Crystal Structure, Solubility, and Pharmacokinetic Study on a Hesperetin Cocrystal with Piperine as Coformer

Hesperetin (HES) is a key biological active ingredient in citrus peels, and is one of the natural flavonoids that attract the attention of researchers due to its numerous therapeutic bioactivities that have been identified in vitro. As a bioenhancer, piperine (PIP) can effectively improve the absorption of insoluble drugs in vivo. In the present study, a cocrystal of HES and PIP was successfully obtained through solution crystallization. The single-crystal structure was illustrated and comprehensive characterization of the cocrystal was conducted. The cocrystal was formed by two drug molecules at a molar ratio of 1:1, which contained O–H–O hydrogen bonds between the carbonyl and ether oxygen of PIP and the phenolic hydroxyl group of HES. In addition, a solubility experiment was performed on powder cocrystal in simulated gastrointestinal fluid, and the result revealed that the cocrystal improves the dissolution behavior of HES compared with that of the pure substance. Furthermore, HES’s bioavailability in the cocrystal was six times higher than that of pristine drugs. These results may provide an efficient oral formulation for HES.

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Design, Synthesis, and Pharmacokinetic Evaluation of O-Carbamoyl Tizoxanide Prodrugs

Medicinal Chemistry ◽

10.2174/1573406416666201120102905 ◽

2020 ◽

Vol 16 ◽

Author(s):

Xi He ◽

Wenjun Hu ◽

Fanhua Meng ◽

Xingzhou Li

Keyword(s):

Plasma Concentration ◽

Broad Spectrum ◽

Plasma Concentrations ◽

Antiviral Drug ◽

Systemic Exposure ◽

Pharmacokinetic Profile ◽

Hydroxyl Group ◽

First Pass

Background: The broad-spectrum antiparasitic drug nitazoxanide (N) has been repositioned as a broad-spectrum antiviral drug. Nitazoxanide’s in vivo antiviral activities are mainly attributed to its metabolitetizoxanide, the deacetylation product of nitazoxanide. In reference to the pharmacokinetic profile of nitazoxanide, we proposed the hypotheses that the low plasma concentrations and the low system exposure of tizoxanide after dosing with nitazoxanide result from significant first pass effects in the liver. It was thought that this may be due to the unstable acyloxy bond of nitazoxanide. Objective: Tizoxanide prodrugs, with the more stable formamyl substituent attached to the hydroxyl group rather than the acetyl group of nitazoxanide, were designed with the thought that they might be more stable in plasma. It was anticipated that these prodrugs might be less affected by the first pass effect, which would improve plasma concentrations and system exposure of tizoxanide. Method: These O-carbamoyl tizoxanide prodrugs were synthesized and evaluated in a mouse model for pharmacokinetic (PK) properties and in an in vitro model for plasma stabilities. Results: The results indicated that the plasma concentration and the systemic exposure of tizoxanide (T) after oral administration of O-carbamoyl tizoxanide prodrugs were much greater than that produced by equimolar dosage of nitazoxanide. It was also found that the plasma concentration and the systemic exposure of tizoxanide glucuronide (TG) were much lower than that produced by nitazoxanide. Conclusion: Further analysis showed that the suitable plasma stability of O-carbamoyl tizoxanide prodrugs is the key factor in maximizing the plasma concentration and the systemic exposure of the active ingredient tizoxanide.

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Ultra-strong bio-glue from genetically engineered polypeptides

Nature Communications ◽

10.1038/s41467-021-23117-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Chao Ma ◽

Jing Sun ◽

Bo Li ◽

Yang Feng ◽

Yao Sun ◽

...

Keyword(s):

Soft Tissues ◽

Covalent Bond ◽

Genetically Engineered ◽

Supramolecular Interactions ◽

Molar Ratio ◽

High Adhesion ◽

Strong Adhesion ◽

Order Of Magnitude

AbstractThe development of biomedical glues is an important, yet challenging task as seemingly mutually exclusive properties need to be combined in one material, i.e. strong adhesion and adaption to remodeling processes in healing tissue. Here, we report a biocompatible and biodegradable protein-based adhesive with high adhesion strengths. The maximum strength reaches 16.5 ± 2.2 MPa on hard substrates, which is comparable to that of commercial cyanoacrylate superglue and higher than other protein-based adhesives by at least one order of magnitude. Moreover, the strong adhesion on soft tissues qualifies the adhesive as biomedical glue outperforming some commercial products. Robust mechanical properties are realized without covalent bond formation during the adhesion process. A complex consisting of cationic supercharged polypeptides and anionic aromatic surfactants with lysine to surfactant molar ratio of 1:0.9 is driven by multiple supramolecular interactions enabling such strong adhesion. We demonstrate the glue’s robust performance in vitro and in vivo for cosmetic and hemostasis applications and accelerated wound healing by comparison to surgical wound closures.

