Plasma Of Wistar Rats Research Articles

Orally administered artesunate modulates activity of cell body defense in plasma and brain of female wistar rats

Orally administered artesunate modulates activity of cell body defense in plasma and brain of female wistar rats

Preclinical pharmacokinetics of M10 after intragastrical administration of M10-H and M10-Na in Wistar rats

As a myricetin derivative, M10 is a potent agent of anti-chronic colonic inflammation. It has better activity than myricetin in preventing azoxymethane/dextran sulfate sodium - induced ulcerative colitis. Here, we introduce a sensitive quantification method based on ultra performance liquid chromatography-tandem mass spectrometry for the determination of M10-H and M10-Na in Wistar rat plasma. Samples were treated with L - ascorbic acid and phosphate buffer solution to maintain stability and with acetonitrile to remove the proteins in the plasma. The supernatant was separated with BEH C18 column and eluted with ultrapure water and acetonitrile both containing 0.1% formic acid. The detection was performed by a triple quadrupole mass spectrometer with positive electrospray ionization mode in multiple reactive monitoring. This method was validated for the carryover effect, selectivity, accuracy, precision, matrix effect, stability, and recovery. A linear correlation was established between concentration and response by the calibration curves over 10–2000 ng·mL−1 (r > 0.99). This method was applied to a pharmacokinetic study of intragastrical administration of M10-H and M10-Na in Wistar rats. In addition, the relative bioavailability of M10-H to M10-Na in Wistar rats was 60 ± 19%, calculated by the ratio of area under concentration (AUC) of M10-H to M10-Na after intragastrical administration of a single dose (100 mg·kg−1 for M10-H and M10-Na, respectively) in Wistar rats.

Understanding the Influence of a Bifunctional Polyethylene Glycol Derivative in Protein Corona Formation around Iron Oxide Nanoparticles

Superparamagnetic iron oxide nanoparticles are one of the most prominent agents used in theranostic applications, with MRI imaging the main application assessed. The biomolecular interface formed on the surface of a nanoparticle in a biological medium determines its behaviour in vitro and in vivo. In this study, we have compared the formation of the protein corona on highly monodisperse iron oxide nanoparticles with two different coatings, dimercaptosuccinic acid (DMSA), and after conjugation, with a bifunctional polyethylene glycol (PEG)-derived molecule (2000 Da) in the presence of Wistar rat plasma. The protein fingerprints around the nanoparticles were analysed in an extensive proteomic study. The results presented in this work indicate that the composition of the protein corona is very difficult to predict. Proteins from different functional categories—cell components, lipoproteins, complement, coagulation, immunoglobulins, enzymes and transport proteins—were identified in all samples with very small variability. Although both types of nanoparticles have similar amounts of bonded proteins, very slight differences in the composition of the corona might explain the variation observed in the uptake and biotransformation of these nanoparticles in Caco-2 and RAW 264.7 cells. Cytotoxicity was also studied using a standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Controlling nanoparticles’ reactivity to the biological environment by deciding on its surface functionalization may suggest new routes in the control of the biodistribution, biodegradation and clearance of multifunctional nanomedicines.

Changes in the Activity of Glutathione Peroxidase in the Blood Plasma and Serum of Rats during Postnatal Development and Aging

The activity of glutathione peroxidase (GPx) in plasma and serum of Wistar rats during postnatal ontogeny and aging is studied. A combination of various substrates is used for assessment of the enzymatic activity. During the period of milk nutrition, since the beginning of the consumption of solid food, GPx activity is rapidly increasing and almost reaches the adult level by 1.5 months. Enzyme activity remains stable in adulthood and has long been high in aging rats. A decrease in GPx activity around 23–26 months of age is revealed, with reduced homocysteine (but not with reduced glutathione) as a GPx substrate. The dramatic increase of GPx activity in plasma from 0.5 to 1–1.5 months of age may be an adaptation to consumption of solid food that may contain substances inducing oxidative stress. Probably, with sufficient selenium consumption, a decrease in GPx activity in rat plasma occurs only in extreme old age and can be considered as an indicator of physiological aging.

