Pharmacokinetic study of ellagic acid in rat after oral administration of pomegranate leaf extract

Method development and validation for pharmacokinetic and tissue distributions of ellagic acid using ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)

Ellagic acid is a dietary polyphenol found in numerous fruits and vegetables, possessing several health benefits such as antioxidant, anticancer and anti-atherosclerotic biological properties. The purpose of this study was to explore the pharmacokinetics and tissue distribution of ellagic acid in rats. A simple, rapid, sensitive and specific liquid chromatography–tandem mass spectrometry method to determine the ellagic acid in plasma and tissue samples was developed and validated. The separation was achieved using reversed-phase ultra-performance liquid chromatography (UPLC), and the mass spectrometric detection was achieved using heated electrospray ionization (negative mode) and multiple ion monitoring (m/z 301/229). A sample cleanup with a solid phase extraction (SPE) step prior to the UPLC-MS/MS analysis was also developed. The SPE and UPLC-MS/MS method established here was successfully applied to reveal the pharmacokinetic profiles and tissue distribution of ellagic acid. After oral administration dosing at 50 mg/kg, plasma levels of ellagic acid peaked at about 0.5 h, with C_max value of 93.6 ng/mL, and the results showed that the ellagic acid was poorly absorbed after oral administration. The pharmacokinetic profile of ellagic acid fitted to a two-compartment model with t_1/2α 0.25 h and t_1/2β 6.86 h, respectively. Following oral administration, ellagic acid was detected in all examined tissues including kidney, liver, heart, lung and brain et al., and the highest levels were found in kidney and liver.

Involvement of L-arginine/NO/cGMP/K(ATP) channel pathway in the peripheral antinociceptive actions of ellagic acid in the rat formalin test

The present study was conducted to evaluate the local antinociceptive actions of EA and the possible involvement of l-arginine/NO/cGMP/KATP channel pathway in this effect using formalin test in rats. To evaluate the involvement of l-arginine/NO/cGMP/KATP channel pathway in the antinociceptive action of EA, rats were pre-treated intraplantarlly with l-NAME (NOS inhibitor, 25-100μg/paw), methylene blue (guanylyl cyclase inhibitor, 100-400μg/paw), glibenclamide (ATP-sensitive K(+) channel blocker, 25-100μg/paw), l-arginine (a nitric oxide precursor, 25-100μg/paw) and sodium nitroprusside (125-500μg/paw). The local peripheral ipsilateral, but not contralateral, administration of EA into the right paw (30-300μg/paw) produced a dose-related antinociception during both early and late phases of formalin test which is comparable with morphine (25μg/paw). Moreover, local pre-treatment with l-NAME, methylene blue and glibenclamide dose-dependently prevented EA (100μg/paw)-induced antinociception in late phase. Additionally, administration of l-arginine and sodium nitroprusside significantly potentiated the antinociception induced by EA in the late phase. However, these treatments had no significant effect on antinociceptive response of EA in the early phase of the formalin test. The results of the present study showed that EA-induced local peripheral antinociception during the both phases of formalin test. Also, our data suggested the activation of the l-arginine/NO/cGMP/KATP channels pathway in EA-induced antinociception in late phase of formalin test. Topical application of EA by ointment or jelly might be a useful method to relieving the inflammatory pain states.

Ellagic acid encapsulated chitosan nanoparticles as anti-hemorrhagic agent

Ellagic acid, a naturally occurring polyphenol was encapsulated in chitosan particles prepared by ionotropic gelation and characterized for its physicochemical properties. A maximum encapsulation efficiency of 49% was achieved. The blood clotting time and clot retraction time were calculated for different concentrations of ellagic acid, chitosan and ellagic acid-encapsulated chitosan. A reduction of 34% in the clot time and 16.4% in the retraction time was observed in ellagic acid-encapsulated chitosan when compared with free ellagic acid at concentrations as low as 0.1mg/mL. The physical blend in comparison to free ellagic acid displayed a reduction of 13.8% and 4.6% in the clotting time and retraction time respectively under similar conditions. This suggests that the encapsulation of ellagic acid favors thrombosis due to synergistic action of chitosan and ellagic acid on same molecular targets. This study demonstrates the potential of ellagic acid-chitosan system as an effective anti-hemorrhagic system.

