Ion-pair compounds of diacerein for enhancing skin permeability in vitro: the compatibility-permeability relationship of counter ion and diacerein.

This research aimed to investigate how the relationship between counter ion and diacerein (DCN) exerts an effect on the skin penetration of DCN ion-pair compounds. After the ion-pair compounds were formed by DCN and organic amines with different functional groups, the hydrogen bond of these compounds was confirmed by Fourier-transform infrared (FTIR) spectroscopy and molecular docking. The skin of porcine ears was employed to conduct the in vitro skin penetration, DCN - triethanolamine was the most potential candidate with the Q24h of 7.89 ± 0.38 µg/cm2 among organic amines with different functional groups. Whereas among the homologous fatty amine, the most permeable compound was DCN - lauryl amine with the Q24h of 11.28 ± 0.48 µg/cm2. Molecular simulation was employed to explore the relationship between counter ion and DCN. It was revealed by the bind energy curve that DCN had the strongest compatibility with triethanolamine among organic amines and laurylamine (N12) among fatty amines. It was amazingly found that the in vitro permeation fluxes of DCN ion-pair compounds would increase with enhancing the compatibility of counter ion and DCN. These findings broadened our understanding of how the relationship between drug and counter ion affects the skin penetration of ion-pair compounds.

The influence of rhein on the absorption of rehmaionoside D: In vivo, in situ, in vitro, and in silico studies.

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Chinese Medicine, Rehmannia glutinosa (Gaertn.) DC., as the principle herb of ShengDiHuang Decotion (SDHD), has the effect of cooling blood and hemostasis, and tonifying the yin and kidney. Rheum L., as adjuvant herbs, assist Rehmannia glutinosa (Gaertn.) DC. to promote blood circulation to remove blood stasis. AIM OF STUDY: To study the mechanism of Rhein (RH) involved in the promotion of Rehmannioside D (RD) absorption by pharmacokinetic studies, single-pass intestinal perfusion, Caco-2 cell models, molecular docking technique and western blotting. MATERIALS AND METHODS: Initially, the intestinal absorption of RD in the presence or absence of RH was conducted through pharmacokinetic studies. Thereafter, the intestinal absorption of RD and RH was studied using the single-pass intestinal perfusion and Caco-2 cell models. Finally, using molecular docking technique and western blotting. RESULTS: We found that the promotion of RD absorption by RH was mediated by breast cancer resistance and multidrug resistance-associated protein 2, thereby affecting the permeability of the intestinal epithelium. Additionally, RH and RD can competitively bind to breast cancer resistance and multidrug resistance-associated protein 2, and that RH inhibits the expression of breast cancer resistance and multidrug resistance-associated protein 2 in the ileum to promote the intestinal absorption of RD. CONCLUSION: This study reveals the mechanisms associated with the RH-mediated promotion of RD absorption and provides a basis for further exploring the synergistic effect of Rehmannia glutinosa (Gaertn.) DC and rhubarb.

Decrease in dysbaric osteonecrosis severity as a result of 45-minute oxygen pre-breathe.

Sudden decompression can result in bubble formation as the result of nitrogen gas (N2) dissolved in tissue during disabled submarine escape (DISSUB). This may cause dysbaric osteonecrosis (DON), a condition in long bones where bubbles in fatty marrow result in ischemia and necrosis. Previous research has shown that oxygen (O2) pre-breathe of two hours resulted in a reduction of DON; however, effects of shorter O2 pre-breathe remain uncertain. This study's aim was to understand the effect of shorter lengths of O2 pre-breathe. Eight adult Suffolk ewes (89.5± 11.5 kg) were exposed to 33 feet of seawater (fsw) for 24 hours. They were placed randomly into four groups and exposed to either 45, 30 or 15 minutes of O2 (91-88%) pre-breathe; the controls received none. They were then rapidly decompressed. Alizarin complexone was later injected intravenously to visualize the extent of DON in the right and left long bones (radii, tibiae, femur and humeri). The 30- and 15-minute pre-breathe groups saw the greatest deposition. There was significant decrease of variance in the 45-minute group when compared with all other treatments, suggesting that 45 minutes of O2 pre-breathe is required to effectively increase confidence in the reduction of DON. Similar confidence was not reflected in the 30-minute and 15-minute groups: 45 minutes of pre-breathe was the minimum amount needed to effectively prevent against DON in DISSUB escape at 33 fsw. However, future research is needed to determine how to calculate effective dosages of O2 pre-breathe to prevent DON in any given scenario.

