Diacerein solid dispersion loaded tablets for minimization of drug adverse effects: statistical design, formulation, in vitro, and in vivo evaluation.

Diacerein is a BCS class II drug employed in osteoarthritis management. The acid/base hydrolysis of the unabsorbed diacerein in the colon is responsible for its laxative effect. Therefore, this work aimed to enhance the solubility, dissolution, and oral bioavailability of diacerein. Such enhancement means lower doses and fewer gastrointestinal adverse effects. A 41.31.21 full factorial design was adopted to prepare 24 solid dispersion formulae. Solid-state characterization showed the dissolution of diacerein crystals as metastable amorphous or microcrystalline forms in a matrix system that enhanced the drug dissolution. Desirability factor suggested compounding an optimized formula (F1) of Pluronic®F68 with 1:3 drug:carrier ratio using rotavap that showed higher drug solubility (187.61 µg/mL) than drug powder (22.5 µg/mL). It achieved higher dissolution efficiency (4.04-fold) and rate (6.6-fold) as well as 100% release in 2 min. F1 was compressed into tablets recording greater dissolution efficiency (1.24-fold) and rate (12.5-fold) than the marketed product. The prepared tablet accomplished a 2.66-fold enhancement in diacerein bioavailability compared to the marketed product. In conclusion, the formulation of diacerein as solid dispersion loaded tablets could be of added value for the treatment of osteoarthritis in terms of enhanced patient compliance. Solid dispersion is an easy and scalable technique.

Development of an ultra-performance liquid chromatography-electrospray ionization-Orbitrap mass spectrometry method for determination of xanthopurpurin in rat plasma and its application to pharmacokinetic study.

A rapid and sensitive method was developed and validated for the quantitative determination of xanthopurpurin (XPP) in rat plasma using ultra-performance liquid chromatography-electrospray ionization-Orbitrap mass spectrometry. XPP inhibits IgE production and prevents peanut-induced anaphylaxis. The XPP and emodin (internal standard) were determined in negative ion mode with m/z 239.0350 → 211.0400 and 269.0455 → 241.0507, respectively. The separation process was achieved using an ACQUITY UPLC HSS T3 column with acetonitrile and 0.1% formic acid in water (85:15). The linear range was 0.5-100 ng/mL, and the correlation coefficient (r2 ) was > 0.993. The inter-day and intra-day precision was within an acceptable range of 15%. The extraction recovery and matrix effect were 78.9-87.2% and 94.3-98.5%, respectively. Under different conditions, the XPP was stable in the range of 5.6-10.6%. This method was successfully applied to study the pharmacokinetics of XPP with an oral dose of 10.0 mg/kg and intravenous dose of 2.0 mg/kg in rats. The absolute oral bioavailability of XPP was 4.6%.

Nine components pharmacokinetic study of rat plasma after oral administration raw and prepared Semen Cassiae in normal and acute liver injury rats.

In China, Semen Cassiae has long been used to protect liver, brighten eyes, and relieve constipation. Prepared Semen Cassiae is produced from raw Semen Cassiae by processing, the two forms of Semen Cassiae have different clinical applications. Pathological state is an important factor affecting the efficacy of drugs, the pharmacokinetic behavior of drugs could be significantly changed when people or animal were under different pathological state. To clarify the effect of processing mechanism and pathological state for pharmacokinetic behavior, the pharmacokinetics of nine components of raw and prepared Semen Cassiae under normal and acute liver injury rats were examined. The results showed that the bimodal phenomenon appeared on the plasma concentration-time profiles of obtusin, emodin, chrysophanol, aloe emodin and rhein. The Tmax of aurantio-obtusin, obtusin, chrysoobtusin, emodin, chrysophanol, aloe emodin, physcion in normal groups administrated prepared Semen Cassiae were shorter than those administrated raw Semen Cassiae. For the AUC0-t , aurantio-obtusin, obtusin, chrysoobtusin, chrysophanol, aloe emodin and physcione in model groups administrated prepared Semen Cassiae were significantly higher than other groups, unlike above components, rhein had poor absorption in model groups. The study would be useful for further studies on pharmacokinetics and clinical application of raw and prepared Semen Cassiae.

Synthesis, screening and nanocrystals preparation of rhein amide derivatives.

