Inhibition of human sulfotransferases (SULTs) by per- and polyfluoroalkyl substances (PFASs) and structure-activity relationship.

Per- and polyfluoroalkyl substances (PFASs) are a family of highly fluorinated aliphatic substances widely used in industrial and commercial applications. This study aims to determine the inhibition of PFASs towards sulfotransferases (SULTs) activity, and trying to explain the toxicity mechanism of PFASs. In vitro recombinant SULTs-catalyzed sulfation of p-nitrophenol (PNP) was utilized as a probe reaction. The incubation system was consisted of PFASs, SULTs, PNP, 3'-phosphoadenosine-5'-phosphosulfate, MgCl2 and Tris-HCl buffer. Ultra-performance liquid chromatography was employed for analysis of the metabolites. All tested PFASs showed inhibition towards SULTs. The longer the carbon chain length of the PFASs terminated with -COOH, the higher is its capability of inhibiting SULT1A3. PFASs with -SO3H had a relatively higher ability to inhibit SULT1A3 activity than those with -COOH, -I and -OH. The inhibition kinetic parameter was 2.16 and 1.42 µM for PFOS-SULT1A1, PFTA-SULT1B1. In vitro in vivo extrapolation showed that the concentration of PFOS and PFTA in human matrices might be higher than the threshold for inducing inhibition of SULTs. Therefore, PFASs could interfere with the metabolic pathways catalyzed by SULTs in vivo. All these results will help to understand the toxicity of PFASs from the perspective of metabolism.

Inhibition of hydroxylated polychlorinated biphenyls (OH-PCBs) on sulfotransferases (SULTs).

Polychlorinated biphenyls (PCBs) have been demonstrated as a kind of the persistent organic pollutants (POPs) that could exert complicated influences towards metabolism in human bodies. Since hydroxylated polychlorinated biphenyls (OH-PCBs) are important metabolites of PCBs, our study focuses on investigating the potential inhibitory capability of OH-PCBs on four human sulfotransferase (SULT) isoforms. P-nitrophenol (PNP) was utilized as nonselective probe substrate for this study, and recombinant SULT isoforms were utilized as the enzyme resources. Ultra-performance liquid chromatography (UPLC)-UV detecting system was used to analyze PNP and its metabolite PNP-sulfate. As result, 100 µM of most tested OH-PCBs significantly inhibited the activity of four SULT isoforms. Concentration-dependent inhibition of OH-PCBs towards SULTs was found, and half inhibition concentration values (IC50) of some inhibition processes were determined. Inhibition kinetics (inhibition kinetic type and parameters) were determined using 4'-OH-PCB106 as the representative OH-PCB, SULT1B1 and SULT1E1 as representative SULT isoforms. The inhibition kinetic parameters (Ki) were 1.73 µM and 1.81 µM for the inhibition of 4'-OH-PCB106 towards SULT1B1 and SULT1E1, respectively. In silico docking simulation was utilized to analyze the inhibition capability of 2'-OH-PCB5, 4'-OH-PCB9, 2'-OH-PCB12 towards SULT1A3.All these results obtained in this study are helpful for further understanding the toxicity of PCBs.

Anxiolytic and Anti-depressive Like Effects of Translocator Protein (18 kDa) Ligand YL-IPA08 in a Rat Model of Postpartum Depression.

Translocator protein 18 kDa (TSPO) is mainly distributed in the outer mitochondrial membrane of steroid-synthesizing cells in the central and peripheral nervous systems. It mediates cholesterol transportation across the phospholipid membrane, which is a prerequisite for neurosteroid synthesis. Though the ligand of TSPO has clinical value in the diagnosis and treatment of neuropsychiatric disorders, the pharmacological study of TSPO for anti-postpartum depression has not been reported. In this study, the classical method of reproductive hormone withdrawal was used to construct a rat model of postpartum depression (PPD). The effect of YL-IPA08, a new ligand compound of TSPO, on PPD was evaluated using multiple behavioral tests at progressive time points. Additionally, real-time quantitative PCR, Western-blotting and an enzyme linked immunosorbent assay were conducted to elucidate the potential molecular mechanism of such effect. We report that the levels of TSPO and neurosteroids in the hippocampus and prefrontal cortex were significantly decreased in PPD rats compared to healthy controls. After 3 weeks of drug treatment, the levels of TSPO and neurosteroids in the hippocampus of PPD rats were increased, and anxiety and depressive like behaviors were alleviated. Meanwhile, compared with sertraline treatment, a positive control in this study, YL-IPA08 treatment had a shorter onset time. Our results suggest that the anxiolytic and anti-depressive activity of YL-IPA08 has significant value in the treatment of PPD and that TSPO may be a potential new target for the treatment of PPD.

