Recent chn_rw items

Bioavailability of ellagic acid in human plasma after consumption of ellagitannins from pomegranate (Punica granatum L.) juice

Mon, 19 Sep 2005 00:00:00 +0000

Background: Ellagic acid (EA) and hydrolyzable ellagitannins (ETs) are dietary polyphenols found in fruits and nuts and implicated with potent antioxidant, anticancer and antiatherosclerotic biological properties. Unfortunately, there are no reports on bioavailability studies of EA or ETs in the human body. Therefore we conducted in vivo studies whereby a human subject consumed pomegranate juice (180 ml) containing EA (25 mg) and ETs (318 mg, as punicalagins, the major fruit ellagitannin). Methods: A rapid plasma extraction procedure utilizing acidic precipitation of proteins, followed by HPLC-UV analyses was employed. Results: EA was detected in human plasma at a maximum concentration (31.9 ng/ml) after 1h post ingestion but was rapidly eliminated by 4h. The calibration curve for quantification of EA was linear (r2 = 0.9975) over the concentration range from 1000 to 15.6 ng/ml. Conclusions: Since EA has reportedly strong affinity for proteins and poor absorption in small...

In vitro antiproliferative, apoptotic and antioxidant activities of punicalagin, ellagic acid and a total pomegranate tannin extract are enhanced in combination with other polyphenols as found in pomegranate juice

Mon, 19 Sep 2005 00:00:00 +0000

Pomegranate (Punica granatum L.) fruits are widely consumed as juice (PJ). The potent antioxidant and anti-atherosclerotic activities of PJ are attributed to its polyphenols including punicalagin, the major fruit ellagitannin, and ellagic acid (EA). Punicalagin, EA, a standardized total pomegranate tannin extract (TPT) and PJ were evaluated for in vitro antioxidant, antiproliferative and apoptotic activities. The antioxidative bioassays used included inhibition of lipid peroxidation and Trolox Equivalent Antioxidant Capacity (TEAC) assays. The antiproliferative assays targeted human oral (KB, CAL27), colon (HT-29, HCT116, SW480, SW620) and prostate (RWPE-1, 22Rv1) tumor cells. Apoptotic effects were evaluated against the HT-29 and HCT116 colon cancer cell lines. Punicalagin, EA and TPT were evaluated at 12.5-100 g/mL for antiproliferative assays. However, to evaluate the synergistic and/or additive contributions from other PJ phytochemicals, PJ was tested at concentrations...

Rapid large scale purification of ellagitannins from pomegranate husk, a by-product of the commercial juice industry

Mon, 19 Sep 2005 00:00:00 +0000

Pomegranate (Punica granatum L.) fruits are widely consumed fresh and in the forms of juice, concentrate, wine and jam. Pomegranate fruit husk is a rich source of hydrolyzable tannins called ellagitannins (ETs). During processing methods in the commercial pomegranate juice (PJ) industry, ETs are extracted from the fruit husk in significant quantities into the juice. Pomegranate husk, a by-product of the PJindustry, is therefore an inexpensive and abundant source of ETs which are present in PJ. Previous methods to isolate pomegranate ETs included labor intensive and time-consuming solid phase extractions by column chromatography (C-18, polyamides, cellulose, Sephadex Lipophilic LH-20, Diaion HP20) and/or use of specialized instruments such as preparative-high performance liquid chromatography (HPLC). We have used an Amberlite XAD-16 resin vacuum-aspirated column to rapidly purify an aqueous extract of pomegranate husk to afford total pomegranate tannins (TPT) in substantial...

Identification of phenolic compounds in strawberries by liquid chromatography electrospray ionization mass spectroscopy

Sun, 18 Sep 2005 00:00:00 +0000

Strawberry (Fragaria x ananassa Duch.) fruits contain phenolic compounds that have antioxidant, anticancer, antiatherosclerotic and anti-neurodegenerative properties. Identification of food phenolics is necessary since their nature, size, solubility, degree and position of glycosylation and conjugation influence their absorption, distribution, metabolism and excretion in humans. Freeze-dried whole strawberry fruit powder and strawberry fruit extracts were analyzed by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) methods. Phenolics were identified as ellagic acid (EA), EA-glycosides, ellagitannins, gallotannins, anthocyanins, flavonols, flavanols and coumaroyl glycosides. The anthocyanidins were pelargonidin and cyanidin, found predominantly as their glucosides and rutinosides. The major flavonol aglycons were quercetin and kaempferol found as their glucuronides and glucosides. LC-ESI-MS/MS methods differentiated EA from quercetin conjugates...

Total Cranberry Extract vs. its Phytochemical Constituents: Antiproliferative and Synergistic Effects against Human Tumor Cell Lines

Sun, 18 Sep 2005 00:00:00 +0000

Cranberries (Vaccinium macrocarpon Ait.) are an excellent dietary source of phytochemicals that include flavonol glycosides, anthocyanins, proanthocyanidins (condensed tannins), and organic and phenolic acids. Using C-18 and Sephadex Lipophilic LH-20 column chromatography, HPLC and tandem LC-ES/MS, we have analyzed, quantified and separated total cranberry extract (TCE) into fractions enriched in sugars, organic acids, total polyphenols, proanthocyanidins and anthocyanins (39.4, 30.0, 10.6, 5.5, 1.2% composition, respectively). Using a luminescent ATP cell viability assay, the antiproliferative effects of TCE (200 g/mL) vs. all fractions were evaluated against human oral (KB, CAL27), colon (HT-29, HCT116, SW480, SW620) and prostate (RWPE-1, RWPE-2, 22Rv1) cancer cell lines. The total polyphenol fraction was the most active fraction against all cell lines with 96.1 and 95% inhibition of KB and CAL27 oral cancer cells, respectively. For the colon cancer cells, the antiproliferative...