Concomitant use of tea catechins affects absorption and serum triglyceride-lowering effects of monoglucosyl hesperidin.

The present study investigated whether combined ingestion of green tea catechins (GTC) and monoglucosyl hesperidin (GHES) influences the pharmacokinetic parameters of polyphenols and serum triglycerides (TG). We conducted 2 randomized, controlled trials. Study 1: 8 healthy male subjects participated in a crossover study in which they ingested a test beverage containing GHES (0, 84, 168, or 336 mg GHES) with GTC, or 336 mg GHES without GTC. After ingestion, the pharmacokinetic changes in plasma hesperetin (HEP) and catechins were measured. Study 2: 36 healthy male and female subjects (mean age, 53 ± 2 years; mean BMI, 25.2 ± 0.5 kg m-2) were recruited for a double-blind, placebo-controlled study in which they ingested a test beverage containing 165 mg GHES with 387 mg GTC or a placebo beverage daily for 4 weeks. Fasting serum TG and other lipids and glucose metabolites were analyzed. Study 1 showed that the pharmacokinetics of HEP did not differ significantly between the 336 mg GHES without GTC treatment and the 168 mg GHES with GTC treatment. Study 2 showed that continuous ingestion of 165 mg GHES and 387 mg GTC for 4 weeks significantly decreased fasting serum TG levels compared with baseline values (change in TG, -30 ± 13 mg dl-1, P = 0.040) in the intention-to-treat analysis. In conclusion, our findings suggest that GTC affects the oral bioavailability of GHES, and combined ingestion of low doses of GHES with GTC effectively improves fasting TG levels.

Boronic-targeted albumin-shell oily-core nanocapsules for synergistic aromatase inhibitor/herbal breast cancer therapy.

Multi-modality strategies of albumin-mediated drug accumulation in tumor, boronate-based active tumor targeting and synergistic cancer therapy were combined together for effective treatment of breast cancer. Herein we report the development of albumin-shell oily-core nanocapsules (NCs), loaded with novel combination of hydrophobic drugs, exemestane (EXE) and hesperetin (HES), for targeted breast cancer therapy. This protein-lipid nanohybrid carrier was successfully fabricated using a simple protein-coating method based on the electrostatic adsorption of negatively charged albumin shell onto the oily core containing cationic surfactant. While EXE was directly encapsulated into the oily core, HES was pre-formulated in the form of phospholipid complex before solubilization in oily phase. In addition to albumin-mediated binding to albondin and SPARC, phenylboronic acid was chemically coupled to the albumin shell to confer additional tumor targeting. The targeted nanocarrier (TNC) demonstrated enhanced internalization into MCF-7 breast cancer cells resulting in synergistic cytotoxic activity with a combination index (CI) of 0.662 and dose reduction index (DRI) of 8.22 and 1.84 for EXE and HES, respectively. In vivo, TNC displayed superior anti-cancer activity in tumor-bearing mice compared to their non-targeted counterparts and the free drug combination. A significant reduction of both tumor volume (7-folds) and Ki67 expression (3-folds) was obtained by the targeted nanocarriers compared to positive control. Overall, the boronic-targeted albumin NCs offer a promising platform for hydrophobic drug combination against cancer therapy.

Absorption and Metabolic Behavior of Hesperidin (Rutinosylated Hesperetin) after Single Oral Administration to Sprague-Dawley Rats.

We investigated the absorption and metabolic behavior of hesperidin (hesperetin-7-O-rutinoside) in the blood system of Sprague-Dawley rats by liquid chromatography- and matrix-assisted laser desorption ionization mass spectrometries (LC-MS and MALDI-MS). After a single oral administration of hesperidin (10 mg/kg), which was expected to be absorbed in its degraded hesperetin form, we detected intact hesperidin in the portal vein blood (tmax, 2 h) for the first time. We successfully detected glucuronized hesperidin in the circulating bloodstream, while intact hesperidin had disappeared. Further MS analyses revealed that homoeriodictyol and eriodictyol conjugates were detected in both portal and circulating blood systems. This indicated that hesperidin and/or hesperetin are susceptible to methylation and demethylation during the intestinal membrane transport process. Sulfated and glucuronized metabolites were also detected in both blood systems. In conclusion, hesperidin can enter into the circulating bloodstream in its conjugated forms, together with the conjugated forms of hesperetin, homoeriodictyol, and/or eriodictyol.