Development of M10, myricetin-3-O-β-d-lactose sodium salt, a derivative of myricetin as a potent agent of anti-chronic colonic inflammation

Myricetin is a natural dietary flavonoid compound with multiple activities, such as anti-oxidant, anti-inflammatory, anti-carcinogenic and anti-proliferative effects. However, myricetin exhibited substantial limitations, such as poor water-solubility, and low stability in body when it was administrated by oral. To solve these problems, we designed and synthesized a series of derivatives based on the structure of myricetin. M10 was produced by adding a hydrophilic glycosylation group and then forming a sodium salt derivative, which exhibited excellent water-solubility (>100 mg/mL), and better stability in Wistar rat plasma and liver microsomes. In vivo study, M10 exhibited higher efficacy than myricetin and mesalazine in a dextran sulfate sodium (DSS) induced mice model with ulcerative colitis. In addition, M10 also exhibited high safety (LD50 > 5 g/kg) in mice. Based on these results, M10 could be developed as a potential therapeutic agent for treatment of ulcerative colitis.

Tadalafil nanocomposites as a dry powder formulation for inhalation, a new strategy for pulmonary arterial hypertension treatment

Tadalafil (a phosphodiesterase-5 inhibitor) is a choice for treatment of pulmonary arterial hypertension (PAH) that is known as an increase in mean pulmonary arterial pressure ≥25 mmHg at rest and ≥30 mmHg during exercise with reduced cardiac output. The aim of this study was to prepare inhalable tadalafil nanocomposites as a dry powder formulation by spray drying technique for increasing bioavailability and treatment efficacy, as well as decreasing systemic side effects.The D-optimal design was used for optimization of formulation parameters. Microparticle size, morphology, crystallinity, density, solubility, redispersion (%), and in-vitro inhalation performance of tadalafil nanocomposites were investigated as physicochemical characteristics. Pharmacokinetic parameters were also evaluated in plasma and lung tissue of Wistar rats after intratracheal insufflation and compared with a control group receiving an oral tadalafil marketed product (dose = 10 mg/kg).The suggested optimum formulation contained stable amorphous particles with almost rounded shape and corrugated surface that were completely redispersed in the lung simulated medium with the mass median geometric diameter of 3.2 μm, density of 1.4 g/cm3, fine particle fraction based on emitted dose (%) of 57.2 ± 6.5%, and 13.7-fold enhancement in dissolution rate. In-vivo studies showed that the ratio of AUC0–24h lung/AUC0–24h plasma, achieved in the treated group after intratracheal insufflation, was significantly higher than the control group that means high local drug concentration and more efficacy. Besides, plasma data analysis indicated high value of MRT (2.3-fold) and tmax (3.7-fold) after intratracheal insufflation of tadalafil nanocomposites in comparison with the conventional oral route, indicating longer retention of tadalafil molecules in the lungs and their slower entry to the systemic blood circulation. In conclusion, it seems that inhalable tadalafil nanocomposites can be introduced as an alternative to oral tadalafil in the treatment of PAH.

Protective Roles of Kolaviron Extract from Garcinia kola Seeds against Isoniazid-induced Kidney Damage in Wistar Rats

Background: Garcinia kola seeds have been observed to be medically important and kolaviron, a bioflavonoid obtained from the seeds was studied for its biological activities. The study investigated the protective effect of kolaviron extract obtained from the seed of Garcinia kola against isoniazid-induced kidney damage.
 Methodology: Kolaviron was extracted from fresh seeds of Garcinia kola (2 kg) using soxhlet extractor and partitioned with chloroform. Nephrotoxicity was induced in wistar rats by oral administration of isoniazid (20 mg/kg bwt) while kolaviron was administered on wistar rats an hour before isoniazid administration and lasted for 30 days. Protective effect of kolaviron was measured in the plasma of wistar rats by estimating the levels of key metabolites used as kidney biomarkers which are total protein, creatinine, urea and uric acid concentration.
 Results: The isoniazid-treated group showed a significant (p < 0.05) decrease in total protein concentration of 3.57 ± 0.12 (mg/dl) while there was a significant (p < 0.05) increase in urea, uric acid and creatinine concentrations with values of 70.30 ± 4.77, 55.71 ± 11.15 and 18.04 ± 5.33 (mg/dl) respectively. However, kolaviron-treated group showed a remarkable increase (6.15 ± 0.96) in total protein concentration while urea, uric acid and creatinine concentrations significantly decreased to 45.25 ± 2.29, 35.60 ± 11.01 and 13.28 ± 4.41 (mg/dl) respectively.
 Conclusion: Kolaviron extract obtained from Garcinia kola seeds exhibited a remarkable protective effect against kidney damage caused by isoniazid by regulating renal biomarkers and preventing toxic affront of isoniazid. Thus, it may be relatively safe when used therapeutically at this dose in the treatment and management of diseases associated with kidney damage.

