No Interference of H9 Extract on Trastuzumab Pharmacokinetics in Their Combinations.

Trastuzumab is used to treat breast cancer patients overexpressing human epidermal growth factor receptor 2, but resistance and toxicity limit its uses, leading to attention to trastuzumab combinations. Recently, the synergistic effect of trastuzumab and H9 extract (H9) combination against breast cancer has been reported. Because drug exposure determines its efficacy and toxicity, the question of whether H9 changes trastuzumab exposure in the body has been raised. Therefore, this study aimed to characterize trastuzumab pharmacokinetics and elucidate the effect of H9 on trastuzumab pharmacokinetics at a combination dose that shows synergism in mice. As a result, trastuzumab showed linear pharmacokinetics after its intravenous administration from 1 to 10 mg/kg. In the combination of trastuzumab and H9, single and 2-week treatments of oral H9 (500 mg/kg) did not influence trastuzumab pharmacokinetics. In the multiple-combination treatments of trastuzumab and H9 showing their synergistic effect (3 weeks of trastuzumab with 2 weeks of H9), the pharmacokinetic profile of trastuzumab was comparable to that of 3 weeks of trastuzumab alone. In tissue distribution, the tissue to plasma ratios of trastuzumab below 1.0 indicated its limited distributions within the tissues, and these patterns were unaffected by H9. These results suggest that the systemic and local exposures of trastuzumab are unchanged by single and multiple-combination treatments of H9.

Evaluation of Pharmacokinetic Feasibility of Febuxostat/L-pyroglutamic Acid Cocrystals in Rats and Mice.

Febuxostat (FBX), a selective xanthine oxidase inhibitor, belongs to BCS class II, showing low solubility and high permeability with a moderate F value (<49%). Recently, FBX/L-pyroglutamic acid cocrystal (FBX-PG) was developed with an improving 4-fold increase of FBX solubility. Nevertheless, the in vivo pharmacokinetic properties of FBX-PG have not been evaluated yet. Therefore, the pharmacokinetic feasibility of FBX in FBX- and FBX-PG-treated rats and mice was compared in this study. The results showed that the bioavailability (F) values of FBX were 210% and 159% in FBX-PG-treated rats and mice, respectively. The 2.10-fold greater total area under the plasma concentration-time curve from time zero to infinity (AUC0-inf) of FBX was due to the increased absorption [i.e., 2.60-fold higher the first peak plasma concentration (Cmax,1) at 15 min] and entero-hepatic circulation of FBX [i.e., 1.68-fold higher the second peak plasma concentration (Cmax,2) at 600 min] in FBX-PG-treated rats compared to the FBX-treated rats. The 1.59-fold greater AUC0-inf of FBX was due to a 1.65-fold higher Cmax,1 at 5 min, and a 1.15-fold higher Cmax,2 at 720 min of FBX in FBX-PG-treated mice compared to those in FBX-treated mice. FBX was highly distributed in the liver, stomach, small intestine, and lungs in both groups of mice, and the FBX distributions to the liver and lungs were increased in FBX-PG-treated mice compared to FBX-treated mice. The results suggest the FBX-PG has a suitable pharmacokinetic profile of FBX for improving its oral F value.

Pharmacokinetic Feasibility of Stability-Enhanced Solid-State (SESS) Tenofovir Disoproxil Free Base Crystal.

