A recently published study evaluated the effects of a green tea constituent (epigallocatechin-3-gallate) and lycopene in animals with experimentally induced Huntington’s disease. Huntington’s disease is a genetically inherited neurodegenerative disease characterized by repetitive abnormal movements called chorea and the decline of mental abilities resulting in dementia. The life expectancy of patients with Huntington’s disease is reduced to around twenty years after symptoms begin due to complications such as pneumonia, heart disease, and physical injury from falls. Currently, there is no cure for the disease but researchers are investigating potential therapies to slow the progression.
In this new study, the neurotoxin 3-nitropropionic acid was administered to rats inducing symptoms similar to Huntington’s disease such as gait and memory impairment, oxidative damage, and disturbed glutathione metabolism. The rats were also treated with two antioxidants, epigallocatechin-3-gallate (EGCG), a constituent found in green tea, and lycopene, which is a bright red carotenoid pigment found in red fruits and vegetables.
Treatment with 3-nitropropionic acid significantly impaired memory in the rats as assessed by maze tasks. Additionally, 3-nitropropionic acid administration significantly decreased levels of reduced glutathione, total glutathione and glutathione-S-transferase in the striatum, hippocampus and cortex areas of the brain. Glutathione metabolism is important as it is a potent antioxidant, which protects cells from reactive oxygen species and free radical damage. Treatment of the rats with lycopene and EGCG significantly improved memory and restored normal glutathione metabolism.
The researchers also treated the rats with L-arginine and N-G-nitro-L-arginine methyl ester (L-NAME), aninhibitor of the enzyme nitric oxide synthase,which catalyzes the production of nitric oxide from L-arginine. Pre-treatment with L-arginine and L-NAME plus sub-effective doses of lycopene and EGCG, enhanced the protective effects of the lycopene and ECGC in preventing the toxic effects of 3-nitropropionic acid.
According to the researchers, “In conclusion, lycopene and EGCG could be used to mange 3-NP induced behavioral and biochemical alterations by involving nitric oxide pathways.”
Reference:
Kumar P, Kumar A. Effect of lycopene and epigallocatechin-3-gallate against 3-nitropropionic acid induced cognitive dysfunction and glutathione depletion in rat: a novel nitric oxide mechanism. Food Chem Toxicol. 2009 Jul 16. Published Online Ahead of Print.