Rat Plasma Research Articles

Synthesis, Biological Evaluation and Reversal of Sulfonated Di- and Triblock Copolymers as Novel Parenteral Anticoagulants.

Despite targeting different coagulation cascade sites, all Food and Drug Administration-approved anticoagulants present an elevated risk of bleeding, including potentially life-threatening intracranial hemorrhage. Existing studies have not thoroughly investigated the efficacy and safety of sulfonate polymers in animal models and fully elucidate the precise mechanisms by which these polymers act. The activity and safety of sulfonated di- and triblock copolymers containing poly(sodium styrenesulfonate) (PSSS), poly(sodium 2-acrylamido-2-methylpropanesulfonate) (PAMPS), poly(ethylene glycol) (PEG), poly(sodium methacrylate) (PMAAS), poly(acrylic acid) (PAA), and poly(sodium 11-acrylamidoundecanoate) (PAaU) blocks are synthesized and assessed. PSSS-based copolymers exhibit greater anticoagulant activity than PAMPS-based ones. Their activity is mainly affected by the total concentration of sulfonate groups and molecular weight. PEG-containing copolymers demonstrate a better safety profile than PAA-containing ones. The selected copolymer PEG47-PSSS32 exhibits potent anticoagulant activity in rodents after subcutaneous and intravenous administration. Heparin Binding Copolymer (HBC) completely reverses the anticoagulant activity of polymer in rat and human plasma. No interaction with platelets is observed. Selected copolymer targets mainly factor XII and fibrinogen, and to a lesser extent factors X, IX, VIII, and II, suggesting potential application in blood-contacting biomaterials for anticoagulation purposes. Further studies are needed to explore its therapeutic applications fully.

The Effect of Cinnamomum Burmanii Ethanol Extract on Isoniazid-induced Serum Levels of Serum Glutamate Piruvate Transaminase (SGPT) Wistar Strain Male Rats

Hepatotoxicity can be caused by excessive drug use, triggered by increased oxidative stress which is considered as the initial mechanism of Drug Induced Liver Injury (DILI). One of the causes of DILI is Isoniazid. One of the plants acting as a hepatoprotector in protecting liver cells is cinnamon (Cinamommum burmanii). This study aims to determine the effect of 96% ethanolic cinnamon extract as a hepatoprotector against an increase in Alanine Transaminase (ALT) levels induced by isoniazid. The parameters used to assess liver damage were rat plasma ALT. The sample used in this study was rat plasma, which was taken through the retro orbital sinus. This research is an experimental study with a sample of 25 experimental animals divided into five groups, namely negative control (K1), positive control l (K2), and experimental group with cinnamon ethanolic extract at a dose of 100 mg/kgbw (K3), 200 mg/kgbw(K4), and 400 mg/kgbw(K5). The research used a post-test-only control group design. The results were analyzed using the One-way ANOVA test followed by the post hoc Tukey test. The results proved that cinnamon ethanolic extract at doses of 100 mg/kgbw (P = 0.029), 200 mg/kgbw (P = 0.001), and 400 mg/kgbw (P = 0.000) was effective in reducing plasma SGPT levels in isoniazid-induced rats when compared with the positive control group (K2). The most effective dose was at 200 mg/kgbw (K4). Thus, this proves that all of the doses in experimental groups have a hepatoprotective effect against isoniazid-induced liver damage. Keywords: Alanine Transaminase (ALT), cinnamon ethanol extract, Drug Induced Liver Injury (DILI), isoniazid

Design, Synthesis, and Biological Evaluation of New Improved Ferrostatin-1 Derived Ferroptosis Inhibitors.

Ferrostatin-1 (Fer-1), a first potent ferroptosis inhibitor, faces limitations in clinical use due to its low potency and metabolic instability. This study introduces a series of novel Ferrostatin-1 analogs designed to enhance plasm stability. Our design strategy focused on the modification of the 3-NH2 of Fer-1 with benzenesulfonyl groups, resulting in analogs 9-25. Biological evaluation revealed that compound 18, with an EC50 value of 0.57 µM, outperformed Fer-1 in inhibiting ferroptosis. It reduced intracellular ferrous ion accumulation, lipid peroxidation, and restored glutathione (GSH) and glutathione peroxidase 4 (GPX4) levels effectively. Moreover, compound 18 exhibited favorable solubility and remarkable metabolic stability in rat plasma. These results position compound 18 as a promising candidate for developing therapeutics against ferroptosis-related diseases.

