Tropical Isabella grape juices: bioactive compounds and antioxidant power depends on harvest season.

Grapes are important sources of antioxidants compounds and one of the most used varieties to elaborate juices is 'Isabel', or 'Isabella', as it is called in North-America. This study aimed to evaluate the antioxidant activity of Isabella grape juices from the tropical semi-arid climate produced in Brazil on March and September, 2010. Total phenolics and anthocyanins were determined, as well as the antioxidant capacity by DPPH, FRAP and hydrophilic ORAC methods. Test T was used to compare statistical difference at 5% of significance level. As expected, the results showed that the season can play a significant role on phenolics content and antioxidant power. Polyphenols content in juices varied from 82.9 ± 0.92 to 102.2 ± 1.59 mg GAE 100 mL-1 and anthocyanins content ranged from 44.3 ± 2.01 to 129.5 ± 2.82 mg cyanidin-3-glucoside 100 mL-1. Regression analyses showed a high correlation of antioxidant capacity and anthocyanins content. Grapes from Sao Francisco River Valley demonstrated to be a good source of antioxidant for human diet

Anti-malarial activity and toxicity assessment of Himatanthus articulatus, a plant used to treat malaria in the Brazilian Amazon

Background: Plasmodium falciparum has become resistant to some of the available drugs. Several plant species are used for the treatment of malaria, such as Himatanthus articulatus in parts of Brazil. The present paper reports the phyto-chemistry, the anti-plasmodial and anti-malarial activity, as well as the toxicity of H. articulatus. Methods: Ethanol and dichloromethane extracts were obtained from the powder of stem barks of H. articulates and later fractionated and analysed. The anti-plasmodial activity was assessed against a chloroquine resistant strain P. falciparum (W2) in vitro, whilst in vivo anti-malarial activity against Plasmodium berghei (ANKA strain) was tested in mice, evaluating the role of oxidative stress (total antioxidant capacity - TEAC; lipid peroxidation – TBARS, and nitrites and nitrates - NN). In addition, cytotoxicity was evaluated using the HepG2 A16 cell-line. The acute oral and sub-chronic toxicity of the ethanol extract were evaluated in both male and female mice. Results: Plumieride was isolated from the ethyl acetate fraction of ethanol extract, Only the dichloromethane extract was active against clone W2. Nevertheless, both extracts reduced parasitaemia in P. berghei-infected mice. Besides, a significant reduction in pulmonary and cerebral levels of NN (nitrites and nitrates) was found, as well as in pulmonary TBARS, indicating a reduced oxidative damage to these organs. The ethanol extract showed low cytotoxicity to HepG2 A16 cells in the concentrations used. No significant changes were observed in the in vivo toxicity studies. Conclusions: The ethanol extract of H. articulatus proved to be promising as anti-malarial medicine and showed low toxicity

The use of oak chips during the fermentation process: effects on phenolic compounds profile and antioxidant activity in Syrah young wines.

The use of oak chips is an alternative method to the traditional barrels in winemaking in order to improve the aged quality of the red wines. This study investigated the influence of adding of oak chips during the fermentation process on phenolic compounds profile and antioxidant activity. The American (Quercus alba) and/or French (Quercus petreae) oak chips were added (4 g L?1 doses) in the alcoholic fermentation and malolactic fermentation or malolactic fermentation alone. Results indicated that Syrah tropical wines presented higher levels (?265 mg L?1) of phenolic compounds compared to wines fermented with oak chips (223?254 mg L?1). Twenty-five phenolics were identified among the wine samples, with gallic (70.67 mg L?1) and malvidin-3-O-glucoside (68.30 mg L?1) as the main compounds. However, the wine with French oak chip added during malolactic fermentation showed a higher antioxidant activity, when using ORAC assay. This study offers a practical application of oak chips in winemaking process as an alternative to produce high quality young red wines with low cost to the wineries in places of oak barrels

Fracturing and fluid-flow during post-rift subsidence in carbonates of the Jandaira Formation, Potiguar Basin, NE Brazil

Pervasive fracture networks are common in many reservoir-scale carbonate bodies even in the absence of large deformation and exert a major impact on their mechanical and flow behaviour. The Upper Cretaceous Jandaíra Formation is a few hundred meters thick succession of shallow water carbonates deposited during the early post-rift stage of the Potiguar rift (NE Brazil). The Jandaíra Formation in the present onshore domain experienced 1000 km2. The carbonates have a gentle, 400–500 m. Deformation was accommodated by a dense network of sub-vertical mode I and hybrid fractures associated with sub-vertical stylolites developed in a stress field characterised by a sub-horizontal σ1 and sub-vertical σ2. The development of a network of hybrid fractures, rarely reported in the literature, activated the circulation of waters charged in the mountainous region, flowing along the porous Açu sandstone underlying the Jandaíra carbonates and rising to the surface through the fractured carbonates. With persisting subsidence, carbonates reached depths of 800–900 m entering a depth interval characterised by a sub-vertical σ1. At this stage, sub-horizontal stylolites developed liberating calcite which sealed the sub-vertical open fractures transforming them in veins and preventing further flow. During Tertiary exhumation, several of the pre-existing veins and stylolites opened and became longer, and new fractures were created typically with the same directions of the older features. The simplicity of our model suggests that most rocks in passive margin settings might have followed a similar evolution and thus display similar structures

Tropical Isabella grape juices: bioactive compounds and antioxidant power depends on harvest season.

Grapes are important sources of antioxidants compounds and one of the most used varieties to elaborate juices is 'Isabel', or 'Isabella', as it is called in North-America. This study aimed to evaluate the antioxidant activity of Isabella grape juices from the tropical semi-arid climate produced in Brazil on March and September, 2010. Total phenolics and anthocyanins were determined, as well as the antioxidant capacity by DPPH, FRAP and hydrophilic ORAC methods. Test T was used to compare statistical difference at 5% of significance level. As expected, the results showed that the season can play a significant role on phenolics content and antioxidant power. Polyphenols content in juices varied from 82.9 ± 0.92 to 102.2 ± 1.59 mg GAE 100 mL-1 and anthocyanins content ranged from 44.3 ± 2.01 to 129.5 ± 2.82 mg cyanidin-3-glucoside 100 mL-1. Regression analyses showed a high correlation of antioxidant capacity and anthocyanins content. Grapes from Sao Francisco River Valley demonstrated to be a good source of antioxidant for human diet