Ginger extract modulates Pb-induced hepatic oxidative stress and expression of antioxidant gene transcripts in rat liver

Abstract

Context: Spices and herbs are recognized sources of natural antioxidants that can protect from oxidative stress, thus play an important role in chemoprevention of liver diseases. Ginger is used worldwide primarily as a spicy condiment. Objective: This study evaluated the ability of ginger extract (GE) to ameliorate oxidative-hepatic toxicity induced by lead acetate (PbAc) in rats. Materials and methods: Five groups of animals were used: group I kept as control; groups II, IV, and V received PbAc (1 ppm in drinking water daily for 6 weeks, and kept for an additional 2 weeks without PbAc exposure); group III treated orally with GE (350 mg/kg body weight, 4 d per week) for 6 weeks; group IV (protective) received GE for 2 weeks before and simultaneously with PbAc; and group V (treatment) received GE for 2 weeks after PbAc exposure. Results: GC-MS analysis of GE revealed its content of gingerol (7.09%), quercetin (3.20%), DL-limonene (0.96%), and zingiberene (0.18%). Treatment of PbAc-treated rats with GE has no effect on hepatic Pb concentrations. However, it maintained serum aspartate aminotransferase level, increased hepatic glutathione (157%), glutathione S-transferase (GST) (228%), glutathione peroxidase (GPx) (138%) and catalase (CAT) (112%) levels, and reduced hepatic malondialdehyde (80%). Co-treatment of PbAc group with GE upregulated mRNA expression of antioxidant genes: GST-a1 (1.4-fold), GPx1 (1.8-fold), and CAT (8-fold), while post-treatment with GE upregulated only mRNA expression of GPx1 (1.5-fold). Conclusion: GE has an antioxidant protective efficacy against PbAc-induced hepatotoxicity, which appears more effective than its therapeutic application. However, the changes in antioxidant gene expression were not reflected at the protein level.

A potential mechanism associated with lead-induced testicular toxicity in rats

“…Pb concentration in testicular and epididymal tissue samples was measured by atomic absorption spectrophotometry (Perkin‐Elmer Model 400, Shelton, CT, USA) as previously described by Mohamed, El‐Nahas, El‐Sayed, and Ashry (). Serum and testicular concentrations of testosterone were measured by commercial radioimmunoassay (RIA) kit from Immunotech (Beckman Coulter, Marseille, France), and 17β‐oestradiol concentrations were estimated by RIA using Spectria Estradiol RIA kit (Orion Diagnostica Oy, Espoo, Finland) according to the manufacturer's instructions and as previously described (Zamrazilova, Sosvorova, Heracek, Sobotka, & Hampl, ).…”

“…Catalase (CAT) activity was determined according to the method described by Aebi () and as previously described by Mohamed et al. (). Lipid peroxide (LPO) was estimated spectrophotometrically by measuring the concentration of malondialdehyde (MDA), an end product of LPO, after the reaction with thiobarbituric acid to form thiobarbituric acid‐reactive substances (TBARs), as described by Mabrouk and Ben Cheikh ().…”

Chronic exposure to low doses of Pb induces hepatotoxicity at the physiological, biochemical, and transcriptomic levels of mice

“…Pb has been found to derail the antioxidant defense system by interfering with the metals that are essential for antioxidant enzyme activities, supporting the role of oxidative stress in lead hepatotoxicity . Recently, a number studies indicated that Pb exposure could induce oxidative stress by increasing ROS and MDA levels and disrupting the activities of some antioxidant enzymes such as SOD, GST, and GSH in different laboratory animals . Reports by Alya et al indicated that MDA levels and SOD activity in the liver and kidney increased significantly in female rats when exposed to 50 mg Pb/l for 40 and 65 days.…”

“…Metal‐induced alterations in antioxidant enzyme activities have been extensively studied . Pb has been found to derail the antioxidant defense system by interfering with the metals that are essential for antioxidant enzyme activities, supporting the role of oxidative stress in lead hepatotoxicity . Recently, a number studies indicated that Pb exposure could induce oxidative stress by increasing ROS and MDA levels and disrupting the activities of some antioxidant enzymes such as SOD, GST, and GSH in different laboratory animals .…”

Identification of zingiber components by gas chromatograph/mass spectrometer and semi-empirical calculations

“…The identification of a component by its retention time (GC) and fragmentation pattern (MS), along with sample specific information afforded to make GC-MS the foremost confirmation method for analyzing herbal extract [7]. Up to date, gas chromatography-mass spectrometry (GC-MS) has played the most important role in the identification of the chemical composition of medical plants [8][9][10].…”