4D-printed shape-programmable [H+]-responsive needles for determination of urea

Four-dimensional printing (4DP) technologies are revolutionizing the fabrication, functionality, and applicability of stimuli-responsive analytical devices. More practically, 4DP technologies are effective in fabricating devices with complex geometric designs and functions, and the degree of shape programming of 4D-printed stimuli-responsive devices can be optimized to become a reliable analytical strategy. Although shape-programming modes play a critical role in determining the analytical characteristics of 4D-printed stimuli-responsive sensing devices, the effect of shape-programming modes on the analytical performance of 4D-printed stimuli-responsive devices remains an unexplored subject. We employed digital light processing three-dimensional printing (3DP) with acrylate-based photocurable resins and 2-carboxyethyl acrylate (CEA)-incorporated photocurable resins for 4DP of the bending, helixing, and twisting needles. Upon immersion in samples with pH values above the pKa of CEA, the electrostatic repulsion among the dissociated carboxyl groups of polyCEA caused swelling of the CEA-incorporated part and [H+]-dependent shape programming. When coupling with the derivatization reaction of the urease-mediated hydrolysis of urea, the decline in [H+] induced shape programming of the needles, offering reliable determination of urea based on the shape-programming angles. After optimizing the experimental conditions, the helixing needles provided the best analytical performance, with the method's detection limit of 0.9 μM. The reliability of this analytical method was validated by determining urea in samples of human urine and sweat, fetal bovine serum, and rat plasma with spike analyses and comparing these results with those obtained from a commercial assay kit. Our demonstration and analytical results suggest the importance of optimizing the shape-programming modes to improve the analytical performance of 4D-printed stimuli-responsive shape-programming sensing devices and emphasize the benefits and applicability of 4DP technologies in advancing the development and fabrication of stimuli-responsive sensing devices for chemical sensing and quantitative chemical analyses.

Pharmacokinetics and related gender difference studies of four active components of Codonopsis Pilosula by LC-MS/MS determination

Ethnopharmacological relevanceCodonopsis pilosula (C. pilosula), commonly known as Dangshen in Chinese, had been used to regulate the immune, digestive, and circulatory systems of human. The reported pharmacokinetic studies on C. pilosula are mainly limited to in vivo profile studies of a single component. It has not been detected simultaneously the in vivo pharmacokinetic profiles of multiple active components as well as related gender difference after oral dosing of the extraction of C. pilosula. Aim of the studyThis study aims to reveal the pharmacokinetic characteristics of the four main active components of C. pilosula after oral dosing of its extraction in rats, and to explain the gender differences in absorption and metabolism. Materials and methodsThe plasma pharmacokinetic characteristics of four main active components of C. pilosula was explored using the established LC-MS/MS method after oral dosing of the extraction of C. pilosula in male and female rats. In vitro intestinal pouch permeability and liver microsome metabolic stability were also observed to classify the possible mechanism of gender difference existed in the pharmacokinetic profiles of the four active components in rats. ResultsFour effective components were absorbed quickly in rats after oral administration of alcoholic extract of C. pilosula (1.36 g/mL, equivalent to 2 g/mL as crude drug), and their exposure order was as follows: Atractylenolide III > Lobetyolin > Tangshenoside I > Syringin. The exposure (AUC) and peak concentration (Cmax) of Atractylenolide III in female rats were much higher than those in male rats, indicating a significant gender difference in pharmacokinetics of Atractylenolide III between female and male animals. With the help of the rat model of intestinal sac in vitro, it was found that Lobetyolin was a hypertonic compound, and both Tangshenoside I and Syringin were compounds with medium permeabiltiy. Notably, the Papp of Atractylenolide III was 3.3 × 10−6 cm/s in male rat intestinal sac assay, while that was 10 × 10−6 cm/s in female rat intestinal sac model, showing a significant gender difference in intestinal permeability (P < 0.05). After the addition of NADPH, the four compounds were reduced in a time-dependent manner, suggesting that CYP450s could catalyze their metabolism. After incubation, the remaining content of Atractylenolide III in the liver microsomes of male and female rats was 27% and 57%, respectively, suggesting slower metabolic rate of in female rat liver microsomes. ConclusionA simple, efficient and reliable LC-MS/MS method for the simultaneous determination of four active index components of C. pilosula, Lobetyolin, Tangshenoside I, Atractylenolide III and Syringin, in rat plasma was established and verified. This method was successfully applied in the pharmacokinetic study after single oral administration of the alcoholic extract of C. pilosula in rats. Gender difference was observed in the pharmacokinetic profile of Atractylenolide III in rats. Intestinal absorption and liver metabolism might be two key factors that resulted in the gender difference in exposure and pharmacokinetics of Atractylenolide III in rats. This study provides supportive data for clinical rational application of C. pilosula in individualized medication therapy.

