissue could have been masked by the bulk of the tissue.…”

The double effect of walnut septum extract (Juglans regia L.) counteracts A172 glioblastoma cell survival and bacterial growth

“…In particular, the dose-dependent antiproliferative effect of walnut septum extract on human A549 lung adenocar-cinoma, human T47D-KBluc and MCF-7 breast cancer cell lines has been demonstrated ( 70 ). In addition, walnut consumption or walnut extracts showed antioxidant, anti-inflammatory and anti-aging properties in the brain ( 26 , 29 , 32 ). However, the antitumor activity of walnut septum extract against one of the most aggressive brain tumors, glioblastoma, has not been investigated.…”

“…In particular, in both animal and human studies it was demonstrated that a walnut diet reduces the brain-accumulation of damaged proteins and reduces brain inflammation associated with aging (26)(27)(28). A previous study has highlighted the strong antioxidant effects of walnut septum extracts (29), suggesting a possible role of such extracts in the maintenance of brain homeostasis (30,31). Therefore, these studies have demonstrated that walnut consumption or walnut extracts are protective for brain aging (32), paving the way for further studies investigating brain tumors.…”

Protective Effects of a Discontinuous Treatment with Alpha-Lipoic Acid in Obesity-Related Heart Failure with Preserved Ejection Fraction, in Rats

“…In brief, plasma nitrate was reduced to nitrite, using vanadium chloride, under acidic conditions, at 37 • C, in a 96 well microtiter plate. The newly obtained nitrite, together with pre-existent plasma nitrite were determined spectrophotometrically, using the Griess reaction (diazotization of sulfanilic acid, followed by coupling with alpha-naphthylamine) [40].…”