Effect of decaffeination of green and roasted coffees on the in vivo antioxidant activity and prevention of liver injury in rats

Decaffeination and roasting affects the composition of the chlorogenic acids in coffee, which have antioxidant potential. The aim of this study was to evaluate the effects of coffee decaffeination on the in vivo antioxidant activity and the prevention of liver damage. The Wistar rats received intraperitoneal doses of carbon tetrachloride and daily doses of Arabica coffee brews (whole and decaffeinated, both green and roasted) by gavage for fifteen days. The activity of liver marker enzymes aspartate aminotransferase, alanine aminotransferase and serum albumin were measured as well as the quantification of the thiobarbituric acid reactive species and the content of liver total lipids. Aspartate aminotransferase and alanine aminotransferase are good indicators of liver damage: the results showed that all studied coffee brews decreased the activity of aspartate aminotransferase and alanine aminotransferase, and liver levels of thiobarbituric acid reactive species and total lipids. The compounds presents in coffee brews are able to decrease the hepatic lipid peroxidation induced by carbon tetrachloride, making a significant hepatoprotective effect, in accordance with the liver function tests. The coffee brews are hepatoprotective regardless of the decaffeination process and our results suggest a better protection against liver damage for the roasted coffee brews compared with green coffee brews.

Avaliação in vitro da atividade antioxidante do extrato hidroalcoólico de folhas de bardana / In vitro evaluation of the antioxidant activity of the hydroalcoholic extract of leaves of bardana

A atividade antioxidante do extrato hidroálcoólico de folhas de bardana (EEB), das frações acetato de etila (ACE) e hexano (HEX) foi avaliada por meio de testes in vitro. O EEB e frações inibiram a peroxidação lipídica em homogeneizado de cérebro de rato, com IC50 de 0,136 ± 0,015; 0,218 ± 0,049 e 0,628 ± 0,092 mg/mL para o EEB, ACE e HEX respectivamente. O EEB, ACE e HEX apresentaram atividade seqüestrante de radicais DPPH, com IC50 de 0,029 ± 0,006; 0,089 ± 0,003 e 0,837 ± 0,160 mg/mL respectivamente. A capacidade antioxidante total do EEB foi significativamente maior (p<0,001) que a das frações sendo de 267,20; 55,49 e 50,02 mM de ácido ascórbico, respectivamente, para o EEB, ACE e HEX. O EEB apresentou 7,88 ± 0,25 por cento (m/m) de compostos fenólicos, que foi significativamente (p<0,001) diferente das ACE e HEX. Os resultados indicam que os extratos analisados apresentam atividade antioxidante, sendo que o EEB foi o mais eficiente. Este é o primeiro trabalho demonstrando a atividade antioxidante de folhas de bardana.

The antioxidant activity of the hydroalcoholic extract of leaves of bardana (EEB), the ethyl acetate (ACE) and hexane (HEX) fractions were evaluated by in vitro assays. The EEB and fractions inhibited the lipid peroxidation in rat brain homogenate, with IC50 of 0.136 ± 0.015; 0.218 ± 0.049 and 0.628 ± 0.092 mg/mL for BEE, EAC and HEX respectively. The EEB, ACE and HEX presented DPPH radical scavenging-activity, with IC50 of 0.029 ± 0.006; 0.089 ± 0.003 and 0.837 ± 0.160 mg/mL respectively. The total antioxidant capacity of the EEB was significantly (p<0.001) higher than the fractions, being 267.20; 55.49 and 50.02 mM of ascorbic acid, respectively for EED, ACE and HEX. The ethanol extract presented 7.88 ± 0.25 percent (w/w) of phenolic compounds that was significantly (p<0.001) different from the ACE and HEX fractions. The results indicate that the analyzed extracts present antioxidant activity, and the EEB was the most efficient. This is the first report on the antioxidant activity of bardana leaves.