Revealing the anti-inflammatory ingredients in wine-processed Radix et Rhizoma Rhei using immobilized cysteinyl leukotriene receptor type 1 as the stationary phase.

Despite the tremendous progress of wine-processed Radix et Rhizoma Rhei (Jiudahuang, JDH) in removing toxic heat from the blood in the upper portion of the body for hundreds of years, the deep understanding of its functional material basis of the anti-inflammatory ingredients remains unclear due to the lack of high specific and efficient methods. Herein, taking Cysteinyl leukotriene receptor type 1(CysLT1R) as the target protein, we established a chromatographic method based on the immobilized CysLT1R using haloalkane dehalogenases (Halo) at the C-terminus of the receptor in one step. After careful characterization by X-ray photoelectronic spectroscopy, immune-fluorometric analysis, and chromatographic investigations, the immobilized receptor was used to screen the anti-inflammatory ingredients in JDH. Aloe-emodin, rhein, emodin, chrysophanol, and physcion were identified as the main anthraquinone exerting anti-inflammatory effects in the drug. The association constants for the five compounds to bind with the receptor were calculated as (0.30 ± 0.06)× 105, (0.35 ± 0.03)× 105, (0.46 ± 0.05)× 105, (1.05 ± 0.14)× 105, and (1.66 ± 0.17)× 105 M-1 by injection amount-dependent method. Meanwhile, hydrogen bonds were identified as the main driving force for the five compounds to bind with CysLT1R by molecular docking. Based on these results, we believe that the immobilized receptor chromatography preserves historic significance in revealing the functional material basis of the complex matrices.

Anthraquinone Removal from Cassia obtusifolia Seed Water Extract Using Baking, Stir-Frying, and Adsorption Treatments: Effects on the Chemical Composition, Physicochemical Properties of Polysaccharides, and Antioxidant Activities of the Water Extract.

Safety issues of the controversial anthraquinones from Cassia obtusifolia seed water extracts (CWEs) limit its application. This work aimed to remove the anthraquinones of CWEs by baking treatment (BT), stir-frying treatment (ST), and adsorption treatment (AT). Effects of these treatments on the chemical composition, physicochemical properties of polysaccharides, and antioxidant activities of CWEs were analyzed and compared. Results indicated that AT exhibited the best removal effect on the total anthraquinone among the three treatments. After AT, the contents of rhein, emodin, aloe-emodin, and aurantio-obtusin of the CWE were below the limit of detection. In addition, AT increased the contents of neutral sugars in CWEs in comparison to BT and ST. None of the treatments had an obvious influence on the structural characteristics of polysaccharides. However, AT decreased the antioxidant activity of CWEs due to their lower anthraquinone content. In summary, AT was considered as an efficient and simple method to remove anthraquinones, while retaining the features of polysaccharides.

Quantitative determination of aloin, antioxidant activity, and toxicity of Aloe vera leaf gel products from Greece.

BACKGROUND: Aloe vera is a popular medicinal plant used widely by the cosmetic, pharmaceutical, and food industries. The A. vera leaf gel, which is used mostly for its positive effects on human health, contains over 75 different bioactive compounds, including aloin. Aloin is a toxic compound, and its content in A. vera leaf gel products depends on the different cultivation conditions and especially on leaf processing. RESULTS: In this study, A. vera leaf gel products, varied in terms of leaf processing, were analyzed using liquid chromatography for their aloin content, their antioxidant activity by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS·+ ) and the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH· ) antioxidant activity assays and their toxicity against Aliivibrio fisheri and SH-SY5Y cells. In the samples processed with industrial methods and in those filtered in the lab, the content of aloin was found below the limit (0.1 mg L-1 ) of the EU legislation however, the unprocessed and unfiltered samples were found to contain more than 10 mg L-1 . Antioxidant activity was estimated to vary from 1.64 to 9.21 µmol Trolox mL-1 for DPPH· and from 0.73 to 5.14 µmol Trolox mL-1 for ABTS·+ . Toxicity values on A. fisheri, expressed as the concentration at 50% loss of initial luminescence, ranged from 0.03 to 0.09 mg mL-1 . The cytotoxic study indicated that aloin A at low concentrations (1 and 10 µg mL-1 ) protects SH-SY5Y cells from toxicity induced by hydrogen peroxide. CONCLUSIONS: Consequently, the filtration process of A. vera leaf gels, either laboratory or industrial, resulted in aloin A content below the EU legislation detection limits. © 2020 Society of Chemical Industry.