Rhein (RH) has many bioactivities, but the application was limited of its poor solubility. The present study aimed to establish an efficient method for the synthesis of rhein amide derivatives (RAD) to increase the solubility and anti-tumour activity. RAD exhibited stronger anti-tumour activity than RH in MTT assay. The solubility and oil/water partition coefficient results indicated that rhein-phenylalanine and rhein-isoleucine have better absorption effect, which was consolidated in pharmacokinetic study. Then, rhein-phenylalanine and rhein-isoleucine were prepared into nanocrystals via the precipitation high-pressure homogenisation method. Additionally, the nanocrystals both displayed much higher dissolution profiles than the bulk drugs. Pharmacokinetics study indicated that the AUC0-∞ and Cmax of nanocrystals increased markedly (p < 0.01). However, the concentration of RH-Phe-NC was far less than RH-Ile-NC in plasma. Consequently, RH-Ile-NC was validated to be an applicable way to improve the bioavailability of RH, which owns a promising future in clinical application.

UHPLC-MS/MS method for the simultaneous quantitation of five anthraquinones and gallic acid in rat plasma after oral administration of prepared rhubarb decoction and its application to a pharmacokinetic study in normal and acute blood stasis rats.

Prepared rhubarb, as one of the main processed products of rhubarb, has a good effect on promoting blood circulation. In this paper we describe a rapid, sensitive, and selective ultra-fast liquid chromatography with tandem mass spectrometry method for simultaneous quantification of five anthraquinones (rhein, aloe-emodin, chrysophanol, emodin, and physcion) and gallic acid in plasma. Chromatographic separation was performed on an Extend C18 column at the temperature of 30°C using a mobile phase that consisted of 0.1% aqueous formic acid and acetonitrile. Satisfactory linearity, precision, accuracy, extraction recovery, and matrix effect have been achieved. Then, the validated method was successfully applied to a comparative pharmacokinetic study. The results might be helpful for guiding clinical application of prepared rhubarb in the future.

A comparative pharmacokinetic study of three flavonoids and three anthraquinones in normal and gastrointestinal motility disorders rat plasma after the oral administration of Wei-Chang-Shu tablet using high-performance liquid chromatography-tandem mass spectrometry.

A simple, fast and reliable high-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous quantification and pharmacokinetic study of three flavonoids (liquiritigenin, isoliquiritigenin and formononetin) and three anthraquinones (emodin, rhein and aloe-emodin), which are the bioactive ingredients of Wei-Chang-Shu tablet found in rat plasma. After extraction by liquid-liquid extraction with ethyl acetate, chromatographic separation was achieved on an Agilent Zorbax SB-C18 column (4.6 × 150 mm, 5 µm) at a flow rate of 1 mL/min by gradient elution using 0.1% aqueous acetic acid and acetonitrile. The detection was performed using a triple quadrupole mass spectrometer equipped with electrospray ionization source in the negative ionization and selected reaction monitoring mode. Method validation was performed in terms of specificity, carryover, linearity (r > 0.99), intra-/inter-day precision (1.0-10.1%), accuracy (relative error, <7.6%), stability (0.6-13.2%), extract recovery (74.9-91.9%) and matrix effect (89.1-109%). The lower limits of quantification of the six analytes varied from 0.92 to 10.4 ng/mL. The validated method was successfully applied to compare the pharmacokinetic properties of Wei-Chang-Shu tablet in normal rats and in rats with gastrointestinal motility disorders. The results indicated that there were obvious differences in the pharmacokinetic behavior between normal and model rats. This study will be helpful in the clinical application of Wei-Chang-Shu tablet.

UPLC-QTOF-MS Identification of the Chemical Constituents in Rat Plasma and Urine after Oral Administration of Rubia cordifolia L. Extract.

An effective ultra-performance liquid chromatography coupled with the quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF/MS) method was developed for analysing the chemical constituents in rat plasma and urine after the oral administration of Rubia cordifolia L. extract. Under the optimized conditions, nine of 11 prototypes in rat plasma and four prototypes in urine were identified or characterized by comparing the retention time, accurate mass, fragmentation patterns, reference compounds, and literature data. In total, six metabolites, including alizarin-1-O-ß-glucuronide, alizarin-2-O-ß-glucuronide, alizarin-1-O-sulfation, alizarin-2-O-sulfation, purpurin-1-O-ß-glucuronide, and purpurin-3-O-ß-glucuronide, were identified in rat plasma, which were confirmed by lavaging standard solutions. Purpurin was found to be able to be transformed into alizarin based on the results in which alizarin was detected in rat plasma after the oral administration of a purpurin solution. In total, four metabolites were found in rat urine, but their chemical structures were not confirmed. The results indicate that the metabolic pathway of alizarin involves glucuronidation and sulfation, with the purpurins having undergone glucuronidation. The components absorbed into the blood, and the metabolites have the opportunity to become bioactive constituents. The experimental results would supply a helpful chemical basis for further research on the mechanism of actions of Rubia cordifolia L.

