Chronic treatment with tocotrienol, an isoform of vitamin E, prevents intracerebroventricular streptozotocin-induced cognitive impairment and oxidative-nitrosative stress in rats.

Abstract

Intracerebroventricular (ICV) streptozotocin (STZ) has been shown to cause cognitive impairment, which is associated with increased oxidative stress in the brain of rats. In the present study, we investigated the effect of both the isoforms of vitamin E, alpha-tocopherol and tocotrienol against ICV STZ-induced cognitive impairment and oxidative-nitrosative stress in rats. Adult male Wistar rats were injected with ICV STZ (3 mg/kg) bilaterally. The learning and memory behavior was assessed using Morris water maze and elevated plus maze. The rats were sacrificed on day 21 and parameters of oxidative stress, nitrite levels and acetylcholinesterase activity were measured in brain homogenate. alpha-Tocopherol as well as tocotrienol treated groups showed significantly less cognitive impairment in both the behavioral paradigms but the effect was more potent with tocotrienol. Both isoforms of vitamin E effectively attenuated the reduction in glutathione and catalase and reduced the malonaldehyde, nitrite as well as cholinesterase activity in the brains of ICV STZ rats in a dose dependent manner. The study demonstrates the effectiveness of vitamin E isoforms, of which tocotrienol being more potent in preventing the cognitive deficits caused by ICV STZ in rats and suggests its potential in the treatment of neurodegenerative diseases such as Alzheimer's disease.

• Authors: Vinod Tiwari, Anurag Kuhad, Mahendra Bishnoi, Kanwaljit Chopra
• Journal: Pharmacology, biochemistry, and behavior (Pharmacol Biochem Behav) Vol. 93 Issue 2 Pg. 183-9 (Aug 2009) ISSN: 1873-5177 [Electronic] United States
• PMID: 19464315 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antioxidants
• Nitrites
• Reactive Nitrogen Species
• Tocotrienols
• Streptozocin
• Catalase
• Superoxide Dismutase
• Acetylcholinesterase
• Glutathione
• alpha-Tocopherol

Topics

• Acetylcholinesterase (metabolism)
• Animals
• Antioxidants (pharmacology)
• Brain (drug effects, enzymology)
• Catalase (metabolism)
• Cognition Disorders (chemically induced, prevention & control, psychology)
• Dementia (chemically induced, prevention & control, psychology)
• Glutathione (metabolism)
• Injections, Intraventricular
• Lipid Peroxidation (drug effects)
• Male
• Maze Learning (drug effects)
• Mitochondria (drug effects, metabolism)
• Motor Activity (drug effects)
• Nitrites (metabolism)
• Oxidative Stress (drug effects)
• Rats
• Rats, Wistar
• Reactive Nitrogen Species (metabolism)
• Streptozocin (administration & dosage, antagonists & inhibitors, toxicity)
• Superoxide Dismutase (metabolism)
• Tocotrienols (pharmacology)
• alpha-Tocopherol (pharmacology)