Black Tea Prevents Cigarette Smoke-Induced Oxidative Damage of Proteins in Guinea Pigs

Abstract

Cigarette smoke (CS) causes oxidative damage and tea polyphenols have strong antioxidant properties. Therefore, we studied the effect of a black tea (BT) infusion on CS-induced oxidative damage of proteins both in vitro and in vivo. In the in vitro experiment, bovine serum albumin (BSA) or a guinea pig tissue microsomal suspension was incubated with an aqueous extract of CS (CS-solution) in the presence or absence of the BT infusion. Protein oxidation was measured by immunoblotting of the dinitrophenylhydrazone derivatives of the protein carbonyls followed by densitometric scanning. Protein degradation was assessed by SDS-PAGE. BT prevented (P < 0.05) CS-induced oxidation of BSA and oxidative degradation of guinea pig lung, liver and heart microsomal proteins. This was also observed when the BT infusion was replaced by its components, i.e, flavonols, theaflavins, thearubigins and catechins. BT prevented microsomal protein degradation by inhibiting oxidative modification of the proteins. The antioxidant effect of BT was similar to that of green tea. In the in vivo experiment, partially ascorbate-deficient guinea pigs were subjected to CS exposure from 5 cigarettes/(guinea pig. d) for 7 d and given water or the BT infusion (20 g/L) to drink. Guinea pigs exposed to CS and given water had extensive oxidation accompanied by 39, 40 and 30% losses (P < 0.05) of microsomal proteins of lung, liver and heart, respectively. However, when the CS-exposed guinea pigs consumed the BT infusion instead of water, the oxidation of microsomal proteins was reduced (P < 0.05) approximately 90, 97 and 70% in lung, liver and heart, respectively. Protein loss was reduced (P < 0.05) approximately 92, 98 and 90% in lung, liver and heart, respectively. The results, if extrapolated to humans, would indicate that regular intake of tea may protect smokers from CS-induced oxidative damage and consequent degenerative diseases.

Protective effect of black tea extract on the levels of lipid peroxidation and antioxidant enzymes in liver of mice with pesticide-induced liver injury

“…15 Nevertheless, not many studies in the current literature have substantially emphasized the in vivo role of black tea, despite the fact that it happens to be the most widely consumed non-alcoholic beverage, second only to water. 16 Further, many studies proclaim the beneficial effects of black and green tea to be identical.…”

Fermentation: The Key Step in the Processing of Black Tea

“…During the fermentation of tea, the conversion of catechins to TF does not significantly change the antioxidant activities of tea (Halder and Bhaduri, 1998;Chan et al, 2007). Black tea prevents cigarette smokeinduced oxidative damage of proteins in guinea pigs, as reported by Misra et al (2003). It was reported that if these results were extrapolated to humans, black tea may prevent cigarette smoke-induced oxidative damage and consequent degenerative diseases.…”

Modulatory effects of black tea polyphenols on oxidant–antioxidant profile and expression of proliferation, apoptosis, and angiogenesis-associated proteins in the rat forestomach carcinogenesis model

“…Black tea polyphenols have been demonstrated to exert their antioxidative properties by chelating metal ions, preventing free radical generation, and inhibiting lipid and protein oxidation. 31,32 Tea has been reported to downregulate PCNA and GST-π in experimental colon carcinogenesis. 33,34 Banerjee et al 35 found a positive correlation between the antiproliferative and proapoptotic effects of black tea polyphenols during benzo[a]pyreneinduced lung carcinogenesis.…”