The occurrence of a novel hydrophilic hydroperoxide, 3-hydroxy-5-hydroperoxy-2-methyl-5,6-dihydropyran-4-one, as a reactive glycation product in human plasma.

This study describes the occurrence of 3-hydroxy-5-hydroperoxy-2-methyl-5,6-dihydropyran-4-one (HMDP) in plasma obtained from normal subjects and patients with type 2 diabetes. We have shown previously that HMDP is a novel hydrophilic hydroperoxide formed in the in vitro Maillard reaction that could be analyzed using ultrasensitive chemiluminescence detection-high-performance liquid chromatography (CL-HPLC). The HMDP concentration was 273+/-227 nmol/l in normal subjects and 656+/-535 nmol/l in patients with diabetes.

Dietary curcuminoids prevent high-fat diet-induced lipid accumulation in rat liver and epididymal adipose tissue.

Curcumin and its structurally related compounds (curcuminoids), the phenolic yellowish pigments of turmeric, display antioxidative, anticarcinogenic and hypocholesterolemic activities. In this study, we investigated the effects of dietary supplemented curcuminoids [commercial grade curcumin: a mixture of curcumin (73.4%), demethoxycurcumin (16.

The growth inhibitory effect of conjugated linoleic acid on a human hepatoma cell line, HepG2, is induced by a change in fatty acid metabolism, but not the facilitation of lipid peroxidation in the cells.

We investigated the growth inhibitory effect of conjugated linoleic acid (CLA) on HepG2 (human hepatoma cell line), exploring whether the inhibitory action occurs via lipid peroxidation in the cells. When the cells were incubated up to 72 h with 5-40 microM of CLA (a mixture of 9c,11t-18:2 and 10t,12c-18:2), cell proliferation was clearly inhibited in a dose and time dependent manner but such an inhibition was not confirmed with linoleic acid (LA). In order to evaluate the possible contribution of lipid peroxidation exerted by CLA to cell growth inhibition, alpha-tocopherol (5-20 microM) and BHT (1-10 microM) as potent antioxidants were added to the medium with CLA (20 microM), which did not restore cell growth at all.

Do conjugated eicosapentaenoic acid and conjugated docosahexaenoic acid induce apoptosis via lipid peroxidation in cultured human tumor cells?

Conjugated eicosapentaenoic acid (CEPA) and conjugated docosahexaenoic acid (CDHA) with triene structure, isomerized by alkaline treatment, showed intensive cytotoxicity with LD(50) at 12 and 16 microM, respectively, in DLD-1 cells (colorectal adenocarcinoma), while they had no effect on normal human fibroblast cell lines such as MRC-5, TIG-103, and KMS-6 cells. Cytotoxic action of CEPA and CDHA was also demonstrated in other tumor cell lines including HepG2, A549, MCF-7, and MKN-7 cells. alpha-Tocopherol suppressed cytotoxicity of CEPA and CDHA in tumor cells, and the cytotoxicity involved membrane phospholipid peroxidation.

Age-related increases in plasma phosphatidylcholine hydroperoxide concentrations in control subjects and patients with hyperlipidemia.

Background: The basal lipid peroxide concentration in the plasma of patients with hyperlipidemia may be related to atherosclerosis. Quantitative determination of lipid peroxides in the plasma is an important step in the overall evaluation of the biochemical processes leading to oxidative injury. Unfortunately, the currently available methods for lipid peroxidation lack specificity and sensitivity.

Newly recognized cytotoxic effect of conjugated trienoic fatty acids on cultured human tumor cells.

We investigated the cytotoxic effect of conjugated trienoic fatty acids on various human tumor cell lines: DLD- 1, colorectal; HepG2, hepatoma; A549, lung; MCF-7, breast; and MKN-7, stomach. Conjugated linoleic acid (CLA) and conjugated linolenic acid were prepared from linoleic acid (18:2, n-6) and alpha-linolenic acid (18:3, n-3), respectively, by treatment with 6.6% or 21% potassium hydroxide.

Direct intestinal absorption of red fruit anthocyanins, cyanidin-3-glucoside and cyanidin-3,5-diglucoside, into rats and humans.

We determined red fruit anthocyanins, cyanidin-3-glucoside (Cy-g) and cyanidin-3,5-diglucoside (Cy-dg), incorporated into plasma and liver of rats and human plasma by UV-HPLC. Fifteen minutes after an oral supplementation of a mixture of 320 mg of Cy-g and 40 mg of Cy-dg/kg of body weight, rats showed an increase to a maximum of 1563 microg (3490 nmol) of Cy-g/L and 195 microg (320 nmol) of Cy-dg/L in plasma and 0.067 microg (0.

Tea catechin supplementation increases antioxidant capacity and prevents phospholipid hydroperoxidation in plasma of humans.

The effect of green tea catechin supplementation on antioxidant capacity of human plasma was investigated. Eighteen healthy male volunteers who orally ingested green tea extract (254 mg of total catechins/subject) showed 267 pmol of epigallocatechin-3-gallate (EGCg) per milliliter of plasma at 60 min after administration. The plasma phosphatidylcholine hydroperoxide (PCOOH) levels attenuated from 73.