Enzymatic Hydrolysis of Rutin: Evaluation of Kinetic Parameters and Anti-Proliferative, Mutagenic and Anti-Mutagenic Effects.

The bioavailability of glucoside flavonoids is influenced by the nature of the sugar, glucosides being absorbed faster than rhamnoglucosides, for example. One strategy to enhance the bioavailability is enzymatic hydrolysis. In this study, some kinetic parameters of hesperidinase-mediated hydrolysis of rutin were evaluated using an UHPLC/QTOF-MSE analysis of the products of a bioconversion reaction. The resulting hydrolyzed rutins (after 4, 8 and 12 h of reaction) were submitted to anti-proliferative and Cytokinesis-Block Micronucleus (CBMN) assays in CHO-K1 cells. In the hesperidinase-mediated hydrolysis, the final concentration of quercetin-3-O-glucoside (Q3G) was directly proportional to the rutin concentration and inversely proportional to the reaction time. At an anti-proliferative concentration (2.5 µg/mL), hydrolyzed rutin derivatives did not show a mutagenic effect, except for the sample with a higher content of Q3G (after 4 h of the enzymatic hydrolysis of rutin). Moreover, the higher Q3G content in hydrolyzed rutin protected the CHO-K1 cells 92% of the time against methyl methanesulfonate-induced mutagenic damage. These results suggested that the anti-mutagenic effect of hydrolyzed rutin might be related to antioxidant and cell death induction. Presenting a good lipophilicity/hydrophilicity ratio, together with antioxidant and anti-mutagenic activities, the hesperidinase-mediated hydrolyzed rutin seemed to be a promisor raw material for the development of food supplements.

Yellow-colored extract from cashew byproduct - Nonclinical safety assessment.

Natural and synthetic dyes are widely used in foodstuff, medicines and cosmetics industries to enhance and/or restore the color of the final products. This study aimed to evaluate the safety of oral consumption of one carotenoids and anacardic acids-enriched extract (CAE), obtained by green extraction from cashew apple residue fibers, a byproduct of the cashew juice industry. Presenting intense yellow color, CAE could be proposed as a new natural dye. Single and repeated-dose oral toxicity (30 days) were evaluated in female Swiss mice at doses ranging from 50 to 1000 mg/kg, while (anti)mutagenic effects were evaluated in CHO-K1 cells (in vitro Cytokinesis-Block Micronucleus assay - CBMN) and in erythrocytes collected from murine bone marrow (in vivo). CAE did not induce toxic or mutagenic effects in female mice even after 30 days of treatment, regardless of the dose used. Considering cyclophosphamide (CPA)-challenged animals treated with CAE, neither antimutagenic effect was observed nor CAE increased CPA-mutagenic effects although in vitro CBMN results indicated that CAE might increase methyl methanesulfonate-induced micronuclei (MN) frequency besides promoting reduction on CPA-induced MN frequency. The obtained results suggest that CAE may be a safe source of carotenoids with potential use as industrial dye.

Essential oil from fruit of Xylopia langsdorffiana: antitumour activity and toxicity.

CONTEXT: The genus Xylopia L. (Annonaceae) includes aromatic plants that have both nutritional and medicinal uses. Essential oils of Xylopia species have antitumour effects. However, the efficacy of the essential oil from the fruit of Xylopia langsdorffiana St. Hil & Tul. (EOX) has not been examined. OBJECTIVE: EOX was evaluated to determine its chemical composition, antitumour activity and toxicity. MATERIALS AND METHODS: EOX was obtained from fresh fruits of X. langsdorffiana subjected to hydrodistillation, and gas chromatography-mass spectrometry was used to characterize the chemical composition of EOX. The toxicity of EOX was evaluated using haemolysis, acute toxicity and micronucleus assays. The in vitro antitumour activity of EOX was investigated using the sulforhodamine B assay. The sarcoma 180 murine tumour model was used to evaluate the in vivo antitumour activity and toxicity of EOX (50 and 100 mg/kg) after 7 d of treatment. RESULTS: The major components of EOX were α-pinene (34.57%) and limonene (31.75%). The HC50 (concentration producing 50% haemolysis) was 293.6 µg/ml. EOX showed greater selectivity for the leukaemia cell line K562, with total growth inhibition (TGI) (concentration producing TGI) of 1.8 µg/ml, and for multidrug-resistant ovarian tumour cell line NCI/ADR-RES (TGI of 45.4 µg/ml). The LD50 was approximately 351.09 mg/kg. At doses of 50 and 100 mg/kg, EOX inhibited the in vivo growth of sarcoma 180 by 38.67 and 54.32%, respectively. EOX displayed minor hepatic alterations characteristic of acute hepatitis and induced no genotoxicity. CONCLUSION: EOX showed in vitro and in vivo antitumour activity and low toxicity, which warrants further pharmacological studies.