Tenofovir (TEV) is a nucleotide reverse transcriptase inhibitor used against human immunodeficiency virus (HIV) reverse transcriptase. To improve the poor bioavailability of TEV, TEV disoproxil (TD), an ester prodrug of TEV, was developed, and TD fumarate (TDF; Viread®) has been marketed due to the hydrolysis of TD in moisture. Recently, a stability-enhanced solid-state TD free base crystal (SESS-TD crystal) was developed with improved solubility (192% of TEV) under gastrointestinal pH condition and stability under accelerated conditions (40 °C, RH 75%) for 30 days. However, its pharmacokinetic property has not been evaluated yet. Therefore, this study aimed to evaluate the pharmacokinetic feasibility of SESS-TD crystal and to determine whether the pharmacokinetic profile of TEV remained unchanged when administering SESS-TD crystal stored for 12 months. In our results, the F and systemic exposure (i.e., AUC and Cmax) of TEV in the SESS-TD crystal and TDF groups were increased compared to those in the TEV group. The pharmacokinetic profiles of TEV between the SESS-TD and TDF groups were comparable. Moreover, the pharmacokinetic profiles of TEV remained unchanged even after the administration of the SESS-TD crystal and TDF stored for 12 months. Based on the improved F after the SESS-TD crystal administration and the stable condition of the SESS-TD crystal after 12 months, SESS-TD crystal may have enough pharmacokinetic feasibility to replace TDF.

Change of metformin concentrations in the liver as a pharmacological target site of metformin after long-term combined treatment with ginseng berry extract.

Metformin as an oral glucose-lowering drug is used to treat type 2 diabetic mellitus. Considering the relatively high incidence of cardiovascular complications and other metabolic diseases in diabetic mellitus patients, a combination of metformin plus herbal supplements is a preferrable way to improve the therapeutic outcomes of metformin. Ginseng berry, the fruit of Panax ginseng Meyer, has investigated as a candidate in metformin combination mainly due to its anti-hyperglycemic, anti-hyperlipidemic, anti-obesity, anti-hepatic steatosis and anti-inflammatory effects. Moreover, the pharmacokinetic interaction of metformin via OCTs and MATEs leads to changes in the efficacy and/or toxicity of metformin. Thus, we assessed how ginseng berry extract (GB) affects metformin pharmacokinetics in mice, specially focusing on the effect of the treatment period (i.e., 1-day and 28-day) of GB on metformin pharmacokinetics. In 1-day and 28-day co-treatment of metformin and GB, GB did not affect renal excretion as a main elimination route of metformin and GB therefore did not change the systemic exposure of metformin. Interestingly, 28-day co-treatment of GB increased metformin concentration in the livers (i.e., 37.3, 59.3% and 60.9% increases versus 1-day metformin, 1-day metformin plus GB and 28-day metformin groups, respectively). This was probably due to the increased metformin uptake via OCT1 and decreased metformin biliary excretion via MATE1 in the livers. These results suggest that co-treatment of GB for 28 days (i.e., long-term combined treatment of GB) enhanced metformin concentration in the liver as a pharmacological target tissue of metformin. However, GB showed a negligible impact on the systemic exposure of metformin in relation to its toxicity (i.e., renal and plasma concentrations of metformin).

Quantum Artificial Neural Network Approach to Derive a Highly Predictive 3D-QSAR Model for Blood-Brain Barrier Passage.

A successful passage of the blood-brain barrier (BBB) is an essential prerequisite for the drug molecules designed to act on the central nervous system. The logarithm of blood-brain partitioning (LogBB) has served as an effective index of molecular BBB permeability. Using the three-dimensional (3D) distribution of the molecular electrostatic potential (ESP) as the numerical descriptor, a quantitative structure-activity relationship (QSAR) model termed AlphaQ was derived to predict the molecular LogBB values. To obtain the optimal atomic coordinates of the molecules under investigation, the pairwise 3D structural alignments were conducted in such a way to maximize the quantum mechanical cross correlation between the template and a target molecule. This alignment method has the advantage over the conventional atom-by-atom matching protocol in that the structurally diverse molecules can be analyzed as rigorously as the chemical derivatives with the same scaffold. The inaccuracy problem in the 3D structural alignment was alleviated in a large part by categorizing the molecules into the eight subsets according to the molecular weight. By applying the artificial neural network algorithm to associate the fully quantum mechanical ESP descriptors with the extensive experimental LogBB data, a highly predictive 3D-QSAR model was derived for each molecular subset with a squared correlation coefficient larger than 0.8. Due to the simplicity in model building and the high predictability, AlphaQ is anticipated to serve as an effective computational screening tool for molecular BBB permeability.

