Latest ArticlesCyclin-dependent kinase 5 (CDK5), a serine/threonine kinase, is one of the non-typical members of the CDKs family. CDK5 is mainly activated by non-cyclin activators p35 or p39 (as well as their respective fragments p25 and p29) to phosphorylate downstream substrates and regulate numerous neural and non-neural functions. Increasing evidence has confirmed that the overactivation of CDK5/p25 complex is closely related to neurodegenerative diseases, cancers, diabetes and inflammation. Consequently, CDK5 has become an important target in multiple diseases treatment. Nevertheless, to date, no selective CDK5 inhibitors are currently in the clinical stage. On the other hand, pan-CDK inhibitors are limited in clinical trials, due to their poor clinical efficacy and toxic side effects caused by the extensive inhibition of other kinases. In view of this, selective CDK5 inhibitors are of great significance not only for elucidating its exact biological functions, but also exploring the possibility of CDK5 inhibitors as a safe and effective therapy. This paper provides a brief overview of the structure and function of CDK5 protein as well as its relationship with diseases. In addition, the structural types and binding modes of CDK5 inhibitors targeting ATP active sites are also highlighted. Finally, we summarize and prospect the strategies to improve the selectivity of CDK5 inhibitors.
The conventional oral drug delivery frequently results in the drug elimination before its complete release due to rapid gastric emptying and short gastrointestinal transport time, thus reducing the bioavailability of drug. In order to maintain an effective concentration of drug in the body and maximize its optimal efficacy, the frequency of administrations often needs to be increased. By contrast, gastric retention drug delivery system (GRDDS), as an innovative method of drug delivery, prolongs the retention time of the drug in the stomach and reduces irritation to the gastrointestinal tract. Consequently, it enhances the bioavailability of drug, reduces dosing frequency for patients and improves treatment adherence. In recent years, domestic and foreign studies have been conducted on gastric retention drug delivery systems. Here, we provide a comprehensive overview of the relevant literature published in recent years, examining their current marketing status, various types, as well as in vivo and in vitro evaluation methods.
Ten compounds were isolated and purified from the dichloromethane extract of stems of Ephedra intermedia by various chromatographic methods. Based on the analysis of physicochemical properties and spectral data, the structures of the ten compounds were identified as 1-allyl-3, 4-dimethoxy-benzene-5-O-β-D-glucopyranoside (1), lyoniresinol (2), secoisolariciresinol (3), 4, 3′, 4′-trihydroxy-3-methoxylignan-9, 9′-diyldiacetate (4), dehydroconiferyl alcohol (5), isocubebin (6), balanophonin B (7), sesquipinsapol B (8), crataegifin A (9), 1-(2-(4-hydroxy-3-methoxyphenyl)-3-(hydroxymethyl)-7-methoxy-2, 3-dihydrobenzofuran-5-yl)ethan-1-one (10). Compound 1 is a new compound, named as 1-allyl-3, 4-dimethhoxy-benzene-5-O-β-D-glucopyranosyl, compounds 2-10 are lignans and isolated from this plant for the first time. Compound 3, 4, 8 possess potentially anti-asthmatic activities.