Analysis of the pharmacokinetics and metabolism of aloe-emodin following intravenous and oral administrations in rats.

Aloe-emodin, a natural polyphenolic anthraquinone, has shown various beneficial bioactivities in vitro. The aim of this study was to investigate the pharmacokinetics and metabolism of aloe-emodin. Aloe-emodin was intravenously and orally administered to rats. The concentrations of aloe-emodin and rhein, a metabolite of aloe-emodin, were determined by HPLC method prior to and after hydrolysis with ß-glucuronidase and sulfatase/ß-glucuronidase. The results showed that the systemic exposures of aloe-emodin and its metabolites were ranked as aloe-emodin glucuronides (G) > rhein sulfates (S) > aloe-emodin > rhein and rhein G when aloe-emodin was given intravenously. In contrast, when aloe-emodin was administered orally, the parent form of aloe-emodin was not absorbed per se, and the systemic exposures of its metabolites were ranked as aloe-emodin G > rhein G > rhein. In conclusion, the metabolites of aloe-emodin are more important than the parent form for the bioactivities in vivo. Copyright © 2016 John Wiley & Sons, Ltd.

Developing an Absorption-Based Quality Control Method for Hu-Gan-Kang-Yuan Capsules by UFLC-QTOF-MS/MS Screening and HPLC-DAD Quantitative Determination.

Traditional Chinese Medicine Preparations (TCMPs) contain massive numbers of ingredients responsible for their multiple efficacies. An absorption-based quality control method for complicated TCMPs using Hu-gan-kang-yuan Capsule (HGKYC) as an example was developed. To select proper chemical markers for quality control of HGKYC, an ultra-fast liquid chromatography (UFLC) coupled with electrospray ionization quadrupole time-off light mass spectrometry (UFLC-QTOF-MS/MS) method was used for the rapid separation and structural identification of the constituents in the HGKYC extract and the rat serum after oral administration of HGKYC. As a result, one hundred and seven prototype constituents including flavonoids, organic acid, phenylpropanoids, anthraquinones, saponins, alkaloids, terpenes, phenols and amino acids in HGKYC extract, and 43 compounds found in rat serum after oral administration of HGKYC were unambiguously identified or tentatively characterized by comparing retention times and MS information with those of authentic standards or available literature references. Finally, a simple, low-cost and effective method of simultaneous determination for baicalein, wogonin, paeonol and emodin in HGKYC was developed using high performance liquid chromatography coupled with a diode array detector. In conclusion, an absorption-based quality control pattern was developed and successfully used for evaluating HGKYC.

An ultra high performance liquid chromatography with tandem mass spectrometry method for plasma and cerebrospinal fluid pharmacokinetics of rhein in patients with traumatic brain injury after administration of rhubarb decoction.

Damage of blood-brain barrier is a common result of traumatic brain injury. This damage can open the blood-brain barrier and allow drug passage. An ultraperformance liquid chromatography with tandem mass spectrometry method was established to determine the concentration of rhein in the biofluids (plasma and cerebrospinal fluid) of patients with a compromised blood-brain barrier following traumatic brain injury after rhubarb administration. Furthermore, the pharmacokinetic profiles were analyzed. A triple-quadruple tandem mass spectrometer with electrospray ionization was used for rhein detection. The mass transition followed was m/z 283.06→239.0. The calibration curve was linear in the concentration range of 10-8000 ng/mL for the biofluids. The intra- and interday precisions were less than 10%. The relative standard deviation of recovery was less than 15% in biological matrices. The pharmacokinetic data showed that rhein was rapidly transported into biofluids, and exhibited a peak concentration 1 h after rhubarb administration. The elimination rate of rhein was slow. The AUCcerebrospinal fluid /AUCplasma (AUC is area under curve) of rhein was approximately 17%, indicating that portions of rhein could pass the impaired blood-brain barrier. The method was successfully applied to quantify rhein in the biofluids of all patients. The data presented can help to guide clinical applications of rhubarb for treating traumatic brain injury.

Effect of glycyrrhizic acid on rhein renal penetration: a microdialysis study in rats.

