scholarly journals Pharmacokinetics and Novel Metabolite Identification of Tartary Buckwheat Extracts in Beagle Dogs Following Co-Administration with Ethanol

Pharmaceutics ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 525
Author(s):  
Yuancai Liu ◽  
Jun Gan ◽  
Wanyu Liu ◽  
Xin Zhang ◽  
Jian Xu ◽  
...  

Alcoholic liver disease (ALD) has become a critical global public health issue worldwide. Tartary buckwheat extracts exhibit potential therapeutic effects against ALD due to its antioxidant and anti-inflammatory activities. However, in vivo pharmacokinetics and metabolite identification of tartary buckwheat extracts have not been clearly elucidated. Accordingly, the current manuscript aimed to investigate pharmacokinetics and to identify novel metabolites in beagle dogs following oral co-administration of tartary buckwheat extracts and ethanol. To support pharmacokinetic study, a simple LC-MS/MS method was developed and validated for simultaneous determination of quercetin and kaempferol in beagle dog plasma. The conjugated forms of both analytes were hydrolyzed by β-glucuronidase and sulfatase followed by liquid-liquid extraction using methyl tert-butyl ether. In addition, another effective approach was established using advanced ultrafast liquid chromatography coupled with a Q-Exactive hybrid quadrupole orbitrap high resolution mass spectrometer to identify the metabolites in beagle dog biological samples including urine, feces, and plasma. The pharmacokinetic study demonstrated that the absolute oral bioavailability for quercetin and kaempferol was determined to be 4.6% and 1.6%, respectively. Oral bioavailability of quercetin and kaempferol was limited in dogs probably due to poor absorption, significant first pass effect, and biliary elimination, etc. Using high resolution mass spectrometric analysis, a total of nine novel metabolites were identified for the first time and metabolic pathways included methylation, glucuronidation, and sulfation. In vivo pharmacokinetics and metabolite identification results provided preclinical support of co-administration of tartary buckwheat extracts and ethanol in humans.

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 372 ◽  
Author(s):  
Priyanka Reddy ◽  
Aaron Elkins ◽  
Joanne Hemsworth ◽  
Kathryn Guthridge ◽  
Simone Vassiliadis ◽  
...  

Lolitrem B is the most potent indole-diterpene mycotoxin produced by Epichloë festucae var. lolii (termed LpTG-1), with severe intoxication cases reported in livestock. To date, there are no in vivo metabolism studies conducted for the mycotoxin. A mouse model assay established for assessing toxicity of indole-diterpenes was used to investigate metabolic products of lolitrem B. Mice were administered lolitrem B at 0.5 and 2.0 mg/kg body weight (b.wt) intraperitoneally before body and brain tissues were collected at 6 h and 24 h post-treatment. Samples were cryoground and subjected to a biphasic or monophasic extraction. The aqueous and lipophilic phases were analysed using liquid chromatography high-resolution mass spectrometry (LC–HRMS); data analysis was performed with Compound Discoverer™ software. A total of 10 novel phase I metabolic products were identified in the lipophilic phase and their distribution in the liver, kidney and various brain regions are described. The biotransformation products of lolitrem B were found to be present in low levels in the brain. Based on structure–activity postulations, six of these may contribute towards the protracted tremors exhibited by lolitrem B-exposed animals.


2020 ◽  
Vol 190 ◽  
pp. 113519
Author(s):  
Martin Uher ◽  
Martin Mžik ◽  
Jana Žďárová Karasová ◽  
David Herman ◽  
Lenka Čechová ◽  
...  

2019 ◽  
Vol 16 (6) ◽  
pp. 500-510
Author(s):  
Rong Chai ◽  
Hailing Gao ◽  
Zhihui Ma ◽  
Meng Guo ◽  
Qiang Fu ◽  
...  

Background: Olmesartan medoxomil (OLM) is a promising prodrug hydrolyzed to olmesartan (OL) during absorption from the gastrointestinal tract. OL is a selective angiotensin II receptor antagonist, with high drug resistance and low drug interaction. However, OLM has low solubility and low bioavailability. Therefore, it is extremely urgent to reduce the drug particle size to improve its biological bioavailability. Objective: The aim of the study was to improve the oral bioavailability of poorly water-soluble olmesartan medoxomil (OLM) by using different particle size-reduction strategies. Method: Raw drug material was micronized or nanosized by either jet or wet milling processes, respectively. The particle sizes of the prepared nanocrystals (100-300 nm) and microcrystals (0.5-16 μm) were characterized by DLS, SEM, and TEM techniques. Solid state characterization by XPRD and DSC was used to confirm the crystalline state of OLM after the milling processes. Results: We demonstrated that OLM nanocrystals enhanced solubility and dissolution in the non-sink condition in which high sensitivity was found in purified water. After 1 h, 65.4% of OLM was dissolved from nanocrystals, while microcrystals and OLMETEC® only showed 37.8% and 31.9% of drug dissolution, respectively. In the pharmacokinetic study using Beagle dogs, an increase in Cmax (~2 fold) and AUC (~1.6 fold) was observed after oral administration of OLM nanocrystals when compared to microcrystals and reference tablets, OLMETEC®. In contrast, OLM microcrystals failed to improve the oral bioavailability of the drugs. Conclusion: Particles size reduction to nano-scale by means of nanocrystals technology significantly increased in vitro dissolution rate and in vivo oral bioavailability of OLM.


RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37459-37466 ◽  
Author(s):  
Zhongyao Tang ◽  
Yuanyuan Hou ◽  
Xueyan Hu ◽  
Aina Liu ◽  
Leefong Yau ◽  
...  

The secondary platycosides, 3-O-β-d-glucopyranosylplatycodigenin and 3-O-β-d-glucopyranosylplatyconic acid, were qualitatively and quantitatively analyzed in vivo for the first time.


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