Dipeptidyl peptidase-4 inhibition by Pterocarpus marsupium and Eugenia jambolana ameliorates streptozotocin induced Alzheimer's disease

Alzheimer's disease (AD), the most common form of dementia, is characterized by the loss of normal functions of brain cells and neuronal death, ultimately leading to memory loss. Recent accumulating evidences have demonstrated the therapeutic potential of anti-diabetic agents, such as dipeptidyl peptidase-4 (DPP-4) inhibitors, for the treatment of Alzheimer's disease (AD), providing opportunities to explore and test the DPP-4 inhibitors for treating this fatal disease. Prior studies determining the efficacy of Pterocarpus marsupium (PM, Fabaceae) and Eugenia jambolana (EJ, Myrtaceae) extracts for ameliorating type 2 diabetes have demonstrated the DPP-4 inhibitory properties indicating the possibility of using of these extracts even for the treating AD. Therefore, in the present study, the neuroprotective roles of PM and EJ for ameliorating the streptozotocin (STZ) induced AD have been tested in rat model. Experimentally, PM and EJ extracts, at a dose range of 200 and 400mg/kg, were administered orally to STZ induced AD Wistar rats and cognitive evaluation tests were performed using radial arm maze and hole-board apparatus. Following 30 days of treatment with the extracts, a dose- and time-dependent attenuation of AD pathology, as evidenced by decreasing amyloid beta 42, total tau, phosphorylated tau and neuro-inflammation with an increase in glucagon-like peptide-1 (GLP-1) levels was observed. Therefore, PM and EJ extracts contain cognitive enhancers as well as neuroprotective agents against STZ induced AD.

Intestinal anti-inflammatory activity of ellagic acid in the acute and chronic dextrane sulfate sodium models of mice colitis

ETHNOPHARMACOLOGICAL RELEVANCE

Pomegranate (Punica granatum L.; Lythraceae) has traditionally been used for the treatment of various inflammatory diseases, including ulcerative colitis (UC). Because its fruits and extracts are rich in ellagitannins, which release ellagic acid when hydrolyzed, consumption of pomegranate products is currently being widely promoted for their potential health effects, including the prevention of inflammatory diseases and cancer. To evaluate the anti-inflammatory effects of ellagic acid on dextran sulfate sodium (DSS)-induced acute and chronic experimental colitis in two different strains of mice and to elucidate its possible mechanisms of action.

MATERIALS AND METHODS

In the acute UC model, female Balb/C mice were treated with DSS (5%) for seven days while concomitantly receiving a dietary supplement of ellagic acid (2%). In the chronic UC model, female C57BL/6 mice received four week-long cycles of DSS (1% and 2%) interspersed with week-long recovery periods along with a diet supplemented with ellagic acid (0.5%).

RESULTS

In acute model of UC, ellagic acid ameliorated disease severity slightly as observed both macroscopically and through the profile of inflammatory mediators (IL-6, TNF-α, and IFN-γ). In the chronic UC model, ellagic acid significantly inhibited the progression of the disease, reducing intestinal inflammation and decreasing histological scores. Moreover, mediators such as COX-2 and iNOS were downregulated and the signaling pathways p38 MAPK, NF-κB, and STAT3 were blocked.

CONCLUSIONS

Our study reinforces the hypothetical use of ellagic acid as an anti-inflammatory complement to conventional UC treatment in chronic UC patients and could be considered in the dietary prevention of intestinal inflammation and related cancer development.

The pharmacological use of ellagic acid-rich pomegranate fruit

In recent years, the therapeutic use of non-drug substances such as herbal and medicinal foods is increasing progressively. Of these substances, Punica granatum L., which is an ancient and highly distinctive fruit, has been proposed for treatment of several different illnesses. Ellagic acid (EA) is one of those biological molecules found in pomegranate and may have therapeutic potential in many diseases. EA has been detected not only in pomegranate but also in a wide variety of fruits and nuts such as raspberries, strawberries, walnuts, grapes and black currants, and is becoming an increasingly popular dietary supplement over recent years. Similar to other ellagitannins (ETs), EA is quite stable under physiological conditions in the stomach. EA and ETs as active agents induce vasorelaxation, oxygen free radical scavenging, hypolipidemic, anti-inflammatory and anti-carcinogenic activities in various animal preparations call an attention to the need for designing adequate tests in humans to assess these potentially useful properties in diseased states.

Pomegranate polyphenols and extract inhibit nuclear factor of activated T-cell activity and microglial activation in vitro and in a transgenic mouse model of Alzheimer disease

Alzheimer disease (AD) brain is characterized by extracellular plaques of amyloid β (Aβ) peptide with reactive microglia. This study aimed to determine whether a dietary intervention could attenuate microgliosis. Memory was assessed in 12-mo-old male amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice via Barnes maze testing followed by division into either a control-fed group provided free access to normal chow and water or a treatment group provided free access to normal chow and drinking water supplemented with pomegranate extract (6.25 mL/L) for 3 mo followed by repeat Barnes maze testing for both groups. Three months of pomegranate feeding decreased the path length to escape of mice compared with their initial 12-mo values (P < 0.05) and their control-fed counterparts (P < 0.05). Brains of the 3-mo study pomegranate-fed mice had lower tumor necrosis factor α (TNF-α) concentrations (P < 0.05) and lower nuclear factor of activated T-cell (NFAT) transcriptional activity (P < 0.05) compared with controls. Brains of the 3-mo pomegranate or control mice were also compared with an additional control group of 12-mo-old mice for histologic analysis. Immunocytochemistry showed that pomegranate- but not control-fed mice had attenuated microgliosis (P < 0.05) and Aβ plaque deposition (P < 0.05) compared with 12-mo-old mice. An additional behavioral study again used 12-mo-old male APP/PS1 mice tested by T-maze followed by division into a control group provided with free access to normal chow and sugar supplemented drinking water or a treatment group provided with normal chow and pomegranate extract-supplemented drinking water (6.25 mL/L) for 1 mo followed by repeat T-maze testing in both groups. One month of pomegranate feeding increased spontaneous alternations versus control-fed mice (P < 0.05). Cell culture experiments verified that 2 polyphenol components of pomegranate extract, punicalagin and ellagic acid, attenuated NFAT activity in a reporter cell line (P < 0.05) and decreased Aβ-stimulated TNF-α secretion by murine microglia (P < 0.05). These data indicate that dietary pomegranate produces brain antiinflammatory effects that may attenuate AD progression.