Comparative pharmacokinetic study of four major bioactive components after oral administration of Zhi-Zi-Hou-Po decoction in normal and corticosterone-induced depressive rats.

A highly selective and efficient LC-MS/MS method was developed to determine the plasma concentration of magnolol, hesperidin, neohesperidin and geniposide following oral administration of Zhi-Zi-Hou-Po decoction in normal and depressed rats. Plasma samples were pretreated by protein precipitation with methanol. Chromatographic separation was performed on an XTerra® MS C18 column using a gradient elution with a mobile phase composed of acetonitrile-0.1% aqueous formic acid. The proposed method was validated to be specific, accurate and precise for the analytes determination in plasma samples. The calibration curves displayed good linearity over definite concentration ranges for the analytes. The intra- and inter-day precision of the proposed method at three different levels were all within <11.13% and the relative errors ranged from -8.46 to 8.93%. The recovery of the four compounds ranged from 82.72 to 89.08% and no apparent matrix effect was observed during sample analysis. After full validation, the established method was successfully applied for comparing the pharmacokinetics of four components between normal and depressed rats. The results showed that the AUC and Cmax of four analytes in depressed rats were significantly different from those in normal rats and might provide helpful information to guide the clinical use of Zhi-Zi-Hou-Po to treat depression.

Pharmacokinetic study of the prokinetic ABCs liquiritigenin, naringenin and hesperitin following the oral administration of Si-Ni-San decoction to functional dyspepsia patients.

1. The pharmacokinetics (PKs) analysis of compounds absorbed after the oral administration of Si-Ni-San (SNS) decoction to functional dyspepsia (FD) patients was designed to detect whether the effects were similar to prokinetics administered to healthy rats, without ethical limitation. 2. First, the absorbed compounds, liquiritigenin (L), naringenin (N) and hesperitin (H) in the plasma were identified by UPLC-MS/MS following the oral administration of SNS decoction to subjects with FD. Next, the natural ratio of LNH in the SNS decoction was determined by UPLC. Third, gastric emptying and intestinal transit after the oral administration of LNH, in combination or alone, was compared with those observed after SNS administration in healthy rats. Additionally, the clinical PKs of LNH was studied. 3. The prokinetic efficacy of LNH administered at their natural ratios (7.5:5:1) increased dose-dependently and was better than the observed efficacy when administered alone in rats. Analysis of the clinical PK parameters, calculated using a one-compartment model, showed that the Cmax parameters of LNH in 3, 4 and 4 h were 639.17, 410.00 and 181.67 µg/L, respectively. 4. The clinical herbal PK analysis of the absorbed LNH preclinical prokinetic compounds, in their natural ratio from SNS, highlights the impact of an herbal translational pharmacology study.

Potential Anti-inflammatory Effects of Hesperidin from the Genus Citrus.

BACKGROUND: The benefits of the Mediterranean diet for protecting against many diseases are usually attributed to high consumption of certain foods, characterized by the presence of bioactive substances such as polyphenols. Inflammation plays an important role in the pathogenesis of numerous diseases such as arthritis, allergies or neurodegenerative disorders. Dietary polyphenols constitute a large family of bioactive substances with potential beneficial effects against a broad group of diseases. Citrus fruits and juices are a rich source of vitamin C and flavonoids, with a potential effect on the inflammatory response. OBJECTIVE: The aim was to evidence the potential anti-inflammatory effects of the flavonoids hesperidin for its possible therapeutic application against diverse pathologies. METHOD: In the present review, available literature about the anti-inflammatory effects of hesperidin is reported and discussed. Moreover, we also discuss the chemistry, bioavailability and proposed mechanisms of action of hesperidin. RESULTS: Hesperidin is a flavonoid present in high concentration in citrus species and has numerous biological properties, principally antioxidant and anti-inflammatory. Several studies have been performed in order to evaluate the effects of hesperidin as anti-inflammatory agent using cellular and animal models and few clinical trials. Hesperidin treatment decreased inflammatory mediators and exerted significant antioxidant effects. The molecular basis for its anti-inflammatory effects seems to be mediated by signalling pathways especially the nuclear factor κß pathway. CONCLUSION: Although hesperidin evidenced anti-inflammatory effects, the specific mechanism of action is not completely known and additional studies are required for elucidation of the molecular targets.