1. Rhein (RH), a primary active component isolated from rhubarb, is effective in protecting against the progression of diabetic nephropathy (DN) progression. Glycyrrhizic acid (GA), an active constituent of liquorice, is also considered to be a protective agent against DN. Here, we evaluated the effect of GA on the renal penetration of RH in rats. 2. Plasma and renal pharmacokinetics were profiled to estimate kidney penetration. After rats were anesthetized, the carotid artery was used for blood collection and a microdialysis probe was inserted into the kidney cortex to collect dialysate samples. 3. When co-administered with GA, the Vss and CL values of RH in plasma increased by 25% and 34%, respectively. The Cmax in kidney dialysates significantly increased 1.3-fold (p<0.05). There was no change in AUC0-∞ in kidney dialysates, but a significant decrease (2×fold) in the plasma was observed. The AUC0-∞kidney/AUC0-∞plasma ratio of RH, representing kidney penetration, increased by 1.4-fold in the group pre-treated with GA compared to the RH alone group. 4. These results demonstrate that GA increases the renal penetration of RH efficiently and may exert a synergistic effect, although the molecular mechanism of interaction requires further investigation.

Identification of chemical constituents and rat metabolites of Kangxianling granule by HPLC-Q-TOF-MS/MS.

A high-performance liquid chromatography coupled with quadrupole time-of-flight mass tandem mass spectrometry method was established to characterize the chemical constituents of Kangxianling granule (KXL), a traditional Chinese medicine formula, and the metabolic profile in rat urine and plasma after oral administration of KXL. A total of 27 compounds in KXL extract and 13 prototype compounds with 12 metabolites in rat urine and plasma were identified. Among the 27 detected compounds, 15 were identified by comparing the retention time and MS data with that of reference compounds and the other 12 compounds were tentatively assigned based on the MS data and reference literature. The main prototype components absorbed in rat were amygdalin, salvianolic acid B, tanshinones and anthraquinones. Hydroxylation, glucuronidation and sulfation were the principal metabolic pathways in rat. The results revealed that the 25 compounds identified in rat urine and plasma were the potential active ingredients of KXL, which provides helpful chemical information for further study of the pharmacology mechanism of KXL.

The Influence of Aconitum carmichaelii Debx. on the Pharmacokinetic Characteristics of Main Components in Rheum palmatum L.

Rhei Radix et Rhizoma was one of the commonly used traditional Chinese medicines, and the compatibility of Rhei Radix et Rhizoma and Aconiti Lateralis Radix Praeparata was the basic herb pair applied in many Chinese traditional prescription. Rhubarb anthraquinones were the main bioactive materials of Rhei Radix et Rhizoma. To elucidate the compatibility of Rhei Radix et Rhizoma and Aconiti Lateralis Radix Praeparata, the pharmacokinetics of rhubarb anthraquinones as the main marker constituents were investigated. In the present study, pharmacokinetic differences of rhubarb anthraquinones were detected after oral administration of extract of Rheum palmatum L. and compatibility with Aconitum carmichaelii Debx. After oral administration, no difference of peak time can be found for anthraquinones between rhubarb group and compatibility group. But Cmax and area under the curve of aloe-emodin, emodin and chrysophanol in compatibility group were significantly higher than that in rhubarb group. Although the Cmax of rhein in compatibility group was much lower than that in rhubarb group, the area under the curve value was similar in two groups. The clearance and t1/2 of rhubarb anthraquinone were also changed after compatibility. The change of pharmacokinetics characteristics of rhubarb anthraquinone after compatibility may be caused by the drug-drug interaction medicated by chemical reaction and cytochromes P450.

Serum concentrations of anthraquinones after intake of Folium Sennae and potential modulation on P-glycoprotein.

Folium Sennae (leaves of Cassia angustifolia or senna) is a laxative and a component in diets for weight control. It contains a variety of anthranoids such as sennosides, aloe-emodin, and rhein. In order to measure the serum concentrations of senna anthranoids, Sprague-Dawley rats were orally administered with single dose and multiple doses of Folium Sennae. The concentrations of anthranoids in serum were determined by HPLC method before and after hydrolysis with sulfatase and ß-glucuronidase. The results showed that in the serum, aloe-emodin glucuronides and rhein glucuronides were the major metabolites. Traces of rhein free form were present transiently during the early phase, whereas the free form of aloe-emodin was not detected. We also evaluated the modulation effect of Folium Sennae on P-glycoprotein by using the LS 180 cell model which showed that it significantly inhibited P-glycoprotein by 16-46 %. In conclusion, senna anthranoids were rapidly and extensively metabolized to rhein glucuronides and aloe-emodin glucuronides in rats. Folium Sennae ingestion inhibited the efflux function of P-glycoprotein in the intestine.