Per- and polyfluoroalkyl substances exert strong inhibition towards human carboxylesterases.

PFASs are highly persistent in both natural and living environment, and pose a significant risk for wildlife and human beings. The present study was carried out to determine the inhibitory behaviours of fourteen PFASs on metabolic activity of two major isoforms of carboxylesterases (CES). The probe substrates 2-(2-benzoyl-3-methoxyphenyl) benzothiazole (BMBT) for CES1 and fluorescein diacetate (FD) for CES2 were utilized to determine the inhibitory potentials of PFASs on CES in vitro. The results demonstrated that perfluorododecanoic acid (PFDoA), perfluorotetradecanoic acid (PFTA) and perfluorooctadecanoic acid (PFOcDA) strongly inhibited CES1 and CES2. The half inhibition concentration (IC50) value of PFDoA, PFTA and PFOcDA for CES1 inhibition was 10.6 µM, 13.4 µM and 12.6 µM, respectively. The IC50 for the inhibition of PFDoA, PFTA and PFOcDA towards CES2 were calculated to be 9.56 µM, 17.2 µM and 8.73 µM, respectively. PFDoA, PFTA and PFOcDA exhibited noncompetitive inhibition towards both CES1 and CES2. The inhibition kinetics parameters (Ki) were 27.7 µM, 26.9 µM, 11.9 µM, 4.04 µM, 29.1 µM, 27.4 µM for PFDoA-CES1, PFTA-CES1, PFOcDA-CES1, PFDoA-CES2, PFTA-CES2, PFOcDA-CES2, respectively. In vitro-in vivo extrapolation (IVIVE) predicted that when the plasma concentrations of PFDoA, PFTA and PFOcDA were greater than 2.77 µM, 2.69 µM and 1.19 µM, respectively, it might interfere with the metabolic reaction catalyzed by CES1 in vivo; when the plasma concentrations of PFDoA, PFTA and PFOcDA were greater than 0.40 µM, 2.91 µM, 2.74 µM, it might interfere with the metabolic reaction catalyzed by CES2 in vivo. Molecular docking was used to explore the interactions between PFASs and CES. In conclusion, PFASs were found to cause inhibitory effects on CES in vitro, and this finding would provide an important experimental basis for further in vivo testing of PFASs focused on CES inhibition endpoints.

Prognostic Performance of SOFA, qSOFA, and SIRS in Kidney Transplant Recipients Suffering from Infection: A Retrospective Observational Study.

INTRODUCTION: The prognostic performance of scoring systems for illness severity in infectious kidney transplant recipients (KTRs) is rarely reported. We investigated the ability of the scores for the quick Sequential Organ Failure Assessment (qSOFA), Sequential Organ Failure Assessment (SOFA) and Systemic Inflammatory Response Syndrome (SIRS) to predict in-hospital mortality, intensive care unit (ICU) admission and mechanical ventilation (MV) requirement. METHODS: This was a second analysis of a retrospective observational study. Scores for SIRS, SOFA and qSOFA were calculated upon hospitalization (infection onset was before hospitalization) or on the day of infection onset (infection episodes were during hospitalization). The primary outcome was in-hospital mortality. The secondary outcomes were ICU admission and MV requirement. Binary logistic regression and area under the receiver operating characteristic curve (AUC) were employed to assess prognostic performance. RESULTS: A total of 161 infectious episodes occurred in 97 KTRs. Forty patients (41%) experienced more than one episode. The SOFA score was available in 161 infections, and scores for qSOFA and SIRS were available in 160 infections. The SIRS score was not different between KTRs with opposite outcomes. The qSOFA score was higher in infections necessitating MV. The SOFA score was significantly higher in the deceased, those needing ICU admission, MV, and for those with positive etiology results. The SOFA score was the only independent predictor of in-hospital mortality, ICU admission, and MV requirement, and the AUCs were 0.879, 0.815, and 0.784, respectively. The optimum cutoff value of predicting the three outcomes was SOFA score ≥ 3. CONCLUSIONS: The SOFA score (but not those for SIRS and qSOFA) independently predicted in-hospital mortality, ICU admission, and MV requirement in infectious KTRs.