Disulfiram partially improves oxidative but not androgen status in rats exposed to cadmium

We investigated the effect of disulfiram (DSF) on reproductive toxicity induced by subchronic exposure to cadmium (Cd). We examined the redox status and systemic testosterone changes in the testes and plasma of Cd-treated male Wistar rats. Rats were treated with 1 mg CdCl2/kg body weight (bw)/day (intraperitoneal administration) for 42 days; in the second experimental group, rats were given 178.5 mg DSF/kg bw/day by oral gavage for 21 days; in the third group, after administration of Cd for 21 days, DSF treatment was introduced on day 22 and lasted until day 42, with continuous Cd intake. Each experimental group had a matching control: untreated rats, rats that received for 21 days olive oil, the solvent for DSF; rats that started with olive oil intake from days 22-42. Exposure of rats to DSF modulated the oxidative status in the testes; thus, coexposure increased the Cd-induced reduction in total superoxide dismutase (tSOD), catalase (CAT), glutathione reductase (GR) and total glutathione-S-transferase (tGST) activities, and lowered the Cd-increased superoxide anion radical (O2 ??) and malondialdehyde (MDA) concentrations. DSF did not affect testosterone production diminished by Cd, as Leydig cells, once impaired by Cd, could not be reactivated by DSF. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III41018] <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/ABS200226010E">10.2298/ABS200226010E</a><u></b></font>

Pharmacokinetics and tissue distribution of monotropein and deacetyl asperulosidic acid after oral administration of extracts from Morinda officinalis root in rats

BackgroundIridoid glycosides (IGs), including monotropein (MON) and deacetyl asperulosidic acid (DA) as the main ingredients, are the major chemical components in Morinda officinalis How. (MO) root, possessing various pharmacological properties including anti-osteoporosis, anti-inflammation and anti-rheumatism activities.The aim of the present study was to further elucidate the pharmacological actions of MO by investigating the pharmacokinetics and tissue distribution of IGs in MO.MethodsAn ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS) method was developed and validated for simultaneous determination of MON and DA levels in plasma and various tissues of Wistar rats. MON, DA and acetaminophen (ACE) as the internal standard (IS) were extracted from rat plasma and tissue samples by direct deproteinization with methanol. The rats were administered orally at 1650 mg/kg MO and 25, 50 and 100 mg/kg MO iridoid glycosides (MOIGs) or intravenously at MOIG 25 mg/kg for pharmacokinetic study of MON and DA. In addition, 100 mg/kg MOIG was administered orally for tissue distribution study of MON and DA. Non-compartmental pharmacokinetic profiles were constructed. Tissue distributions were calculated according to the validated methods.ResultsSignificant differences in the pharmacokinetic parameters were observed in male and female rats. The AUC0-t, Cmax and bioavailability of MON and DA in female rats were higher than those in male rats. MON and DA mainly distributed in the intestine and stomach after oral administration, and noteworthily high concentrations of MON and DA were detected in the rat hypothalamus.ConclusionThe results of the present study may shed new lights on the biological behavior of MOIGs in vivo, help explain their pharmacological actions, and provide experimental clues for rational clinical use of these IGs extracted from the MO root.

Oxidative stress, cholinesterase activity, and DNA damage in the liver, whole blood, and plasma of Wistar rats following a 28-day exposure to glyphosate.

