Screening for antioxidant activity of local herbs and sample preparation and time response for development of toxicity of oxidative stress induced by xanthine and xanthine oxidase / Noorul Aimi Daud

Nineteen types Malaysian herbs were investigated for their antioxidant capacity by the radical scavenging assay measured by photochemiluminescence. The highest antioxidant capacity was found in Eugenia Polyanthum (daun salam), followed by Diplazium Esculentum (pucuk paku). Oxygen free radicals (OFRs) generated during biological processes are reportedly involved in the pathogenesis of several disease states. Xanthine solution (0.025 mg/ml) was prepared in normal saline. A system for generation of OFRs in vivo that was commonly employed was obtained by injection of X (0.25 mg/kg) and XO (0.025 mg/ml) to mice via the tail veins. This study was conducted as a replacement for the initial study planned which was to look at the toxicity of Diplazium Esculentum extract. The objective of the present study was to determine the time response for development of oxidative stress (as evidenced by lipid peroxidation) and also to document effects of X+XO on several blood parameters. Mice were administered with X+XO (i.v) and sacrificed at 0, 1,6 and 24 hours later. Another group of mice given only normal saline was also sacrificed at 0 hour to act as control for the group given X+XO and killed at 0 h. Results of the study showed that the development of lipid peroxidation by X+XO is dependent upon time. Lipid peroxidation in the lungs develops after 6h while that in the liver developed after Ih of X+XO administration but was resolved by 24h while lung lipid peroxidation continued to occur. Upon necropsy, mice given X+XO showed heamorrhage in the lungs although the weight of lung relative to the body weight was not changed. X+XO did not cause lipid peroxidation in the kidney or heart. When blood was analysed, X+XO was not found to change the liver maker enzyme indicating that the liver lipid peroxidation did not lead to leakage of glutamate oxalo-acetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) into the blood. X+XO administration however, did cause some muscle damage initially and also some increase in protein catabolism as evidenced by an increase in Blood Urea Nitrogen (BUN). In summary, X+XO is an effective system and can be used to induce lipid peroxidation in vivo.