CYP3A Activation and Glutathione Depletion Aggravate Emodin-Induced Liver Injury.

1,3,8-Trihydroxy-6-methylanthraquinone (emodin), a widely existing natural product in herbal medicines, has been reported to be hepatotoxic, but the exact underlying mechanism is still not fully understood. The objective of the present study was to evaluate the role of CYP3A and glutathione (GSH) in emodin-induced liver injury. Primary human hepatocytes were exposed to emodin with and without addition of CYP3A inducer/inhibitor and GSH synthesis inhibitor. It was found that emodin-mediated cytotoxicity increased when CYP3A was activated and GSH was depleted. Hepatotoxicity induced by emodin in rats by activation/inhibition of CYP3A and depletion of GSH was further investigated. Administration of emodin in combination with l-buthionine sulfoximine (BSO) or dexamethasone (DEX) resulted in aggravated liver injury, whereas pretreatment with ketoconazole (KTZ) suppressed the side effects caused by emodin. In addition, plasma exposure of emodin and its glucuronide metabolite were measured by ultraperformance liquid chromatography triple quadrupole mass spectrometry. Emodin and its glucuronide were lower in BSO-, DEX-, and KTZ- co-treated rats compared with those administered with emodin alone. In conclusion, these mentioned results suggested that CYP3A induction and GSH depletion might be involved in hepatotoxicity induced by emodin. This study may help to understand the risk factors and the mechanism of hepatotoxicity of emodin in humans.

Use of liquid chromatography hybrid triple-quadrupole mass spectrometry for the detection of emodin metabolites in rat bile and urine.

Emodin is the representative form of rhubarb, which is widely used in traditional Chinese medicine for the treatment of purgative, anti-inflammatory, antioxidative and antiviral, etc. Previous reports demonstrated that emodin glucuronide was the major metabolite in plasma. Owing to the extensive conjugation reactions of polyphenols, the aim of this study was to identify the metabolites of emodin in rat bile and urine. Neutral loss and precursor ion scan methods of triple-quadrupole mass spectrometer revealed 13 conjugated metabolites in rat bile and 22 metabolites in rat urine, which included four phase I and 18 phase II metabolites. The major metabolites in rat biosamples were emodin glucuronoconjugates. Moreover, rhein monoglucuronide, chrysophanol monoglucuronide and rhein sulfate were proposed for the first time after oral administration of emodin. Overall, liquid chromatography hybrid triple-quadrupole mass spectrometry analysis leads to the discovery of several novel emodin metabolites in rat bile and urine and underscores that conjugated with glucuronic acid is the main metabolic pathway.

An experimental study on providing a scientific evidence for seven-time alcohol-steaming of Rhei Rhizoma when clinically used.

BACKGROUND: Rhei Rhizoma (RR) has been widely used as laxative and processed to alter its therapeutic actions or reduce its side effects. In this study, we evaluated experimentally the clinical application guideline that RR should be alcohol-steamed seven times before being used in elderly patients, as described in Dongeuibogam, the most famous book on Korean traditional medicine. METHODS: Unprocessed RR (RR-U) was soaked in rice wine, steamed and then fully dried (RR-P1). The process was repeated four (RR-P4) or seven times (RR-P7). Reversed-phase high-performance liquid chromatography was used to determine the RR-U, RR-P1, RR-P4 and RR-P7 (RRs) constituents. To evaluate the effect of RRs on liver toxicity, human hepatoma cells (HepG2) were treated with RRs at 100 µg/mL for 4 h and then cell viabilities were measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. To confirm the effects in vivo, 5-week-old male Sprague-Dawley rats were treated with RRs at 3 g/kg/day for 21 days. Body weight and serum biochemical parameters were measured and liver histology was assessed. RESULTS: The levels of sennosides decreased in processed RRs in an iteration-dependent manner, while the emodin level was unaffected. In HepG2 cells, cell viability was reduced with RR-U, while the toxicity decreased according to the number of processing cycles. The changes in body weight, relative liver weight and liver enzymes of RR-U-treated rats were reduced in processed RRs-treated rats. Histopathological analysis indicated swelling and cholestasis improved following seven times alcohol-steaming cycles. CONCLUSIONS: These results provide experimental evidence that RR-P7 almost completely reduces RR hepatotoxicity.

