This study investigated the effect of curcumin on aluminium-induced alterations in ageing-related parameters: lipid peroxidation, superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-s-transferase (GST), protein kinase C (PKC), Na(+), K(+)-adenosine triphosphatase (Na(+), K(+)-ATPase) and acetylcholinesterase (AChE) in the cerebral cortex and hippocampus of the brain of 10- and 24-month-old rats. Measurements taken from aluminium-fed rats were compared with those from rats in which curcumin and aluminium were co-administered. In aluminium-treated rats the levels of lipid peroxidation, PKC and AChE were enhanced while the activities of SOD, GPx, GST and Na(+), K(+)-ATPase were significantly decreased in both the brain regions of both age-groups. In animals co-administered with curcumin and aluminium, the levels of lipid peroxidation, activities of PKC and AChE were significantly lowered while the activities of SOD, GPx, GST and Na(+), K(+)-ATPase were significantly enhanced in the two brain regions studied indicating curcumin's protective effects against aluminium toxicity. Though the magnitudes of curcumin-induced alterations varied in young and old animals, the results of the present study also demonstrated that curcumin exerts a protective effect against aluminium-induced elevation of ageing-related changes by modulating the extent of oxidative stress (by upregulating the activities of antioxidant enzymes) and by regulating the activities of Na(+), K(+) ATPase, PKC and AChE. Therefore, it is suggested that curcumin counters aluminium-induced enhancement in ageing-related processes.