The Protective Effect of α-Lipoic Acid against Gold Nanoparticles (AuNPs)-Mediated Liver Damage Is Associated with Upregulating Nrf2 and Suppressing NF-κB

The Efficiency of Chitosan Against Tert Butylhydroquinone (TBHQ)-Induced Neurobehavioral Changes and Toxicity Effects in Male Rats

BACKGROUND

We investigated chitosan's protective effects against tertiary butylhydroquinone (TBHQ)-induced toxicity in adult male rats, focusing on cognitive functions and oxidative stress in the brain, liver, and kidneys.

METHODS

Rats were divided into four groups (n = 8/group): (1) Control, (2) Chitosan only, (3) TBHQ only, and (4) Chitosan + TBHQ.

RESULTS

TBHQ exposure led to significant cognitive impairments and increased oxidative stress, marked by elevated malondialdehyde (MDA) and decreased superoxide dismutase (SOD) and glutathione (GSH) levels. Behavioral tests, including the Morris Water Maze (MWM) as well as Passive Avoidance Learning (PAL) tasks, confirmed memory and learning deficits in the TBHQ group. Histopathological analysis showed damage in the brain, liver, and kidney tissues of TBHQ-exposed rats. Chitosan treatment significantly mitigated these effects, reducing oxidative stress markers and preserving tissue integrity. These findings suggest that chitosan's antioxidant properties may provide a therapeutic benefit against TBHQ-induced neurotoxicity and organ damage.

CONCLUSIONS

These findings suggest that chitosan exerts potent neuroprotective effects, potentially through its antioxidant and anti-inflammatory properties, and could serve as a therapeutic agent against TBHQ-induced toxicity.

6-gingerol effect on rat liver following exposure to gold nanoparticles: From histopathologic findings to inflammatory and oxidative stress biomarkers

Gold nanoparticles (AuNPs) have unique features which could be beneficial to various aspects of clinics and industry. Long-term exposure to AuNPs damages the physiologic functions and tissue structure of organs. Gingerol has anti-inflammatory and antioxidant properties. This study explored the effect of 6-gingerol on alleviation of AuNPs exposure effects in rats' liver. Thirty-two male Wistar rats were randomly assigned to four groups of negative control (received no AuNPs or treatment), positive control (received AuNPs but not treatment), and two study arms (both received AuNPs and one group 50 and the other 100 mg/Kg body weight 6-gingerol). All injections were performed intraperitoneally. After 30 days, serum levels of ALP, AST, ALT were assessed through ELISA method by an autoanalyzer while GGT, SOD, GPx, CAT, IL-6, IL-1β, TNF-α, CRP, 8-OHdG, MDA, and Bax/Bcl2 were measured using an ELISA reader. Paraffin-embedded tissue sections of the livers from all groups were also prepared and H&E staining was performed on them for investigation of tissue changes. Statistical analyses were performed using SPSS version 26 and p = 0.05 was considered as the level of significancy. AuNPs exposure significantly increased the levels of ALP, AST, ALT, GGT, CRP, IL-6, IL-1β, TNF-α, Bax/Bcl2, 8-OHdG, MDA (p < 0.001) in positive control groups compared to negative controls, while treatment with 6-gingerol significantly decreased the mentioned enzyme levels (p < 0.001). The level of antioxidant enzymes of SOD, GPx, and CAT, on the other hand, was found to be highest and lowest in negative and positive controls, respectively (p < 0.001). Treatment with 6-gingerol significantly decreased the mentioned enzyme levels (p < 0.001). Histology results showed no signs of degeneration, necrosis, or immune cell infiltration in negative controls, while positive controls showed dilated central veins and hyperemia along with infiltration of mononuclear immune cells to the portal area, tissue degeneration, and necrosis. The study arms showed improved signs as they showed normal trabecular structures with no clear portal space. Treatment with 6-gingerol seems to significantly and efficiently reduce the hepatic side effects of AuNPs exposure in Wistar rats.

Polymeric nanocomposite electrode for enhanced electrochemical detection of α-lipoic acid: Application in neuroinflammation prevention and clinical analysis

Using poly (vanillin-co-chitosan)/functionalized MWCNTs/GCE (PV-CS/f-MWCNTs/GCE) as a polymeric nanocomposite modified electrode, the present investigation has been conducted on the electrochemical detection of α-lipoic acid (α-LA) to prevent the activation of microglia inflammation of the nervous system. The manufacture of modified polymeric nanocomposite electrodes was carried out using the established electropolymerization process. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analyses of structure revealed that the electropolymerization of poly (vanillin-co-chitosan) on the surface of the f-MWCNTs modified electrode was successful. Vanillin-co-chitosan electropolymerization on f-MWCNTs as electroactive sheets can enhance the signal for α-LA electrochemical sensors, according to research on the electrochemical characteristics utilizing cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methodologies. The PV-CS/f-MWCNTs/GCE demonstrated that it had a sensitivity of 0.04664 μA/μM, a detection limit of 0.012 μM, and an excellent response, linear range, and wide linear range to α-LA from 0 to 3000 μM. The results of the application of PV-CS/f-MWCNTs/GCE for determining the concentration of α-LA in a prepared real sample of human serum by DPV and human lipoic acid ELISA Kit analyses via standard addition method illustrated the substantial conformity between the findings of both assays. The results of the DPV analyses resulted in acceptable recovery values (97.60%-99.10%) and appropriate values of the Relative Standard Deviation (RSD) (3.58%-5.07%), which demonstrated the great applicability and accuracy of the results of PV-CS/f-MWCNTs/GCE for determining α-LA concentration in biological fluids and pharmaceutical specimens.