Erythrocyte-Camouflaged Mesoporous Titanium Dioxide Nanoplatform for an Ultrasound-Mediated Sequential Therapies of Breast Cancer.

BACKGROUND: The hypoxic microenvironment promotes tumor resistance to most treatments, especially highly oxygen-dependent sonodynamic therapy (SDT). METHOD AND RESULTS: In view of the aggravation of hypoxia by oxygen consumption during SDT, a biomimetic drug delivery system was tailored to integrate SDT with hypoxia-specific chemotherapy. In this system, mesoporous titanium dioxide nanoparticles (mTNPs) were developed to deliver the hypoxia-activated prodrug AQ4N with high loading efficiency. Subsequently, a red blood cell (RBC) membrane was coated onto the surface of mTNP@AQ4N. RBC-mTNPs@AQ4N inherited the immune escape ability from RBC membranes, thus efficiently reducing the immunological clearance and improving the work concentration. Upon activation by ultrasound (US), mTNPs as sonosensitizers generate reactive oxide species (ROS), which not only induce apoptosis and necrosis but also disrupt RBC membranes to achieve the US-mediated on-demand release of AQ4N. The released AQ4N was activated by hypoxia to convert into toxic products, which effectively supplemented the inefficiency of SDT in hypoxic tissues. Importantly, SDT-aggravated hypoxia further potentiated this hypoxia-specific chemotherapy of AQ4N. CONCLUSION: Based on the sequential strategy, RBC-mTNPs@AQ4N exhibited an excellent synergistic therapeutic effect, thus potentially advancing the development of SDT in cancer treatments.

Near-Infrared Photo-controlled Permeability of a Biomimetic Polymersome with Sustained Drug Release and Efficient Tumor Therapy.

Synthetic polymersomes have structure similarity to bio-vesicles and could disassemble in response to stimuli for "on-demand" release of encapsulated cargos. Though widely applied as a drug delivery carrier, the burst release mode with structure complete destruction is usually taken for most responsive polymersomes, which would shorten the effective drug reaction time and impair the therapeutic effect. Inspired by the cell organelles' communication mode via regulating membrane permeability for transportation control, we highlight here a biomimetic polymersome with sustained drug release over a specific period of time via near-infrared (NIR) pre-activation. The polymersome is prepared by the self-assembling amphiphilic diblock copolymer P(OEGMA-co-EoS)-b-PNBOC and encapsulates the hypoxia-activated prodrug AQ4N and upconversion nanoparticle (PEG-UCNP) in its hydrophilic centric cavity. Thirty minutes of NIR pre-activation triggers cross-linking of NBOC and converts the permeability of the polymersome with sustained AQ4N release until 24 h after the NIR pre-activation. The photosensitizer EoS is activated and aggravates environmental hypoxic conditions during a sustained drug release period to boost the AQ4N therapeutic effect. The combination of sustained drug release with concurrent hypoxia intensification results in a highly efficient tumor therapeutic effect both intracellularly and in vivo. This biomimetic polymersome will provide an effective and universal tumor therapeutic approach.

Preparation of solid dispersion systems for enhanced dissolution of poorly water soluble diacerein: In-vitro evaluation, optimization and physiologically based pharmacokinetic modeling.

Diacerein (DCN), a BCS II compound, suffers from poor aqueous solubility and limited bioavailability. Solid dispersion systems (SD) of DCN were prepared by solvent evaporation, using hydrophilic polymers. In-vitro dissolution studies were performed and dissolution parameters were evaluated. I-Optimal factorial design was employed to study the effect of formulation variables (drug:polymer ratio and polymer type) on the measured responses including; drug content (DC) (%), dissolution efficiency at 15 min (DE (15 min)%) and 60 min (DE (60 min)%) and mean dissolution time (MDT) (min). The optimized SD was selected, prepared and evaluated, allowing 10.83 and 3.42 fold increase in DE (15 min)%, DE (60 min)%, respectively and 6.07 decrease in MDT, compared to plain drug. DSC, XRD analysis and SEM micrographs confirmed complete amorphization of DCN within the optimized SD. Physiologically based pharmacokinetic (PBPK) modeling was employed to predict PK parameters of DCN in middle aged healthy adults and geriatrics. Simcyp® software established in-vivo plasma concentration time curves of the optimized SD, compared to plain DCN. Relative bioavailability of the optimized SD compared to plain drug was 229.52% and 262.02% in healthy adults and geriatrics, respectively. Our study reports the utility of PBPK modeling for formulation development of BCS II APIs, via predicting their oral bio-performance.