Pharmacokinetic Properties of Moracin C in Mice.

Moracin C from Morus alba fruits, also known as the mulberry, has been proven to exhibit inhibitory activities against lipoxygenase enzymes, TNF-α and interleukin-1ß secretion, and proprotein convertase subtilisin/kexin type 9 expression. Despite the various pharmacological activities of moracin C, its pharmacokinetic characteristics have yet to be reported. Here, the pharmacokinetic parameters and tissue distribution of moracin C have been investigated in mice, and the plasma concentration of moracin C with multiple dosage regimens was simulated via pharmacokinetic modeling. Our results showed that moracin C was rapidly and well absorbed in the intestinal tract, and was highly distributed in the gastrointestinal tract, liver, kidneys, and lungs. Moracin C was distributed in the ileum, cecum, colon, and liver at a relatively high concentration compared with its plasma concentration. It was extensively metabolized in the liver and intestine, and its glucuronidated metabolites were proposed. In addition, the simulated plasma concentrations of moracin C upon multiple treatments (i.e., every 12 and 24 h) were suggested. We suggest that the pharmacokinetic characteristics of moracin C would be helpful to select a disease model for in vivo evaluation. The simulated moracin C concentrations under various dosage regimens also provide helpful knowledge to support its pharmacological effect.

Effect of treatment period with LC478, a disubstituted adamantayl derivative, on P-glycoprotein inhibition: its application to increase docetaxel absorption in rats.

1. Treatment periods of P-glycoprotein (P-gp) inhibitors have revealed different efficacies. We have previously reported dose-dependent inhibition of P-gp in single-treatment with LC478. However, whether repeated treatment with LC478 can inhibit P-gp even at its ineffective single-treatment dose remains unknown. 2. Therefore, the purpose of this study was to assess the effect of repeated treatment (i.e., 7-day treatment) with LC478 on P-gp known to affect docetaxel bioavailability in rats. Effects of LC478 on P-gp mediated efflux and expression in MDCK-MDR1 cells, P-gp ATPase activity, and binding site with P-gp were evaluated.3. The 7-day treatment with LC478 increased docetaxel absorption via intestinal P-gp inhibition in rats. Intestinal concentrations of LC478 were 8.31-10.3 µM in rats after 7-day treatment of LC478. These concentrations were close to 10 µM that reduced P-gp mediated docetaxel efflux and P-gp expression in MDCK-MDR1 cells. Considering that intestinal LC478 concentrations after 1-day treatment were 2.68-4.19 µM, higher LC478 concentrations after 7-day treatment might have driven P-gp inhibition and increased docetaxel absorption. LC478 might competitively inhibit P-gp considering its stimulated ATPase activity and its binding site with nucleotide binding domain of P-gp. 4. Therefore, repeated treatment with LC478 can determine its feasibility for P-gp inhibition and changing docetaxel bioavailability.