Flavonoid-rich fraction of Monodora tenuifolia Benth seeds improves antioxidant status in male Wistar rats with streptozotocin-induced Diabetes mellitus

BackgroundOxidative stress is a disruption in the balance between free radicals and the body's natural defenses. This study investigated the modulatory effect of a flavonoid-rich fraction of Monodora tenuifolia seed (FRFMTS) on oxidative stress and antioxidant enzymes in diabetic Wistar rats. The plant seeds were collected, and identified then, hydro-ethanolic extract was obtained with 80 % (v/v) ethanol and partitioned with solvents to obtain the FRFMTS. Diabetes mellitus was induced with a single dose of 40 mg/kg bwt streptozotocin and the rats were treated according to their grouping; group 1: non-diabetic control, groups 2 and 3: non-diabetic treated with 25 mg/kg FRFMTS and 50 mg/kg FRFMTS, respectively. Group 4: diabetic control group, groups 5 and 6: diabetic groups treated with 25 mg/kg and 50 mg/kg FRFMTS, respectively, while group 7: diabetic treated with 6.67 mg/kg metformin. Antioxidant status, oxidative stress biomarkers and activities of antioxidant enzymes were determined in plasma, heart, and kidney tissues using established procedures. ResultsPlasma total antioxidant status (TAS) was increased significantly (p < 0.05) in diabetic rats upon treatment with 25 mg/kg FRFMTS (70.4 %), while 50 mg/kg FRFMTS increased TAS by 70 %. The activities of glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in the plasma, heart, and kidney of diabetic rats significantly decreased (61.3 %, 58.8 % and 31.4 % respectively) while lipid peroxidation (LPO) was elevated when compared with normal control groups. Flavonoid-rich fraction of M. tenuifolia at 25 mg/kg bwt and 50 mg/kg bwt significantly increased the activity GPx enzyme by 32.3 % and 72 % in plasma, while there was no significant differences in both kidney and heart of diabetic rats when compared with diabetic control groups. The treatment of diabetic rats with 25 mg/kg FRFMTS and 50 mg/kg FRFMTS improved SOD activity in the plasma (51.5 % and 69.8 %), heart (32.3 % and 27.6 %) and kidney (31.4 % and 27.1 %) respectively, and CAT activity in plasma (44.2 % and 57 %), heart (28.6 % and 60 %) and kidney (69.6 % and 76.7 %) respectively. The concentration of malondialdehyde (MDA) in lipid peroxidation assay in the heart and kidney of diabetic rats treated with 25 mg/kg FRFMTS and 50 mg/kg FRFMTS reduced significantly by (62.5 % and 71.1 % in heart), while 50 mg/kg FRFMTS significantly reduced MDA in kidney by 43.8 %. ConclusionsThe results showed that FRFMTS reduces oxidative stress and enhances the activities of antioxidant enzymes in STZ-diabetic Wistar rats. As such, FRFMTS could be useful in the management of oxidative stress-mediated diabetic complications.

