Simultaneous quantification of atractyloside and carboxyatractyloside in rat plasma by LC-MS/MS: Application to a pharmacokinetic study after oral administration of Xanthii Fructus extract.

Xanthii Fructus is extensively used as an herbal medicine. Ingestion of this herb is associated with severe hepatotoxicity and nephrotoxicity. Atractyloside and carboxyatractyloside are two dominative toxic constituents in Xanthii Fructus. However, their pharmacokinetic study is lacking. In this study, a novel high-performance liquid chromatography-tandem mass spectrometry method was developed to simultaneously quantify the rat plasma concentrations of atractyloside and carboxyatractyloside. After protein precipitation, the analytes were chromatographic separated on a ZORBAX Eclipse Plus column (2.1 × 150 mm id, 5 µm) under gradient elute. In the negative electrospray ionization mode, the transitions at m/z 725.3→645.4 for atractyloside, m/z 769.3→689.4 for carboxyatractyloside, and m/z 479.2→121.1 for paeoniflorin (the internal standard) were acquired by multiple reaction monitoring. This analytical method showed good linearity over 1-500 ng/mL for atractyloside and 2-500 ng/mL for carboxyatractyloside with acceptable precision and accuracy. No matrix effect, instability and carryover occurred in the analysis procedure. The extraction recoveries were greater than 85.0%. This method was applied to a preliminary pharmacokinetic study by orally administering Xanthii Fructus extract (9 g/kg) to rats, which was useful to evaluate the role of these two compounds in Xanthii Fructus-induced toxicity.

Bioavailability and Biological Effects of 2- O-ß-d-Glucopyranosyl-carboxyatractyligenin from Green Coffee in Caenorhabditis elegans.

Targeted analysis of Coffea arabica and Coffea canephora green coffees (total sample size n = 57) confirmed 2- O-ß-d-glucopyranosyl-carboxyatractyligenin (6) as the quantitatively dominating carboxyatractyligenin derivative. Its abundance in Arabicas (2425 ± 549 nmol/g, n = 48) exceeded that in Robustas (34 ± 12 nmol/g, n = 9) roughly by a factor of 70. Coffee processing involving heat (e.g., steam treatment and decaffeination) reduced concentrations of 6 and increased those of the decarboxylated derivative. The bioavailability of compound 6 in Caenorhabditis elegans was demonstrated by ultraperformance liquid chromatography-tandem mass spectrometry analysis of extracts prepared from nematode cultures incubated in a liquid medium containing 6. A toxicity assay performed to assess the impact of 6 in vivo showed a 20-fold higher median lethal dose (LD50 = 11.7 ± 1.2 mM) concentration compared to that of the known phytotoxic adenine-nucleotide transporters inhibitor carboxyatractyloside (2, LD50 = 0.61 ± 0.05 mM), whereas 1 mM 6 and 0.1 mM 2 were sufficient to decrease the survival of wild type C. elegans, already 10-20-fold lower doses reduced reproduction. Because the insulin/insulin-like growth factors signaling cascade (IIS) is a key regulator of life span and stress resistance, the impact of compound 6 on the survival of long-living daf-2 C. elegans was tested. As the susceptibility of these nematodes to 6 was as high as that in wild type, an impact on central metabolic processes independent of IIS was suggested. Analysis of the in vivo adenosine triphosphate (ATP) content of adult C. elegans revealed no changes after 1 and 24 h, but a 50% reduction after treatment with 1 mM 6 during the entire postembryonic development. These data speak for a developmental-stage-dependent modulation of the ATP pool by 6.

UPLC-MS/MS of Atractylenolide I, Atractylenolide II, Atractylenolide III, and Atractyloside A in Rat Plasma after Oral Administration of Raw and Wheat Bran-Processed Atractylodis Rhizoma.

Atractylodis Rhizoma is the dried rhizome of Atractylodes lancea (Thunb.) DC. or Atractylodes chinensis (DC.) Koidz and is often processed by stir-frying with wheat bran to reduce its dryness and increase its spleen tonifying activity. However, the mechanism by which the processing has this effect remains unknown. To explain the mechanism based on the pharmacokinetics of the active compounds, a rapid, sensitive ultra-performance liquid chromatography-tandem mass spectrometry method was developed to analyze atractylenolides I, II, and III, and atractyloside A simultaneously in rat plasma after oral administration of raw and processed Atractylodis Rhizoma. Acetaminophen was used as the internal standard and the plasma samples were pretreated with methanol. Positive ionization mode coupled with multiple reaction monitoring mode was used to analyze the four compounds. The method validation revealed that all the calibration curves displayed good linear regression over the concentration ranges of 3.2⁻350, 4⁻500, 4⁻500, and 3.44⁻430 ng/mL for atractylenolides I, II, and III, and atractyloside A, respectively. The relative standard deviations of the intra- and inter-day precisions of the four compounds were less than 6% with accuracies (relative error) below 2.38%, and the extraction recoveries were more than 71.90 ± 4.97%. The main pharmacokinetic parameters of the four compounds were estimated with Drug and Statistics 3.0 and the integral pharmacokinetics were determined based on an area under the curve weighting method. The results showed that the integral maximum plasma concentration and area under the curve increased after oral administration of processed Atractylodis Rhizoma.

Biodistribution of Alpha-Fetoprotein-Containing Noncovalent Complex Aimpila with Antitumor Activity.

Biodistribution of [125I]Aimpila (20 mg/kg) in the tumor and normal tissues, including the mammary gland tissue, after single oral dose was studied in BALB/c nude mice with T47D/ReCAF+++ human breast tumor sensitive to this drug and in closely related BALB/c nude+mice without tumors. The maximum concentration of [125I]Aimpila was in fact the same in the tumor and in the mammary gland, while the time course of its accumulation/elimination differed. The time of the maximum accumulation of the drug in the tumor was shorter and its persistence longer than in normal tissue. After 24 h, label concentration in the tumor was 4.5 times higher (p=0.002). Differences in the time course of label accumulation in the tumor were detected. The maximum ratio of tumor/blood concentrations of the preparation was recorded in 1 h after administration. [125I]Aimpila and [125I]alpha-fetoprotein accumulated in the tumor in comparable concentrations and were eliminated simultaneously at the same rate. The results of comparative analysis of accumulation of the labeled compounds in Aimpila-sensitive T47D/RECAF+++ tumor from 0.5 to 9.0 h after drug administration could be interpreted as a result of possible receptor-mediated binding of the complex with the tumor at the expense of the alpha-fetoprotein transporting part. Differences in the parameters of [125I]Aimpila biodistribution in the tumor and normal mammary tissue indirectly attested to selective antiproliferative activity of the complex.

Brain mitochondrial alterations after chronic alcohol consumption

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The aim of this study was to demonstrate the existence of alterations in glutathione and cholesterol homeostasis in brain mitochondria from alcoholic rats. Glutathione concentration decreased, whereas oxidized glutathione and cholesterol contents increased in these organelles, suggesting the ethanol-induced generation of reactive oxygen species, and the impairment of mitochondrial uptake of glutathione, possibly due to the increase in cholesterol deposition. The release of apoptogenic proteins was increased after stimulating mitochondria from the brain of alcoholic rats with atractyloside. As a conclusion, chronic alcohol consumption might sensitize brain mitochondria to apoptotic stimuli, and promote the subsequent release of apoptotic proteins (AU)