Pharmacokinetics of anthraquinones in rat plasma after oral administration of a rhubarb extract.

A sensitive and specific LC-MS/MS method was developed for simultaneous determination of aloe-emodin, rhein, emodin, chrysophanol and physcion and their conjugates in rat plasma. The lower limit of quantitation of each anthraquinone was 0.020-0.040 µm. Intra-day and inter-day accuracies were 90.1-114.3% and the precisions were <14.6%. The matrix effects were 104.0-113.2%. The method was successfully applied to a pharmacokinetic study in rats receiving a rhubarb extract orally. The area under the concentration-time curve (AUC0-t ) and peak concentration (Cmax ) of free aloe-emodin and emodin in rat plasma were much lower than those of rhein. The amounts of chrysophanol and physcion were too low to be continuously detected. After treating the plasma samples with ß-glucuronidases, each anthraquinone was detectable throughout the experimental period (36 h) and showed much higher plasma concentrations and AUC0-t . The free/total ratios of aloe-emodin, rhein and emodin were 6.5, 49.0 and 1.7% for Cmax and 3.7, 32.5 and 1.1% for AUC0-t , respectively. The dose-normalized AUC0-t and Cmax of the total of each anthraquinone were in the same descending order: rhein > emodin > chrysophanol > physcion > aloe-emodin. These findings reveal phase II conjugates as the dominant in vivo existing forms of rhubarb antharquinones and warrant a further study to evaluate their contribution to the herbal activity.

Simultaneous determination of aurantio-obtusin, chrysoobtusin, obtusin and 1-desmethylobtusin in rat plasma by UHPLC-MS/MS.

A sensitive and reliable ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the simultaneous determination of four active components of Semen Cassiae extract (aurantio-obtusin, chrysoobtusin, obtusin and 1-desmethylobtusin) in rat plasma after oral administration. Chromatographic separation was achieved on an Agilent Poroshell 120 C18 column with gradient elution using a mobile phase that consisted of acetonitrile-ammonium acetate in water (30 mm) at a flow rate of 0.4 mL/min. Detection was performed by a triple-quadrupole tandem mass spectrometer in multiple reaction monitoring mode. The calibration curve was linear over a range of 3.24-1296 ng/mL for aurantio-obtusin, 0.77-618 ng/mL for chrysoobtusin, 34.55-1818 ng/mL for obtusin and 1.86-1485 ng/mL for 1-desmethylobtusin. Inter- and intra-day assay variation was <15%. All analytes were shown to be stable during all sample storage and analysis procedures.

Determination of bioactive components in Chinese herbal formulae and pharmacokinetics of rhein in rats by UPLC-MS/MS.

Rhein (4,5-dihydroxy-9,10-dioxoanthracene-2-carboxylic acid, cassic acid) is a pharmacological active component found in Rheum palmatum L. the major herb of San-Huang-Xie-Xin-Tang (SHXXT), a medicinal herbal product used as a remedy for constipation. Here we have determined multiple bioactive components in SHXXT and investigated the comparative pharmacokinetics of rhein in rats. A sensitive and specific method combining liquid chromatography with electrospray ionization tandem mass spectrometry has been developed and validated to simultaneously quantify six active compounds in the pharmaceutical herbal product SHXXT to further study their pharmacokinetics in rats. Multiple reaction monitoring (MRM) was employed for quantification with switching electrospray ion source polarity between positive and negative modes in a single run. There were no significant matrix effects in the quantitative analysis and the mean recovery for rhein in rat plasma was 91.6%±3.4%. The pharmacokinetic data of rhein demonstrate that the herbal formulae or the single herbal extract provide significantly higher absorption rate than the pure compound. This phenomenon suggests that the other herbal ingredients of SHXXT and rhubarb extract significantly enhance the absorption of rhein in rats. In conclusion, the herbal formulae (SHXXT) are more efficient than the single herb (rhubarb) or the pure compound (rhein) in rhein absorption.

[Simultaneous determination of four anthraquinones in rat plasma by HPLC-FLD method and its pharmacokinetic study].