B-004 Method Validation of Lactate in the Plasma of Rats

Abstract Background The objective of this study is to validate Lactate (LAC) measurement in rat plasma using the ADVIA 1800 analyzer. Methods LAC was validated in rat plasma using the ADVIA 1800 analyzer. Validation testing included intra-assay and inter-assay precision, accuracy, linearity of dilution, limit of quantitation (LOQ), limit of detection (LOD), reference interval, carry-over, correlation, recovery, and stability. Samples were collected into tubes containing sodium fluoride. Intra-assay precision was determined by analyzing two biological samples and the two quality control levels of Bio-Rad Lyphochek Assayed Chemistry Control 10 consecutive times. Inter-assay precision was determined by analyzing the two quality control levels in duplicate for six days over a 10-day period. Accuracy was calculated using the data obtained from the inter-assay precision testing. For linearity of dilution, Audit MicroControl General Chemistry Linearity Kit and biological samples were diluted and analyzed in duplicate. The LOQ was determined by diluting the calibrator material to produce a value at the low end of the reportable range. Diluted material was tested six times. The LOD was determined by assaying the appropriate blank 10 times. The reference interval was determined by analyzing 21 plasma samples. Correlation between the two ADVIA 1800 analyzers was determined by assaying 10 samples on both analyzers once. The carry-over of the assay was determined by analyzing the high-level quality control material followed by the low-level quality control material. Recovery was determined by analyzing a pair of test samples in duplicate that have been spiked and diluted. The proportional error between the two test samples was calculated. Stability of plasma samples was tested on wet ice, refrigerated, and frozen (at -70°C) for various durations of storage. Results Measurement of LAC in rat plasma met the acceptance criteria for precision, accuracy, linearity of dilution, limit of quantitation, carry-over, recovery, and stability. For intra-assay precision in specimen and control material, the %CV was within ±20%. The inter-assay precision %CV was within ±20%. The total error observed (TEobs) was within ±20% for accuracy and the obtained mean of the control material was within the manufacturer’s acceptable range. For linearity of dilution, the coefficient of determination was ≥ 0.9000, the slope was within 1.00 ± 0.25, and TEobs for each plasma and linearity kit dilution was ≤20%. The LOQ was set at the lowest concentration for which the TEobs was within ±20%. The LOD was calculated by adding the mean concentration obtained and three times the standard deviation. The reference interval was set to the 2.5th to 97.5th percentile interval using Excel software. The carry-over was acceptable at ≤2%. Correlation between the two ADVIA 1800 analyzers was determined to describe any bias in result interpretation. Recovery was acceptable as the proportional error was within ±20%. Stability at all storage conditions was found to be acceptable with a mean %difference within ±20%. Conclusions LAC in rat plasma met the acceptance criteria for all required validation parameters. The ADVIA 1800 analyzer can be used for preclinical studies to test LAC in rat plasma.

Simultaneous Determination of Levo-tetrahydropalmatine and Naltrexone in Rat Plasma by LC-MS/MS and its Application in a Pharmacokinetic Study.

Levo-tetrahydropalmatine and low-dose naltrexone are used in association with reducing cocaine-related cravings, but there are no analytical methods for the quantitative simultaneous analysis of this drug combination. A highly selective and sensitive LC-MS/MS assay was developed and validated to simultaneously quantify l-THP and naltrexone. The analytical method for l-THP offers improved sensitivity compared to previously published methods. The product ion transitions of l-THP and naltrexone were 357.0→193.0 and 342.2→324.1, respectively. Chromatographic separations were performed using a BEH-C18 column by an isocratic elution mode with acetonitrile and 0.1% formic acid in water containing 3 mM ammonium acetate. L-THP and naltrexone were extracted from rat plasma using a liquidliquid extraction method. For l-THP and naltrexone, the assay displayed good linear response over a concentration range of 0.5-1000 ng/mL and 0.25-500 ng/mL, respectively. The intra-day accuracy of the method for l-THP and naltrexone was 93.8-101% with a precision (%CV) of 2.43-8.15% and 93.4-108% with a precision of 3.47-8.22%. The inter-day accuracy for l-THP and naltrexone was 91.2-102% with a CV of 2.46-8.06% and 91.5-97.8% with a CV of 3.29-8.92%, respectively. The assay has been used for pharmacokinetic studies of l-THP and naltrexone in the rat.