Design and Evaluation of Rhein-Based MRI Contrast Agents for Visualization of Tumor Necrosis Induced by Combretastatin A-4 Disodium Phosphate.

PURPOSE: Visualization of tumor necrosis can determine tumor response to therapy. Our previous study showed that the rhein-based magnetic resonance imaging (MRI) contrast agent with alkane linker (GdL2) could clearly image tumor necrosis. However, its water solubility and cell safety needed to be improved. Herein, three rhein-based MRI agents with ether or lysine linkers were designed. PROCEDURES: Three rhein-based MRI agents were synthesized with a tetracarbon ether (GdP1), a hexacarbon ether (GdP2), and a lysine (GdP3) linker, respectively. Their octanol-water partition coefficients (log P) and cytotoxicity were determined. Necrosis avidity of the leading agent was explored on HepG2 cells and ischemia reperfusion-induced liver necrosis (IRLN) rats by MRI. The effect of visualization of tumor necrosis was tested on nude mice with W256 tumor treated by combretastatin-A4 phosphate (CA4P). DNA binding assays were applied to evaluate the possible necrosis-avidity mechanism of the leading agent. RESULTS: The log P of three agents (- 1.66 ± 0.09, - 1.74 ± 0.01, - 1.95 ± 0.01) decreased when compared with GdL2, indicating higher water solubility. GdP1 not only presented lower cytotoxicity and good necrotic affinity in vitro and in vivo, but also can be fast excreted by renal. According to MRI results of tumor, distinct visualization of tumor necrosis can be discernible from 3 to 4.5 h post-injection of GdP1. In DNA-binding assays, the fluorescence quenching constant KSV (1.00 × 104 M-1) and the ultraviolet binding constant Kb (1.11 × 104 M-1) suggested that GdP1 may bind to DNA through intercalation. CONCLUSION: GdP1 may serve as a potential candidate for early evaluation of tumor response to CA4P treatment.

Pharmacokinetics and tissue distribution study of obtusifolin in rats by liquid chromatography-tandem mass spectrometry.

This paper reports the validation of an assay for obtusifolin based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and its application to a preclinical pharmacokinetic study in rats. After sample preparation of plasma and tissue homogenates by protein precipitation, the analyte and internal standard (IS) were separated by a reversed-phase chromatographic system in a run time of 5.0 min and detected by negative ion electrospray ionization followed by selected reaction monitoring of the precursor-to-product ion transitions at m/z 283.0-268.1 for obtusifolin and m/z 329.0-314.1 for IS. The assay was linear in the concentration range 1.0-500 ng/ml with the LLOQ of 1.0 ng/ml. In the pharmacokinetic study of an intragastric administration of 1.3 mg/kg obtusifolin, the maximum plasma concentration of obtusifolin was 152.5 ± 62.3 ng/ml, reached at 0.39 ± 0.17 h. The AUC0-t and AUC0-∞ were 491.8 ± 256.7 and 501.7 ± 256.7 ng × h/ml, respectively, with an elimination half-life of 3.1 ± 0.7 h. Obtusifolin was rapidly distributed into tissues, with the highest distribution in the liver and less in the brain. These results will give some insights for further pharmacological investigation of obtusifolin.

Development of orally disintegrating tablets containing solid dispersion of a poorly soluble drug for enhanced dissolution: In-vitro optimization/in-vivo evaluation.

