The Protective Effect of Astaxanthin on Cognitive Function via Inhibition of Oxidative Stress and Inflammation in the Brains of Chronic T2DM Rats

Abstract

Currently, there are no effective treatments for diabetes-related cognitive dysfunction. Astaxanthin (AST), the most powerful antioxidant in nature, exhibits diverse biological functions. In this study, we tried to explore whether AST would ameliorate cognitive dysfunction in chronic type 2 diabetes mellitus (T2DM) rats. The T2DM rat model was induced via intraperitoneal injection of streptozotocin. Forty Wistar rats were divided into a normal control group, an acute T2DM group, a chronic T2DM group, and an AST group (treated with AST at a dose of 25 mg/kg three times a week). The Morris water maze test showed that the percentage of time spent in the target quadrant of the AST group was identical to that of the chronic T2DM group, while the escape latency of the AST group was decreased in comparison to that of the chronic T2DM group. Histology of the hippocampus revealed that AST ameliorated the impairment in the neurons of diabetic rats. Western blot showed that AST could upregulate nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) expression and inhibit nuclear transcription factor kappa B (NF-κB) p65 activation in the hippocampus. We found that AST increased the level of superoxide dismutase (SOD) and decreased the level of malondialdehyde (MDA) in the hippocampus. In addition, the levels of interleukin 1 beta (IL-1β) and interleukin 6 (IL-6) were reduced in the AST group compared with those in the chronic T2DM group. The findings of this research imply that AST might inhibit oxidative stress and inflammatory responses by activating the Nrf2-ARE signaling pathway.

Astaxanthin Suppresses Cigarette Smoke-Induced Emphysema through Nrf2 Activation in Mice

“…Astaxanthin has attracted attention due to its strong antioxidant properties, and there have been many reports focusing on its antioxidant activity. Astaxanthin has been shown to protect various cells from oxidative stress in vitro [31][32][33][34] and to protect the brain, eyes, salivary glands, skeletal muscle, liver, kidney, and lungs from oxidative stress in vivo [12][13][14][15][16][17][35][36][37][38][39]. These results indicate that astaxanthin is distributed throughout the body and has systemic effects.…”

“…These results indicate that astaxanthin is distributed throughout the body and has systemic effects. Moreover, previous studies have reported that astaxanthin enhances Nrf2 expression in various organs including the lungs [13][14][15][16][17]. Additionally, some studies have investigated the pathway of Nrf2 activation by astaxanthin.…”

“…This compound has potent antioxidant activity, which has been shown to be greater than that of other carotenoids and vitamin E [11,12]. In addition, several studies have reported that astaxanthin activates the Nrf2-ARE signaling pathway as the mechanism for exerting its antioxidant effects [13][14][15][16][17]. However, the suppression of cigarette smoke-induced emphysema by astaxanthin via its antioxidant activity has not yet been reported.…”

The comparison of krill oil extracted through ethanol–hexane method and subcritical method

“…In addition, the unique and particular amphiphilic nature of PLs brings emulsification properties to KO, thus improving the bioavailability of EPA and DHA (Schuchardt et al., ). Moreover, compared with FO, KO has a significant amount of astaxanthin, a potent and naturally occurring antioxidant, which can not only reduce the oxidation of KO (Hussein et al., ), but also provides health‐promoting properties such as reducing the incidence of inflammation, cancer, diabetes, immune function, and hyperlipidemia (Feng et al., ; Kim et al., ; Sun et al., ).…”

Diabetes–Alzheimer's Disease Link: Targeting Mitochondrial Dysfunction and Redox Imbalance

“…Recently, it was demonstrated that astaxanthin, a special carotenoid with antioxidant properties, reduced plasma glucose and insulin levels and improved whole body insulin sensitivity and insulin-stimulated glucose uptake in diabetic patients (118). Moreover, it was recently shown that the administration of astaxanthin to a T2D rat model was able to revert brain oxidative stress levels through the upregulation of nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase 1 expression and the inhibition of nuclear transcription factor kappa B p65 activation in the hippocampus (66). In the same study, the authors found increased SOD levels and decreased malondialdehyde (MDA) levels in the hippocampus of the diabetic animals treated with astaxanthin when compared with nontreated T2D group (66).…”