Inhibition of UDP-glucuronosyltransferases (UGTs) by bromophenols (BPs).

Bromophenols (BPs) are important organic compounds which have become dominant pollutants during these years. Our present study investigated the potential inhibition behaviour of BPs on the activity of one of the most important phase II drug-metabolizing enzymes (DMEs), UDP-glucuronosyltransferases (UGTs). Recombinant UDP-glucuronosyltransferases (UGTs)-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was utilized as the probe reaction. 100 µM of BPs was utilized as the inhibition screening concentrations, and the complete inhibition profile of UGT isoforms by BPs was obtained. UGT1A7 was the most vulnerable UGT isoform towards BPs. Some structure-activity relationship for the inhibition of UGTs by BPs was found, and this relationship can be furtherly explained by the hydrophobic contacts of BPs with the activity cavity of UGTs using in silico docking method. The inhibition kinetics determination showed that the inhibition kinetic parameter Ki value was calculated to be 2.85, 3.99 and 31.00 µM for the inhibition of UGT1A3, UGT1A7, and UGT2B7 by representative BPs, 2,4,6-TBP. Combined with in vivo exposure concentration of 2,4,6-TBP, in vitro-in vivo extrapolation (IVIVE) was employed to demonstrate the moderate possibility for the inhibition of UGT1A3 and UGT1A7 by 2,4,6-TBP. In conclusion, our study gave the full description towards the inhibition of BPs towards UGT isoforms, which will provide a new perspective for elucidating the toxicity mechanism of bromophenols (BPs).

Risk factors and etiology of repeat infection in kidney transplant recipients.

Kidney transplantation (KT) is the best therapy available for patients with end-stage renal disease, but postoperative infections are a significant cause of mortality.In this retrospective study the frequency, risk factors, causative pathogens, and clinical manifestations of infection in KT recipients from Beijing Chao-Yang Hospital, Capital Medical University were investigated. Ninety-seven KT recipients who were hospitalized with infection between January 2010 and December 2016 were included. Clinical characteristics, surgery details, laboratory results, and etiology were compared in patients who developed single infection and patients who developed repeated infection (2 or more) after KT.A total of 161 infections were adequately documented in a total of 97 patients, of which 57 patients (58.8%) had 1 infection, 24 (24.7%) had 2, 11 (11.3%) had 3; 3 (3.1%) had 4, and 2 (2.1%) had 5 or more. The most common infection site was the urinary tract (90 infections; 56%), both overall and in the repeated infection group. The most frequently isolated pathogen was Pseudomonas aeruginosa. In the repeated infection patients, in most cases of P. aeruginosa infection (54%) it was cultured from urine. For first infections, a time between KT and infection of ≤ 21 days (area under receiver operating characteristic curve [AUC] 0.636) and a tacrolimus level ≥ 8 ng/mL (AUC 0.663) independently predicted repeat infection. The combination of these two predictive factors yielded an AUC of 0.716, which did not differ statistically significantly from either predictor alone.With regard to first infections after KT, a time between KT and infection of ≤ 21 days, and a tacrolimus level ≥ 8 ng/mL each independently predicted repeated infection in KT recipients.

Per- and polyfluoroalkyl substances display structure-dependent inhibition towards UDP-glucuronosyltransferases.