In vitro anti-osteoporosis properties of diverse Korean Drynariae rhizoma phenolic extracts.

Drynariae rhizoma has been used to prevent bone loss that occurs with increasing age. However, the chemical compounds in extracts that act on bone metabolism in herbal medicine are poorly understood. This study aimed to investigate and compare the extraction efficacy of polyphenolic compounds, antioxidant activity, and in vitro anti-osteoporosis properties of water extract (DR-DW) and ethanol extract (DR-EtOH) from D. rhizoma. Total phenolics and flavonoids were better extracted with 70% EtOH, and this extraction method also resulted in higher antioxidant activity and in vitro anti-osteoporosis properties in these extracts. In particular, the contents of phloroglucinol, protocatechuic acid ethyl ester, 2-amino-3,4-dimethyl-benzoic acid, 3-(3,5-dimethyl-pyrazol-1-yl)-benzoic acid, chlorogenic acid, syringic acid, trans-ferulic acid, (-)-epigallocatechin, epigallocatechin gallate, quercetin dehydrate, luteolin and emodin in DR-EtOH were higher than those in DR-DW. These results indicated that DR-EtOH could be a good source of natural herbs with anti-osteoporosis properties.

Anti-inflammatory and antioxidant effects of Aloe saponaria Haw in a model of UVB-induced paw sunburn in rats.

Ultraviolet B (UVB) irradiation mainly affects biological tissues by inducing an increase in reactive oxygen species (ROS) production which leads to deleterious outcomes for the skin, including pain and inflammation. As a protective strategy, many studies have focused on the use of natural products. The aim of this study was to investigate the effects of Aloe saponaria on nociceptive, inflammatory, and oxidative parameters in a model of UVB-induced sunburn in adult male Wistar rats. Sunburned animals were topically treated with vehicle (base cream), 1% silver sulfadiazine (positive control) or A. saponaria (10%) once a day for 6days. UVB-induced nociception (allodynia and hyperalgesia), inflammation (edema and leukocyte infiltration) and oxidative stress (increases in H2O2, protein carbonyl levels and lipid peroxidation and a decrease in non protein thiol content) were reduced by both A. saponaria and sulfadiazine topical treatment. Furthermore, A. saponaria or its constituents aloin and rutin reduced the oxidative stress induced by H2O2 in skin homogenates in vitro. Our results demonstrate that topical A. saponaria treatment displayed anti-nociceptive and anti-inflammatory effects in a UVB-induced sunburn model, and these effects seem to be related to its antioxidant components.

Development and validation of a highly rapid and sensitive LC-MS/MS method for determination of SZ-685C, an investigational marine anticancer agent, in rat plasma--application to a pharmacokinetic study in rats.

A sensitive and rapid method was developed and validated for the quantitative analysis of the novel anticancer agent SZ-685C in rat plasma using high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) in negative ion mode in order to support the following pre-clinical and clinical studies. SZ-685C and the internal standard (IS, emodin) were extracted from rat plasma by a simple liquid-liquid extraction technique using ethyl acetate as extraction solvent. Chromatographic separation was performed on an Elite Hypersil BDS C18 column (100 mm × 2.1 mm i.d., 3 µm). Elution was carried out using methanol/acetonitrile/2mM ammonium formate (pH 4) (80:15:5 (v/v/v)) at a flow-rate of 0.3 mL/min with a run time of 2.5 min. This assay was linear over a concentration range of 50-10,000 ng/mL with a lower limit of quantification of 50 ng/mL. The intra- and inter-batch precision was less than 15% for all quality control samples at concentrations of 100, 1000 and 7500 ng/mL. These results indicate that the method was efficient with a short run time and acceptable accuracy, precision and sensitivity. This method was successfully applied to explore pharmacokinetics of SZ-685C in rats after oral and intravenous administration of this agent. The absolute bioavailability is about 54.8-66.8% and the t(1/2) is 5.7-9.2h, these results provide basic information for further comprehensive pre-clinical research.