Rhamnosomes: A new generation of flexible vesicles for a boosted targeted nose-to-brain delivery of selegiline in the treatment of Parkinson's disease

Extensive hepatic metabolism of Selegiline, a selective monoamine oxidase B inhibitor for newly diagnosed Parkinson's disease patients, causes limited brain bioavailability. To improve efficacy, a new generation of flexible lipidic vesicles, Rhamnosomes, comprising alternating lecithin and Rhamnolipid moieties, and decorated with lactoferrin to actively target Selegiline to the brain is proposed.Rhamnosomes were optimized using design of expert, where lipid amount, Soybean lecithin:Rhamnolipid ratio and sonication time were varied. Polyelectrolyte complexation was employed for Lactoferrin conjugation to Rhamnosomes. A pharmacokinetic study in rat plasma and brain was conducted. Optimized Rhamnosomes had a particle size of 107nm, polydispersity index of 0.23, zeta potential of -41mV, entrapment efficiency of 78%, relative deformability of 36sec and ex-vivo skin permeation reaching 60% after 24 hr. The plasma half life of Rhamnosomes was 3.24 times the market product and 2.63 times the intravenous solution, whereas, lactoferrin-conjugated Rhamnosomes exhibited 7 times higher absolute bioavailability than the market product and more than double its brain drug targeting efficiency. Prominent direct nose-to-brain transport values further proved the efficiency of intranasally delivered Selegiline-loaded Lactoferrin conjugated Rhamnosomes to actively target the brain in a non-invasive approach for the treatment of Parkinson's disease.

Quantitative analysis of three bioactive components of Biancaea decapetala extracts in rat plasma and RAW264.7 cells using UPLC-MS/MS and its application to comparative pharmacokinetics in normal and diseased states

Quantitative analysis of three bioactive components of Biancaea decapetala extracts in rat plasma and RAW264.7 cells using UPLC-MS/MS and its application to comparative pharmacokinetics in normal and diseased states

Pharmacokinetic and tissue distribution study of pectolinarigenin in rats using UPLC-MS/MS

Pectolinarigenin (PEC), a natural flavonoid isolated from Cirsium japonicum, exhibits promising therapeutic potential for multiple cancers. In present study, a simple and sensitive UPLC-MS/MS method was established for the quantification of PEC in rat plasma and tissues. The assay procedure involved a one-step protein precipitation with tadalafil as the internal standard, and separation on a Welch Xtimate UHPLC C18 column by gradient elution of acetonitrile/aqueous formic acid (0.1 %, v/v) at a flow rate of 0.2 m L·min−1. The detection was conducted using multiple-reaction monitoring via an electrospray ionization source in positive ionization mode. The established method was proved to be highly sensitive with a good linearity (R2 > 0.99) in respective concentration range (0.1–100 ng·mL−1 in plasma and 1–10000 ng·mL−1 in tissues) and acceptable extraction recovery (≥71.17 %), matrix effect and stability, which was applied to study the pharmacokinetics and tissue distribution of PEC after intravenous (100 μg·kg−1) and oral administration (10, 20 and 40 mg·kg−1). PEC was promptly absorbed (Tmax ≤ 0.222 h) and maintained at a low level with slow elimination (t1/2 z ≥ 14.47 h) in rats after oral administration, resulting in extremely low bioavailability (0.56–0.68 %). However, PEC is widely distributed in rat tissues with high exposure in GI tract, liver and kidney. The bioavailability and tissue affinity were firstly revealed, which will guide directions for further development of PEC as an anti-tumor drug candidate.

Rapid Characterization of the Potential Active of Sinomenine in Rats by Ultra-High-Performance Liquid Chromatography-Quadrupole-Exactive Orbitrap Mass Spectrometry and Molecular Docking.