Per- and polyfluoroalkyl substances (PFASs) are a large group of chemicals and can be detected in environmental and human samples all over the world. Toxicity of existing and emerging PFASs will be a long-term source of concern. This study aimed to investigate structure-dependent inhibitory effects of 14 PFASs towards the activity of 11 UDP-glucuronosyltransferase (UGT) isoforms. In vitro UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was employed to determine the inhibition of PFASs towards different UGT isoforms. All the PFASs showed <75% of inhibition or stimulation effects on UGT1A3, UGT1A7, UGT1A9, UGT2B4, UGT2B7 and UGT2B17. However, PFASs showed broad inhibition on the activity of UGT1A1 and UGT1A8. The activity of UGT1A1 was inhibited by 98.8%, 98%, 79.9%, 77.1%, and 76.9% at 100 µmoL/L of perfluorodecanoic acid (PFDA), perfluorooctanesulfonic acid potassium salt (PFOS), perfluorotetradecanoic acid (PFTA), perfluorooctanoic acid (PFOA) and perfluorododecanoic acid (PFDoA), respectively. UGT1A8 was inhibited by 97.6%, 94.8%, 86.3%, 83.4% and 77.1% by PFDA, PFTA, perfluorooctadecanoic acid (PFOcDA), PFDoA and PFOS, respectively. Additionally, PFDA significantly inhibited UGT1A6 and UGT1A10 by 96.8% and 91.6%, respectively. PFDoA inhibited the activity of UGT2B15 by 88.2%. PFDA and PFOS exhibited competitive inhibition towards UGT1A1, and PFDA and PFTA showed competitive inhibition towards UGT1A8. The inhibition kinetic parameter (Ki) were 3.15, 1.73, 13.15 and 20.21 µmoL/L for PFDA-1A1, PFOS-1A1, PFDA-1A8 and PFTA-1A8, respectively. The values were calculated to be 0.3 µmoL/L and 1.3 µmoL/L for the in vivo inhibition of PFDA towards UGT1A1-and UGT1A8-catalyzed metabolism of substances, and 0.2 µmoL/L and 2.0 µmoL/L for the inhibition of PFOS towards UGT1A1 and the inhibition of PFTA towards UGT1A8, respectively. Molecular docking indicated that hydrogen bonds and hydrophobic interactions contributed to the interaction between PFASs and UGT isoforms. In conclusion, exposure to PFASs might inhibit the activity of UGTs to disturb metabolism of endogenous compounds and xenobiotics. The structure-related effects of PFASs on UGTs would be very important for risk assessment of PFASs.

Hydroxy metabolites of polychlorinated biphenyls (OH-PCBs) exhibit inhibitory effects on UDP-glucuronosyltransferases (UGTs).

Hydroxy metabolites of polychlorinated biphenyls (OH-PCBs) are important substance basis for the toxicity of PCBs. This study aims to investigate the inhibition of OH-PCBs on the activity of UDP-glucuronosyltransferases (UGTs), trying to elucidate the toxicity mechanism of PCBs from a new perspective. In vitrohuman recombinant UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was used as the probe reaction. The number of chlorine atom can affect the inhibition potential of OH-PCBs towards different isoforms of UGTs, and complex structure-activity relationship was found for the inhibition of OH-PCBs on the activities of UGT isoforms. For the inhibition kinetic determination, 2'OHPCB106 and 4'OHPCB106 were selected as the representative OH-PCBs, and UGT1A1, 1A7, and 2B7 were chosen as the representative UGT isoforms. Competitive inhibition of 2'OHPCB106 and 4'OHPCB106 on the activities of UGT1A1, UGT1A7, and UGT2B7 was found. For 2'OHPCB106, the inhibition kinetic parameters (Ki) were calculated to be 0.4 µM for UGT1A1, 1.3 µM for UGT1A7, and 2.7 µM for UGT2B7, respectively. For 4'OHPCB106, Ki values were calculated to be 0.7 µM for UGT1A1, 6.8 µM for UGT1A7, and 4.8 µM for UGT2B7, respectively. In silico docking method was utilized to elucidate the inhibition difference of UGT1A1 by four OH-PCBs with similar structures (4'OHPCB9, 4'OHPCB26, 4'OHPCB112 and 4'OHPCB165). In conclusion, these data will be helpful for understanding the toxicity mechanisms of PCBs from a view of metabolic interference.

New insights for risks of chlorophenols (CPs) exposure: Inhibition of UDP-glucuronosyltransferases (UGTs).

Chlorophenols (CPs) are important pollutants extensively utilized in industry, agriculture and forestry. The present study aims to determine the inhibition of CPs on the activity of the important phase II drug-metabolizing enzymes (DMEs) UDP-glucuronosyltransferases (UGTs). 100 µM of fourteen CPs were used for preliminary screening using in vitro incubation. Furthermore, half inhibition concentration (IC50) and inhibition kinetics were determined for CPs with significant inhibition towards UGT isoforms. In silico docking was used to explain the inhibition difference among CPs. Multiple UGT isoforms were inhibited by CPs. In silico docking showed that higher free binding energy due to hydrophobic interactions of 2.4-Dichlorophenol (2.4-DCP) or 4-Chloro-3-methylphenol (4C3MP) with UGT1A9 contributed to stronger inhibition potential of 2.4-Dichlorophenol (2.4-DCP) or 4-Chloro-3-methylphenol (4C3MP) towards UGT1A9 than 4-CP. Pentachlorophenol (PCP) was chosen as the representative CPs to determine the IC50 value towards UGT1A6, UGT1A9 and UGT2B7. IC50 was calculated to be 0.33 µM, 0.24 µM and 31.35 µM for the inhibition of PCP towards UGT1A6, UGT1A9 and UGT2B7. PCP was demonstrated to show competitive inhibition towards UGT1A6, UGT1A9 and UGT2B7, and the inhibition kinetic parameters (Ki) was calculated to be 0.18 µM, 0.01 µM and 5.37 µM for the inhibition of PCP towards UGT1A6, UGT1A9 and UGT2B7. All these information will be beneficial for elucidating the risk of CPs exposure from a new perspective.