[Effect of Saposhnikoviae Radix on pharmacokinetics and tissue distributions of active components in Tongxie Yaofang in rats].

Tongxie Yaofang (TXYF) is a famous formula that has been used for treating gastrointestinal diseases in traditional Chinese medicine(TCM). Saposhnikoviae Radix is considered as a meridian guiding drug in TXYF and could enhance the effectiveness of prescription. However, the scientific evidence for this effect is still not clear. To reveal the interactions of Saposhnikoviae Radix with other herbs, we conducted this study on the pharmacokinetic profile and tissue distribution of active ingredients of TXYF in rats. The concentrations of four components in blood and tissues were determined by UPLC-MS/MS after oral administration with TXYF. The detection was carried out by electrospray ionization mass spectrometry in the multiple reaction monitoring (MRM) mode. The positive and negative ion switching technique was performed in the same analysis. The results revealed that Saposhnikoviae Radix could enhance Cmax, AUC0-t, and AUC0-∞ of paeoniflorin and hesperidin, and increase the distribution of atractylenolide-I, paeoniflorin and hesperidin in liver, spleen, brain and small intestine. Saposhnikoviae Radix increased the ratio of brain to blood concentrations of atractylenolide-I, paeoniflorin and hesperidin. Meanwhile, it reduced the ratio of lung to blood concentrations of atractylenolide-I and paeoniflorin. Saposhnikoviae Radix, and may enhance the effectiveness of prescriptions by promoting distribution of other herbs in brain.

Bioavailability of orange juice (poly)phenols: the impact of short-term cessation of training by male endurance athletes.

Background: Physical exercise has been reported to increase the bioavailability of citrus flavanones.Objective: We investigated the bioavailability of orange juice (OJ) (poly)phenols in endurance-trained males before and after cessation of training for 7 d.Design: Ten fit, endurance-trained males, with a mean ± SD maximal oxygen consumption of 58.2 ± 5.3 mL · kg-1 · min-1, followed a low (poly)phenol diet for 2 d before drinking 500 mL of OJ containing 398 µmol of (poly)phenols, of which 330 µmol was flavanones. After the volunteers stopped training for 7 d the feeding study was repeated. Urine samples were collected 12 h pre- and 24 h post-OJ consumption. Bioavailability was assessed by the quantitative analysis of urinary flavanone metabolites and (poly)phenol catabolites with the use of high-pressure liquid chromatography-high resolution mass spectrometry.Results: During training, 0-24-h urinary excretion of flavanone metabolites, mainly hesperetin-3'-O-glucuronide, hesperetin-3'-sulfate, naringenin-4'-O-glucuronide, naringenin-7-O-glucuronide, was equivalent to 4.2% of OJ flavanone intake. This increased significantly to 5.2% when OJ was consumed after the volunteers stopped training for 7 d. Overall, this trend, although not significant, was also observed with OJ-derived colonic catabolites, which, after supplementation in the trained state, were excreted in amounts equivalent to 51% of intake compared with 59% after cessation of training. However, urinary excretion of 3 colonic catabolites of bacterial origin, most notably, 3-(3'-hydroxy-4'-methoxyphenyl)hydracrylic acid, did increase significantly when OJ was consumed postcessation compared with precessation of training. Data were also obtained on interindividual variations in flavanone bioavailability.Conclusions: A 7-d cessation of endurance training enhanced, rather than reduced, the bioavailability of OJ flavanones. The biological significance of these differences and whether they extend to the bioavailability of other dietary (poly)phenols remain to be determined. Hesperetin-3'-O-glucuronide and the colonic microbiota-derived catabolite 3-(3'-hydroxy-4'-methoxyphenyl)hydracrylic acid are key biomarkers of the consumption of hesperetin-O-glycoside-containing OJ and other citrus products. This trial was registered at clinicaltrials.gov as NCT02627547.

Pharmacokinetics and pharmacodynamics of Da-Cheng-Qi decoction in the liver of rats with severe acute pancreatitis.