Pomegranate Juice Does Not Impair Clearance of Oral or Intravenous Midazolam, a Probe for Cytochrome P450-3A Activity: Comparison With Grapefruit Juice

The effect of pomegranate juice (PJ) or grapefruit juice (GFJ) on CYP3A activity was studied in vitro and in healthy human volunteers. In human liver microsomes, the mean 50% inhibitory concentrations (IC(50)) for PJ and GFJ versus CYP3A (triazolam alpha-hydroxylation) were 0.61% and 0.55%, (v/v) respectively, without preincubation of inhibitor with microsomes. After preincubation, the IC(50) for PJ increased to 0.97% (P < .05), whereas the IC(50) for GFJ decreased to 0.41% (P < .05), suggesting mechanism-based inhibition by GFJ but not PJ. Pretreatment of volunteer subjects (n = 13) with PJ (8 oz) did not alter the elimination half-life, volume of distribution, or clearance of intravenous midazolam (2 mg). Administration of PJ also did not affect C(max), total area under the curve (AUC), or clearance of oral midazolam (6 mg). However, GFJ (8 oz) increased midazolam C(max) and AUC by a factor of 1.3 and 1.5, respectively, and reduced oral clearance to 72% of control values. Thus, PJ does not alter clearance of intravenous or oral midazolam, whereas GFJ impairs clearance and elevates plasma levels of oral midazolam.

Pomegranate: a fruit that ameliorates metabolic syndrome

Pomegranate is an ancient fruit that is still part of the diet in the Mediterranean area, the Middle East, and India. Health-promoting effects have long been attributed to this fruit. Modern research corroborates the use of pomegranate as a folk remedy for diabetes and metabolic syndrome, and is responsible for a new evaluation of nutritional and pharmaceutical aspects of pomegranate in the general public. In the last decade, industry and agricultural production have been adapted to meet higher market demands for pomegranate. In vivo and in vitro studies have demonstrated that pomegranate exerts hypoglycaemic effects, including increased insulin sensitivity, inhibition of α-glucosidase, and impact on glucose transporter type 4 function, but is also responsible for a reduction of total cholesterol, and the improvement of blood lipid profiles, as well as anti-inflammatory effects through the modulation of peroxisome proliferator-activated receptor pathways. These effects may also explain how pomegranate-derived compounds function in the amelioration of adverse health effects caused by metabolic syndrome. Pomegranate contains polyphenols such as ellagitannins and anthocyanins, as well as phenolic acids, fatty acids and a variety of volatile compounds. Ellagitannins are some of the most prevalent compounds present in pomegranate, and may be responsible for certain benevolent characteristics associated with pomegranate. A brief overview of rising health problems due to obesity will be provided, followed by characterisation of the biological activity, bioavailability, and safety of pomegranate and pomegranate-derived compounds. Although the fruit is consumed in many countries, epidemiological and clinical studies are unavailable. Additional research is necessary to corroborate the promise of current in vivo and in vitro findings.

Ellagic acid ameliorates lung injury after intestinal ischemia-reperfusion

Background:

The aim of this study was to investigate the possible protective role of antioxidant treatment with ellagic acid (EA) on lung injury after intestinal ischemia-reperfusion (I/R) injury using biochemical and histopatological approaches.

Materials and Methods:

Forty rats were divided into four groups as control, control + EA, I/R, and I/R + EA. The control and control + EA groups were also anesthetized and subjected to laparotomy, but without clamp application. The control + EA and I/R + EA groups were given EA (85 mg/kg) orally prior to experiment. The I/R and I/R + EA groups underwent 30 minutes of intestinal ischemia and 1 hour of reperfusion. In all groups, serum total antioxidant capacity (TAC) and malondialdehyde (MDA) levels were determined. TAC, total oxidative status (TOS), and oxidative stress index (OSI) in lung tissue were measured. Lung tissue histopathology was also evaluated by light microscopy.