Diacerein (DCN), a potent anti-inflammatory API used to treat osteoarthritis yet, it suffers from poor water solubility which affects its oral absorption. Unabsorbed colonic DCN is converted into rhein, which is responsible for laxation as a main side effect of DCN treatment. Therefore, in this study orally disintegrating tablets (ODTs) loaded with optimized DCN solid dispersion system were prepared using different co-processed excipients (Prosolv® ODT, Pharmaburst® 500 and F-melt®), aiming to achieve improved solubility, rapid absorption and consequently limited amount of rhein reaching the colon. Prepared ODTs were evaluated for physical characteristics, in-vitro drug release, disintegration and wetting times. Dissolution parameters; dissolution efficiency percent at 10 (DE (10 min)%) and 30 (DE (30 min)%) min and mean dissolution time (MDT) were determined. The optimized ODT showed 1.50 and 1.12 fold increase in DE (10 min)% and DE (30 min)%, respectively and 2 fold decrease in MDT, compared to Diacerein® capsules. In-vivo anti-inflammatory effect of optimized ODT, using rat paw edema revealed significant increase in edema inhibition (p < 0.0465) and promoted onset of action compared to Diacerein® capsules at 0.5 hr. It could be concluded that optimized ODT could be promising for enhanced dissolution and rapid absorption of DCN from the oral cavity.

Pharmacology, toxicity and pharmacokinetics of acetylshikonin: a review.

CONTEXT: Acetylshikonin, a naphthoquinone derivative, is mainly extracted from some species of the family Boraginaceae, such as Lithospermum erythrorhizon Sieb. et Zucc., Arnebia euchroma (Royle) Johnst., and Arnebia guttata Bunge. As a bioactive compound, acetylshikonin has attracted much attention because of its broad pharmacological properties. OBJECTIVE: This review provides a comprehensive summary of the pharmacology, toxicity, and pharmacokinetics of acetylshikonin focussing on its mechanisms on the basis of currently available literature. METHODS: The information of acetylshikonin from 1977 to 2020 was collected using major databases including Elsevier, Scholar, PubMed, Springer, Web of Science, and CNKI. Acetylshikonin, pharmacology, toxicity, pharmacokinetics, and naphthoquinone derivative were used as key words. RESULTS: According to emerging evidence, acetylshikonin exerts a wide spectrum of pharmacological effects such as anticancer, anti-inflammatory, lipid-regulatory, antidiabetic, antibacterial, antifungal, antioxidative, neuroprotective, and antiviral properties. However, only a few studies have reported the adverse effects of acetylshikonin, with respect to reproductive toxicity and genotoxicity. Pharmacokinetic studies demonstrate that acetylshikonin is associated with a wide distribution and poor absorption. CONCLUSIONS: Although experimental data supports the beneficial effects of this compound, acetylshikonin cannot be considered as a therapy drug without further investigations, especially, on the toxicity and pharmacokinetics.

Acetylshikonin isolated from Lithospermum erythrorhizon roots inhibits dihydrofolate reductase and hampers autochthonous mammary carcinogenesis in Δ16HER2 transgenic mice.

Breast cancer (BC) is the most common cancer in women and, among different BC subtypes, triple negative (TN) and human epidermal growth factor receptor 2 (HER2)-positive BCs have the worst prognosis. In this study, we investigated the anticancer activity of the root ethanolic and hexane extracts from Lithospermum erythrorhizon, a traditional Chinese herbal medicine known also as tzu ts'ao or tzu-ken, against in vitro and in vivo models of TNBC and HER2-positive BC. Treatment with L. erythrorhizon root extracts resulted in a dose-dependent inhibition of BC cell viability and in a significant reduction of the growth of TNBC cells transplanted in syngeneic mice. Acetylshikonin, a naphthoquinone, was identified as the main bioactive component in extracts and was responsible for the observed antitumor activity, being able to decrease BC cell viability and to interfere with autochthonous mammary carcinogenesis in Δ16HER2 transgenic mice. Acetylshikonin anticancer effect depends on its ability to act as a potent inhibitor of dihydrofolate reductase (DHFR), to down-regulate key mediators governing cancer growth and progression, such as HER2, Src and STAT3, and to induce apoptosis by caspase-3 activation. The accumulation of acetylshikonin in blood samples as well as in brain, kidney, liver and tumor tissues was also investigated by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) highlighting that L. erythrorhizon treatment is effective in delivering the active compound into the target tissues. These results provide evidence that L. erythrorhizon extract and in particular its main component acetylshikonin are effective against aggressive BC subtypes and reveal new acetylshikonin mechanisms of action.