AIM: To explore the pharmacokinetics and pharmacodynamics of Da-Cheng-Qi decoction (DCQD) in the liver of rats with severe acute pancreatitis (SAP) based on an herbal recipe tissue pharmacology hypothesis. METHODS: Healthy male Sprague-Dawley rats were randomly divided into a sham operation group (SOG); a model group (MG); and low-, median- and high-dose treatment groups (LDG, MDG, and HDG, respectively). Different dosages (6, 12 and 24 g/kg for the LDG, MDG, and HDG, respectively) of DCQD were administered to the rats with SAP. The tissue concentrations of aloe-emodin, rhein, emodin, chrysophanol, honokiol, rheo chrysophanol, magnolol, hesperidin, naringenin and naringin in the liver of the treated rats were detected by high-performance liquid chromatography tandem mass spectrometry. Alanine transaminase (ALT) and aspartate transaminase (AST) in serum, inflammatory mediators in the liver and pathological scores were evaluated. RESULTS: The major components of DCQD were detected in the liver, and their concentrations increased dose-dependently. The high dose of DCQD showed a maximal effect in ameliorating the pathological damages, decreasing the pro-inflammatory mediators tumor necrosis factor-α and interleukin (IL)-6 and increasing anti-inflammatory mediators IL-4 and IL-10 in the liver. The pathological scores in the pancreas for the MG were significantly higher than those for the SOG (P < 0.05). DCQD could reduce the pathological scores in the pancreas and liver of the rats with SAP, especially in the HDG. Compared to the SOG, the ALT and AST levels in serum were higher in the MG (P < 0.05), while there was no statistical difference in the MG and HDG. CONCLUSION: DCQD could alleviate liver damage by altering the inflammatory response in rats with SAP based on the liver distribution of its components.

Health-promoting effects of the citrus flavanone hesperidin.

Hesperidin, a member of the flavanone group of flavonoids, can be isolated in large amounts from the rinds of some citrus species. Considering the wide range of pharmacological activities and widespread application of hesperidin, this paper reviews preclinical and clinical trials of hesperidin and its related compounds, including their occurrence, pharmacokinetics, and some marketed products available. Preclinical studies and clinical trials demonstrated therapeutical effects of hesperidin and its aglycone hesperetin in various diseases, such as neurological disorders, psychiatric disorders, and cardiovascular diseases and others, due to its anti-inflammatory, antioxidant, lipid-lowering, and insulin-sensitizing properties.

[Effect of different compatibility of zhizi dahuang decoction on pharmacokinetics of naringenin and hesperetin].

An HPLC-UV method was developed for the determination of total naringenin and total hesperetin in rat plasma after oral administration of Citrus aurantium Immaturus extracts and Zhizi Dahuang decoction. Plasma samples were pretreated with liquid-liquid extraction procedure and acid hydrolysis method was used for converting conjugated naringenin and hesperetin to their respective free forms. Plasma samples were separated on a C18 column (4.6 mm x 150 mm, 5 microm), using 0.1% phosphoric acid and methanol as mobile phase at a flow rate of 1.0 mL x min(-1) with gradient elution. DAS 2.0 software was applied to calculate the pharmacokinetic parameters while the SPSS 16.0 software was used for statistical analysis. Significant differences were observed, the C(max) AUC(0-t) of total naringenin in ZS group was 73.5% and 65.9% higher than those in ZZDHD group, respectively; the C(max), AUC(0-t) of total hesperetin in ZS group was 63.5% and 119.1% higher than those in ZZDHD group, respectively. There is a obvious decrease in C(max) and AUC(0-t) of total naringenin and total hesperetin after compatibility and their pharmacokinetic characteristics changed greatly due to the combination of other herbs. The established method was rapid, sensitive, selective and accurate, and it could be applied in the determination of total naringenin and total hesperetin in rat plasma.

Bioavailability of dietary (poly)phenols: a study with ileostomists to discriminate between absorption in small and large intestine.