Lonicera japonica extract increases metformin distribution in the liver without change of systemic exposed metformin in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Flower and flower bud of Lonicera japonica, Lonicerae Flos, have been popularly used as medicinal plant for the treatment of clearing heat and thirst, thereby improving diabetic or diabetic associated symptoms (thirst and poor eyesight). AIM OF THE STUDY: Organic cation transporters (OCTs) and multi-drug and toxin extrusion proteins (MATEs) are known to play important roles in metformin transport in the liver and kidneys. Thus, there might be interactions between Lonicerae Flos and metformin via OCTs and MATEs. Also treatment period has been issued in transporter-mediated drug interactions. The objective of this study was to determine the effect of Lonicerae Flos ethanol extract (LJ) on metformin pharmacokinetics and its glucose lowering activity in different treatment periods. MATERIALS AND METHODS: Effect of LJ on metformin uptake was evaluated in vitro HEK-293 cells expressing human OCTs or MATEs. Treatment period-dependent impact of LJ on systemic exposure and hepatic distribution of metformin as well as its glucose tolerance activity were assessed in in vivo rats. RESULTS: LJ substantially inhibited MATE1-mediated metformin uptake in vitro. In evaluating treatment period effects of LJ and metformin, 1-, 7-, and 28-day co-treatments of LJ with metformin did not change systemic exposure of metformin compared to those in metformin alone. Whereas, 28-day co-treatment of LJ with metformin increased metformin concentration in liver as a pharmacological target site of metformin. It could be due to the reduced MATE1-mediated metformin efflux from hepatocytes to bile by MATE1 inhibition in liver. Glucose tolerance activity was also enhanced by 28-day co-treatment of LJ and metformin compared to metformin alone. CONCLUSIONS: In 28-day co-treatment of LJ and metformin, LJ increased metformin concentration in liver and improved glucose tolerance activity without systemic exposure change of metformin, suggesting the importance to consider treatment period effect and both systemic exposure and tissue distribution in drug interactions.

Gα12 ablation exacerbates liver steatosis and obesity by suppressing USP22/SIRT1-regulated mitochondrial respiration.

Nonalcoholic fatty liver disease (NAFLD) arises from mitochondrial dysfunction under sustained imbalance between energy intake and expenditure, but the underlying mechanisms controlling mitochondrial respiration have not been entirely understood. Heterotrimeric G proteins converge with activated GPCRs to modulate cell-signaling pathways to maintain metabolic homeostasis. Here, we investigated the regulatory role of G protein α12 (Gα12) on hepatic lipid metabolism and whole-body energy expenditure in mice. Fasting increased Gα12 levels in mouse liver. Gα12 ablation markedly augmented fasting-induced hepatic fat accumulation. cDNA microarray analysis from Gna12-KO liver revealed that the Gα12-signaling pathway regulated sirtuin 1 (SIRT1) and PPARα, which are responsible for mitochondrial respiration. Defective induction of SIRT1 upon fasting was observed in the liver of Gna12-KO mice, which was reversed by lentivirus-mediated Gα12 overexpression in hepatocytes. Mechanistically, Gα12 stabilized SIRT1 protein through transcriptional induction of ubiquitin-specific peptidase 22 (USP22) via HIF-1α increase. Gα12 levels were markedly diminished in liver biopsies from NAFLD patients. Consistently, Gna12-KO mice fed a high-fat diet displayed greater susceptibility to diet-induced liver steatosis and obesity due to decrease in energy expenditure. Our results demonstrate that Gα12 regulates SIRT1-dependent mitochondrial respiration through HIF-1α-dependent USP22 induction, identifying Gα12 as an upstream molecule that contributes to the regulation of mitochondrial energy expenditure.

Sauchinone controls hepatic cholesterol homeostasis by the negative regulation of PCSK9 transcriptional network.

Whole-transcriptome analysis and western blotting of sauchinone-treated HepG2 cells demonstrated that sauchinone regulated genes relevant to cholesterol metabolism and synthesis. In particular, it was found that the expression of proprotein convertase subtilisin/kexin type 9 (PCSK9) was downregulated, and the expression of low density lipoprotein receptor (LDLR) was upregulated in sauchinone-treated HepG2 cells. Consequently, LDL-cholesterol (LDL-C) uptake was increased. As a transcriptional regulator of PCSK9 expression, sterol regulatory elements binding protein-2 (SREBP-2) was proposed by transcriptome analysis and western blotting. Oral administration of sauchinone increased hepatic LDLR through PCSK9 inhibition in obese mice and showed the reduced serum LDL-C levels and downstream targets of SREBP-2. Thus, it is evident that sauchinone reduces hepatic steatosis by downregulating the expression of hepatic PCSK9 via SREBP-2.

