Berry fruits are widely consumed in our diet and have attracted much attention due to their potential human health benefits. Berries contain a diverse range of phytochemicals with biological properties such as antioxidant, anticancer, anti-neurodegerative, and anti-inflammatory activities. In the current study, extracts of six popularly consumed berries--blackberry, black raspberry, blueberry, cranberry, red raspberry and strawberry--were evaluated for their phenolic constituents using high performance liquid chromatography with ultraviolet (HPLC-UV) and electrospray ionization mass spectrometry (LC-ESI-MS) detection. The major classes of berry phenolics were anthocyanins, flavonols, flavanols, ellagitannins, gallotannins, proanthocyanidins, and phenolic acids. The berry extracts were evaluated for their ability to inhibit the growth of human oral (KB, CAL-27), breast (MCF-7), colon (HT-29, HCT116), and prostate (LNCaP) tumor cell lines at concentrations ranging from 25 to 200 micro g/mL. With increasing concentration of berry extract, increasing inhibition of cell proliferation in all of the cell lines were observed, with different degrees of potency between cell lines. The berry extracts were also evaluated for their ability to stimulate apoptosis of the COX-2 expressing colon cancer cell line, HT-29. Black raspberry and strawberry extracts showed the most significant pro-apoptotic effects against this cell line. The data provided by the current study and from other laboratories warrants further investigation into the chemopreventive and chemotherapeutic effects of berries using in vivo models.
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 the bioavailability studies of EA or ETs in the human body. We conducted in vivo studies whereby a human subject consumed pomegranate juice (PJ) (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 1 h postingestion but was rapidly eliminated by 4 h. The calibration curve for quantification of EA was linear (r 2 = 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 animals, further studies to investigate whether the presence of free EA in human plasma may be due to its release from the hydrolysis of ETs, facilitated by physiological pH and/or gut microflora action, is warranted. EA can be considered as a biomarker for future human bioavailability studies involving consumption of ETs from food sources. D
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. Freezedried 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 since both aglycons have identical molecular weights (302 g/mol). The identification of strawberry phenolics is necessary to generate standardized materials for in vitro and in vivo studies and for the authentication of strawberry-based food products.
Our group has shown in a phase II clinical trial that pomegranate juice (PJ) increases prostate specific antigen (PSA) doubling time in prostate cancer (CaP) patients with a rising PSA. Ellagitannins (ETs) are the most abundant polyphenols present in PJ and contribute greatly towards its reported biological properties. On consumption, ETs hydrolyze to release ellagic acid (EA), which is then converted by gut microflora to 3,8-dihydroxy-6H-dibenzo [b,d]pyran-6-one (urolithin A, UA) derivatives. Despite the accumulating knowledge of ET metabolism in animals and humans, there is no available data on the pharmacokinetics and tissue disposition of urolithins. Using a standardized ET-enriched pomegranate extract (PE), we sought to further define the metabolism and tissue distribution of ET metabolites. PE and UA (synthesized in our laboratory) were administered to C57BL/6 wild-type male mice, and metabolite levels in plasma and tissues were determined over 24 h. ET metabolites were concentrated at higher levels in mouse prostate, colon, and intestinal tissues as compared to other tissues after administration of PE or UA. We also evaluated the effects of PE on CaP growth in severe combined immunodeficient (SCID) mice injected subcutaneously with human CaP cells (LAPC-4). PE significantly inhibited LAPC-4 xenograft growth in SCID mice as compared to vehicle control. Finally, EA and several synthesized urolithins were shown to inhibit the growth of human CaP cells in vitro. The chemopreventive potential of pomegranate ETs and localization of their bioactive metabolites in mouse prostate tissue suggest that pomegranate may play a role in CaP treatment and chemoprevention. This warrants future human tissue bioavailability studies and further clinical studies in men with CaP.