A feeding study was carried out in which six healthy ileostomists ingested a juice drink containing a diversity of dietary (poly)phenols derived from green tea, apples, grapes and citrus fruit. Ileal fluid and urine collected at intervals over the ensuing 24 h period were then analysed by HPLC-MS. Urinary excretions were compared with results obtained in an earlier study in which the juice drink was ingested by ten healthy control subjects with an intact colon. Some polyphenol components, such as (epi)catechins and (epi)gallocatechin(s), were excreted in urine in similar amounts in ileostomists and subjects with an intact colon, demonstrating that absorption took place principally in the small intestine. In the urine of ileostomists, there were reduced levels of other constituents, including hesperetin-7-O-rutinoside, 5-O-caffeoylquinic acid and dihydrochalcones, indicating their absorption in both the small and large intestine. Ileal fluid analysis revealed that even when absorption occurred in the small intestine, in subjects with a functioning colon a substantial proportion of the ingested components still pass from the small into the large intestine, where they may be either absorbed before or after catabolism by colonic bacteria.

Pharmacokinetics of hesperetin and naringenin in the Zhi Zhu Wan, a traditional Chinese medicinal formulae, and its pharmacodynamics study.

Zhi Zhu Wan (ZZW), a classical Chinese medical formulae consisted of Atractylodes Rhizome and Fructus Citrus Immaturus, has been commonly used for treatment of gastrointestinal diseases. Hesperetin and naringenin are the main components of ZZW, and both can alleviate intestinal tract disorders. In this work, plasma pharmacokinetics and pharmacodynamics characteristics of ZZW after oral administration were investigated using a rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry method with an electrospray ionization source in positive ion mode. Biosamples were prepared using methanolic precipitation, and the separation of hesperetin and naringenin was achieved on a Waters ACQUITY HSS BEH (2.1 mm × 5 mm, 1.7 µm) column by linear gradient elution, and the total run time was only 3 min. Data were analyzed and estimated using WinNonlin Professional version 5.1. With pharmacokinetic analysis, the estimated pharmacokinetic parameters (i.e. C(max), area under the concentration-time curve (AUC) and t(1/2)), were C(max) = 776.06 ng/mL, AUC = 9473 ng/mL·h, t1/2 = 5.26 h for hesperetin and C(max) = 2910.6 ng/mL, AUC = 40607.9 ng/mL·h, t1/2 = 4.69 h for naringenin, respectively. In the present study, we have also valuated and clarified the effect of ZZW on small intestinal movement. It was found that ZZW can accelerate intestinal motility in mice and may hold a promising treatment for intestinal diseases.

Effect of formula compatibility on the pharmacokinetics of components from Dachengqi Decoction [See Text] in rats.

OBJECTIVE: To investigate the effect of prescription compatibility on the pharmacokinetics of components from Dachengqi Decoction (DCQD, ) in rats. METHODS: Twenty-four male rats were randomly and equally divided into the DCQD group, Dahuang (Radix et Rhizoma Rhei, Polygonaceae) group, Houpo (Magnolia officinalis Rehd., Magnoliaceae) group, and Zhishi (Fructus Aurantii Immaturus, Rutaceae) group. The blood samples were collected before dosing and subsequently at 10, 15, 20, 30, 45 min, 1, 2, 4, 8, and 12 h following gavage. The levels of aloe-emodin, rhein, emodin, chrysophanol, honokiol, magnolol, hesperidin, and naringin in rat serum were quantified using a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for pharmacokinetic study. RESULTS: The area under the curve (AUC), mean retention time (MRT), the peak concentration (C(max)) of aloe-emodin, rhein, emodin, and chrysophanol in the DCQD group were significantly different compared with the Dahuang group (P <0.05, respectively). The mean plasma concentration, C(max), and the absorption of Dahuang's component in the DCQD group were obviously lower at each time point than those in the Dahuang group, while the elimination process of Dahuang's component was obviously delayed (P <0.05). Half-lives of aloe-emodin, chrysophanol, and rhein were also extended in the DCQD group (P <0.05, respectively). In the DCQD group, the mean plasma concentration, AUC, C(max) and absorption of honokiol, and magnolol were significantly lower (P <0.01, respectively) at each time point than those in the Houpo group, while the drug distribution half-life time (T(1/2α)), the drug eliminated half-life time (T(1/2ß)), MRT, and time of peak concentration (T(max)) were significantly delayed (P <0.05, respectively). Pharmacokinetic parameters of hesperidin and naringin in the Zhishi group were not significantly different as compared with the DCQD group (P >0.05, respectively), while the MRT of naringin was significantly longer. CONCLUSIONS: The compatibility in Chinese medicine could affect the drug's pharmacokinetics in DCQD, which proves that the prescription compatibility principle of Chinese medicine formulations has its own pharmacokinetic basis.