Houttuynia cordata extract increased systemic exposure and liver concentrations of metformin through OCTs and MATEs in rats.

The synergistic activity of Houttuynia cordata ethanol extract (HCT) and metformin combination in diabetic rats has been previously reported, but the fundamental causes remain unsolved. Organic cation transporters (OCTs) and multidrug and toxin extrusion proteins (MATEs) transport metformin to the liver and kidneys. Therefore, pharmacological activity and systemic exposure of metformin in HCT-metformin combination were determined from pharmacokinetic change and glucose-lowering activity using in vitro HEK-293 cells expressing human OCTs or human MATEs and in vivo rats. HCT inhibited human OCT2 and human MATE1-mediated metformin transports in vitro. In in vivo rats, treatment with HCT and metformin for 28 days in rats (28MH rats) reduced the rat Oct2-mediated renal excretion of metformin and thereby the increased systemic exposure of metformin compared with only metformin-treated rats for 28 days (28M rats). In 28MH rats, rat Oct1-mediated metformin uptake into the liver was enhanced, leading to an improved glucose-lowering effect without hypoglycaemia compared with 28M rats. There was no impairment of renal function in HCT and metformin treatments. These results suggest that HCT-metformin combination therapy is applicable in terms of efficacy and safety.

Inhibitory Effect of Sauchinone on UDP-Glucuronosyltransferase (UGT) 2B7 Activity.

Herb-drug interaction (HDI) limits clinical application of herbs and drugs, and inhibition of herbs towards uridine diphosphate (UDP)-glucuronosyltransferases (UGTs) has gained attention as one of the important reasons to cause HDIs. Sauchinone, an active lignan isolated from aerial parts of Saururus chinensis (Saururacease), possesses anti-oxidant, anti-inflammatory, and anti-viral activities. In pharmacokinetics of sauchinone, sauchinone is highly distributed to the liver, forming extensive metabolites of sauchinone via UGTs in the liver. Thus, we investigated whether sauchinone inhibited UGTs to explore potential of sauchinone-drug interactions. In human liver microsomes (HLMs), sauchinone inhibited activities of UGT1A1, 1A3, 1A6, and 2B7 with IC50 values of 8.83, 43.9, 0.758, and 0.279 µM, respectively. Sauchinone also noncompetitively inhibited UGT1A6 and 2B7 with Ki values of 1.08 and 0.524 µM, respectively. In in vivo interaction study using mice, sauchinone inhibited UGT2B7-mediated zidovudine metabolism, resulting in increased systemic exposure of zidovudine when sauchinone and zidovudine were co-administered together. Our results indicated that there is potential HDI between sauchinone and drugs undergoing UGT2B7-mediated metabolism, possibly contributing to the safe use of sauchinone and drug combinations.

Mangosteen Extract Prevents Dextran Sulfate Sodium-Induced Colitis in Mice by Suppressing NF-κB Activation and Inflammation.

In this study, the anti-inflammatory effects of mangosteen extract (MGE) on dextran sulfate sodium (DSS)-induced colitis in mice and nuclear factor (NF)-κB pathway modulation were investigated. Acute colitis was induced by administering 3% DSS in drinking water for 7 days, and three groups of Institute of Cancer Research mice were treated with 30 and 120 mg/kg MGE or 5-aminosalicylic acid for 7 days; an additional two groups of mice served as healthy and disease controls. The results indicated that MGE significantly prevented weight loss, reduced disease activity index scores, and preserved colon length compared with the findings in the untreated colitis group. MGE downregulated the NF-κB pathway by inhibiting the phosphorylation of IκB and IKK in a dose-dependent manner. These findings suggest that MGE alleviates ulcerative colitis by modulating the NF-κB pathway.