Anti-inflammatory role of gold nanoparticles in the prevention and treatment of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease that causes memory and cognitive dysfunction and reduces a person's decision-making and reasoning functions. AD is the leading cause of dementia in the elderly. Patients with AD have increased expression of pro-inflammatory cytokines in the nervous system, and the sustained inflammatory response impairs neuronal function. Meanwhile, long-term use of anti-inflammatory drugs can reduce the incidence of AD to some extent. This confirms that anti-neuroinflammation may be an effective treatment for AD. Gold nanoparticles (AuNPs) are an emerging nanomaterial with promising physicochemical properties, anti-inflammatory and antioxidant. AuNPs reduce neuroinflammation by inducing macrophage polarization toward the M2 phenotype, reducing pro-inflammatory cytokine expression, blocking leukocyte adhesion, and decreasing oxidative stress. Therefore, AuNPs are gradually attracting the interest of scholars and are used for treating inflammatory diseases and drug delivery. Herein, we explored the role and mechanism of AuNPs in treating neuroinflammation in AD. The use of AuNPs for treating AD is a topic worth exploring in the future, not only to help solve a global public health problem but also to provide a reference for treating other neuroinflammatory diseases.

Concomitant Sub-Chronic Administration of Small-Size Gold Nanoparticles Aggravates Doxorubicin-Induced Liver Oxidative and Inflammatory Damage, Hyperlipidemia, and Hepatic Steatosis

This study examined the effect of gold nanoparticles (AuNPs) on doxorubicin (DOX)-induced liver damage and steatosis in rats and tested its effect mechanism. Wistar male rats were divided into four groups (each of eight rats) as control, AuNPs (50 µL of 10 nm), DOX (15 mg/kg; 3 mg/kg/week), and DOX + AuNPs-treated rats. DOX is known to induce fasting hyperglycemia and hyperinsulinemia in treated rats. Individual treatment of both DOX and AuNPs also promoted liver damage, increased circulatory levels of ALT and AST, and stimulated serum and liver levels of TGs, CHOL, LDL-c, and FFAs. They also stimulated MDA, TNF-α, and IL-6, reduced GSH, SOD, HO-1, and CAT, upregulated mRNA levels of Bax and caspases-3 and -8 and downregulated mRNA levels of Bcl2 in the livers of rats. However, while DOX alone reduced hepatic levels of PPARα, both AuNPs and DOX stimulated mRNA levels of SREBP1, reduced the mRNA, cytoplasmic and nuclear levels of Nrf2, and increased mRNA, cytoplasmic, and nuclear levels of NF-κB. The liver damage and the alterations in all these parameters were significantly more profound when both AuNPs and DOX were administered together. In conclusion, AuNPs exaggerate liver damage, hyperlipidemia, and hepatic steatosis in DOX-treated rats by activating SREBP1 and NF-κB and suppressing the Nrf2/antioxidant axis.

α-Lipoic Acid Alleviated Fluoride-Induced Hepatocyte Injury via Inhibiting Ferroptosis

Fluoride is widely used in agricultural production and food packaging. Excessive fluoride in water and food is a serious threat to liver health. α-Lipoic acid, a natural free radical scavenger, has hepatoprotective properties. However, the protective effect of α-lipoic acid on fluorohepatotoxicity is uncertain. The aim of this study was to investigate the mechanism of ferroptosis in α-lipoic acid preventing fluoride-induced hepatotoxicity. Five-week-old ICR mice were treated with sodium fluoride (100 mg/L) and/or α-lipoic acid (200 mg/kg) for 9 weeks. The results showed that α-lipoic acid attenuated fluoride-induced damage to liver morphology and ultrastructure. Moreover, α-lipoic acid alleviated fluoride-induced iron accumulation, increased oxidative stress, and elevated lipid peroxidation in the liver. In addition, the mechanism study found that α-lipoic acid prevented fluoride-induced ferroptosis through the System Xc^-/GPX4 axis, lipid peroxidation axis, and iron metabolism axis, but it was interestingly not regulated by mitochondrial free radical axis in the hepatocytes. Altogether, this study indicated that α-lipoic acid prevents fluoride-induced liver injury by inhibiting ferroptosis, which has potential implications for the prevention and treatment of fluoride-induced liver injury.