LC determination and pharmacokinetic study of the main phenolic components of Portulaca oleracea L. extract in rat plasma after oral administration.

This study investigated the pharmacokinetics of hesperidin (HP), ferulic acid (FA) and p-coumaric acid (CA) in rat plasma after oral administration of Portulaca oleracea L. extract (POE). The plasma concentrations were determined by HPLC with vitexin-2″-O-rhamnoside (VR) as internal standard. The calibration curves were linear over the range 0.1-5 µg mL(-1), 0.1-5 µg mL(-1)and 0.015-3 µg mL(-1) for HP, FA and CA, respectively. The validated method was suitable to the pharmacokinetic study of HP, FA and CA in rats after oral administration at a single dose of POE.

[Identification of the metabolites of Sinisan extract in rat plasma, urine, feces and bile after intragastric administration].

Sinisan is a widely used traditional Chinese medicine (TCM) in treating various diseases; however, the in vivo metabolic profile of its multiple components remains unknown. In this paper, ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was applied to identify the metabolites of Sinisan extract in rat plasma, urine, feces and bile after intragastric administration. Using MS(E) and mass defect filter techniques, 41 metabolites of 10 parent compounds (naringin, naringenin, hesperidin, neohesperidin, liquiritin, liquiritigenin, glycyrrhizic acid, glycyrrhetinic acid, saikosaponin a and saikosaponin d) were detected and tentatively identified. It was shown by our results that these compounds was metabolized to the forms of hydroxylation, glucuronidation, sulfation, glucuronidation with sulfation and glucuronidation with hydroxylation in vivo.

Pharmacokinetic comparison in rats of six bioactive compounds between Da-Cheng-Qi decoction and its parent herbal medicines.

Da-Cheng-Qi decoction (DCQD) is a purgative compound prescription used in China and East Asia. In this paper, pharmacokinetic differences of six major active components (rhein, emodin, aloe-emodin, magnolol, naringenin and hesperetin) between DCQD and its three constitutional herbal medicines, i.e., Radix et Rhizoma Rhei, Cortex Magnoliae officinalis and Fructus Aurantii Immaturus were investigated in rats after oral administration. Plasma samples were analyzed for the quantification of the six active components using validated LC-MS/MS methods. Unpaired Student's t-test was used for statistical comparison. Significant differences (p < 0.05) in the main pharmacokinetic parameters for rhein, emodin, aloeemodin, magnolol, naringenin and hesperetin were found between DCQD and the decoction of its constitutional single herbal medicines, which demonstrated the presence of drug-drug interactions between these constitutional raw materials of DCQD occurring either in the procedure of decoction or during ADME process.

Phase II metabolism of hesperetin by individual UDP-glucuronosyltransferases and sulfotransferases and rat and human tissue samples.

Phase II metabolism by UDP-glucuronosyltransferases (UGTs) and sulfotransferases (SULTs) is the predominant metabolic pathway during the first-pass metabolism of hesperetin (4'-methoxy-3',5,7-trihydroxyflavanone). In the present study, we have determined the kinetics for glucuronidation and sulfonation of hesperetin by 12 individual UGT and 12 individual SULT enzymes as well as by human or rat small intestinal, colonic, and hepatic microsomal and cytosolic fractions. Results demonstrate that hesperetin is conjugated at positions 7 and 3' and that major enzyme-specific differences in kinetics and regioselectivity for the UGT and SULT catalyzed conjugations exist. UGT1A9, UGT1A1, UGT1A7, UGT1A8, and UGT1A3 are the major enzymes catalyzing hesperetin glucuronidation, the latter only producing 7-O-glucuronide, whereas UGT1A7 produced mainly 3'-O-glucuronide. Furthermore, UGT1A6 and UGT2B4 only produce hesperetin 7-O-glucuronide, whereas UGT1A1, UGT1A8, UGT1A9, UGT1A10, UGT2B7, and UGT2B15 conjugate both positions. SULT1A2 and SULT1A1 catalyze preferably and most efficiently the formation of hesperetin 3'-O-sulfate, and SULT1C4 catalyzes preferably and most efficiently the formation of hesperetin 7-O-sulfate. Based on expression levels SULT1A3 and SULT1B1 also will probably play a role in the sulfo-conjugation of hesperetin in vivo. The results help to explain discrepancies in metabolite patterns determined in tissues or systems with different expression of UGTs and SULTs, e.g., hepatic and intestinal fractions or Caco-2 cells. The incubations with rat and human tissue samples support an important role for intestinal cells during first-pass metabolism in the formation of hesperetin 3'-O-glucuronide and 7-O-glucuronide, which appear to be the major hesperetin metabolites found in vivo.