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Long-Acting Risperidone Dual Control System: Preparation, Characterization and Evaluation In Vitro and In Vivo

Pharmaceutics ◽

10.3390/pharmaceutics13081210 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1210

Author(s):

Xieguo Yan ◽

Shiqiang Wang ◽

Kaoxiang Sun

Keyword(s):

Drug Loading ◽

Entrapment Efficiency ◽

In Vitro Dissolution ◽

Dissolution Behavior ◽

In Vivo Evaluation ◽

Long Term Treatment ◽

Long Acting

Schizophrenia, a psychiatric disorder, requires long-term treatment; however, large fluctuations in blood drug concentration increase the risk of adverse reactions. We prepared a long-term risperidone (RIS) implantation system that can stabilize RIS release and established in-vitro and in-vivo evaluation systems. Cumulative release, drug loading, and entrapment efficiency were used as evaluation indicators to evaluate the effects of different pore formers, polymer ratios, porogen concentrations, and oil–water ratios on a RIS implant (RIS-IM). We also built a mathematical model to identify the optimized formulation by stepwise regression. We also assessed the crystalline changes, residual solvents, solubility and stability after sterilization, in-vivo polymer degradation, pharmacokinetics, and tissue inflammation in the case of the optimized formulation. The surface of the optimized RIS microspheres was small and hollow with 134.4 ± 3.5 µm particle size, 1.60 SPAN, 46.7% ± 2.3% implant drug loading, and 93.4% entrapment efficiency. The in-vitro dissolution behavior of RIS-IM had zero-order kinetics and stable blood concentration; no lag time was released for over three months. Furthermore, the RIS-IM was not only non-irritating to tissues but also had good biocompatibility and product stability. Long-acting RIS-IMs with microspheres and film coatings can provide a new avenue for treating schizophrenia.

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Effect of the cholesterol content of small unilamellar liposomes on their stability in vivo and in vitro

Biochemical Journal ◽

10.1042/bj1860591 ◽

1980 ◽

Vol 186 (2) ◽

pp. 591-598 ◽

Cited By ~ 398

Author(s):

Christopher Kirby ◽

Jacqui Clarke ◽

Gregory Gregoriadis

Keyword(s):

Blood Plasma ◽

Intravenous Injection ◽

Whole Blood ◽

Cholesterol Content ◽

Molar Ratio ◽

Phosphatidylcholine Liposomes ◽

Effective Use ◽

Positively Charged

Small unilamellar neutral, negatively and positively charged liposomes composed of egg phosphatidylcholine, various amounts of cholesterol and, when appropriate, phosphatidic acid or stearylamine and containing 6-carboxyfluorescein were injected into mice, incubated with mouse whole blood, plasma or serum or stored at 4°C. Liposomal stability, i.e. the extent to which 6-carboxyfluorescein is retained by liposomes, was dependent on their cholesterol content. (1) Cholesterol-rich (egg phosphatidylcholine/cholesterol, 7:7 molar ratio) liposomes, regardless of surface charge, remained stable in the blood of intravenously injected animals for up to at least 400min. In addition, stability of cholesterol-rich liposomes was largely maintained in vitro in the presence of whole blood, plasma or serum for at least 90min. (2) Cholesterol-poor (egg phosphatidylcholine/cholesterol, 7:2 molar ratio) or cholesterol-free (egg phosphatidylcholine) liposomes lost very rapidly (at most within 2min) much of their stability after intravenous injection or upon contact with whole blood, plasma or serum. Whole blood and to some extent plasma were less detrimental to stability than was serum. (3) After intraperitoneal injection, neutral cholesterol-rich liposomes survived in the peritoneal cavity to enter the blood circulation in their intact form. Liposomes injected intramuscularly also entered the circulation, although with somewhat diminished stability. (4) Stability of neutral and negatively charged cholesterol-rich liposomes stored at 4°C was maintained for several days, and by 53 days it had declined only moderately. Stored liposomes retained their unilamellar structure and their ability to remain stable in the blood after intravenous injection. (5) Control of liposomal stability by adjusting their cholesterol content may help in the design of liposomes for effective use in biological systems in vivo and in vitro.