Inhibition of UDP-glucuronosyltransferases (UGTs) by phthalate monoesters.

Phthalate monoesters are important metabolites of phthalate esters (PAEs) which have been extensively utilized in industry. This study aims to investigate the inhibition of phthalate monoesters on the activity of various isoforms of UDP-glucuronosyltransferases (UGTs), trying to elucidate the toxicity mechanism of environmental endocrine disruptors from the new perspectives. In vitro recombinant UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was employed to evaluate 8 kinds of phthalate monoesters on 11 sorts of main human UGT isoforms. 100 µM phthalate monoesters exhibited negligible inhibition towards the activity of UGT1A1, UGT1A3, UGT1A6, UGT1A8, UGT1A10, UGT2B4, UGT2B7, UGT2B15 and UGT2B17. The activity of UGT1A7 was strongly inhibited by monoethylhexyl phthalate (MEHP), but slightly inhibited by all the other phthalate monoesters. UGT1A9 was broadly inhibited by monobenzyl phthalate (MBZP), monocyclohexyl phthalate (MCHP), MEHP, monohexyl phthalate (MHP) and monooctyl phthalate (MOP), respectively. MEHP exhibited competitive inhibition towards UGT1A7, and MBZP, MCHP, MEHP, MHP and MOP showed competitive inhibition towards UGT1A9. The inhibition kinetic parameters (Ki) were calculated to be 11.25 µM for MEHP-UGT1A7, and 2.13, 0.09, 1.17, 7.47, 0.16 µM for MBZP-UGT1A9, MCHP-UGT1A9, MEHP-UGT1A9, MHP-UGT1A9, MOP-UGT1A9, respectively. Molecular docking indicated that both hydrogen bonds formation and hydrophobic interactions significantly contributed to the interaction between phthalate monoesters and UGT isoforms. All these information will be beneficial for understanding the adverse effects of PAEs.

Everolimus-inhibited multiple isoforms of UDP-glucuronosyltransferases (UGTs).

1. Everolimus is an inhibitor of mammalian target of rapamycin (mTOR) and has been clinically utilized to prevent the rejection of organ transplants. This study aims to determine the inhibition of everolimus on the activity of phase-II drug-metabolizing enzymes UDP-glucuronosyltransferases (UGTs). 2. The results showed that 100 µM of everolimus exerted more than 80% inhibition toward UGT1A1, UGT-1A3 and UGT-2B7. UGT1A3 and UGT2B7 were selected to elucidate the inhibition mechanism, and in silico docking showed that hydrogen bonds and hydrophobic interactions mainly contributed to the strong binding of everolimus toward the activity cavity of UGT1A3 and UGT2B7. Inhibition kinetic-type analysis using Lineweaver-Burk plot showed competitive inhibition toward all these UGT isoforms. The inhibition kinetic parameters (Ki) were calculated to be 2.3, 0.07 and 4.4 µM for the inhibition of everolimus toward UGT1A1, UGT-1A3 and UGT-2B7, respectively. 3. In vitro-in vivo extrapolation (IVIVE) showed that [I]/Ki value was calculated to be 0.004, 0.14 and 0.002 for UGT1A1, UGT-1A3 and UGT-2B7, respectively. Therefore, high DDI potential existed between everolimus and clinical drugs mainly undergoing UGT1A3-catalyzed glucuronidation.

The inhibition of UDP-glucuronosyltransferases (UGTs) by tetraiodothyronine (T4) and triiodothyronine (T3).