The Metabolism and Pharmacokinetics of Rhein and Aurantio-Obtusin.

BACKGROUND: Anthraquinones, rhein and aurantio-obtusin were isolated from the herb Duhaldea nervosa for the first time by our group, which were also found in plants that belong to the plant family Compositae. Anthraquinone compounds have a range of pharmacological activities such as anti-inflammatory, anti-cancer, antioxidation, anti-diabetes, etc. and can be used as a laxative, for liver protection, treatment of chronic renal failure, etc. However, in recent years, anthraquinones have been reported to be cytotoxic to the liver and kidneys. Therefore, it is very important to study the pharmacokinetics and metabolism of rhein and aurantio-obtusin, which are common ingredients in many traditional Chinese medicines (TCM). According to our research, the pharmacokinetics and metabolism of rhein and aurantio-obtusin are comprehensively summarized in the paper for the first time. OBJECTIVE: The study provides comprehensive information on pharmacokinetics and metabolism of rhein and aurantio- obtusin in different Species; meanwhile, the aim of this review is also to provide a reference for a reasonable application of TCM enriched with these two ingredients. METHODS: The metabolism and pharmacokinetics of rhein and aurantio-obtusin were searched by the Web of Science, PubMed, Google scholar and some Chinese literature databases. RESULTS: Rhein and aurantio-obtusin exist mainly in the form of metabolites in the body. Rhein and aurantio-obtusin and its metabolites might be responsible for pharmacological effects in the body. Therefore, the significance of studying the in vivo metabolites of rhein and aurantio-obtusin is not only essential to clarify their pharmacological mechanism, but also to find new active compound ingredients. The metabolism of rhein is different in different species, so the toxicity effects of rhein may also be different after oral administration in different species; however, the metabolic profiles of aurantio-obtusin in the liver microsomes of different species are similar. CONCLUSION: This paper not only provides detail regarding the pharmacokinetics of rhein and aurantio-obtusin, but it is anticipated that it will also facilitate further study on the metabolism of rhein and aurantio-obtusin.

Identification of rhein as the metabolite responsible for toxicity of rhubarb anthraquinones.

Rhubarb is a popular food in Europe with laxative properties attributed to anthraquinones. Long term usage of rhubarb anthraquinones has been linked to colonic toxicity, including the formation of melanosis coli, which is associated with increased risk of colon cancer. The major purgative anthraquinone in rhubarb is thought to be sennoside A, which is metabolised by colonic microflora. Here, we sought to identify the toxic metabolite responsible for melanosis coli in rats dosed with rhubarb anthraquinones for up to 90 days. Three metabolites were detected in rat faeces using HPLC. Of these, rhein was identified as the metabolite that accumulated most over time. Fecal flora from treated rats were capable of greater biotransformation of sennoside A to rhein compared to that from control rats. Cell culture experiments suggested that apoptosis and autophagy induced by rhein is the likely mechanism of chronic toxicity of rhubarb anthraquinones.

In vitro targeted screening and molecular docking of stilbene, quinones, and flavonoid on 3T3-L1 pre-adipocytes for anti-adipogenic actions.

In metabolic disorders like obesity, NAFLD and T2DM, adipocytes are dysfunctional. Hence, pharmacological interventions have importance in preventing differentiation of adipocytes and stimulating lipid uptake. We, therefore, investigated the effects of arbutin (ARB), purpurin (PUR), quercetin (QR), and pterostilbene (PTS) on adipocyte differentiation and lipid uptake using 3T3-L1 adipocytes. Further, in silico docking studies were achieved to investigate interactions of ARB, PUR, QR, and PTS with beta-ketoacyl reductase (KR) and thioesterase (TE) domains of fatty acid synthase (FAS) enzyme. Mature 3T3-L1 adipocytes were used to investigate the anti-adipogenic effect of selected pharmacological agents by Oil Red O staining and in vitro fatty acid uptake analysis. Molecular docking studies were performed to predict the binding interactions of selected compounds with KR and TE domains of FAS enzyme. All these agents significantly decrease the adipocyte differentiation and showed the stimulatory effect on fatty acid uptake in 3T3-L1 adipocytes. However, PTS and PUR proved to be anti-adipogenic, whereas ARB and QR showed significant effect on fatty acid uptake, compared to others. Similarly, all the compounds displayed significant binding interactions with KR and TE domains of FAS enzyme, supporting the results of in vitro studies. Graphical abstract.

