Free-radical scavenging by Ouratea parviflora in experimentally-induced liver injuries.

The antioxidant potential of crude extracts and fractions from leaves of Ouratea parviflora, a Brazilian medicinal plant used for the treatment of inflammatory diseases, was investigated in vitro through the scavenging of radicals 2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), hydroxyl radical (HO*), superoxide anion (O2*-), and lipid peroxidation in rat liver homogenate. The crude extract (CEOP) and hydro-alcoholic fraction (OP4) showed strong inhibitory activity toward lipid peroxidation induced by tert-butyl peroxide (IC50 = 2.3 +/- 0.2 and 1.9 +/- 0.1 microg/ml, respectively). The same products exhibited a strong concentration-dependent inhibition of deoxyribose oxidation (14.9 +/- 0.2 and 0.2 +/- 0.1 microg/ml, respectively), and also showed a considerable antioxidant activity against O2*- (87.3 +/- 0.1 and 73.1 +/- 0.4 microg/ml, respectively) and DPPH radicals (55.4 +/- 0.3 and 38.3 +/- 0.4 microg/ml, respectively). The protective effects of CEOP and OP4 were also studied in mouse liver. CCl4 significantly increased (by 90%) levels of lipid hydroperoxides, carbonyl protein content (64%), DNA damage index (133%), aspartate aminotransferase (261%), alanine aminotransferase (212%), catalase activity (23%), and also caused a decrease of 60% in GSH content. The results showed that CEOP and OP4 exerted cytoprotective effects against oxidative injury caused by CCl4 in rat liver, probably related to the antioxidant activity showed by the in vitro free radical scavenging property.

Increased micronucleated cell frequency related to exposure to radiation emitted by computer cathode ray tube video display monitors

It is well recognized that electromagnetic fields can affect the biological functions of living organisms at both cellular and molecular level. The potential damaging effects of electromagnetic fields and very low frequency and extremely low frequency radiation emitted by computer cathode ray tube video display monitors (VDMs) has become a concern within the scientific community. We studied the effects of occupational exposure to VDMs in 10 males and 10 females occupationally exposed to VDMs and 20 unexposed control subjects matched for age and sex. Genetic damage was assessed by examining the frequency of micronuclei in exfoliated buccal cells and the frequency of other nuclear abnormalities such as binucleated and broken egg cells. Although there were no differences regarding binucleated cells between exposed and control individuals our analysis revealed a significantly higher frequency of micronuclei (p < 0.001) and broken egg cells (p < 0.05) in individuals exposed to VDMs as compared to unexposed. We also found that the differences between individuals exposed to VDMs were significantly related to the sex of the individuals and that there was an increase in skin, central nervous system and ocular disease in the exposed individuals. These preliminary results indicate that microcomputer workers exposed to VDMs are at risk of significant cytogenetic damage and should periodically undergo biological monitoring.