Results:

TAC levels were higher in control, EA, and I/R + EA groups while TOS, OSI, and MDA levels were lower in these groups compared with I/R group. Serum MDA levels were significantly higher in I/R + EA group than that of control group. Lung tissue TAC levels were lower in I/R + EA group while OSI values were higher in that groups compared with EA group. Histological tissue damage was milder in the EA treatment group than in the I/R group.

Conclusion:

These results suggest that EA treatment protected the rats lung tissue against intestinal I/R injury.

A New Method for Preparative Separation and Purification of Ellagic Acid Employing PH-Gradient Counter-Current Chromatography

Ellagic acid is widely used as today’s functional food ingredients and health-care food supplements because of its biological activities. pH-gradient counter-current chromatography was applied to the successful separation of ellagic acid from a crude sample. The experiment was performed with a two-phase solvent system composed of methyl tert-butyl ether-butanol- acetonitrile-distilled water (4:2:3:8, v/v) where 10 mM trifluoroacetic acid (TFA) was added to the upper organic stationary phase as a retainer and 10 mM ammonia to the aqueous mobile phase as an eluter. The separation of 0.6 g crude sample yielded ellagic acid at a high purity of over 98% as determined by HPLC, MS and NMR. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Pharmacokinetics and tissue distribution of 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside from traditional Chinese medicine Polygonum multiflorum following oral administration to rats

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum multiflorum is an important traditional Chinese medicine used for health promotion and disease treatment. One major bioactive compound in P. multiflorum is a stilbene glycoside (2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside, PM-SG), which possesses antioxidative, anti-inflammatory and endothelial-protective activities.

MATERIALS AND METHODS

The purpose of the present study was to investigate in vivo pharmacokinetics and tissue distribution of PM-SG after oral administration of Polygonum multiflorum extract to rats by using a reversed-phase high-performance liquid chromatography coupled with liquid-liquid phase extraction. The pharmacokinetic parameters were determined using both compartmental and non-compartmental analyses.

RESULTS

All calibration curves for PM-SG in rat plasma and tissues were linear (all r(2)>0.99) over the range of 0.27-185.00 μg/ml. The intra- and inter-day variations were less than 3% at concentration range of 8.7-131.2 μg/ml and good overall recoveries (97.7-101.5%) were obtained at the same range. The maximum concentration (C(max)) and the time to reach this concentration (T(max)) of PM-SG were 31.9 μg/ml and 40.0 min, respectively. The pharmacokinetic profiles estimated by fitting two-compartment and non-compartment models revealed that PM-SG was rapidly absorbed into the body fluids and widely distributed throughout the body, with great efficiency of utility, followed by quick elimination. The highest PM-SG levels were detected in liver and lungs (90.3 ± 20.8 μg/g and 86.8 ± 9.0 μg/g, respectively) whereas little in brain and testes, indicating PM-SG can hardly penetrate the blood-brain and blood-testicle barriers.

CONCLUSIONS

This was the first report on the favorable pharmacokinetic profiles of PM-SG in rat plasma and tissues after oral administration. It may provide a meaningful basis for clinical application of such a bioactive compound of herbal medicines.

Berries: improving human health and healthy aging, and promoting quality life--a review

The importance of the diet in relation to human health has increased the interest of consumers on nutraceuticals rich foods, and especially on fruits and vegetables. Berries are rich sources of a wide variety of antioxidant phenolics; these phytochemicals include flavonoids, stilbenes, tannins, and phenolic acids. Reactive oxidant species and free radicals are produced in an extensive range of physiological processes. In addition to the antioxidant defenses produced in the body, there are exogenous sources supplied by the diet; this is the case of berry fruits, among others. The insufficiency of antioxidant defense mechanisms is associated to the pathology of chronic disorders such as cardiovascular diseases, inflammation, and diabetes. Therefore, the enforcement of the latter mechanisms is of the utmost importance. The isolation and characterization of compounds that may delay the onset of aging is receiving intense research attention; some berry phenolics are being associated with this functional performance. Berry phenolics may also act as antimicrobials which may be of help in the control of the wild spectra of pathogens, in view of recent problems associated with antibiotic resistance. Most of the research works on the antioxidant activity of bioactive constituents of berries has been carried out using in vitro assays. In view of this, the human studies investigating the bioavailability and potential toxicity of phenolics are receiving more attention. Finally, we would like to emphasize the necessity of associating new plant breeding and genetic studies of berries with the expression and overexpression of compounds for human health and healthy aging.

Bioavailability challenges associated with development of anti-cancer phenolics

Phenolics including many polyphenols and flavonoids have the potentials to become chemoprevention and chemotherapy agents. However, poor bioavailability limits their biological effects in vivo. This paper reviews the factors that affect phenolics absorption and their bioavailabilities from the points of view of their physicochemical properties and disposition in the gastrointestinal tract. The up-to-date research data suggested that solubility and metabolism are the primary reasons that limit phenolic aglycones' bioavailability although stability and poor permeation may also contribute to the poor bioavailabilities of the glycosides. Future investigations should further optimize phenolics' bioavailabilities and realize their chemopreventive and chemotherapeutic effects in vivo.

