Ilex spinigera (Aquifoliaceae) plant is an evergreen tree or shrub with thick glossy dark green leaves and red fruits. This plant has medicinal properties and has been used traditionally in northern Iran for malaria treatment. The aim of this work is to evaluate the antioxidative activities and the inhibitory effect of I.spinigera on the oxidation of DNA. We have found no reports about the popu...

Arahypin-16 (1), a new prenylated resveratrol with a unique dihydrobenzofuran ring, has been isolated as a microbial metabolite of resveratrol (2) from whole-cell fermentation of Aspergillus sp. SCSIOW2. The stereochemistry of 1 was determined by ECD calculations. 1 showed about half of the extracellular radical scavenging effect (IC50 = 161.4 μM) compared with resveratrol (IC50 = 80.5 μM), whi...

Epicatechin conjugates obtained from grape have shown antioxidant activity in various systems. However, how these conjugates exert their antioxidant benefits has not been widely studied. We assessed the activity of epicatechin and epicatechin conjugates on the erythrocyte membrane in the presence and absence of a peroxyl radical initiator, to increase our understanding of their mechanisms. Thus...

Objective: Terminalia arjuna is commonly known as Arjuna and widely used as cardioprotective agent in Indian traditional medicine. The present study was undertaken to evaluate the protective effect of ethanolic extract of T. arjuna bark (TAA) and its fractions, including dichloromethane (TAD), ethyl acetate (TAE), butanol (TAB) and water (TAW) against free radicals, protein oxidation and DNA da...

Aphanizomenon flos-aquae (AFA) is a fresh water unicellular blue-green alga (cyanophyta) rich in phycocyanin (PC), a photosynthetic pigment with antioxidant and anti-inflammatory properties. The purpose of this study was to evaluate the ability of a novel natural extract from AFA enriched with PC to protect normal human erythrocytes and plasma samples against oxidative damage in vitro. In red b...

High-density lipoprotein (HDL) has been proposed as the principal carrier of hydroperoxides in plasma, based upon data gathered with an HPLC-chemiluminescence technique. To test this hypothesis we have measured total lipid hydroperoxides in native plasma using the ferrous oxidation in Xylenol Orange (FOX) assay and then fractionated plasma into very-low-density lipoprotein (LDL) and HDL fractio...

Purified serum paraoxonase (PON1) had been shown to attenuate the oxidation of LDL in vitro. We critically reevaluated the antioxidant properties of serum PON1 in the in vitro assays initiated with copper or the free radical generator 2,2'-azobis-2-amidinopropane hydrochloride (AAPH). The antioxidant activity of different purified PON1 preparations did not correlate with their arylesterase (AE)...

Hepatocytes expressing liver fatty acid binding protein (L-FABP) are known to be more resistant to oxidative stress than those devoid of this protein. The mechanism for the observed antioxidant activity is not known. We examined the antioxidant mechanism of a recombinant rat L-FABP in the presence of a hydrophilic (AAPH) or lipophilic (AMVN) free radical generator. Recombinant L-FABP amino acid...