ANTIOXIDANT EFFECTS OF Convolvulus pluricalus IN RAT BRAIN MITOCHONDRIA AGAINST OXIDATIVE DAMAGE INDUCED BY GAMMA RADIATION AND PHOTOSENSITIZATION

摘要

Aqueous and methanolic extracts of natural herb, Convolvulus pluricalus (CP) was monitored for their antioxidant ability against photosensitization and radiation induced damages in rat brain mitochondria. Both the extracts of CP (50 mu g /ml assay) showed significant protection against the formation of the lipid peroxidation product, TBARS. Protein oxidation and degradation of proteins was shown to be significantly high following photosensitization, while CP extracts could effectively modify these damages. Exposure ofplasmid DNA pBR322 to gamma radiation resulted in enhanced formation of single strand breaks (SSB). Simultaneous treatment of pBR322 DNA with CP extracts during radiation effectively prevented the damage. Further, these extracts also showed inhibition against stable radicals, 2, 2'- azino-bis (3- ethylbenzthiazoline-6- sulfonic acid (ABTS) and 1, 1-diphenyl-2-picryl hydrazyl (DPPH). The scavenging capacity of the extracts was quantified by pulse radiolysis experiments. Hence, Convolvulus pluricalus may emerge as potent antioxidant/radioprotector, capable of scavenging singlet oxygen, hydroxyl radical, as well as other stable radicals, ABTS and DPPH.