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Drug Disposition in the Lower Gastrointestinal Tract: Targeting and Monitoring

Pharmaceutics ◽

10.3390/pharmaceutics13020161 ◽

2021 ◽

Vol 13 (2) ◽

pp. 161

Author(s):

Glenn Lemmens ◽

Arno Van Camp ◽

Stephanie Kourula ◽

Tim Vanuytsel ◽

Patrick Augustijns

Keyword(s):

Drug Absorption ◽

Drug Disposition ◽

Drug Stability ◽

Ussing Chamber ◽

Dissolution Kinetics ◽

Comprehensive Overview ◽

Drug Molecules ◽

Epithelial Physiology

The increasing prevalence of colonic diseases calls for a better understanding of the various colonic drug absorption barriers of colon-targeted formulations, and for reliable in vitro tools that accurately predict local drug disposition. In vivo relevant incubation conditions have been shown to better capture the composition of the limited colonic fluid and have resulted in relevant degradation and dissolution kinetics of drugs and formulations. Furthermore, drug hurdles such as efflux transporters and metabolising enzymes, and the presence of mucus and microbiome are slowly integrated into drug stability- and permeation assays. Traditionally, the well characterized Caco-2 cell line and the Ussing chamber technique are used to assess the absorption characteristics of small drug molecules. Recently, various stem cell-derived intestinal systems have emerged, closely mimicking epithelial physiology. Models that can assess microbiome-mediated drug metabolism or enable coculturing of gut microbiome with epithelial cells are also increasingly explored. Here we provide a comprehensive overview of the colonic physiology in relation to drug absorption, and review colon-targeting formulation strategies and in vitro tools to characterize colonic drug disposition.

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Effects of dietary alteration of bicarbonate and magnesium on rat bone

AJP Renal Physiology ◽

10.1152/ajprenal.1986.250.2.f302 ◽

1986 ◽

Vol 250 (2) ◽

pp. F302-F307 ◽

Cited By ~ 4

Author(s):

J. M. Burnell ◽

C. Liu ◽

A. G. Miller ◽

E. Teubner

Keyword(s):

Crystal Structure ◽

Bone Formation ◽

X Ray Diffraction ◽

X Ray ◽

Growing Rats ◽

Final Composition ◽

Rat Bone

To study the effects of bicarbonate and magnesium on bone, mild acidosis and/or hypermagnesemia were produced in growing rats by feeding ammonium chloride and/or magnesium sulfate. Bone composition, quantitative histomorphometry, and mineral x-ray diffraction (XRD) characteristics were measured after 6 wk of treatment. The results demonstrated that both acidosis (decreased HCO3) and hypermagnesemia inhibited periosteal bone formation, and, when combined, results were summative; and the previously observed in vitro role of HCO3- and Mg2+ as inhibitors of crystal growth were confirmed in vivo. XRD measurements demonstrated that decreased plasma HCO3 resulted in larger crystals and increased Mg resulted in smaller crystals. However, the combined XRD effects of acidosis and hypermagnesemia resembled acidosis alone. It is postulated that the final composition and crystal structure of bone are strongly influenced by HCO3- and Mg2+, and the effects are mediated by the combined influence on both osteoblastic bone formation and the growth of hydroxyapatite.

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Epimers of Vitamin D: A Review

International Journal of Molecular Sciences ◽

10.3390/ijms21020470 ◽

2020 ◽

Vol 21 (2) ◽

pp. 470 ◽

Cited By ~ 7

Author(s):

Bashar Al-Zohily ◽

Asma Al-Menhali ◽

Salah Gariballa ◽

Afrozul Haq ◽

Iltaf Shah

Keyword(s):

