Activity-guided fractionation of a methanol extract from the fruit of Manilkara zapota cv. Tikal resulted in the isolation of two new antioxidants, methyl 4-O-galloylchlorogenate (1) and 4-O-galloylchlorogenic acid (2), along with eight known polyphenolic antioxidants, namely, methyl chlorogenate (3), dihydromyricetin (4), quercitrin (5), myricitrin (6), (+)-catechin (7), (-)-epicatechin (8), (+)-gallocatechin (9), and gallic acid (10). Of the 10 polyphenols, 1 showed the highest antioxidant activity (IC(50) = 12.9 microM) in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assay and displayed cytotoxicity in the HCT-116 and SW-480 human colon cancer cell lines with IC(50) values of 190 and 160 microM, respectively. Compound 2 showed high antioxidant activity (IC(50) = 23.5 microM) in the DPPH free-radical assay and displayed cytotoxicity in the HCT-116 and SW-480 human colon cancer cell lines with IC(50) values of 154 and 134 microM, respectively.

Pouteria campechiana, Pouteria sapota, and Pouteria viridis are tropical plants in the Sapotaceae family that bear edible fruits. The fresh fruits of these three Pouteria species were each extracted, and activity-guided fractionations were performed to identify the antioxidant constituents. Seven polyphenolic antioxidants, gallic acid (1), (+)-gallocatechin (2), (+)-catechin (3), (-)-epicatechin (4), dihydromyricetin (5), (+)-catechin-3-O-gallate (6), and myricitrin (7), were isolated and identified. Extracts of the three Pouteria fruits were analyzed by a selected ion monitoring liquid chromatography-mass spectrometry method to quantify their polyphenolic antioxidants. The highest level of the seven measured polyphenols was found in P. sapota, the second highest in P. viridis, and the lowest in P. campechiana. The levels of the seven polyphenols corresponded with the results of the 1,1-diphenyl-2-picrylhydrazyl assay, by which P. sapota had the highest antioxidant activity, P. viridis the second highest, and P. campechiana the lowest.

The EtOAc extract obtained from ten edible North American plants, Acorus calamus, Clintonia borealis, Gaultheria shallon, Juniperus osteosperma, Opuntia polyacantha, Prunus americana, Prunus virginiana, Sambucus cerulea, Sorbus americana and Vaccinium parvifolium, were tested in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical assay. High antioxidant activity was obtained from the extracts of three fruits, Gaultheria shallon, Sambucus cerulea and Prunus americana and one extracted rhizome, Acorus calamus. Catechin and epicatechin, potent polyphenolic antioxidants, were identified in the EtOAc extracts of Gaultheria shallon and Sambucus cerulea by reversed-phase thin-layer chromatography (TLC) and reversed-phase high-performance liquid chromatography (HPLC).

Biological nitrogen fixation is essential to crop production, but it can be inhibited by high concentrations of reactive oxygen species (ROS) due to irreversible inactivation of the nitrogenase complex, thus...

To assess the effect of corn peptides (CPs) as an antioxidant on ethanol (EtOH)induced oxidative stress in HepG2 cells, the cells were preincubated with CPs for 4 h before treated with EtOH. Methyl thiazolyl tetrazolium and flow cytometry assay were performed to detect the viability of CP-treated HepG2 cells and control cells. The activities of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined by corresponding kits, respectively. The results showed that treatment with 300 mmol/L EtOH for 24 h resulted in a death of around 50% of the HepG2 cells. Pretreatments of appropriate concentrations of CPs (more than 5 mg/mL, particularly at 20 mg/ mL) significantly prevented EtOH-induced cytotoxicity and reduced the increase of ALT, AST, LDH and MDA contents, as well as inhibited the reduction of SOD contents in the HepG2 cells, indicating that CPs protected the cells from oxidative damage induced by EtOH metabolism, and thus had a great application potential in hepatoprotective nutraceuticals.

Our work demonstrated that the anti-fibrotic effect of TPL on IR-induced pulmonary fibrosis was related to its inhibition on the axis of alveolar macrophages-NOXes-ROS-myofibroblasts.

This study investigated the long-term (8 weeks) anti-hypertensive effects of 10 mg/kg tripeptides isolated from Spirulina platensis, Ile-Gln-Pro (IQP) and Val-Glu-Pro (VEP), and S. platensis hydrolysates (SH) on spontaneously hypertensive rats. The treatment period was 6 weeks, and observation continued for another 2 weeks. After treatment, weighted systolic blood pressure, weighted diastolic blood pressure, left ventricular mass index, and right ventricular mass index of groups treated with IQP, VEP, and SH were significantly lower than those of the group treated with distilled water, even when the treatments had been withdrawn for 2 weeks. Quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blotting showed the mRNA expression levels and protein/peptide concentrations of the main components of the renin angiotensin system in myocardium were significantly affected by treatment: angiotensin converting enzyme, angiotensin II, and angiotensin type 1 receptor were down-regulated, whereas angiotensin type 2 receptor, angiotensin converting enzyme 2, angiotensin-(1-7), and Mas receptor were up-regulated.

No abstract