Studies suggest that consumption of berry fruits, including strawberries ( Fragaria x ananassa Duch.), may have beneficial effects against oxidative stress mediated diseases such as cancer. Berries contain multiple phenolic compounds, which are thought to contribute to their biological properties. Comprehensive profiling of phenolics from strawberries was previously reported using high-performance liquid chromatography with mass spectrometry (HPLC-MS) detection. The current study reports the isolation and structural characterization of 10 phenolic compounds from strawberry extracts using a combination of Amberlite XAD16-resin and C18 columns, HPLC-UV, and nuclear magnetic resonance (NMR) spectroscopy methods. The phenolics were cyanidin-3-glucoside ( 1), pelargonidin (2), pelargonidin-3-glucoside (3), pelargonidin-3-rutinoside (4), kaempferol (5), quercetin (6), kaempferol-3-(6'-coumaroyl)glucoside) (7), 3,4,5-trihydroxyphenyl-acrylic acid (8), glucose ester of ( E)- p-coumaric acid (9), and ellagic acid . Strawberry crude extracts and purified compounds 1- 10 were evaluated for antioxidant and human cancer cell antiproliferative activities by the Trolox equivalent antioxidant capacity (TEAC) and luminescent ATP cell viability assays, respectively. Among the pure compounds, the anthocyanins 1 (7156 microM Trolox/mg), 2 (4922 microM Trolox/mg), and 4 (5514 microM Trolox/mg) were the most potent antioxidants. Crude extracts (250 microg/mL) and pure compounds (100 microg/mL) inhibited the growth of human oral (CAL-27, KB), colon (HT29, HCT-116), and prostate (LNCaP, DU145) cancer cells with different sensitivities observed between cell lines. This study adds to the growing body of data supporting the bioactivities of berry fruit phenolics and their potential impact on human health.
Pomegranate (Punica granatum L.) fruits are widely consumed fresh and in processed forms as juice, jams and wine. Pomegranate fruit husk/peel is a rich source of hydrolyzable tannins called ellagitannins (ETs). In the commercial pomegranate juice (PJ) industry, these ETs are extracted from the husk in significant quantities into the juice due to their hydrophilic properties. Pomegranate husk, a by-product of the PJ industry, is therefore an inexpensive and abundant source of ETs. 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 yields (58-60 g TPT/kg husk; time <1 h). Using analytical HPLC and tandem LC-ES/MS, evaluation of TPT showed that it contains the major fruit husk ET, punicalagin (80-85% w/w) and ellagic acid (EA; 1.3% w/w) and unquantified amounts of punicalin and EA-glycosides (hexoside, rhamnoside and pentoside). Since pomegranate ETs are reported to show potent antioxidant, antiatherosclerotic and anticancer activities, this method can be used for the large-scale production of TPT for future in vitro and in vivo biological studies. This method is practical for industrial applications and could provide a low-cost means to use a currently underutilized food by-product to develop phytoceuticals with potential health benefits or to develop products for use in the cosmetic and food biopreservative industries.
The health benefits associated with tea consumption have resulted in the wide inclusion of green tea extracts in botanical dietary supplements, which are widely consumed as adjuvants for complementary and alternative medicines. Tea contains polyphenols such as catechins or flavan-3-ols including epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate (EGCG), as well as the alkaloid, caffeine. Polyphenols are antioxidants, and EGCG, due to its high levels, is widely accepted as the major antioxidant in green tea. Therefore, commercial green tea dietary supplements (GTDS) may be chemically standardized to EGCG levels and/or biologically standardized to antioxidant capacity. However, label claims on GTDS may not correlate with actual phytochemical content or antioxidant capacity nor provide information about the presence and levels of caffeine. In the current study, 19 commonly available GTDS were evaluated for catechin and caffeine content (using high-performance liquid chromatography) and for antioxidative activity [using trolox equivalent antioxidant capacity (TEAC) and oxygen radical antioxidant capacity (ORAC) assays]. Product labels varied in the information provided and were inconsistent with actual phytochemical contents. Only seven of the GTDS studied made label claims of caffeine content, 11 made claims of EGCG content, and five specified total polyphenol content. Caffeine, EGCG, and total polyphenol contents in the GTDS varied from 28 to 183, 12-143, and 14-36% tablet or capsule weight, respectively. TEAC and ORAC values for GTDS ranged from 187 to 15340 and from 166 to 13690 mumol Trolox/g for tablet or capsule, respectively. The antioxidant activities for GTDS determined by TEAC and ORAC were well-correlated with each other and with the total polyphenol content. Reliable labeling information and standardized manufacturing practices, based on both chemical standardization and biological assays, are recommended for the quality control of botanical dietary supplements.
In summary, both BTP and GTP induced weight loss in association with alteration of the microbiota and increased hepatic AMPK phosphorylation. We hypothesize that BTP increased pAMPK through increased intestinal SCFA production, while GTPs increased hepatic AMPK through GTP present in the liver.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.