Tannins: current knowledge of food sources, intake, bioavailability and biological effects

Tannins are a unique group of phenolic metabolites with molecular weights between 500 and 30 000 Da, which are widely distributed in almost all plant foods and beverages. Proanthocyanidins and hydrolysable tannins are the two major groups of these bioactive compounds, but complex tannins containing structural elements of both groups and specific tannins in marine brown algae have also been described. Most literature data on food tannins refer only to oligomeric compounds that are extracted with aqueous-organic solvents, but a significant number of non-extractable tannins are usually not mentioned in the literature. The biological effects of tannins usually depend on their grade of polymerisation and solubility. Highly polymerised tannins exhibit low bioaccessibility in the small intestine and low fermentability by colonic microflora. This review summarises a new approach to analysis of extractable and non-extractable tannins, major food sources, and effects of storage and processing on tannin content and bioavailability. Biological properties such as antioxidant, antimicrobial and antiviral effects are also described. In addition, the role of tannins in diabetes mellitus has been discussed.

Enhanced oral bioavailability and antioxidant profile of ellagic acid by phospholipids

Ellagic acid (EA) has been reported as a potent antioxidant from natural resources with several nutritional benefits. The major disadvantage of this phytoconstituent is its rapid elimination from the body after administration. To overcome this limitation, a novel dietary formulation of EA with phospholipid was developed to investigate the effect of this complex on carbon tetrachloride induced liver damage in rats. The antioxidant activity of the complex (equivalent of EA = 25 and 50 mg/kg of body weight) and free EA (25 and 50 mg/kg of body weight) was evaluated by measuring various enzymes in oxidative stress condition. The complex significantly protected the liver by restoring the activity of superoxide dismutase, catalase and liver glutathione, and thiobarbituric acid reactive substances with respect to the carbon tetrachloride treated group (P < 0.05 and < 0.01). The complex provided better protection to rat liver than free EA at the same dose. The serum concentration of EA obtained from the complex (equivalent to 80 mg/kg of EA) was higher (C(max) = 0.54 microg/mL) than that of pure EA (80 mg/kg) (C(max) = 0.21 microg/mL), and the complex maintained effective concentration for a longer period of time in serum. The experimental outcome highlighted better hepatoprotective activity of the EA complex due to its potential antioxidant property compared with the free EA tested at the same dose level.

Drug development for liver diseases: focus on picroliv, ellagic acid and curcumin

The use of herbal drugs for the treatment of liver diseases has a long tradition in many eastern countries. The easy accessibility without the need for laborious pharmaceutical synthesis has drawn increased attention towards herbal medicines. Few herbal preparations exist as standardized extracts with major known ingredients or even as pure compounds. Some of the herbals, which show promising activity, are ellagic acid for antifibrotic treatment, phyllanthin for treating chronic hepatitis B, glycyrrhizin to treat chronic viral hepatitis and picroliv for liver regeneration. These compounds, which have proven antioxidant, antiviral or anticarcinogenic properties, can serve as primary compounds for further development as hepatoprotective drugs. This review provides the chemistry, pharmacology and future aspects of picroliv, ellagic acid and curcumin with focus on hepatoprotective properties. These phytochemicals may prove to be very useful in the treatment of hepatotoxicity induced by viral agents, toxic drugs and plant poisons. The high safety profile may be an added advantage. However, poor bioavailability and temperature and light sensitivity can reduce the efficacy of drugs like curcumin. In future, the derivatives or new combinations of these drugs may prove to be useful.

Sustained release nanoparticulate formulation containing antioxidant-ellagic acid as potential prophylaxis system for oral administration

The aim of the present work was to develop ellagic acid (EA) loaded poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles for oral administration. PLGA nanoparticles were prepared by a method based on the concept of emulsion-diffusion-evaporation by using polyethylene glycol (PEG) 400 as a cosolvent for solubilizing the drug. While developing this method, didodecyldimethylammomium bromide (DMAB) and polyvinyl alcohol (PVA), alone and in combination with chitosan (CS) were employed. DMAB stabilized particles were the smallest of all the formulations with a particle size of 148.5 nm. PVA alone gave particles of 269.7 nm but a blend with CS (80:20) resulted in an increase in particle size (359.6 +/- 23.6 nm). Initial release of EA from nanoparticles in pH 7.4 phosphate buffer was rapid, followed by a slower sustained release. Release rates followed the order PVA > PVA-CS > DMAB. Release rate from the PLGA-DMAB particles was slowest, which is attributed to higher hydrophobicity of DMAB as compared to PVA, preventing diffusion of drug out of polymeric matrix. Insolubility of CS at alkaline pH could have retarded the release in case of PVA-CS system. In situ intestinal permeability study of pure drug and the drug encapsulated in nanoparticles prepared using PVA, PVA-CS blend and DMAB as stabilizer in rats showed 66, 75, 73 and 87% permeation, respectively. EA showed good free radical scavenging effect in a yeast cell culture model as well as in a cell free system.