Evaluate the interventional effect of Lycium barbarum leaves extract on cataract rats and its effects on plasma and liver tissue metabolites. The ultimate goal is to explore the scientific connotation of Lycium barbarum leaves extract on vision improvement. All experiments were approved by the experimental animal ethics committee from Nanjing University of Chinese Medicine (202306A067). D-Galactose (D-gal) induced cataract model in rats was established. The lens opacity, lens and liver tissue pathology, level of oxidative stress and polyol metabolism regulation in the lens, level of oxidative stress in serum and liver tissue, and the content of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in serum and liver tissue were analysed to evaluate the effect of Lycium barbarum leaves extract on cataract. The metabolite profiles of plasma and liver tissue of rats were analyzed by UPLC-QTOF-MS/MS. Principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) were used to compare and analyze the metabolic data in control group and cataract group, and screen potential biomarkers. The related metabolic pathways were further constructed by KEGG database analysis. The results showed that lens and liver pathology of cataract rats were improved after being intervened by the leaves extract of Lycium barbarum. The contents of AR and Ca2+ were significantly decreased in lens, and the contents of SDH and GSH and the ability of CAT were significantly increased; the content of GSH and the ability of SOD were significantly improved in serum and liver tissue, the content of MDA, the abilities of ALT and AST and the level of inflammatory factors were significantly reduced. The metabolomics results showed that there were 15 different metabolites in plasma and liver tissue of cataract rats, and 9 different biomarkers including retinyl ester, stearic acid, and palmitic acid, were returned by Lycium barbarum leaves extract. As revealed by pathway enrichment in plasma and liver tissue, it was found that the retinol metabolic pathway was mainly regulated by Lycium barbarum leaves extract. In summary, Lycium barbarum leaves can effectively alleviate the pathological changes of cataract, inhibit inflammation and improve antioxidant capacity, which may relate to the retinol metabolic pathway. It provides scientific basis and support for revealing the scientific connotation of the effect of Lycium barbarum leaves on vision improvement.
Tablets represent the most widely used oral solid dosage form in the pharmaceutical industry. Puerarin monohydrate (PUEM), a solid form of the natural antihypertensive drug puerarin, is commercially available. However, the low solubility of PUEM poses a significant challenge for the development of its tablet dosage form. In this study, we successfully prepared the sodium chelates of puerarin (PUE-Na·7H2O) using reactive crystallization techniques. The crystal structure of PUE-Na·7H2O was analyzed using single crystal technology, which revealed the structural characteristics of its metal chelate. Our thermodynamic studies demonstrated that the formation of PUE-Na·7H2O involved the simultaneous deprotonation of PUE and the chelation of PUE- and Na+. This reaction process was spontaneous and exothermic (ΔG < 0, ΔH < 0), and reducing the temperature facilitated the formation of the chelate. Nucleation kinetics studies revealed that chelate molecules were more likely to nucleate and crystallize under low temperature, high concentration, and high rotational speed conditions. Compared to commercially available PUEM, PUE-Na·7H2O showed significantly improved water solubility, with a 33.5-fold increase in solubility and a 37.6-fold decrease in intrinsic dissolution rate. Our study identified drug-sodium chelation as an effective means for improving drug solubility and elucidated the mechanisms governing its formation kinetics and thermodynamics. These findings could provide new solutions for related product development and tremendous commercial opportunities.
In this study, deep eutectic solvents (DESs) were used as excipients to prepare solid dispersion (SD) of scutellarin. The SD of scutellarin were prepared by melting method with cumulative dissolution rate as the index of investigation. The preparation conditions of SD of scutellarin were optimized by single factor experiment, which investigated the type of the carrier material, the type of DESs, and the ratio of the drug to the carrier. The optimum preparation conditions of DESs-SD were as follows: using Poloxamer 407 as the carrier material, PEG 200/urea (2∶1) as the DESs system, and the ratio of carrier, DESs, and drug was 6∶1∶1. The drug loading capacity of scutellarin in SD was 12.53% under the optimum preparation conditions. Differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray powder diffraction and scanning electron microscope exhibited that scutellarin was amorphous form in the SD system. Furthermore, the stability of the DESs-based SD of scutellarin was evaluated by high temperature, high humidity, and strong light tests, which showed that the cumulative dissolution rate and scutellarin content of SD decreased with time under these conditions. Finally, the result of pharmacokinetic studies indicated that the oral absorption of the scutellarin could be increased using DESs as an excipient in the preparation of SD. The animal experiment was approved by the Experimental Animal Ethics Committee of Fujian University of Traditional Chinese Medicine (approval number: FJTCMIACUC 2023048). Consequently, this research offers a novel and effective approach for using DESs to enhance the oral bioavailability of active substances with low water solubility.