Sinomenium acutum (Thunb.) Rehd. et Wils is widely used in the treatment of rheumatoid arthritis, with its alkaloid compound sinomenine (SIN) being renowned for its significant anti-inflammatory properties. However, despite its widespread application, the in vivo anti-inflammatory mechanisms and metabolic pathways of SIN remain incompletely understood. This study established a rapid and reliable method based on an ultra-high-performance liquid chromatography method coupled with Quadrupole-Exactive Orbitrap mass spectrometry and molecular docking to identify and characterize SIN and 69 metabolites in rat plasma, urine, and feces, revealing primary metabolic pathways of hydroxylation, demethylation, sulfation, and glucuronidation. Molecular docking results revealed that phase I reactions, including dedimethylation, demethylation, dehydrogenation, and dihydroxylation, along with their composite reactions, were pivotal in influencing SIN's in vivo anti-inflammatory activity. M28, M36, and M59 are potentially the most anti-inflammatory active metabolites of SIN in vivo. This comprehensive analysis unveils SIN's metabolic pathways, offering insights into its biological processes and suggesting a novel approach for exploring active drug constituents. These findings pave the way for further understanding SIN's anti-inflammatory mechanisms, contributing significantly to the development of new therapeutic strategies.

The Pharmacokinetic Interaction of Tirabrutinib with Voriconazole, Itraconazole, and Fluconazole in SD Rats by UPLC-MS/MS.

Tirabrutinib is an orally effective, approved, and highly selective second-generation Bruton's tyrosine kinase (BTK) inhibitor for the treatment of recurrent or refractory primary central nervous system lymphoma (PCNSL). This study aimed to develop an ultra-high performance liquid chromatography- tandem mass spectrometry (UPLC-MS/MS) method for the determination of tirabrutinib concentration in rat plasma, where zanubrutinib was used as an internal standard (IS). This method was also applied to study whether tirabrutinib would interact with voriconazole, itraconazole, and fluconazole in rats, providing a reference value for clinical medication guidance. In the current study, the organic solvent protein precipitation method was used to treat plasma samples, which is simple and reproducible. Tirabrutinib (m/z 455.32 → 320.21) and zanubrutinib (m/z 472.13 → 455.04) were separated on a Waters Acquity BEH C18 column (2.1 × 50 mm, 1.7 μm) and detected by multiple reaction monitoring (MRM) in positive ionization mode. The method showed good linearity in the range of 5-3000 ng/mL for tirabrutinib with the lower limit of quantification (LLOQ) of 5 ng/mL. The recovery and matrix effects were 85.7-91.0% and 102.0-113.3%, respectively. The accuracy, precision, stability, and carry-over effect were also acceptable. The method could also be used for determining the pharmacokinetic interaction of tirabrutinib in rats. The results showed AUC0→∞ of tirabrutinib to be increased by 139.3% and 83.9% in the presence of voriconazole and fluconazole, respectively, while itraconazole had little effect. It is necessary to monitor the concentration of tirabrutinib in patients when it is combined with voriconazole and fluconazole to achieve a better therapeutic effect and reduce the risk of adverse reaction. Further research should be conducted in the future.

Plasma C24:0 ceramide impairs adipose tissue remodeling and promotes liver steatosis and glucose imbalance in offspring of rats

Fetal programming by exposure to high-energy diets increases the susceptibility to type 2 diabetes mellitus (T2DM2) in the offspring. Glucose imbalance during fetal programming might be associated to still unknown selective lipid species and their characterization might be beneficial for T2DM diagnosis and treatment. We aim to characterize the effect of the lipid specie, C24:0 ceramide, on glucose imbalance and metabolic impairment in cellular and murine models. A lipidomic analysis identified accumulation of C24:0 ceramide in plasma of offspring rats exposed to high-energy diets during fetal programing, as well as in obese-T2DM subjects. In vitro experiments in 3T3L-1, hMSC and HUH7 cells and in in vivo models of Wistar rats and C57BL/6 mice demonstrated that C24:0 ceramide disrupted glucose balance, and differentiation and lipid accumulation in adipocytes, whereas promoted liver steatosis. Mechanistically, C24:0 ceramide impaired mitochondrial fatty acid oxidation in adipocytes and hepatic cells, tentatively by favoring reactive oxygen species accumulation and calcium overload in the mitochondria; and also, activates endoplasmic reticulum (ER) stress in hepatocytes. We propose that C24:0 ceramide accumulation in the offspring followed a prenatal diet exposure, impair lipid allocation into adipocytes and enhances liver steatosis associated to mitochondrial dysfunction and ER stress, leading to glucose imbalance.