Bioavailable constituents/metabolites of pomegranate (Punica granatum L) preferentially inhibit COX2 activity ex vivo and IL-1beta-induced PGE2 production in human chondrocytes in vitro

Several recent studies have documented that supplementation with pomegranate fruit extract inhibits inflammatory symptoms in vivo. However, the molecular basis of the observed effects has not been fully revealed. Although previous studies have documented the inhibition of nitric oxide and cyclooxygenase (COX) activity in vitro by plant and fruit extracts added directly into the culture medium but whether concentrations of bioactive compounds sufficient enough to exert such inhibitory effects in vivo can be achieved through oral consumption has not been reported. In the present study we determined the effect of rabbit plasma obtained after ingestion of a polyphenol rich extract of pomegranate fruit (PFE) on COX enzyme activity ex vivo and the IL-1beta-induced production of NO and PGE2 in chondrocytes in vitro. Plasma samples collected before and 2 hr after supplementation with PFE were tested. Plasma samples collected after oral ingestion of PFE were found to inhibit the IL-1beta-induced PGE2 and NO production in chondrocytes. These same plasma samples also inhibited both COX-1 and COX-2 enzyme activity ex vivo but the effect was more pronounced on the enzyme activity of COX-2 enzyme. Taken together these results provide additional evidence of the bioavailability and bioactivity of compounds present in pomegranate fruit after oral ingestion. Furthermore, these studies suggest that PFE-derived bioavailable compounds may exert an anti-inflammatory effect by inhibiting the inflammatory cytokine-induced production of PGE2 and NO in vivo.

Improvement of cisplatin-induced injuries to sperm quality, the oxidant-antioxidant system, and the histologic structure of the rat testis by ellagic acid

OBJECTIVE

To investigate whether ellagic acid (EA) has a possible protective effect against cisplatin (CP)-induced negative changes in epididymal sperm characteristics and the histologic structure of testis and prostate associated with oxidative stress in rats.

DESIGN

Experimental study.

SETTING

Firat University Medical School Experimental Research Center, Elazig, Turkey.

PATIENT(S)

Eight-week-old adult male Sprague Dawley rats (n = 24).

INTERVENTION(S)

Cisplatin was administered to rats at a single dose of 7 mg/kg IP. Ellagic acid was administered both separately and simultaneously with CP by gavage daily for 10 days at the dose of 10 mg/kg.

MAIN OUTCOME MEASURE(S)

Reproductive organ weights, epididymal sperm characteristics, and histopathologic structure of testes and ventral prostate were determined along with malondialdehyde (MDA) and glutathione (GSH) levels and glutathione-peroxidase (GSH-Px) and catalase (CAT) activities of plasma, sperm, and testicular tissue.

RESULT(S)

Ellagic acid ameliorated the CP-induced reductions in weights of testes, epididymides, seminal vesicles, and prostate along with epididymal sperm concentration and motility. Additionally, EA decreased the CP-induced increments in abnormalities of sperm. Whereas CP increased the MDA levels of plasma, sperm, and testicular tissue, it decreased the GSH-Px and CAT activities in the study samples compared with the control group. The administration of EA to CP-treated rats decreased the MDA level and increased GSH-Px and CAT activities in these samples. Cisplatin caused degeneration, necrosis, interstitial edema, and reduction in germinative cell layer thickness and rarely reduction in spermatogenic activity in some seminiferous tubules. The CP-induced changes in histopathologic findings of testis were partially reversed by treatment with EA. No significant changes were observed in the histopathologic structure of the prostate among any of groups.

CONCLUSION(S)

Ellagic acid has a protective effect against testicular toxicity caused by CP. This protective effect of EA seems to be closely involved with the suppressing of oxidative stress.

Pomegranate ellagitannin-derived metabolites inhibit prostate cancer growth and localize to the mouse prostate gland

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.

Determination of ellagic acid in oak leaves and in sheep ruminal fluid by ion-pair RP-HPLC

An isocratic ion-pair high-performance liquid chromatography (IP-RP-HPLC) method with UV detection was developed to identify and quantify ellagic acid (EA). This phenolic compound is widely distributed in the plants and is often present in the diet of ruminants. The method was validated and validation parameters were: linearity range 5-100 mg/L; correlation coefficient, 0.9995; mean recoveries (99.94 and 101.07%) and detection limit 1.4 mg/L. Method was applied for the determination of ellagic acid in oak leaves and in ruminal fluid from to a vitro ruminal system. The proposed method proved to be rapid and accurate and can be successfully used in ruminant nutrition studies.