α-Mangostin ameliorates dextran sulfate sodium-induced colitis through inhibition of NF-κB and MAPK pathways.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) of the colon as a target site. Previous reports regarding the efficacy of α-mangostin (αMG) to inhibit nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) as well as relatively high distribution to the colon suggested the therapeutic potential of this compound in UC model. In dextran sodium sulfate (DSS)-induced colitis mice (DSS mice), the disease activity index scores involving diarrhea, bloody stool, body weight reduction, and myeloperoxidase (MPO) activities of the esophagus and colon increased with the reduced colon length. Also histologic disturbances and changes of NF-κB and MAPK pathways including phosphorylation of IκB kinase, ERK1/2, SAPK/JNK and p38 were observed in the colon of the DSS mice. However, all of these impaired conditions in the DSS mice were restored by αMG treatment, and the intestinal metabolism of αMG decreased, increasing its distribution to the colons in the DSS mice compared with the control mice. All of these results suggest that high distribution of αMG in the colon might attenuate DSS-induced colitis by inhibiting NF-κB and MAPK pathways in the colon.

Multidrug and toxin extrusion protein 1-mediated interaction of metformin and Scutellariae radix in rats.

1. The metformin and Scutellariae radix extract (SB) combination has been previously reported to enhance anti-diabetic activity. Considering that organic cation transporters (OCTs) and multi-drug and toxin extrusion proteins (MATEs) in the liver and kidney are determinant factors on hepatic distribution and renal clearance of metformin, the effects of SB on OCT or MATE-mediated systemic exposure of metformin as well as on glucose tolerance and hypoglycemia were examined. 2. Although SB inhibited metformin uptake through human transporters OCT1 and MATE1 in vitro, the systemic exposures of metformin in vivo rats were not altered after metformin treatment with and without SB due to unchanged renal excretion of metformin. 3. However, 28-day metformin treatment with SB decreased the mRNA level of hepatic MATE1 in rats, resulting in reduced biliary excretion of metformin and thereby higher concentration of metformin in the liver. In addition, in rats with 28-day metformin treatment with SB, glucose tolerance and plasma lactate level were enhanced, while hypoglycemia was not detected. 4. Thus in rats, intervention of SB on transporter-mediated metformin transportation partially improves glucose tolerance without hypoglycemia and increases hepatic distribution of metformin. Also the further investigations in humans are required to clarify the relevance of these findings to the clinical significance.

Dose-Independent ADME Properties and Tentative Identification of Metabolites of α-Mangostin from Garcinia mangostana in Mice by Automated Microsampling and UPLC-MS/MS Methods.

The information about a marker compound's pharmacokinetics in herbal products including the characteristics of absorption, distribution, metabolism, excretion (ADME) is closely related to the efficacy/toxicity. Also dose range and administration route are critical factors to determine the ADME profiles. Since the supply of a sufficient amount of a marker compound in in vivo study is still difficult, pharmacokinetic investigations which overcome the limit of blood collection in mice are desirable. Thus, we have attempted to investigate concurrently the ADME and proposed metabolite identification of α-mangostin, a major constituent of mangosteen, Garcinia mangostana L, in mice with a wide dose range using an in vitro as well as in vivo automated micro-sampling system together. α-mangostin showed dose-proportional pharmacokinetics at intravenous doses of 5-20 mg/kg and oral doses of 10-100 mg/kg. The gastrointestinal absorption of α-mangostin was poor and the distribution of α-mangostin was relatively high in the liver, intestine, kidney, fat, and lung. α-mangostin was extensively metabolized in the liver and intestine. With regards to the formation of metabolites, the glucuronidated, bis-glucuronidated, dehydrogenated, hydrogenated, oxidized, and methylated α-mangostins were tentatively identified. We suggest that these dose-independent pharmacokinetic characteristics of α-mangostin in mice provide an important basis for preclinical applications of α-mangostin as well as mangosteen. In addition, these experimental methods can be applied to evaluate the pharmacokinetics of natural products in mice.