1. UDP-glucuronosyltransferases (UGTs) are important drug-metabolizing enzymes (DMEs) catalyzing the glucuronidation elimination of various xenobiotics and endogenous substances. Endogenous substances are important regulators for the activity of various UGT isoforms. Triiodothyronine (T3) and thyroxine (T4) are important thyroid hormones essential for normal cellular differentiation and growth. The present study aims to elucidate the inhibition behavior of T3 and T4 on the activity of UGT isoforms. 2. In vitro recombinant UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was used to screen the inhibition potential of T3 and T4 on the activity of various UGT isoforms. Initial screening results showed that T4 exerted stronger inhibition potential than T3 on the activity of various UGT isoforms at 100 µM. Inhibition kinetics was determined for the inhibition of T4 on the representative UGT isoforms, including UGT1A1, -1A3, -1A7, -1A8, -1A10 and -2B7. The results showed that T4 competitively inhibited the activity of UGT1A1, -1A3, -1A7, 1A10 and -2B7, and noncompetitively inhibited the activity of UGT1A8. The inhibition kinetic parameters were calculated to be 1.5, 2.4, 11, 9.6, 4.8 and 3.0 µM for UGT1A1, -1A3, -1A7, -1A8, -1A10 and -2B7, respectively. In silico docking method was employed to demonstrate why T4 exerted stronger inhibition than T3 towards UGT1A1. Stronger hydrogen bonds and hydrophobic interaction between T4 and activity cavity of UGT1A1 than T3 contributed to stronger inhibition of T4 towards UGT1A1. 3. In conclusion, more clinical monitoring should be given for the patients with the elevation of T4 level due to stronger inhibition of UGT isoforms-catalyzed metabolism of drugs or endogenous substances by T4.

Inhibitory effects of fifteen phthalate esters in human cDNA-expressed UDP-glucuronosyltransferase supersomes.

Phthalate esters (PAEs) have been extensively used in industry as plasticizers and there remains concerns about their safety. The present study aimed to determine the inhibition of phthalate esters (PAEs) on the activity of the phase II drug-metabolizing enzymes UDP-glucuronosyltransferases (UGTs). In vitro recombinant UGTs-catalyzed glucuronidation of 4-methylumbelliferone was used to investigate the inhibition potentials of PAEs towards various s UGTs. PAEs exhibited no significant inhibition of UGT1A1, UGT1A3, UGT1A8, UGT1A10, UGT2B15, and UGT2B17, and limited inhibition of UGT1A6, UGT1A7 and UGT2B4. However, UGT1A9 was strongly inhibited by PAEs. In silico docking demonstrated a significant contribution of hydrogen bonds and hydrophobic interactions contributing to the inhibition of UGT by PAEs. The Ki values were 15.5, 52.3, 23.6, 12.2, 5.61, 2.79, 1.07, 22.8, 0.84, 73.7, 4.51, 1.74, 0.58, 6.79, 4.93, 6.73, and 7.23 µM for BBOP-UGT1A6, BBZP-UGT1A6, BBOP-UGT1A7, BBZP-UGT1A7, DiPP-UGT1A9, DiBP-UGT1A9, DCHP-UGT1A9, DBP-UGT1A9, BBZP-UGT1A9, BBOP-UGT1A9, DMEP-UGT1A9, DPP-UGT1A9, DHP-UGT1A9, DiBP-UGT2B4, DBP-UGT2B4, DAP-UGT2B4, and BBZP-UGT2B4, respectively. In conclusion, exposure to PAEs might influence the metabolic elimination of endogenous compounds and xenobiotics through inhibiting UGTs.

Inhibition of human CYP3A4 and CYP3A5 enzymes by gomisin C and gomisin G, two lignan analogs derived from Schisandra chinensis.

Gomisin C (GC) and gomisin G (GG) are two lignan analogs isolated from the Traditional Chinese Medicine Schisandra chinensis which possesses multiple pharmacological activities. However, the potential herb-drug interactions (HDI) between these lignans and other drugs through inhibiting human cytochrome P450 3A4 (CYP3A4) and CYP3A5 remains unclear. In the present study, the inhibitory action of GC and GG on CYP3A4 and CYP3A5 were investigated. The results demonstrated that both GC and GG strongly inhibited CYP3A-mediated midazolam 1'-hydroxylation, nifedipine oxidation and testosterone 6ß-hydroxylation. Notably, the inhibitory intensity of GC towards CYP3A4 was stronger than CYP3A5 when using midazolam and nifedipine as substrates. While inhibition of GC towards CYP3A5 was weaker than CYP3A4 when using testosterone as substrate. In contrast, GG showed a stronger inhibitory activity on CYP3A5 than CYP3A4 without substrate-dependent behavior. In addition, docking simulations indicated that the π-π interaction between CYP3A4 and GC, and hydrogen-bond interaction between CYP3A5 and GG might result in their different inhibitory actions. Furthermore, the AUC of drugs metabolized by CYP3A was estimated to increase by 8%-321% and 2%-3190% in the presence of GC and GG, respectively. These findings strongly suggested that GC and GG showed high HDI potentials, and the position of methylenedioxy group determined their different inhibitory effect towards CYP3A4 and CYP3A5, which are of significance for the application of Schisandra chinensis-containing herbs.