The pathogenesis of depression is complex, and some existing monoamine antidepressants have problems such as drug resistance or off-target failure. Traditional Chinese medicine has the characteristics of "multi-component and multi-target", and has been used in the treatment of depression in clinical practice. Yueju pill is effective in the treatment of depression. Geniposide and ligustrazine, the active ingredients of Gardeniae fructus and Ligusticum sinense 'Chuanxiong', play a key role in the treatment of depression. In this study, based on the neuroprotective activity of genipin and the rapid antidepressant activity of tetramethylpyrazine, a series of novel genipin derivatives were designed and synthesized through pharmacophore assembly principle, and their neuroprotective activity and antidepressant effect were investigated. The results showed that the novel genipin derivatives had well neuroprotective activity on the glutamate-induced HT-22 cell model, with compounds W-1 and W-3 showing better protective activity. In behavioral despair depression (BDD) model mice, compound W-3 was found to have better antidepressant activity than W-1 in tail suspension test and forced swimming test. Further study on the behavior of chronic unpredictable mild stress (CUMS) model mice showed that W-3 could significantly improve the depression-like behavior of model mice. All animal experiments were approved by the Experimental Animal Ethics Committee of Anhui University of Chinese Medicine (approval number: AHUCM-mouse-2022027). The effects of the preferred compound W-3 on protein kinase A (PKA), cAMP response element binding protein (CREB), brain-derived neurotrophic factor (BDNF), 5-hydroxytryptamine 1A (5-HT1A) receptor, N-methyl-D-aspartate ionic glutamate receptor 2A (GluN2A) and N-methyl-D-aspartate ionic glutamate receptor 2B (GluN2B) were analyzed by Western blot. W-3 treatment significantly up-regulated the protein expression of PKA, CREB, BDNF and 5-HT1A, and down-regulated the protein expression of GluN2A and GluN2B. The results of qRT-PCR were consistent with those of Western blot. According to the above results, compound W-3 has a potential antidepressant effect, and its mechanism may be related to the activation of PKA-CREB-BDNF signaling pathway by regulating the expression of GluN2A, GluN2B and 5-HT1A receptor proteins.
Nitazoxanide is an FDA-approved antiprotozoal drug. Our previous study found that oral administration of nitazoxanide inhibited Western diet (WD)-induced hepatic steatosis in ApoE-/- mice. However, the specific mechanism remains to be elucidated. In the present study, we performed an untargeted metabolomics approach to reveal the effect of nitazoxanide on the liver metabolic profiles in WD-fed ApoE-/- mice, and carried out the cellular experiments to elucidate the underlying mechanisms. UPLC-MS-based untargeted metabolomics analysis was used to investigate the effect of nitazoxanide on global metabolite changes in liver tissues. The differential metabolites were screened for enrichment analysis and pathway analysis. Hepatocytes were treated with tizoxanide, the metabolite of nitazoxanide, to investigate the underlying mechanism based on the findings in metabolomics study. The improvement of liver lipid metabolism disorders by nitazoxanide treatment in WD-fed ApoE-/- mice was mainly through regulating glycerophospholipid metabolism, D-glutamine and glutamate metabolism, glutathione metabolism, and arginine biosynthesis metabolism. Tizoxanide, the active metabolite of nitazoxanide, increased glutathione (GSH) contents and glutamate-cysteine ligase catalytic subunit (Gcl-c) and glutathione reductase (Gsr) mRNA expressions in HepG2 cells. Tizoxanide increased cystathionine β-synthase (CBS) and phosphatidylethanolamine N-methyltransferase (PEMT) protein levels, inhibited lipid accumulation in hepatocytes induced by free fatty acid (FFA). Tizoxanide increased S-adenosyl-L-homocysteine hydrolase (SAHH) protein levels in HepG2 cells and mouse primary liver cells stimulated with free fatty acid (FFA). Tizoxanide increased N-acetyl glutamate synthase (Nags) and carbamoylphosphate synthetase 1 (Cps1) mRNA expressions in HepG2 cells. In conclusion, nitazoxanide improves WD-induced hepatic steatosis in ApoE-/- mice and the underlying mechanisms include increasing CBS expression, GSH content, PEMT protein expression, Nags and Cps1 mRNA expression in hepatocytes.