Vitamin D ◽

Biological Activity ◽

Hydroxyl Group ◽

Vitamin D Metabolites ◽

Dihydroxyvitamin D3 ◽

In Vivo Models ◽

Vitamin D Receptors ◽

Potential Factors

In this review, we discuss the sources, formation, metabolism, function, biological activity, and potency of C3-epimers (epimers of vitamin D). We also determine the role of epimerase in vitamin D-binding protein (DBP) and vitamin D receptors (VDR) according to different subcellular localizations. The importance of C3 epimerization and the metabolic pathway of vitamin D at the hydroxyl group have recently been recognized. Here, the hydroxyl group at the C3 position is orientated differently from the alpha to beta orientation in space. However, the details of this epimerization pathway are not yet clearly understood. Even the gene encoding for the enzyme involved in epimerization has not yet been identified. Many published research articles have illustrated the biological activity of C3 epimeric metabolites using an in vitro model, but the studies on in vivo models are substantially inadequate. The metabolic stability of 3-epi-1α,25(OH)2D3 has been demonstrated to be higher than its primary metabolites. 3-epi-1 alpha, 25 dihydroxyvitamin D3 (3-epi-1α,25(OH)2D3) is thought to have fewer calcemic effects than non-epimeric forms of vitamin D. Some researchers have observed a larger proportion of total vitamin D as C3-epimers in infants than in adults. Insufficient levels of vitamin D were found in mothers and their newborns when the epimers were not included in the measurement of vitamin D. Oral supplementation of vitamin D has also been found to potentially cause increased production of epimers in mice but not humans. Moreover, routine vitamin D blood tests for healthy adults will not be significantly affected by epimeric interference using LC–MS/MS assays. Recent genetic models also show that the genetic determinants and the potential factors of C3-epimers differ from those of non-C3-epimers.Most commercial immunoassays techniques can lead to inaccurate vitamin D results due to epimeric interference, especially in infants and pregnant women. It is also known that the LC–MS/MS technique can chromatographically separate epimeric and isobaric interference and detect vitamin D metabolites sensitively and accurately. Unfortunately, many labs around the world do not take into account the interference caused by epimers. In this review, various methods and techniques for the analysis of C3-epimers are also discussed. The authors believe that C3-epimers may have an important role to play in clinical research, and further research is warranted.

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An In-Silico Study on Selected Organosulfur Compounds as Potential Drugs for SARS-CoV-2 Infection via Binding Multiple Drug Targets

10.26434/chemrxiv.12505343 ◽

2020 ◽

Author(s):

Liya Thurakkal ◽

Satyam Singh ◽

Sushabhan Sadhukhan ◽

Mintu Porel

Keyword(s):

Drug Targets ◽

Target Prediction ◽

Multiple Drug ◽

Organosulfur Compounds ◽

Potential Candidate ◽

Health Crisis ◽

Drug Molecules ◽

Main Protease

The emerging paradigm shift from ‘one molecule, one target, for one disease’ towards ‘multi-targeted small molecules’ has paved an ingenious pathway in drug discovery in recent years. This idea has been extracted for the investigation of competent drug molecules for the unprecedented COVID-19 pandemic which became the greatest global health crisis now. Perceiving the importance of organosulfur compounds against SARS-CoV-2 from the drugs under clinical trials, a class of organosulfur compounds effective against SARS-CoV were selected and studied the interaction with multiple proteins of the SARS-CoV-2. One compound displayed inhibition against five proteins (both structural and non-structural) of the virus namely, main protease, papain-like protease, spike protein, helicase and RNA dependent RNA polymerase. Consequently, this compound emanates as a potential candidate for treating the virulent disease. The pharmacokinetics, ADMET properties and target prediction studies carried out in this work further inflamed the versatility of the compound and urge to execute in-vitro and in-vivo analysis on SARS-CoV-2 in the future.

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Steroidal glycoalkaloids fromSolanum nigrumtarget cytoskeletal proteins: anin silicoanalysis

PeerJ ◽

10.7717/peerj.6012 ◽

2019 ◽

Vol 7 ◽

pp. e6012 ◽

Cited By ~ 2

Author(s):

Rumana Ahmad

Keyword(s):

