Curcumin and piperine abrogate lipid and protein oxidation induced by d-galactose in rat brain

• Chronic exposure to d-galactose induces oxidative damage and cognitive impairment.
• Effect of piperine alone, curcumin alone and in combination was studied.
• Protein and lipid oxidation was determined.
• Behavior and cerebellar changes were determined.
• Combination exerted substantial benefit in preventing neurodegeneration.

Cerebellar atrophy during ageing can produce neurobehavioural changes characterized by cognitive and motor impairment. Chronic exposure to d-galactose, a reducing sugar can accelerate ageing by producing an unprecedented rise in oxidative load. This can enhance neuronal damage by promoting the oxidation of protein and lipids. We perceived that the simultaneous administration of piperine and curcumin, two powerful antioxidants can exert neuroprotective effect by inhibiting damage caused by the chronic exposure to d-galactose. Young Wistar rats treated with d-galactose (150 mg/kg, s.c.) were simultaneously treated with piperine alone, curcumin separately; and in combination for a period of 56 days by the oral route. A vehicle control, d-galactose alone and naturally aged control were also evaluated. Cognitive changes, motor impairment, protein carbonyls, protein thiols, advanced oxidation protein products, 4 hydroxynonenol and nitric oxide levels were determined in the brain homogenate. In order to ascertain the impact of cerebellum on motor performance, histopathological changes in the cerebellum were also established. Results obtained from our studies reflect a marked improvement in memory, sensorimotor performance, reduced oxidative and nitrosative burden on simultaneous treatment with piperine and curcumin. Furthermore, alterations produced in the Purkinje cells were minimized on treatment with the combination. Our studies demonstrated the influence of protein and lipid oxidation products on behavioural changes in d-galactose induced ageing model. Incorporation of these antioxidants might reduce the risk of developing neurodegenerative disorders, an important counterpart of advancing age.