Network Pharmacology and Bioactive Equivalence Assessment Integrated Strategy Driven Q-markers Discovery for Da-Cheng-Qi Decoction to Attenuate Intestinal Obstruction.

BACKGROUND: Intestinal obstruction (IO) is a kind of acute abdomen with high morbidity and mortality. Patients suffer from poor quality of life and tremendous financial pressure. Da-Cheng-Qi decoction (DCQD), a classical purgation prescription, has clinically been proven to be an effective treatment for IO. PURPOSE: Network pharmacology integrated with bioactive equivalence assessment was used to discover the quality marker (Q-marker) of DCQD against IO. METHODS: As there is hardly any targets recorded in database, thus the collection of IO targets was conducted by searching those of alternative diseases which have similar pathological symptoms with IO. In order to improve the reliability of the obtained targets, IO metabolomics data was introduced. Active compounds combination (ACC) was focused as potential Q-markers via component-target network analysis and function query from the identified components corresponding to the common targets. Bioequivalence between ACC and DCQD was assessed from the aspects of intestine motility (somatostatin secretion), inflammation (IL-6 secretion) and injury (wound healing assay) in vitro and was further validated in ileus rat model. PPI network analysis of core targets followed by gene pedigree classification and experimental validation confirmed the potential intervention pathway. RESULTS: A combination of 11 ingredients, including emodin, physcion, aloe-emodin, rhein, chrysophanol, gallic acid, magnolol, honokiol, naringenin, tangeretin, and nobiletin was finally confirmed bioequivalence with DQCD to some extent and could serve as Q-markers for DCQD to attenuate IO. PI3K/AKT was verified as a possible affected pathway that DCQD exerted the effectiveness against IO. CONCLUSION: For the disease with few recorded targets, searching those of alternative diseases which have similar pathological symptoms could be a feasible and effective approach. The proposed network pharmacology integrated bioactive equivalence evaluation paradigm is efficient to discover Q-marker of herbal formulae.

Discovery of necrosis avidity of rhein and its applications in necrosis imaging.

Necrosis-avid agents possess exploitable theragnostic utilities including evaluation of tissue viability, monitoring of therapeutic efficacy as well as diagnosis and treatment of necrosis-related disorders. Rhein (4,5-dihydroxyl-2-carboxylic-9,10-dihydrodiketoanthracene), a naturally occurring monomeric anthraquinone compound extensively found in medicinal herbs, was recently demonstrated to have a newly discovered necrosis-avid trait and to show promising application in necrosis imaging. In this overview, we present the discovering process of rhein as a new necrosis-avid agent as well as its potential imaging applications in visualisation of myocardial necrosis and early evaluation of tumour response to therapy. Moreover, the molecular mechanism exploration of necrosis avidity behind rhein are also presented. The discovery of necrosis avidity with rhein and the development of rhein-based molecular probes may further expand the scope of necrosis-avid compounds and highlight the potential utility of necrosis-avid molecular probes in necrosis imaging.

Development of an ultra-performance liquid chromatography-electrospray ionization-Orbitrap mass spectrometry method for determination of xanthopurpurin in rat plasma and its application to pharmacokinetic study.

A rapid and sensitive method was developed and validated for the quantitative determination of xanthopurpurin (XPP) in rat plasma using ultra-performance liquid chromatography-electrospray ionization-Orbitrap mass spectrometry. XPP inhibits IgE production and prevents peanut-induced anaphylaxis. The XPP and emodin (internal standard) were determined in negative ion mode with m/z 239.0350 → 211.0400 and 269.0455 → 241.0507, respectively. The separation process was achieved using an ACQUITY UPLC HSS T3 column with acetonitrile and 0.1% formic acid in water (85:15). The linear range was 0.5-100 ng/mL, and the correlation coefficient (r2 ) was > 0.993. The inter-day and intra-day precision was within an acceptable range of 15%. The extraction recovery and matrix effect were 78.9-87.2% and 94.3-98.5%, respectively. Under different conditions, the XPP was stable in the range of 5.6-10.6%. This method was successfully applied to study the pharmacokinetics of XPP with an oral dose of 10.0 mg/kg and intravenous dose of 2.0 mg/kg in rats. The absolute oral bioavailability of XPP was 4.6%.

