D-ribose-L-cysteine reduces oxidative stress and inflammatory cytokines to mitigate liver damage, and memory decline induced by copper sulfate in mice.

Background: Current evidences have implicated copper in amyloid aggregation that trigger the downstream oxidative stress-mediated neuroinflammation that characterized memory deterioration in patients with Alzheimer's disease (AD). Thus, this study was designed to evaluate the effect of D-Ribose-L-Cysteine (DRLC), a potent antioxidant agent, on copper sulfate (CuSO)-induced memory deterioration and the biochemical mechanisms underpinning its action in mice.

Methods: Male Swiss mice were randomly distributed into 5 groups (n = 10/group). Mice in group 1 were given distilled water (control), group 2 CuSO (100 mg/kg) while groups 3-5 were pretreated with CuSO (100 mg/kg) 30 min before administration of DRLC (10, 25 and 50 mg/kg). Treatments were given through oral gavage, daily for 28 days. Memory function was evaluated on day 28 using Y-maze test. The isolated liver and brain tissues were then processed for oxidative stress biomarkers, and proinflammatory cytokines [tumor necrosis factor- α (TNF-α) and interleukin-6)] assays. Brian acetylcholinesterase (AChE) and liver enzymes [aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were also determined.

Results: DRLC reversed memory impairment and dysregulated levels of malondialdehyde, glutathione, nitrite and glutathione S-transferase in the liver and brain tissues of mice pretreated with CuSO. The increased proinflammatory cytokines concentrations in the liver and brain tissues of mice pretreated with CuSO were reduced by DRLC. The elevated brain AChE and liver enzymes activities induced by CuSO were also reduced by DRLC.

Conclusion: Taken together, these findings suggest that DRLC attenuates CuSO-induced memory dysfunctions in mice through enhancement of antioxidative pathway, inhibition of pro-inflammatory cytokines and augmentation of liver function.