effect of folic acid and vitamin-c administration on paraoxonase and arylesterase -1 activities in rats intoxicated with lead

Paraoxonase and aryl-esterase-1 (pon-1) in serum of rats intoxicated with lead then administered folic acid and vitamin-c was investigated in forty male albino rats (160-190 g) randomly separated into 2 groups of 20 rats each namely: lead acetate (60 mg kg^ -1) and normal saline was given to each group for 6 weeks and there after administered folic acid (500 μg kg^ -1) and/or vitamin-c (60 mg kg^-1) orally for 4 weeks. blood sample was obtained at the end from each rat for biochemical assessment. results obtained indicated significant (p<0.05) reduction in activities of arylesterase (60.51±8.52 u l^-1) and paraoxonase (74.95±3.63 u l^-1) of non-supplemented, rats intoxicated with lead compared to 121.51±7.34 and 98.19±2.25 u l^-1 respectively for the control groups. similarly, the values of catalase (10.54±0.46 u mg^-1) and superoxide dismutase (4.93±0.66 u mg^-1), differ significantly (p<0.05) in the non-supplemented group intoxicated with lead as compared to 31.62±0.67 u mg^-1, and 28.46±1.54 u mg^-1 respectively for the control groups. malonyldialdehyde level (0.58±0.29 nmol l^-1) decreased significantly (p<0.05) in the control group as compared to the 5.21±0.16 nmol l^-1 observed in the non-supplemented group intoxicated with lead. significant (p<0.05) decrease was observed for high-density lipoprotein cholesterol level (41.08±0.48 mg l^-1) in the non-supplemented, rats intoxicated with lead as compared to the level (78.67±0.66 mg l^-1) noticed in the control group. findings from this study deduced that sub-chronically lead intoxication may cause cardiovascular diseases as evident in the decreased activities of arylesterase and paraoxonase. however, administration of folic acid and vitamin-c to the rats intoxicated with lead improves the catalytic activities of pon-1, and this may mitigate lead-induced cardiovascular disease risk.