Naphthoquinones, benzoquinones, and anthraquinones: Molecular docking, ADME and inhibition studies on human serum paraoxonase-1 associated with cardiovascular diseases.

Paraoxonase-1 (PON1) has essential roles such as protecting low-density lipoprotein against detoxification and oxidation of highly toxic compounds. Quinones are a class of compounds and a type of plant-derived secondary metabolites. Here, PON1 was purified using very simple methods and evaluation of the interactions between the enzyme and some quinones. It was found that these quinones displayed effective inhibitor properties for PON1 with the IC50 values in the range of 3.27-82.90 µM and the K i values in the range of 2.50 ± 0.65 to 30.90 ± 7.20 µM. These quinones displayed distinct inhibition mechanisms. It was determined that except for 5-hydroxy-2-methyl-1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone all quinones exhibit competitive inhibition effects. Also, molecular docking and in silico ADME studies were performed. Usage of drugs including quinone derivatives in structure with biological activity would be hazardous in some cases.

Pickering stabilized nanocellulose-alginate: A diosgenin-mediated delivery of quinalizarin as a potent cyto-inhibitor in human lung/breast cancer cell lines.

The current study explores the facile fabrication of multilayer self-assembled electrostatic oil-in-water Pickering emulsions (PEs) using quaternized nanocellulose (Q-NC) and diosgenin-conjugate alginate (DGN-ALG) particles as stabilizers to form hydrocolloid nanocarriers. The conditions of formulation such as storage time, pH, temperature and salt effect on the emulsion stability were evaluated. The results deduced showed good emulsion droplet stability over a period of 30 days. Morphological analysis revealed the hydrodynamic sizes of the PE droplets to be spherically shaped with an average diameter of 150 ± 3.51 nm. Creaming index, wettability and critical aggregation concentrations (CAC) as well as chemical characterization of the PEs were examined. In vitro release kinetics of encapsulated quinalizarin as a model drug was investigated with a determined cumulative drug release (CDR) of 89 ± 1.21% in simulated pH blood medium of pH 7.4. In addition, cellular internalization of the PEs was studied via confocal microscopy imaging and showed high cellular uptake. Also, evaluated in vitro cytotoxicity by MTT assay demonstrated excellent anticancer activity in human lung (A549) and breast (MCF-7) cancer cell lines.

A comparative pilot study of oral diacerein and locally treated diacerein-loaded nanoparticles in a model of osteoarthritis.

Diacerein (DIA) is a slow-acting drug for osteoarthritis (OA). Oral DIA administration, however, exerts side effects including diarrhea and urine discoloration. We fabricated DIA-loaded poly(d,l-lactide-co-glycolide) nanoparticles (DIA/PLGA NPs) that allow sustained release of DIA. In vitro, rat synoviocytes were used to investigate the cytotoxicity and anti-inflammatory effects of DIA-loaded NPs. In vivo, monosodium iodoacetate (MIA)-induced OA rats were divided into seven groups that included non-treated healthy control rats and rats injected with MIA alone or in combination with NPs, DIA(5%) solution, DIA(1%)/NPs, DIA(5%)/NPs, or oral DIA. The in vitro studies revealed that DIA/PLGA NPs dose-dependently suppressed mRNA levels of pro-inflammatory cytokines and enzymes, including interleukin-1 (IL-1), IL-6, tumor necrosis factor-α, matrix metalloproteinase-3 (MMP-3), MMP-13, cyclo-oxygenase-2, and a disintegrin and metalloproteinase with thrombospondin motifs-5 in synoviocytes. The in vivo studies demonstrated that intra-articular treatment of OA rat models with DIA-loaded PLGA NPs markedly decreased mRNA levels of these pro-inflammatory factors and increased those of anti-inflammatory cytokines (IL-4 and IL-10). Micro-computed tomography and histological evaluations indicated that intra-articular injection of DIA-loaded NPs was effective in protecting against cartilage degradation. Administration of DIA/PLGA NPs via intra-articular injection is promising for inhibiting inflammation and protecting against cartilage degradation in OA.