Browsing by Author "Ribeiro, Maria H."
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- Anti-inflammatory activity of naringin and the biosynthesised naringenin by naringinase immobilized in microstructured materials in a model of DSS-induced colitis in micePublication . Amaro, Maria Ines; Rocha, Joao; Vila-Real, Helder; Eduardo-Figueira, Maria; Mota-Filipe, Helder; Sepodes, Bruno; Ribeiro, Maria H.A great number of antioxidants are naturally present in citrus juice, being responsible for their potentially protective action against inflammation. Naringin, a bitter compound, in citrus, is hydrolysed by naringinase into tasteless naringenin and to rhamnose and glucose. The aim of this study was to evaluate the anti-inflammatory activity of naringin and naringenin in an acute model of induced colitis in mice. Microstructured particles were used for naringinase immobilization. The influence of naringin and naringinase concentration on the bioconversion was evaluated through a central composite design. Colitis was induced by feeding mice 7% dextran sodium sulphate (DSS) dissolved in drinking water for 5 days. Intestine dry/wet weight ratio (indicator of intestine edema), nitrates/nitrites (indicators of inflammatory process), and tissue malondialdehyde levels (indicator of lipid peroxidation) were evaluated. Our results indicate that treatment with both naringin and naringenin significantly reduced the formation of intestine edema, suggesting an anti-inflammatory activity in this model of colitis in mice. (C) 2009 Elsevier Ltd. All rights reserved.. - Fundacao para a Ciencia e Tecnologia, Portugal [SFRH/BD/30716/2006]. - Helder Vila Real was supported by Fundacao para a Ciencia e Tecnologia, Portugal. Grant No. SFRH/BD/30716/2006.
- Effect of naringin enzymatic hydrolysis towards naringenin on the anti-inflammatory activity of both compoundsPublication . Ribeiro, Isabel A.; Rocha, Joao; Sepodes, Bruno; Mota-Filipe, Helder; Ribeiro, Maria H.The aim of this work was the hydrolysis of naringin towards naringenin with immobilized naringinase and the evaluation of their anti-inflammatory activity. An acute local inflammation model (rat paw edema induced by X-carrageenan) was chosen to evaluate the contribution of antioxidant properties to a possible anti-inflammatory effect. Grapefruit juice was processed with naringinase immobilized in k-carrageenan (2%) beads (approximate to 3 mm). A 95% naringin conversion in grapefruit juice was obtained with immobilized naringinase (1000 mg L-1), with an activity of 19.5 mg mL(-1) min(-1) and the formation of 215 mg L-1 of naringenin. Ascorbic acid and indometacine were used as positive anti-inflammatory controls. All results were analysed using ANOVA with Dunnett's Post-test. The results show that rats (n = 9) pre-treated with a solution of naringin, rats (n = 9) pre-treated with a solution of naringenin (in concentrations equal as in grapefruit juice) and rats (n = 9) treated with a solution of naringenin and naringin, revealed a significant reduction on edema formation, 6h after X-carrageenan injection. Naringenin demonstrated a high in vivo anti-inflammatory activity, only 8% of paw edema (p0.001) was observed in rats pre-treated with a solution of naringenin. Comparability studies, in rats administered orally with grapefruit juice (before and after processing), showed that enzymatic processing did not affect the anti-inflammatory properties of the juice. (C) 2007 Elsevier B.V. All rights reserved.
- Immobilization of naringinase by selective adsorption and covalent binding to microstructured particlesPublication . Russo, Joana; Barreiro, Maria Ines; Vila-Real, Helder; Ribeiro, Maria H.