In this 28 day-study, we evaluated the effects of herbicide glyphosate administered by gavage to Wistar rats at daily doses equivalent to 0.1 of the acceptable operator exposure level (AOEL), 0.5 of the consumer acceptable daily intake (ADI), 1.75 (corresponding to the chronic population-adjusted dose, cPAD), and 10 mg kg-1 body weight (bw) (corresponding to 100 times the AOEL). At the end of each treatment, the body and liver weights were measured and compared with their baseline values. DNA damage in leukocytes and liver tissue was estimated with the alkaline comet assay. Oxidative stress was evaluated using a battery of endpoints to establish lipid peroxidation via thiobarbituric reactive substances (TBARS) level, level of reactive oxygen species (ROS), glutathione (GSH) level, and the activity of glutathione peroxidase (GSH-Px). Total cholinesterase activity and the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were also measured. The exposed animals gained less weight than control. Treatment resulted in significantly higher primary DNA damage in the liver cells and leukocytes. Glyphosate exposure significantly lowered TBARS in the liver of the AOEL, ADI, and cPAD groups, and in plasma in the AOEL and cPAD group. AChE was inhibited with all treatments, but the AOEL and ADI groups significantly differed from control. Total ChE and plasma/liver ROS/GSH levels did not significantly differ from control, except for the 35 % decrease in ChE in the AOEL and ADI groups and a significant drop in liver GSH in the cPAD and 100xAOEL groups. AOEL and ADI blood GSH-Px activity dropped significantly, but in the liver it significantly increased in the ADI, cPAD, and 100xAOEL groups vs. control. All these findings show that even exposure to low glyphosate levels can have serious adverse effects and points to a need to change the approach to risk assessment of low-level chronic/sub-chronic glyphosate exposure, where oxidative stress is not necessarily related to the genetic damage and AChE inhibition.

Quantification and Brain Targeting of Eugenol-Loaded Surface Modified Nanoparticles Through Intranasal Route in the Treatment of Cerebral Ischemia.

To enhance brain bioavailability for intranasally administered Eugenol-encapsulated-chitosan-coated-PCL-Nanoparticles (CS-EUG-PCL-NPs). Chitosan-coated-PCL-Nanoparticles (CS-PCL-NPs) were developed through double emulsification-solvent evaporation technique and further characterized for particle size, zeta potential, size distribution, encapsulation efficiency as well as in vitro drug release. UPLC-PDA method was developed to evaluate brain-drug uptake for optimized CS-EUG-PCL-NPs and to determine it's pharmacokinetic in rat's brain as well as plasma. Mean particles size (224.5±5.31), polydispersity index (PDI) i. e. (0.216±0.020) and entrapment efficiency (68.13±5.03) was determined for developed NPs. UPLC-PDA-eλ study showed a significantly high mucoadhesive potential of CS-EUG-PCL-NPs and least for conventional and homogenized nanoformulation; elution time for EUG and internal standard (IS) thymoquinone as 3.50 and 3.61 min were observed respectively. Furthermore, intra and inter-assay (%CV) of 0.25-1.57, %accuracy (97.11-99.00%) as well as a linear dynamic range (100.00 ng/mL-2500.0 ng/mL), was observed. Pharmacokinetic studies in Wistar rat brain and plasma exhibited a high AUC0-24 alongwith an amplified Cmax (p**<0.01) as compared to i. v. treated group. Intranasal administration of developed CS-coated-EUG-loaded-PCL-NPs enhanced the drug bioavailability in rat brain and thus preparation of Eugenol-NPs may help treat cerebral ischemia effectively. The toxicity studies performed at the end revealed safe nature of optimized nanoformulation.

Rasagiline-encapsulated chitosan-coated PLGA nanoparticles targeted to the brain in the treatment of parkinson's disease

ABSTRACTThe aim of this study was to investigate the brain targeting potential of rasagiline-encapsulated chitosan-coated PLGA nanoparticles (RSG-CS-PLGA-NPs) delivered intranasally into the brain. Chitosan-coated PLGA nanoparticles (RSG-CS-PLGA-NPs) were developed through double emulsification-solvent evaporation technique. RSG-CS-PLGA-NPs were characterized for particle size, zeta potential, size distribution, encapsulation efficiency, and in vitro drug release. The mean particle size, polydispersity index, and encapsulation efficiency were found to be 122.38 ± 3.64, 0.212 ± 0.009, and 75.83 ± 3.76, respectively. High-performance liquid chromatography–mass spectroscopy and mass spectroscopy study showed a significantly high mucoadhesive potential of RSG-CS-PLGA-NPs and least for conventional and homogenized nanoformulation. Pharmacokinetic results of RSG-CS-PLGA-NPs in Wistar rat brain and plasma showed a significantly high (**p < 0.005) AUC0-24 and amplified Cmax over intravenous treatment group. Finally, the investigation demonstrated that intranasal delivery of mucoadhesive nanocarrier showed significant enhancement of bioavailability in brain, after administration of the RSG-CS-PLGA-NPs which could be a substantial achievement of direct nose to brain targeting in Parkinson’s disease therapy and related brain disorders.