Endobronchial Ultrasound-guided Transbronchial Needle Aspiration versus Standard Bronchoscopic Modalities for Diagnosis of Sarcoidosis: A Meta-analysis.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an effective technique used to precisely detect enlarged mediastinal lymph nodes. The efficacy of EBUS-TBNA versus standard modalities for the diagnosis of sarcoidosis remains to be elucidated. In this meta-analysis, we compared the efficacies of these methods. METHODS: We searched PubMed, Embase, The Cochrane Library, Wanfang, Cpvip, CNKI, and the bibliographies of the relevant references. We analyzed the data obtained with Revman 5.2 (Nordic Cochrane Center, Copenhagen, Denmark) and Stata 12.0 software (Stata Corporation, College Station, TX, USA). The Mantel-Haenszel method was used to calculate the pooled odds ratio (OR) and 95% confidence intervals (CIs). RESULTS: Sixteen studies with a total of 1823 participants met the inclusion criteria, and data were extracted regarding the diagnostic yield of each approach. The ORs for EBUS-TBNA versus transbronchial lung biopsy (TBLB) for the diagnosis of sarcoidosis ranged from 0.26 to 126.58, and the pooled OR was 5.89 (95% CI, 2.20-15.79, P = 0.0004). These findings indicated that EBUS-TBNA provided a much higher diagnostic yield than TBLB. The pooled OR for EBUS-TBNA + TBLB + endobronchial biopsy (EBB) versus TBNA + TBLB + EBB was 1.54 (95% CI, 0.61-3.93, P = 0.36), implying that there was no significant difference between their diagnostic yields. However, clinical heterogeneity was reflected in the nature of the studies and in the operative variables. CONCLUSIONS: The results of this meta-analysis suggest that EBUS-TBNA + TBLB + EBB could be used for the diagnosis of sarcoidosis, if available. At medical centers without EBUS-TBNA, TBNA + TBLB + EBB could be used instead.

New insights into the risk of phthalates: Inhibition of UDP-glucuronosyltransferases.

Wide utilization of phthalates-containing products results in the significant exposure of humans to these compounds. Many adverse effects of phthalates have been documented in rodent models, but their effects in humans exposed to these chemicals remain unclear until more mechanistic studies on phthalate toxicities can be carried out. To provide new insights to predict the potential adverse effects of phthalates in humans, the recent study investigated the inhibition of representative phthalates di-n-octyl ortho-phthalate (DNOP) and diphenyl phthalate (DPhP) towards the important xenobiotic and endobiotic-metabolizing UDP-glucuronosyltransferases (UGTs). An in vitro UGTs incubation system was employed to study the inhibition of DNOP and DPhP towards UGT isoforms. DPhP and DNOP weakly inhibited the activities of UGT1A1, UGT1A7, and UGT1A8. 100 µM of DNOP inhibited the activities of UGT1A3, UGT1A9, and UGT2B7 by 41.8% (p < 0.01), 45.6% (p < 0.01), and 48.8% (p < 0.01), respectively. 100 µM of DPhP inhibited the activity of UGT1A3, UGT1A6, and UGT1A9 by 81.8 (p < 0.001), 49.1% (p < 0.05), and 76.4% (p < 0.001), respectively. In silico analysis was used to explain the stronger inhibition of DPhP than DNOP towards UGT1A3 activity. Kinetics studies were carried our to determine mechanism of inhibition of UGT1A3 by DPhP. Both Dixon and Lineweaver-Burk plots showed the competitive inhibition of DPhP towards UGT1A3. The inhibition kinetic parameter (Ki) was calculated to be 0.89 µM. Based on the [I]/Ki standard ([I]/Ki < 0.1, low possibility; 1>[I]/Ki > 0.1, medium possibility; [I]/Ki > 1, high possibility), these studies predicted in vivo drug-drug interaction might occur when the plasma concentration of DPhP was above 0.089 µM. Taken together, this study reveales the potential for adverse effects of phthalates DNOP and DPhP as a result of UGT inhibition.

Ulinastatin decreases permeability of blood--brain barrier by inhibiting expression of MMP-9 and t-PA in postoperative aged rats.

