Prominent free radicals scavenging activity of tannic acid in lead-induced oxidative stress in experimental mice

Abstract

Lead (Pb) is known to disrupt the pro-oxidant/antioxidant balance of tissues leading to biochemical and physiological dysfunction. The present study was designed to investigate the effect of tannic acid on some biochemical parameters in Swiss albino mice exposed to lead acetate. The levels of thiobarbaturic acid-reactive substances (TBARS) as an index of lipid peroxidation, nitric oxide (NO), and serum lead (Pb) were significantly increased following intragastric administration of 50 micromole lead acetate/kg body weight three times a week, every other day for three weeks, compared to the corresponding control values. On the other hand, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione-S-transferase (GST) and glutathione content (GSH) and serum copper (Cu) and zinc (Zn) were significantly diminished relative to the control values. The administration of 20 mg tannic acid/kg body weight three times a week every other day for three weeks, enhanced the endogenous antioxidant capacity of the cells by increasing the activities of antioxidant enzymes (SOD, CAT, GSH-R, GST), GSH content and serum Cu and Zn levels. Compared to the lead acetate-exposed group, the levels of TBARS, NO and Pb were decreased in the lead acetate exposed group treated with tannic acid. These results afford evidence supporting the hypothesis that lead induces oxidative stress in hepatic cells. Moreover, tannic acid has a potential in sustaining global antioxidant effect in hepatic cells leading to decreased oxidative stress and cellular damage initiated through free radical production by lead acetate.

Effect of oral administration of ethanolic root extract of Tinospora cordifolia on aflatoxin B1-induced toxicity in swiss albino mice

“…A major defense mechanism in the human system involves the antioxidant enzymes including SOD, CAT and GPx which convert active oxygen molecules into non-toxic compounds, which include free radical scavengers and chain reaction terminators. [46,47] They also play an important role in balancing between free radical generation and scavenging reaction in cell and thus maintaining optimum level of free radicals. SOD, CAT, GPx and GR constitute a mutually supportive team of defense against reactive oxygen species (ROS).…”

Oxidative stress and metal carcinogenesis

“…One of the main mechanisms of Pb-mediated oxidative damage is due to the direct formation of ROS including singlet oxygen, H 2 O 2 , and hydroperoxides [179]. Another mechanism is involved in Pb-mediated depletion of the cellular antioxidant pool; Pb not only decreases GSH level and GR activity but also inhibits recycling of oxidized glutathione and reduces CAT, SOD, and GPx levels [180,181]. This mechanism is also related to the ability of Pb to enhance the toxic potential of other carcinogenic metals.…”

Free Radicals and Gastric Cancer

“…Flavonoids are known to have antioxidant activity and various foods are containing such components as blueberry, onion, lettuce, tomato, and tea (Crozier et al, 2000). Tea is a good scavenger of free radicals as indicated previously (El-Sayed et al, 2006;Oyama et al, 2010).…”