Bis(4,4'-dimethyl-2,2'-bipyridine)oxidovanadium(IV) Sulfate Dehydrate: Potential Candidate for Controlling Lipid Metabolism?

Vanadium is a trace element mainly connected with regulation of insulin metabolism which is particularly important in diabetes. In recent years, organic complexes of vanadium seem to be more interesting than inorganic salts. Nevertheless, the effect of vanadium on lipid metabolism is still a problematic issue; therefore, the main purpose of this study was to investigate the effect of 3 organic complexes of vanadium such as sodium (2,2′-bipyridine)oxidobisperoxovanadate(V) octahydrate, bis(2,2′-bipyridine)oxidovanadium(IV) sulfate dehydrate, and bis(4,4′-dimethyl-2,2′-bipyridine)oxidovanadium(IV) sulfate dihydrate in conjunction with high-fat as well as control diet in nondiabetes model on the following lipid parameters: total cholesterol, triglycerides, and high density lipoprotein as well as activity of paraoxonase 1. All of these parameters were determined in plasma of Wistar rats. The most significant effect was observed in case of bis(4,4′-dimethyl-2,2′ bipyridine)oxidovanadium(IV) sulfate dehydrate in rats fed with high-fat diet. Based on our research, bis(4,4′-dimethyl-2,2′-bipyridine)oxidovanadium(IV) sulfate dihydrate should be the aim of further research and perhaps it will be an important factor in the regulation of lipid metabolism.

Investigation of mitigating effect of colon-specific prodrugs of boswellic acid on 2,4,6-trinitrobenzene sulfonic acid-induced colitis in Wistar rats: Design, kinetics and biological evaluation.

AIMTo develop a colon-targeting bioreversible delivery system for β-boswellic acid (BBA) and explore utility of its prodrugs in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats.METHODSSynthesis of 4 co-drugs of BBA with essential amino acids was achieved by CDI coupling, followed by their spectral characterization. In vitro kinetics were studied by HPLC in aqueous buffers, homogenates of gastrointestinal tract and fecal matter. In vivo kinetic studies were performed in Wistar rat plasma, urine and feces. The prodrugs were screened in TNBS-induced colitis modeled Wistar rats. Statistical significance was assumed at P < 0.05, P < 0.01, P < 0.001 when compared with disease controls using one-way and two-way ANOVAs.RESULTSProdrugs were stable in 0.05 mol/L HCl buffer (pH 1.2) and stomach homogenates. Negligible hydrolysis was observed in phosphate buffer and intestinal homogenates. Substantial release (55%-72% and 68%-86%) of BBA was achieved in rat fecal matter and homogenates of colon. In vivo studies of BBA with L-tryptophan (BT) authenticated colon-specific release of BBA. But, surprisingly substantial concentration of BBA was seen to reach the systemic circulation due to probable absorption through colonic mucosa. Site-specifically enhanced bioavailability of BBA could be achieved in colon, which resulted in demonstration of significant mitigating effect on TNBS-induced colitis in rats without inducing any adverse effects on stomach, liver and pancreas. Prodrug of BT was found to be 1.7% (P < 0.001) superior than sulfasalazine in reducing the inflammation to colon among all prodrugs tested.CONCLUSIONThe outcome of this study strongly suggests that these prodrugs might have dual applicability to inflammatory bowel disease and chronotherapy of rheumatoid arthritis.

INVESTIGATION OF THE IN VIVO EFFECTS OF NIGERIAN NATURAL BENTONITE CLAY ON PLASMA CALCIUM AND PHOSPHORUS IN WISTAR ALBINO RATS

Bentonite is a widely used clay for so many purposes, especially as a body detoxifier. In this research, the investigation of the effect of bentonite on calcium and phosphorus levels in Wistar rat plasma was examined. A total of 45 female and male adult Wistar albino rats were used. The rats were put into 5 groups of 9 rats each. Group 1, 2, 3 and 4 were given varying concentrations of bentonite (0.02g, 0.04g, 0.05g, 0.07g respectively) while group 5 was kept as control and was fed with basal diet. The experiment lasted for 28 days. The results showed that there was a slight increase in the calcium levels (P≤0.05). In addition, there was also a significant increase (3.60mmol/l) in phosphorus levels observed for 28 days duration of the experiment. This indicates that long-term exposure to increasing concentration of bentonite has a significant effect on the electrolyte levels in rat plasma and by extrapolation, the human body. As a result, care should be taken while ingesting bentonite for other health benefits to avoid hypercalcemia and hyperphosphatemia. It is also recommended that blood test is undertaken at regular intervals for heavy users of the bentonite product.