Binding Affinity ◽

Anticancer Agents ◽

Principal Component ◽

Cytoskeletal Proteins ◽

Hydroxyl Group ◽

Docking Analysis ◽

Drug Candidates ◽

Division Cell

BackgroundSolanum nigrum(black nightshade;S. nigrum), a member of family Solanaceae, has been endowed with a heterogeneous array of secondary metabolites of which the steroidal glycoalkaloids (SGAs) and steroidal saponins (SS) have vast potential to serve as anticancer agents. Since there has been much controversy regarding safety of use of glycoalkaloids as anticancer agents, this area has remained more or less unexplored. Cytoskeletal proteins like actin play an important role in maintaining cell shape, synchronizing cell division, cell motility, etc. and along with their accessory proteins may also serve as important therapeutic targets for potential anticancer candidates. In the present study, glycoalkaloids and saponins fromS. nigrumwere screened for their interaction and binding affinity to cytoskeletal proteins, using molecular docking.MethodsBioactivity score and Prediction of Activity Spectra for Substances (PASS) analysis were performed using softwares Molinspiration and Osiris Data Explorer respectively, to assess the feasibility of selected phytoconstituents as potential drug candidates. The results were compared with two standard reference drugs doxorubicin hydrochloride (anticancer) and tetracycline (antibiotic). Multivariate data obtained were analyzed using principal component analysis (PCA).ResultsDocking analysis revealed that the binding affinities of the phytoconstituents towards the target cytoskeletal proteins decreased in the order coronin>villin>ezrin>vimentin>gelsolin>thymosin>cofilin. Glycoalkaloid solasonine displayed the greatest binding affinity towards the target proteins followed by alpha-solanine whereas amongst the saponins, nigrumnin-I showed maximum binding affinity. PASS Analysis of the selected phytoconstituents revealed 1 to 3 violations of Lipinski’s parameters indicating the need for modification of their structure-activity relationship (SAR) for improvement of their bioactivity and bioavailability. Glycoalkaloids and saponins all had bioactivity scores between −5.0 and 0.0 with respect to various receptor proteins and target enzymes. Solanidine, solasodine and solamargine had positive values of druglikeness which indicated that these compounds have the potential for development into future anticancer drugs. Toxicity potential evaluation revealed that glycoalkaloids and saponins had no toxicity, tumorigenicity or irritant effect(s). SAR analysis revealed that the number, type and location of sugar or the substitution of hydroxyl group on alkaloid backbone had an effect on the activity and that the presence of α-L-rhamnopyranose sugar at C-2 was critical for a compound to exhibit anticancer activity.ConclusionThe present study revealed some cytoskeletal target(s) forS. nigrumphytoconstituents by docking analysis that have not been previously reported and thus warrant further investigations bothin vitroandin vivo.

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A specialized flavone biosynthetic pathway has evolved in the medicinal plant,Scutellaria baicalensis

Science Advances ◽

10.1126/sciadv.1501780 ◽

2016 ◽

Vol 2 (4) ◽

pp. e1501780 ◽

Cited By ~ 58

Author(s):

Qing Zhao ◽

Yang Zhang ◽

Gang Wang ◽

Lionel Hill ◽

Jing-Ke Weng ◽

...

Keyword(s):

Herbal Remedy ◽

Wide Spectrum ◽

Human Tumor ◽

Scutellaria Baicalensis ◽

Hydroxyl Group ◽

Mouse Tumor ◽

Gene Encoding ◽

Beneficial Effects

Wogonin and baicalein are bioactive flavones in the popular Chinese herbal remedy Huang-Qin (Scutellaria baicalensisGeorgi). These specialized flavones lack a 4′-hydroxyl group on the B ring (4′-deoxyflavones) and induce apoptosis in a wide spectrum of human tumor cells in vitro and inhibit tumor growth in vivo in different mouse tumor models. Root-specific flavones (RSFs) fromScutellariahave a variety of reported additional beneficial effects including antioxidant and antiviral properties. We describe the characterization of a new pathway for the synthesis of these compounds, in which pinocembrin (a 4′-deoxyflavanone) serves as a key intermediate. Although two genes encoding flavone synthase II (FNSII) are expressed in the roots ofS.baicalensis, FNSII-1 has broad specificity for flavanones as substrates, whereas FNSII-2 is specific for pinocembrin. FNSII-2 is responsible for the synthesis of 4′-deoxyRSFs, such as chrysin and wogonin, wogonoside, baicalein, and baicalin, which are synthesized from chrysin. A gene encoding a cinnamic acid–specific coenzyme A ligase (SbCLL-7), which is highly expressed in roots, is required for the synthesis of RSFs by FNSII-2, as demonstrated by gene silencing. A specific isoform of chalcone synthase (SbCHS-2) that is highly expressed in roots producing RSFs is also required for the synthesis of chrysin. Our studies reveal a recently evolved pathway for biosynthesis of specific, bioactive 4′-deoxyflavones in the roots ofS.baicalensis.

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