This paper aims to develop a method for the determination of aloe-emodin, rhein, chrysophanol and physcion and study the pharmacokinetic properties of four anthraquinones in rat plasma after oral administration of gardenia and rhubarb decoction. The plasma concentrations at different time points of four anthraquinones were determined by HPLC-FLD method. Plasma samples were extracted with liquid-liquid extraction procedure. Plasma samples were separated on a C18 column (4.6 mm x 150 mm, 5 µm), using 0.2% acetic acid and methanol as mobile phase at a flow rate of 1.0 mL min(-1) with gradient elution. The excitation and emission wavelengths were set at 430, 525 nm, respectively. DAS 2.0 software was applied to calculate the pharmacokinetic parameters. The results showed four anthraquinones can be absorbed. The main parameters of aloe-emodin, rhein, chrysophanol and physcion were as follows: C(max) for aloe-emodin was (0.085 ± 0.058), (3.772 ± 1.152), (0.464 ± 0.267), (0.028 ± 0.008) mg x L(-1) respectively; t(max) for rhein was (1.042 ± 0.510), (0.805 ± 0.307), (1.167 ± 0.283), (0.616 ± 0.162) h respectively; t½ for chrysophanol was (3.557 ± 1.250), (6.879 ± 1.126), (5.196 ± 2.032), (4.337 ± 1.816) h; AUC(0-t) for physcion was (0.504 ± 0.130), (9.558 ± 1.106), (2.545 ± 1.554), (0.052 ± 0.018) mg x h x L(-1). This paper developed a selective, accurate and sensitive HPLC-FLD method for the simultaneous determination of four anthraquiones in rat plasma.

Simultaneous determination and pharmacokinetics of five rhubarb anthraquinones in dog plasma by HPLC after orally administration the rhubarb extract.

Rhubarb is widely used in the treatment of obstipation, gastrointestinal indigestion and other diseases in China and other Asian countries for thousands of years. Anthraquinones are the major group of polyphenol constituents including aloe-emodin, rhein, emodin, chrysophanol and physcion. In order to evaluate the pharmacokinetics of five rhubarb anthraquinones, a high-performance liquid chromatography with fluorescence detection (HPLC-FLD) method for simultaneous determination of aloe-emodin, rhein, emodin, chrysophanol and physcion in dog plasma was established. Solid phase extraction (SPE) was applied to the extraction and purification of samples. The calibration curves of five anthraquinones showed good linearity with r greater than 0.9925. The average extraction recoveries, examined at three concentration levels, carried from 92.1% to 102.3%, and the accuracies ranged from 87.7% to 102.5% with precision (RSD) <10%. The pharmacokinetic paremeters of five anthraquinones were investigated systematically after orally administration the rhubarb extract. Five anthraquinones were rapidly absorbed and Tmax for aloe-emodin, rhein, emodin, chrysophanol and physcion was at 0.75, 1.50, 0.75, 1.0 and 2.0 h respectively. The Cmax of five anthraquinones was 0.031, 3.39, 0.27, 0.036 and 0.032 µg/mL while the AUC of five anthraquinones was 0.35 ± 0.058, 32.22 ± 8.29, 2.97 ± 0.66, 0.43 ± 0.10 and 0.41 ± 0.12 mg h/L, respectively.

Pharmacokinetic and pharmacodynamic studies of four major phytochemical components of Da-Cheng-Qi decoction to treat acute pancreatitis.

The medicinal herb formulation Da-Cheng-Qi decoction (DCQD) has been shown to ameliorate the severity of acute pancreatitis by regulating an apoptosis-necrosis switch in cells. The active components responsible for this effect and their detailed mechanism of action remain unclear. Here we determine the pharmacokinetic characteristics of the four most abundant compounds in DCQD using a rat model of severe acute pancreatitis. Acute pancreatitis-like symptoms were first induced in rats and then they were given DCQD orally. Rhein was found in rat serum at much higher levels than magnolol, hesperidin, or naringin, even though it was the least abundant of the four compounds in the DCQD. We also examined pharmacodynamics in AR42J cells stimulated with 10(-8) M cerulein as a cellular model of acute pancreatitis. After pretreating AR42J cells with individual compounds and then exposing them to cerulein, we determined cell viability, levels of apoptosis and necrosis, and numbers of cells positive for reactive oxygen species (ROS). Pretreatment with any of the four DCQD compounds increased cell viability and the apoptosis index, while also reducing necrosis and ROS generation. The compounds showed maximal effect in AR42J cells around the same time that they showed maximum serum concentration in rats. Although all four components appear to play a role in an apoptosis-necrosis cellular switch in vitro, rhein may be the most bioactive DCQD ingredient.