High-Throughput UPLC-MS Method for the Determination of N-Acetyl-l-Cysteine: Application in Tissue Distribution Study in Wistar Rats.

N-Acetylcysteine (NAC) is the N-acetyl derivative of the amino acid l-cysteine and is extensively used as a medicine to treat a variety of diseases. High-throughput ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) method has been developed for the quantitative assessment of N-acetyl-l-cysteine. The method was further applied to study the distribution of the intraperitoneal injected drug into different tissues and plasma of Wistar rats, including liver, kidney, heart, lungs and spleen. The drug was having highest concentration in plasma and liver followed by kidney, lungs, heart and spleen. Method validation studies suggested being linear in the range of 1-15 µg mL(-1) for liver, kidney, heart, lungs and spleen and 1-120 µg mL(-1) for the plasma. The limit of detection and limit of quantitation were found to be 0.20 and 0.66 µg mL(-1), respectively. The recovery studies suggested that in all the cases, the obtained recovery was in the range of 98.51-101.88%. Our analyses provide a validated UPLC-MS method for the determination of NAC and its successful application for the analysis in plasma and tissues obtained from Wistar rats.

Dose- and time-dependent changes in tissue levels of tetrabromobisphenol A (TBBPA) and its sulfate and glucuronide conjugates following repeated administration to female Wistar Han Rats.

Tetrabromobisphenol A (TBBPA), a nongenotoxic flame retardant, causes uterine tumors in female rats. A proposed mode of action (MoA) for these tumors involves an increase in the bioavailability of estradiol as a result of TBBPA inhibiting estrogen sulfotransferases (ES), the enzymes responsible for inactivating and enhancing the elimination of estradiol. The objective of this study was to evaluate the effect of dose and repeated administration of TBBPA on the level of TBBPA, TBBPA-glucuronide (GA) and TBBPA-sulfate (S) conjugates in plasma, liver and uterus of female Wistar Han rats administered TBBPA (50, 100, 250, 500 or 1000 mg/kg) for 28 consecutive days. In accordance with this objective, TBBPA sulfation was used as a surrogate for evaluating the potential for estradiol sulfation to be limited at high dose levels of TBBPA. Blood samples were collected at 4 and 8 h post-dosing on study day 7, 14, and 28, while liver and uterus were collected at the same time points following 28 days of dosing. Tissue samples were analyzed for TBBPA, TBBPA-GA and TBBPA-S by LC–MS/MS. A dose-related increase in the concentration of all three analytes occurred in plasma (day 7, 14, and 28) as well as liver and uterus tissue (day 28) at both 4 and 8 h post dose. The plasma concentration of TBBPA-GA and TBBPA-S was higher in animals dosed for 28 days compared to those dosed for 7 or 14 days showing an increase in systemic circulation of these conjugates with repeated administration. The balance of these conjugates was also different in tissues with TBBPA-S > TBBPA-GA at high doses in the liver and TBBPA-GA > TBBPA-S in both plasma and uterus. In all three tissues the ratio of TBBPA-S/TBBPA-GA showed a decreasing trend with dose, suggesting that at high TBBPA dose levels sulfation of TBBPA becomes limited. This effect was most apparent in the liver and plasma at 28 days of administration. Together these data show that administration of high doses of TBBPA associated with the induction of uterine tumors, results in a disruption in the balance of conjugates reflected by a decrease in the TBBPA-S/TBBPA-GA ratio. A limitation in the sulfation of TBBPA in vivo supports in vitro data defining TBBPA as an inhibitor of ES activity, thus providing further support that the proposed MoA occurs under conditions of high dose, chronic TBBPA administration to Wistar Han rats. Given that the uterine tumors observed in rats (250–1000 mg/kg-day) only occur at very high doses that perturb homeostatic control, it is unlikely such effects would occur in humans given that current TBBPA exposure levels are approximately eight orders of magnitude lower than these doses that are associated with exceeding the capacity of conjugation pathways in animal studies.