Occurrence of emodin, chrysophanol and physcion in vegetables, herbs and liquors. Genotoxicity and anti-genotoxicity of the anthraquinones and of the whole plants.

1,8-Dihydroxyanthraquinones, present in laxatives, fungi imperfecti, Chinese herbs and possibly vegetables, are in debate as human carcinogens. We screened a variety of vegetables (cabbage lettuce, beans, peas), some herbs and herbal-flavoured liquors for their content of the 'free' anthraquinones emodin, chrysophanol and physcion. For qualitative and quantitative analysis, reversed-phase HPLC (RP-LC), gas chromatography-mass spectrometry (GC-MS) and RP-LC-MS were used. The vegetables showed a large batch-to-batch variability, from 0.04 to 3.6, 5.9 and 36 mg total anthraquinone per kg fresh weight in peas, cabbage lettuce, and beans, respectively. Physcion predominated in all vegetables. In the herbs grape vine leaves, couch grass root and plantain herb, anthraquinones were above the limit of detection. Contents ranged below 1 mg/kg (dry weight). All three anthraquinones were also found in seven of 11 herbal-flavoured liquors, in a range of 0.05 mg/kg to 7.6 mg/kg. The genotoxicity of the analysed anthraquinones was investigated in the comet assay, the micronucleus test and the mutation assay in mouse lymphoma L5178Y tk+/- cells. Emodin was genotoxic, whereas chrysophanol and physcion showed no effects. Complete vegetable extract on its own did not show any effect in the micronucleus test. A lettuce extract completely abolished the induction of micronuclei by the genotoxic anthraquinone danthron. Taking into consideration the measured concentrations of anthraquinones, estimated daily intakes, the genotoxic potency, as well as protective effects of the food matrix, the analysed constituents do not represent a high priority genotoxic risk in a balanced human diet.

Polarographic and absorptive stripping voltammetric determination of mitoxantrone, emodin and chrysarobin using mercury and glassy carbon electrodes.

Polarographic and voltammetric methods were used to study drugs of anthrone derivatives: mitoxandrone (antineoplastic), emodin (cathartic) and chrysarobin (antipsoriatic) on mercury and glassy carbon electrodes. The surface-active properties were exploited for developing a highly sensitive adsorptive stripping voltammetric method for determination of trace amounts of these compounds. Effective pre-concentration was obtained at glassy carbon electrode, with the surface species being measured via its reduction or oxidation, respectively. It was concluded that observed cathodic and anodic currents had the diffusive character. A simple, quick and accurate methods for the determination of all studied compounds in pure form and mitoxantrone in vials have been developed. The acetate buffer pH 4.6 containing 5 to 30% ethanol was used as a supporting electrolyte. The linear calibration range was 0.5 = 100 microg cm-3 on mercury and 25 - 250 ng cm-3 on glassy carbon electrode.

Analytics of senna drugs with regard to the toxicological discussion of anthranoids.

Toxicological studies indicate that two hydroxyanthraquinones (HAs), aloe-emodin and emodin, present as minor components in senna, might represent a genotoxic or cancerogenetic risk for man. Since aloe-emodin and emodin occur in senna in the free form as well as their glucosides and dianthrone glucosides, a HPLC method was established to allow the quantification of all free and glycosidic 1,8-dihydroxy anthranoids. The sum of the free HAs and their calculated content in each of their prodrug forms is defined as the potential HA content. For the comparison of different senna drugs in respect to the genotoxic risk arising from their potential aloe-emodin or emodin contents, a risk index has been established.