Comparative study between the 3D‐liver spheroid models developed from HepG2 and immortalized hepatocyte‐like cells with primary hepatic stellate coculture for drug metabolism analysis and anticancer drug screening

Liver spheroids may be the best alternative models for evaluating efficacy and toxicity of the new anticancer candidates and diagnostics for hepatocellular carcinoma (HCC). Here, novel 3D-liver spheroid models are constructed from human hepatoma cells (HepG2)/ immortalized human hepatocyte-like cells (imHCs) with primary hepatic stellate cells (HSCs) coculture using the ultralow attachment technique. Spheroid morphology, HSC distribution, metabolic activity, protein expressions, and drug penetration are evaluated. All developed 3D spheroid models exhibit in spherical shape with narrow size distribution, diameter between 639–743 (HepG2-10%HSC) and 519–631 (imHC-10%HSC) µm. Both imHC mono and coculture models significantly express normal liver biomarkers at the higher level than HepG2 models. While 3D-HepG2 models significantly exhibit HCC biomarkers at the higher level than imHC models. HepG2 and imHC spheroids express basal cytochrom P450 (CYP450) enzymes at different levels depending on cell types, culture period, and ratio of coculture. Their metabolic activities for dextromethorphan (CYP2D6) tolbutamide (CYP2C9) and midazolam (CYP3A4) are routinely evaluated. For midazolam metabolism, imHC models allow the detection of phase II metabolic enzymes (UGT2B4 and UGT2B7). The presence of HSC in HepG2-HSC model increases biological barrier for doxorubicin (DOX) penetration, and escalates IC50 of DOX from 61.4 to 127.2 µg mL−1

Pharmacokinetics of mitragynine in man

Satariya Trakulsrichai,1,2 Korbtham Sathirakul,3,4 Saranya Auparakkitanon,5 Jatupon Krongvorakul,5 Jetjamnong Sueajai,5 Nantida Noumjad,5 Chonlaphat Sukasem,5 Winai Wananukul2,6 1Department of Emergency Medicine, Faculty of Medicine Ramathibodi Hospital, 2Ramathibodi Poison Center, Faculty of Medicine Ramathibodi Hospital, 3Department of Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand; 4Center for Drug Research Discovery and Development, Thammasat Univerisity, Prathumthani, Thailand; 5Department of Pathology, Faculty of Medicine Ramathibodi Hospital, 6Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Background: Kratom, known botanically as Mitragyna speciosa (Korth.), is an indigenous tree in Southeast Asia. Kratom is currently easily available worldwide via special shops and the Internet to use as a drug of abuse, opioid alternative, or pain killer. So far, the pharmacokinetics of this plant has been studied only in animals, and there is no such study in humans. The major abundant active alkaloid in Kratom, mitragynine, is one of the promising new chemical substances to be developed as a new drug. The aim of this study was to examine the pharmacokinetics of mitragynine and assess the linearity in pharmacokinetics in chronic users.Methods: Since Kratom is illegal in Thailand, studies in healthy subjects would be unethical. We therefore conducted a prospective study by enrolling ten chronic, regular, healthy users. We adjusted the steady state in each subject by giving a known amount of Kratom tea for 7 days before commencement of the experiment. We admitted and gave different oral doses to subjects to confirm linearity in pharmacokinetics. The mitragynine blood concentrations at 17 times points and the urine concentrations during the 24-hour period were collected and measured by liquid chromatography-tandem mass spectrometry method. Results: Ten male subjects completed the study without adverse reactions. The median duration of abuse was 1.75 years. We analyzed one subject separately due to the abnormal behavior of blood concentration. From data of nine subjects, the pharmacokinetic parameters established were time to reach the maximum plasma concentration (0.83±0.35 hour), terminal half-life (23.24±16.07 hours), and the apparent volume of distribution (38.04±24.32 L/kg). The urine excretion of unchanged form was 0.14%. The pharmacokinetics were observed to be oral two-compartment model. Conclusion: This was the first pharmacokinetic study in humans, which demonstrated linearity and was consistent with the oral two-compartment model with a terminal half-life of about 1 day. The pharmacokinetic linearity and parameters reported are necessary pharmacological information of Kratom, and there is a possibility for it to be developed medically as a pain killer or better opioid substitute in the future. Keywords: kratom, human, pharmacokinetic