The effect of subchronic inhalations of nitric oxide on metabolic processes in blood of experimental animals

Metabolic processes were investigated in plasma and erythrocytes of Wistar rats exposed to daily 10-min sessions of NO inhalation for 30 days. These included determination of glucose and lactate, catalase activity, and activities of aldehyde dehydrogenase (ALDH), lactate dehydrogenase (LDH), and catalase. NO inhalation in a concentration of 20 ppm, 50 ppm and 100 ppm caused an increase in glucose and lactate. Inhalation of 100 ppm NO also increased catalase activity. Inhalation of all NO concentrations resulted in a decrease of ALDH activity, while the decrease in LDH activity was observed at NO concentrations of 50-100 ppm.

Pharmacokinetic and tissue distribution studies of 1,9-pyrazoloanthrone, a c-Jun-N-terminal kinase inhibitor in Wistar rats by a simple and sensitive HPLC method

JNK pathway activates c-Jun(s) which are responsible for cell apoptosis; as a result, inhibitors of JNK pathway have the potential to prevent dopaminergic neurons from death and decrease the loss of dopamine in substantia nigra pars compacta (SNpc). Recent in-vitro studies show that 1,9-pyrazoloanthrone (1,9-P) a potent JNK-3 inhibitor prevents the apoptosis of dopaminergic cells of brain. In the present study we formulated liposomes to increase the bioavailability of 1,9-P in the brain and developed a simple, sensitive and selective high performance liquid chromatographic method and validated for the estimation of 1,9-P in Wistar rat plasma and tissue samples. Plasma and tissue samples were extracted by protein precipitation technique using acetonitrile (ACN) and rasagiline as the internal standards. Chromatography was performed on Hibar C18 column with mobile phase of ammonium acetate (10mM, pH 8.0 adjusted with ammonia) and ACN at a flow rate of 1mL/min. The lower limit of quantification of the developed method was found to be 2.0ng/mL and 4.0ng/g in plasma and tissue samples respectively. The liposomes of 1,9-P administered to animals at the dose equivalent to 15mg/kg orally demonstrated remarkable absorption into the systemic circulation with maximum concentration (∼7500ng/mL) within 2.0h. The order of the area under curve was found to be kidney>liver>brain>lungs>spleen>heart. The liposomes of 1,9-P were rapidly taken up into brain and showed a good brain concentration after 2.0h; sustenance up to 4.0h was achieved which is better than 1,9-P solution.

Pre-clinical pharmacokinetics of the hERG blocking iboga alkaloid voacangine from Voacanga africana

The bark of Voacanga africana Stapf ex Scott Elliot and related species is not only used in African folk medicine, but also as legal high with increasing popularity in Europe. Voacangine (1), its major iboga-type alkaloid, was recently identified as potent hERG channel blocker in vitro which might point towards possible cardiotoxicity [1]. Since there is no in vivo characterisation of 1, the aim of this study was to assess its pharmacokinetics after oral administration of both, the pure compound and an ethanol extract of V. africana bark (VABE) containing 9.71% of 1, to allow for a critical discussion of its potential cardiotoxic risk in vivo. A precise and sensitive LC-MS/MS method was developed and validated according to FDA guidelines to detect 1 in plasma of male Wistar rats. Within the investigated drug concentration, 1 showed a high plasma protein binding of 98.7 ± 0.29%. Pharmacokinetics was evaluated by comparing four groups (G1-G4; n = 5 – 7/group). G1 received a single 5 mg/kg i.v. bolus of 1; G2 and G3 received single 25 mg/kg or 50 mg/kg doses of 1 p.o., resp.; G4 received a single oral dose of 500 mg/kg of VABE. Non compartmental analysis showed a volume of distribution (Vz) of 6.1 ± 3.4 L/kg after i.v. dosing, a clearance (CL) of 1.4 ± 1 L/h/kg, and an average half-life (t1/2) of 6.0 ± 2.0h. No statistical differences were observed in CL, Vz and t1/2 after oral application of 1, and indicated linear pharmacokinetics. Oral bioavailability (F) of 1 was 12% when given as pure compound. In VABE, a decrease of F was observed for 1 (8%). These findings provide first data to estimate the in vivo hERG channel related cardiotoxic risk of 1.