Adipokines level in plasma, hypothalamus, ovaries, and adipose tissue of rat's polycystic ovary syndrome model

Research questionDo the levels of adipokines (adiponectin, apelin, chemerin and vaspin) in plasma, hypothalamus, ovaries, and periovarian adipose tissue differ during polycystic ovarian syndrome (PCOS)? DesignThe PCOS was induced in rats by oral administration of nonsteroidal aromatase inhibitor letrozole. To determine the plasma levels of adiponectin, apelin, chemerin, and vaspin we performed enzyme-linked immunosorbent assays. To assess the expression (gene and protein) and immunolocalization of these adipokines and their receptors, namely Adipor1 and Adipor2 for adiponectin; Aplnr for apelin; Ccrl2, Cmklr1, and Gpr1 for chemerin; and Grp78 for vaspin in the hypothalamus, ovaries, and periovarian adipose tissue we conducted by real-time PCR, Western blot and immunohistochemistry, respectively. ResultsWe noted that PCOS modulates the plasma levels of adipokines (decreased adiponectin, increased apelin, chemerin, and vaspin) and the expression of adipokines and their receptors in the hypothalamus, ovaries, and periovarian adipose tissue compared with healthy rats. ConclusionsThis study confirmed a strong relationship between PCOS and adipokines and suggest that adipokines may be a biomarker of PCOS.

Retinol semisolid preparations in cosmetics: transcutaneous permeation mechanism and behaviour

Retinol is widely used to treat skin ageing because of its effect on cell differentiation, proliferation and apoptosis. However, its potential benefits appear to be limited by its skin permeability. Herein, we investigated the transcutaneous behavior of retinol in semisolid cosmetics, in both in vitro and in vivo experiments. In vitro experiments used the modified Franz diffusion cell combined with Raman spectroscopy. In in vivo experiments, the content of retinol in rat skin and plasma was detected with HPLC. Retinol in semisolid cosmetics was mainly concentrated in the stratum corneum in the skin of the three animal models tested, and in any case did not cross the skin barrier after a 24 h dermatologic topical treatment in Franz diffusion cells tests. Similar results were obtained in live mice and rats, where retinol did not cross the skin barrier and did not enter the blood circulation. Raman spectroscopy was used to test the penetration depth of retinol in skin, which reached 16 μm out of 34 μm in pig skin, whereas the skin of mouse and rat showed too strong bakground interference. To explore epidermal transport mechanism and intradermal residence, skin transcriptomics was performed in rats, which identified 126 genes upregulated related to retinol transport and metabolism, relevant to the search terms “retinoid metabolic process” and “transporter activity”. The identity of these upregulated genes suggests that the mechanism of retinol action is linked to epidermis, skin, tissue and epithelium development.

Pharmacological efficacy study of the cardio-cerebral stasis transforming medicines on cerebral ischemia and myocardial infarction in rats

The purpose of this study was to investigate the efficacy and mechanisms of cardio-cerebral stasis transforming medicines (CCSTM) against cerebral infarction (CI) and myocardial infarction (MI). CI modeling was conducted using the refined Longa suture-occluded technique, while MI modeling was accomplished through the occlusion of the anterior descending branch of the left coronary artery. We found that compared with the model groups, CCSTM decreased the infarct size in models of CI and MI in a dose-dependent manner. After brain ischemia, CCSTM decreased the level of myeloperoxidase (MPO) and malondialdehyde (MDA), and increased the level of superoxide dismutase (SOD). Besides, CCSTM reduced the concentrations of lactate dehydrogenase (LDH), malondialdehyde MDA, and endothelin (ET) in the plasma of rats injured with MI. Histological examination of brain sections revealed that CCSTM alleviated cerebral damage after ischemia compared with the model group. CCSTM can reduce myocardial and cerebral infarction injury, and the oxidation level after myocardial and cerebral infarction in rats.

Enantioselective Separation and Pharmacokinetics of a Chiral 1,4-Dihydropyrimidine Derivative in Rats: A Combined Chromatography and Docking Approach.