Pharmaceutical cocrystals is an advanced technology to improve the physicochemical and biological properties of drugs. However, there are few studies on the in vivo metabolism of pharmaceutical cocrystals. In this study, the pharmacokinetics of wogonin cocrystal in normal rats was further studied on the basis of the previous preparation of wogonin-aloperine cocrystal. Firstly, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for simultaneous determination of wogonin and its metabolite wogonoside in rat plasma, and to investigate the methodology. The method was applied to the pharmacokinetic study of wogonin-aloperine cocrystal (Wog-Alop) in rats. The results showed that wogonin and its metabolite wogonoside had a good linear relationship in the range of 1-800 ng·mL-1, and the precision, accuracy, matrix effect and stability in this range met the requirements of biological analysis. Compared with direct administration of wogonin, the Cmax of wogonin and its metabolite in rats increased to 7.44-fold and 9.15-fold, AUC0-t increased to 1.67-fold and 3.72-fold, and oral bioavailability of wogonin increased to 187.66% after cocrystal administration. Wog-Alop cocrystal can significantly improve the Cmax, AUC, and oral bioavailability of wogonin and its metabolite, which provides a new perspective for the clinical application of wogonin. This study was approved by the Experimental Animal Ethics Review Committee of Beijing University of Chinese Medicine (approval number: BUCM-2023032307-1148).
Liver is the main organ of glucose and lipid metabolism, and persistent hyperglycemia is a common cause of liver injury. Panax notoginsenosides (PNS) is the main active ingredient in Panax notoginseng, which have anti-inflammatory and antioxidant effects. In this study, quantitative proteomics combined with experimental verification was used to explore the protective effect of PNS on liver injury in type 2 diabetes mellitus (T2DM) mice and its potential mechanism. All experiments were approved by the Ethical Committee Experimental Animal Center of North Sichuan Medical College (NSMC2022023). Hematoxylin-eosin (H & E) staining and transmission electron microscopy were used to observe the effect of PNS on the histopathological changes of liver in T2DM mice. TdT-mediated dUTP Nick-end labeling (TUNEL) staining was used to analyze the effect of PNS on hepatocyte apoptosis in T2DM mice. Reactive oxygen species (ROS) and malonaldehyde (MDA) kits were used to detect the effect of PNS on oxidative damage of liver in T2DM mice. Subsequently, proteomics profiling of mice in T2DM and T2DM+PNS groups were investigated based on quantitative proteomics. Differentially expressed proteins were screened out according to fold change and significance level in T2DM and T2DM+PNS groups, respectively. Pathway enrichment analysis of these differential proteins was done using GeneAnalytics database. Gene ontology analysis was conducted by Metascape database. Protein-protein interaction networks were constructed based on STRING database. Western blot was used to detect protein expression. These results showed that PNS could improve liver abnormalities, inhibit hepatocyte apoptosis, and improve the morphology of mitochondria and endoplasmic reticulum in T2DM mice. Proteome data demonstrated that 489 genes expression changed significantly in liver of T2DM mice compared with normal, and 42 ones were significantly reversed after PNS treatment and returned to normal levels. Pathway analysis showed that sterol hormone biosynthesis, adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling pathway, oxidative stress, insulin signaling, phosphatidylinositol pathway, tumor necrosis factor-α (TNF-α) mediated inflammation, insulin resistance, and mTOR signaling pathway exhibited notable changes based on pathway enrichment ratio and significance level. It is worth noting that PNS could improve the abnormal changes of AMPK, TNF-α, apoptosis and insulin pathways. Western blot manifested that PNS inhibit the expression of Bax, Grp78 and Chop, reduce ratio of cleaved casp6/casp6, increase the levels of pAMPKα, HO-1 and Nu-Nrf2 in the liver of T2DM mice. These results suggested that PNS may play protective roles in the liver of T2DM mice by inhibiting apoptosis via activating AMPK/Nrf2/HO-1 signaling pathway, alleviating oxidative stress and endoplasmic reticulum stress.