Biodegradable in situ gelling system for subcutaneous administration of ellagic acid and ellagic acid loaded nanoparticles: Evaluation of their antioxidant potential against cyclosporine induced nephrotoxicity in rats

Ellagic acid (EA) is a potent antioxidant marketed as a nutritional supplement. Its pharmacological activity has been reported in wide variety of disease models; however its use has been limited owing to its poor biopharmaceutical properties, thereby poor bioavailability. The objective of the current study was to develop chitosan-glycerol phosphate (C-GP) in situ gelling system for sustained delivery of ellagic acid (EA) via subcutaneous route. EA was incorporated in the system employing propylene glycol (PG) and triethanolamine (TEA) as co-solvents; on the other hand EA loaded PLGA nanoparticles (np) were dispersed in the gelling system using water. These in situ gelling systems were thoroughly characterized for mechanical, rheological and swelling properties. These systems are liquid at room temperature and gels at 37 degrees C. The EA C-GP system showed an initial burst release in vitro with about 85% drug released in 12 h followed by a steady release till 160 h, on the other hand EA nanoparticles entrapped in the C-GP system displayed sustained release till 360 h. The histopathological analysis indicates the absence of inflammation on administration, suggesting that these formulations are safe during the studied period. Furthermore, the antioxidant potential of EA C-GP and EA np C-GP gels has been evaluated against cyclosporine induced nephrotoxicity in rats. The data indicates that formulations were effective against cyclosporine induced nephrotoxicity, where the EA C-GP gels showed activity at 10 times lower dose and the EA np C-GP gels at 150 times lower dose when compared to orally given EA. Formulating nanoparticles of EA and incorporating them in C-GP system results in 15 times lowering of dose in comparison EA C-GP gels which is quite significant. Together, these results indicate that the bioavailability of ellagic acid can be improved by subcutaneous formulations administered as simple EA or EA nps.

The inhibition of human glutathione S-transferases activity by plant polyphenolic compounds ellagic acid and curcumin

Glutathione S-transferases (GSTs) are multifunctional detoxification proteins that protect the cell from electrophilic compounds. Overexpression of GSTs in cancer results in resistance to chemotherapeutic agents and inhibition of the over expressed GST has been suggested as an approach to combat GST-induced resistance. The inhibition of human recombinant GSTs by natural plant products was investigated in this study. Using 1-chloro-2,4 dinitrobenzene (CDNB) as a substrate, ellagic acid and curcumin were shown to inhibit GSTs A1-1, A2-2, M1-1, M2-2 and P1-1 with IC(50) values ranging from 0.04 to 5 microM whilst genistein, kaempferol and quercetin inhibited GSTs M1-1 and M2-2 only. The predominant mode of inhibition with respect to the G and H-sites were mixed inhibition and uncompetitive to a lesser extent. The K(i) (K(i)(')) values for ellagic acid and curcumin with respect to GSH and CDNB were in the range 0.04-6 microM showing the inhibitory potency of these polyphenolic compounds. Ellagic acid and curcumin also showed time- and concentration-dependent inactivation of GSTs M1-1, M2-2 and P1-1 with curcumin being a more potent inactivator than ellagic acid. These results facilitate the understanding of the interaction of human GSTs with plant polyphenolic compounds with regards to their role as chemomodulators in cases of GST-overexpression in malignancies.

Pomegranate juice ellagitannin metabolites are present in human plasma and some persist in urine for up to 48 hours

Ellagitannins (ETs) from pomegranate juice (PJ) are reported to have numerous biological properties, but their absorption and metabolism in humans are poorly understood. To investigate the pharmacokinetics of pomegranate ETs, 18 healthy volunteers were given 180 mL of PJ concentrate, and blood samples were obtained for 6 h afterwards. Twenty-four-hour urine collections were obtained on the day before (-1), the day of (0), and the day after (+1) the study. Ellagic acid (EA) was detected in plasma of all subjects with a maximum concentration of 0.06 +/- 0.01 micromol/L, area under concentration time curve of 0.17 +/- 0.02 (micromol x h) x L(-1), time of maximum concentration of 0.98 +/- 0.06 h, and elimination half-life of 0.71 +/- 0.08 h. EA metabolites, including dimethylellagic acid glucuronide (DMEAG) and hydroxy-6H-benzopyran-6-one derivatives (urolithins), were also detected in plasma and urine in conjugated and free forms. DMEAG was found in the urine obtained from 15 of 18 subjects on d 0, but was not detected on d -1 or +1, demonstrating its potential as a biomarker of intake. Urolithin A-glucuronide was found in urine samples from 11 subjects on d 0 and in the urine from 16 subjects on d +1. Urolithin B-glucuronide was found in the urine of 3 subjects on d 0 and in the urine of 5 subjects on d +1. Urolithins, formed by intestinal bacteria, may contribute to the biological effects of PJ as they may persist in plasma and tissues and account for some of the health benefits noted after chronic PJ consumption. Whether genetic polymorphisms in EA-metabolizing enzymes (e.g., catechol-O-methyl transferase and glucuronosyl transferase) are related to variations in response to PJ remains to be established.