Chirality in 1,4-Dihydropyrimidines influences their pharmacological properties and synthetic strategies. Enantiomers of chiral drugs often exhibit different pharmacokinetic profiles. Therefore, separating and studying individual enantiomers is crucial to optimize drug efficacy and safety. Enantiomeric separation of ±4-(4-chlorophenyl)-6-methyl-2-oxo-N-(O-toyl)-1,2,3,4-tetrahydropyrimidine-5-carboxamide (DP-1), which is a 1,4-Dihydropyrimidine derivative is achieved on CHIRALCEL® OD-H column (particle size: 5 μm, inner diameter: 4.6 mm, length:150 mm), following by investigating the kinetic properties of (R) and (S) enantiomers. The separation was achieved with a mobile phase composed of 70% (v/v) isopropyl alcohol and 30% (v/v) n-hexane. For the bioanalytical study, acetonitrile was used to precipitate the rat plasma samples and validated the method according to USFDA guidelines. The validated bioanalytical method was then successfully applied to determine the pharmacokinetic parameters of the drug in biological samples. Molecular modeling techniques, specifically docking simulations, were employed to predict the elution order of DP-1 enantiomers. The docking results revealed moderate binding interactions between the enantiomers and the chiral stationary phase (CSP), which aligns with the theoretical expectation that stronger interactions lead to longer retention times on the column.

The pharmacokinetics and tissue distribution of curcumin following inhalation administration in rats-A comparative analysis with oral and intravenous routes.

A sensitive and simple method using ultra-liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and validated to determine the concentration of curcumin in rat plasma and tissue samples. Emodin was selected as the internal standard (IS), and biological samples were pretreated with simple one-step acetonitrile precipitation. The calibration curves exhibited linearity within the range of 1-1000 ng/ml for both rat plasma and tissue samples. The accuracy and precision of intra-day as well as inter-day determinations ranged from 99.3% to 117.3% and from 98.2% to 105.1%, respectively. This method demonstrated excellent recovery rates ranging from 76.4% to 96.4% along with minimal matrix effect ranging from 86.5% to 99.6%. The effectiveness of this method was successfully demonstrated through its application in an in vivo pharmacokinetic and tissue distribution study after single administration via inhalation (100 mg/kg), oral gavage (100 mg/kg) and intravenous injection (2.5mg/kg) of curcumin in rats. The results revealed that inhalation significantly improved the bioavailability of curcumin, with most of the drug being deposited in the lung. These findings highlight inhalation as an effective route for targeted delivery of drugs directly into lung tissues, thus suggesting potential future applications for treating pulmonary diseases utilizing inhaled curcumin.

Exploring the progression of drug dependence in a methamphetamine self-administration rat model through targeted and non-targeted metabolomics analyses

Persistent neurochemical and biological disturbances resulting from repeated cycles of drug reward, withdrawal, and relapse contribute to drug dependence. Methamphetamine (MA) is a psychostimulant with substantial abuse potential and neurotoxic effects, primarily affecting monoamine neurotransmitter systems in the brain. In this study, we aimed to explore the progression of drug dependence in rat models of MA self-administration, extinction, and reinstatement through targeted and non-targeted metabolomics analyses. Metabolic profiles were examined in rat plasma during the following phases: after 16 days of MA self-administration (Group M); after 16 days of self-administration followed by 14 days of extinction (Group MS); and after self-administration and extinction followed by a reinstatement injection of MA (Group MSM). Each group of MA self-administration, extinction, and reinstatement induces distinct changes in the metabolic pathways, particularly those related to the TCA cycle, arginine and proline metabolism, and arginine biosynthesis. Additionally, the downregulation of glycerophospholipids and sphingomyelins in Group MSM suggests their potential role in MA reinstatement. These alterations may signify the progressive deterioration of these metabolic pathways, possibly contributing to drug dependence following repeated cycles of drug reward, withdrawal, and relapse. These results provide valuable insights into the metabolic changes associated with MA use at various stages, potentially facilitating the discovery of early diagnostic biomarkers and therapeutic targets for MA use disorders.