Increased bioavailability of hesperetin-7-glucoside compared with hesperidin results in more efficient prevention of bone loss in adult ovariectomised rats.

Hesperidin (Hp), a citrus flavonoid predominantly found in oranges, shows bone-sparing effects in ovariectomised (OVX) animals. In human subjects, the bioavailability of Hp can be improved by the removal of the rhamnose group to yield hesperetin-7-glucoside (H-7-glc). The aim of the present work was to test whether H-7-glc was more bioavailable and therefore more effective than Hp in the prevention of bone loss in the OVX rat. Adult 6-month-old female Wistar rats were sham operated or OVX, then pair fed for 90 d a casein-based diet supplemented or not with freeze-dried orange juice enriched with Hp or H-7-glc at two dose equivalents of the hesperetin aglycone (0.25 and 0.5 %). In the rats fed 0.5 %, a reduction in OVX-induced bone loss was observed regarding total bone mineral density (BMD):+7.0 % in OVX rats treated with Hp (HpOVX) and +6.6 % in OVX rats treated with H-7-glc (H-7-glcOVX) v. OVX controls (P < 0.05). In the rats fed 0.25 % hesperetin equivalents, the H-7-glcOVX group showed a 6.6 % improvement in total femoral BMD v. the OVX controls (P < 0.05), whereas the Hp diet had no effect at this dose. The BMD of rats fed 0.25 % H-7-glc was equal to that of those given 0.5 % Hp, but was not further increased at 0.5 % H-7-glc. Plasma hesperetin levels and relative urinary excretion were significantly enhanced in the H-7-glc v. Hp groups, and the metabolite profile showed the absence of eriodictyol metabolites and increased levels of hesperetin sulphates. Taken together, improved bioavailability of H-7-glc may explain the more efficient bone protection of this compound.

In vivo pharmacokinetics of hesperidin are affected by treatment with glucosidase-like BglA protein isolated from yeasts.

Hesperidin is an abundant flavanone glycoside in citrus fruits and has been reported to possess a wide range of biological activities. However, hesperidin has poor bioavailability. Here, we tested the hypothesis that hesperetin found in chenpi will have a better bioavailability than hesperidin and that treatment of hesperidin with the glucosidase-like yeast Bg1A protein will increase its bioavailability. The results indicate that hesperidin in pure or extract form is hydrolyzed by BglA protein extracted from Sporobolomyces singularis or expressed in Escherichia coli BL21 (DE3). This biotransformation affected the plasma pharmacokinetics of total hesperetin in rats, in that the plasma T max was significantly shorter after administration of BglA protein-treated hesperidin than after administration of hesperidin extract. In addition, the area under the curve values for total hesperetin after administration of Bg1A-treated hesperidin were approximately 4-fold higher by oral administration and 3-fold higher by intravenous administration, respectively. In contrast, the plasma clearance value and volume of distribution after administration of Bg1A-treated hesperidin extract or pure hesperetin were significantly smaller than after administration of untreated hesperidin extract or pure hesperidin. This is the first study that systemically determines the absolute bioavailability of hesperidin and hesperetin simultaneously, shows clearly that hesperetin is more bioavailable than hesperidin regardless of the route of administration, and shows that prior transformation of hesperidin to hesperetin via fermentation should significantly increase its bioavailability because of the action of the yeast glycosidase-like protein BglA.