In vitro antileukaemic activity of extracts from berry plant leaves against sensitive and multidrug resistant HL60 cells

The aim of the present study was to determine in vitro antileukaemic activity of extracts obtained from selected berry plant leaves (Fragaria x ananassa Duch. cv Elsanta, raspberry Rubus ideus L. cv Polana and blueberry Vaccinium corymbosum L. cv Bluecrop) against promyelocytic HL60 cell line and its multidrug resistant sublines exhibiting two different MDR phenotypes: HL60/VINC (overexpressing P-glycoprotein) and HL60/DOX (overexpressing MRP1 protein). It was found that the blueberry extract was the most efficient against sensitive HL60 cell line (about 2-fold more active than strawberry and raspberry extracts) but presented much lower activity towards resistant cells. In contrast, strawberry and raspberry extracts exhibited the high cytotoxic activity against sensitive leukaemia HL60 cell line as well as its MDR sublines. The values of resistance factor (RF) found for these extracts were very low lying in the range 0.32/2.0.

Inhibitory effect of an ellagic acid-rich pomegranate extract on tyrosinase activity and ultraviolet-induced pigmentation

A pomegranate extract (PE) from the rind containing 90% ellagic acid was tested for its skin-whitening effect. PE showed inhibitory activity against mushroom tyrosinase in vitro, and the inhibition by the extract was comparable to that of arbutin, which is a known whitening agent. PE, when administered orally, also inhibited UV-induced skin pigmentation on the back of brownish guinea pigs. The intensity of the skin-whitening effect was similar between guinea pigs fed with PE and those fed with L-ascorbic acid. PE reduced the number of DOPA-positive melanocytes in the epidermis of UV-irradiated guinea pigs, but L-ascorbic acid did not. These results suggest that the skin-whitening effect of PE was probably due to inhibition of the proliferation of melanocytes and melanin synthesis by tyrosinase in melanocytes. PE, when taken orally, may be used as an effective whitening agent for the skin.

Pharmacokinetic study ofp-coumaric acid in mouse after oral administration of extract ofAnanas comosus L. leaves

Quantification of p-coumaric acid in mouse plasma following oral administration of Ananas comosus L. leaves was achieved by reversed-phase high-performance liquid chromatography using a mobile phase of water-acetonitrile (82:18, v/v) and UV detection at 310 nm. The method was linear (determination coefficient, r2 = 0.9997) within the tested range (0.04-1.28 microg/mL). Intra- and inter-day precision coefficients of variation and accuracy bias were acceptable (maximal CV value was 4.06% for intra-day and 4.19% for inter-day) over the entire range. The recoveries were 90.63, 97.98 and 100.01% for concentrations of 0.04, 0.32 and 1.28 microg/mL, respectively. This is a very rapid, sensitive and economical way to determine p-coumaric acid concentration in mouse plasma after oral administration of A. comosus leaves. The concentration-time curve was fitted to the one-compartment model. This is the first time that p-coumaric acid extracted from A. comosus leaves was detected by HPLC-UV method and its pharmacokinetic characteristic was comprehensively studied.

Maternal dietary supplementation with pomegranate juice is neuroprotective in an animal model of neonatal hypoxic-ischemic brain injury

Neonatal hypoxic-ischemic brain injury remains a significant cause of morbidity and mortality and lacks effective therapies for prevention and treatment. Recently, interest in the biology of polyphenol compounds has led to the discovery that dietary supplementation with foods rich in polyphenols (e.g. blueberries, green tea extract) provides neuroprotection in adult animal models of ischemia and Alzheimer's disease. We sought to determine whether protection of the neonatal brain against a hypoxic-ischemic insult could be attained through supplementation of the maternal diet with pomegranate juice, notable for its high polyphenol content. Mouse dams were provided ad libitum access to drinking water with pomegranate juice, at one of three doses, as well as plain water, sugar water, and vitamin C water controls during the last third of pregnancy and throughout the duration of litter suckling. At postnatal day 7, pups underwent unilateral carotid ligation followed by exposure to 8% oxygen for 45 min. Brain injury was assessed histologically after 1 wk (percentage of tissue area loss) and biochemically after 24 h (caspase-3 activity). Dietary supplementation with pomegranate juice resulted in markedly decreased brain tissue loss (>60%) in all three brain regions assessed, with the highest pomegranate juice dose having greatest significance (p < or = 0.0001). Pomegranate juice also diminished caspase-3 activation by 84% in the hippocampus and 64% in the cortex. Ellagic acid, a polyphenolic component in pomegranate juice, was detected in plasma from treated but not control pups. These results demonstrate that maternal dietary supplementation with pomegranate juice is neuroprotective for the neonatal brain.