Green tea activity and iron overload induced molecular fibrogenesis of rat liver

Abstract

Iron overload toxicity was shown to associate with chronic liver diseases which lead to hepatic fibrosis and subsequently the progression to cancer through oxidative stress and apoptotic pathways. Green tea potential activity as chelating, anti-oxidative, or anti-apoptotic mechanisms against metal toxicity was poorly clarified. Here, we are trying to evaluate the anti-oxidant and anti-apoptotic properties of green tea in the regulation of serum hepcidin levels, reduction in iron overloads, and improve of liver fibrosis in iron overloaded experimental rats. Three groups of male adult rats were randomly classified into three groups and treated as follows: control rats, iron treated rats for two months in drinking water followed by either vehicle or green tea extract (AGTE; 100 mg/kg) treatment for 2 more months. Thereafter, we studied the effects of AGTE on iron overload-induced lipid peroxidation, anti-oxidant depletion, liver cell injury and apoptosis. Treatment of iron-overloaded rats with AGTE resulted in marked decreases in iron accumulation within liver, depletion in serum ferritin, and hepcidin levels. Iron-overloaded rats had significant increase in malonyldialdehyde (MDA), a marker of lipid peroxidation and nitric oxide (NO) in liver when compared to control group. Also, significant change in cytochrome c and DNA content as apoptotic markers were reported in iron treated rats. The effects of iron overload on lipid peroxidation, NO levels, cytochrome c and DNA content were significantly reduced by the intervention treatment with AGTE (P < 0.001). Furthermore, the endogenous anti-oxidant capacities/levels (TAC) in liver were also significantly decreased in chronic iron overload and administration of AGTE restored the decrease in the hepatic antioxidant activities/levels. Also, hepatic hepcidin was shown to be significantly correlated with oxidative and apoptotic relating biomarkers as well as an improvement in liver fibrosis of iron treated rats following AGTE treatment. In-vitro analysis showed that, the improvement in iron toxicity of the liver depend mainly on antioxidant and protective ability of green tea polyphenolic compounds especiallyepigallocatechin-3-gallate (EGCG). Our study showed that green tea extract (GTE) ameliorates iron overload induced hepatotoxicity, apoptosis and oxidative stress in rat liver via inhibition of hepatic iron accumulation; improve of liver antioxidant capacity, and down regulation of serum hepcidin as well as reduction in the release of apoptotic relating proteins.

Circulating Hypoxia Responsive microRNAs (HRMs) and Wound Healing Potentials of Green Tea in Diabetic and Nondiabetic Rat Models

“…Total flavonoid (TFC) and phenolic contents (TPC) were estimated spectrophotometrically in green tea extract by using 2% aluminum chloride and diluted Folin-Ciocalteu as reagents [42–44]. The absorbance of the reaction mixtures produced was measured at 430 nm and 725 nm respectively as previously reported [44]. Standard calibrated curves of rutin and Gallic Acid were used to estimate flavonoids and poly phenolic compounds in green tea samples.…”

“…Standard calibrated curves of rutin and Gallic Acid were used to estimate flavonoids and poly phenolic compounds in green tea samples. The data obtained were expressed in mg rutin equivalent (RE) per g for flavonoids and Gallic Acid Equivalents/100 mg for poly phenolic compounds, respectively [42–44]. Epigallocatechin 3-gallate (EGCG) as active constituent was estimated in green tea extract by using HPLC method.…”

“…Epigallocatechin 3-gallate (EGCG) as active constituent was estimated in green tea extract by using HPLC method. EGCG content was estimated in 32% (w/w) of the GTE product and was kept in the dark at −20°C until studied [44–46].…”

“…The data were measured by using spectrophotometric analysis as previously reported [44, 47–49]. Various concentrations from the extracted green tea were prepared in hot water and both radical scavenging and antioxidant activities of green tea against DPPH and β -Carotene-linoleic acid were estimated as absorbance at λ = 517 nm according toT1Radical scavenging activity%=Ac−AsAc×100(See [44]) where (Ac) is the absorbance of the control and (As) is the absorbance of the sample.T1Antioxidant activity%=Abs0−Ab…”

“…Nitric oxide (NO) was estimated as nitrite, a stable NO oxidation product in the tissue homogenates from excised wounds of all studied treated and nontreated groups. It was assessed in the tissue homogenates via using the Griess reaction method as described previously [44, 62]. Equal volumes of standard (0–100 mol/L Na nitrite) or sample were added to the Griess reagent which consisted of equal volumes of 10 g/L sulfanilamide (in 0.5%, nitrite free H 3 PO 4 ) and 1 g/L of naphthylethylenediamine.…”