Tissue-type plasminogen activator (t-PA) and matrix metalloproteinase-9 (MMP-9) have been reported to play important roles in increased permeability of blood-brain barrier (BBB) under many pathological circumstances. We have showed that Ulinastatin, a broad-spectrum serine protease inhibitor, could alleviate inflammation in the hippocampus of aged rats following partial hepatectomy. In this study, we investigate the expression and potential roles of t-PA and MMP-9 in the protective effect of Ulinastatin. We found that partial hepatectomy increased Evans blue leakage in hippocampus at day 1 and 3 postoperatively. Furthermore, surgery decreased the protein levels of claudin-5, ZO-1, and NF-kB p65 while upregulating the mRNA and protein levels of t-PA and MMP-9 in brain capillaries. All these effects caused by surgery were partially reversed by administering Ulinastatin. Our study sheds light on the roles of t-PA and MMP-9 of BBB in post-surgical neuroinflammation and postoperative cognitive dysfunction. Besides, it could also help to understand the mechanism of Ulinastatin alleviating neuroinflammation.

Chiral Inhibition of Rivaroxaban Derivatives Towards UDP-Glucuronosyltransferase (UGT) Isoforms.

Rivaroxaban is an oral direct factor Xa (FXa) inhibitor clinically used to prevent and treat thromboembolic disorders. Drug-drug interaction (DDI) exist for rivaroxaban and the inhibitors of CYP3A4/5. This study aims to investigate the inhibition of rivaroxaban and its derivatives with a chiral center towards UDP-glucuronosyltransferases (UGTs). Chemical synthesis was performed to obtain rivaroxaban derivatives with different chiral centers. UGTs supersomes-catalyzed 4-methylumbelliferone (4-MU) glucuronidation was employed to evaluate the inhibition potential towards various UGT isoforms. A significant influence of rivaroxaban derivatives towards UGT1A3 was observed. Chiral centers produce different effects towards the effect of four pairs of rivaroxaban derivatives towards UGT1A3 activity, with stronger inhibition potential of S1 than R1, but stronger inhibition capability of R2, R3, R4 than S2, S3, and S4. Competitive inhibition of R3 and R4 towards UGT1A3 was demonstrated by Dixon and Lineweaver-Burk plots. In conclusion, the significant influence of rivaroxaban derivatives towards UGT1A3's activity was demonstrated in the present study. The chirality centers highly affected the inhibition behavior of rivaroxaban derivatives towards UGT1A3.

Whole Lung Lavage Treatment of Chinese Patients with Autoimmune Pulmonary Alveolar Proteinosis: A Retrospective Long-term Follow-up Study.

BACKGROUND: Pulmonary alveolar proteinosis (PAP) is a rare lung disease, the most common type of which is autoimmune PAP. The gold standard therapy for PAP is whole lung lavage (WLL). Few studies have reported the optimal technique with which to evaluate the response to WLL. In this study, we aimed to identify parameters with which to assess the need for repeat WLL during a long-term 8-year follow-up. METHODS: We conducted a retrospective analysis of 120 patients with autoimmune PAP with 80 of whom underwent WLL. Physiologic, serologic, and radiologic features of the patients were analyzed during an 8-year follow-up after the first WLL treatment. RESULTS: Of the 40 patients without any intervention, 39 patients either achieved remission or remained stable and only one died of pulmonary infection. Of the 56 patients who underwent WLL for 1 time, 55 remained free from a second WLL and 1 patient died of cancer. Twenty-four required additional treatments after their first WLL. The baseline PaO 2 (P = 0.000), PA-aO 2 (P = 0.000), shunt fraction rate (P = 0.001), percent of predicted normal diffusing capacity of the lung for carbon monoxide (DLCO%Pred) (P = 0.016), 6-min walk test (P = 0.013), carcinoembryonic antigen (CEA) (P = 0.007), and neuron-specific enolase (NSE) (P = 0.003) showed significant differences among the three groups. The need for a second WLL was significantly associated with PaO 2 (P = 0.000), CEA (P = 0.050) , the 6-minute walk test (P = 0.026), and DLCO%Pred (P = 0.041). The DLCO%Pred on admission with a cut-off value of 42.1% (P = 0.001) may help to distinguish whether patients with PAP require a second WLL. CONCLUSIONS: WLL is the optimal treatment method for PAP and provides remarkable improvements for affected patients. The DLCO%Pred on admission with a cut-off value of 42.1% may distinguish whether patients with PAP require a second WLL.