ABSTRACT
Background: The role of heavy metals in the etio-pathogenesis of attention deficit hyperactivity disorder (ADHD) is a burning enigma. The available studies with discordant results are from different geographical localities with different monitoring, regulations and sociocultural backgrounds. The differential association of heavy metals with ADHD severity and phenotypes has not been adequately examined. Also, there are concerns about laboratory quality control. Therefore, the present case control study was formulated.Methods: Thirty children with ADHD diagnosed by DSM IV criteria and thirty group age matched controls were enrolled. Detailed perinatal, past, developmental and possible exposure history to various heavy metals was taken. Severity of ADHD was assessed using ConnersTM Parent reporting questionnaire. Blood level of metals was estimated by inductively coupled plasma- atomic emission spectroscopy (ICP-AES).Results: The mean blood lead, mercury, cadmium, arsenic, zinc were comparable in children with ADHD and group age matched controls. The mean blood lead, mercury and cadmium levels in study population was higher than found in studies from developed countries. Elevated arsenic, mercury and cadmium were found in both cases and controls. Blood zinc correlated significantly with inattention T score and blood mercury with hyperactivity-impulsitivity T score of Conners parent rating scale. Blood cadmium was present in greater proportion of predominant hyperactive-impulsive type patients.Conclusions: Zinc deficiency correlates with inattention; cadmium and mercury toxicity correlate with hyperactivity. Mean blood levels of heavy metals is elevated in a substantial proportion of study population. So, there is an urgent need for sensitization and environmental control.
ABSTRACT
The effect of curcumin, a dietary antioxidant was studied against kainic acid (KA)-induced seizures and on markers of oxidative stress. Rats were administered KA (10 mg/kg, ip) and observed for behavioral changes, incidence and latency of convulsions and mortality over four hours. The rats were thereafter sacrificed for estimation of oxidative stress parameters; malondialdehyde (MDA) and glutathione (GSH). Curcumin was administered 30 min before KA at doses of 50, 100 and 200 mg/kg, ip. KA induced long-lasting seizures and associated symptoms. The brain level of MDA was significantly (P<0.05) raised after KA administration (536±44 nmol/g wet tissue) as compared to saline treated group (200±36 nmol/g wet tissue) and significantly decreased the levels of GSH. Pretreatment with curcumin (100 and 200 mg/kg, ip) significantly increased the latency of seizures (120+20 min and 115±5.7 min respectively) as compared to the vehicle treated KA group. Curcumin (100 and 200 mg/ kg, ip) significantly prevented the increase in MDA levels and ameliorated the fall in glutathione. Curcumin at the dose of 50 mg/kg had no effect on any of oxidative stress parameters. The study reports the potential antiepileptic effect of antioxidant curcumin.