Latest ArticlesBexarotene is a synthetic analogue of retinoic acid and exerts protective effects on the nervous system. However, low bioavailability and poor solubility of the crystal type I form severely limits the application of bexarotene in the clinic. A co-amorphous sample of bexarotene-PVP-K30 was prepared and the structure was characterized by X-ray diffraction and infrared spectroscopy. To determine the pharmacokinetics and tissue distribution of bexarotene, an LC-MS method was established to profile and quantify bexarotene in plasma and tissues of SD rats. In vitro dissolution indicated that the co-amorphous form improved the dissolution of bexarotene in pure water 4.17-fold. After rats were orally administered bexarotene or bexarotene-PVP-K30 co-amorphous (equivalent to 30 mg·kg-1 bexarotene) the AUC of bexarotene was 7 034.89 and 10 174.03 μg·L-1·h respectively, the peak time was advanced from 7.33 h to 0.9 h with the amorphous form, and Cmax was enhanced from 627.76 to 3 011.88 μg·L-1. The co-amorphous form yielded higher concentrations of bexarotene in various tissues, especially brain, liver and kidney. Animal welfare and experimental procedures complied with the rules of the Animal Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences. The results indicate that bexarotene-PVP-K30 co-amorphous improves the pharmacokinetic characteristics of bexarotene and provides preclinical data in support of bexarotene-PVP-K30 for the treatment of brain diseases.
Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the content of cadmium (Cd) and arsenic (As) in earthworms. A physiologically-based extraction test (PBET) digestion in vitro/MDCK cell model was established to investigate the bioaccessibility of Cd and As in earthworms. The hazard index (HI) method and the margin of exposure (MOE) method were used to assess the risks of the total content and the bioaccessible content of Cd and As. The results showed that the total content of Cd and As in six batches of earthworms ranged from 8.319 to 33.606 mg·kg-1 and from 0.532 to 16.412 mg·kg-1, respectively. After uptake by MDCK cells, the bioaccessibility of Cd in earthworms ranged from 10.13% to 64.16%, and the bioaccessibility of As was from 2.72% to 46.57%. The results of risk assessment showed that before uptake by MDCK cells, the MOE values of As and HI values of Cd for all batches of earthworms were greater than 1, which suggests that the risks of As are acceptable but the risks of Cd are unacceptable. After transportation by MDCK cells, except for one batch of earthworms, the HI values of Cd in the other five batches were less than 1, which suggests that the risks are at a safe level. This study provides important technical support for a more objective and scientific assessment of the health risks of heavy metals in traditional Chinese medicines, and for a more scientific and reasonable standard limit of heavy metals.
"Beany flavor" is one of the important authentic characteristics of Astragali Radix. It is important to clarify the material basis of "Beany flavor" in the characterization of authentic medicinal materials and establishing quality control methods for authentic medicinal materials. At present, the analysis of volatile components in different habitats has been reported, but systematic comprehensive research has not been conducted. The SPME-GC-MS technique was used to analyze the volatile components of Astragali Radix from three producing areas:Shanxi (wild-simulated Astragali Radix), Gansu (cultivated Astragali Radix) and Inner Mongolia (cultivated Astragali Radix). Combined with the method of multivariate statistical analysis, the difference of volatile components of Astragali Radix from the three different producing areas is discussed. Multivariate statistical analysis and evaluation was conducted through principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). Seventy-six volatile components of Astragali Radix from the three producing areas were identified by SPME-GC-MS. PCA model results showed that the volatile components correlated with their producing areas. PLS-DA demonstrated that the volatile components of Astragali Radix samples from different producing areas were significantly different. Six volatile substances including hexanoic acid, hexanal, 2-butyl-2-octenal, 1-hexanol, benzyl alcohol and 2-butylfuran were quantified. The ratio of hexanal to hexanoic acid in Astragali Radix from different areas and cultivation methods was significantly different:the ratio of hexanal:hexanoic acid in wild-simulated Astragali Radix of Shanxi was 7.8:1, while the ratio of hexanal:hexanoic acid in cultivated Astragali Radix of Inner Mongolia and Gansu was 2.3:1 and 0.96:1, respectively. The volatile components identified in this study provide a foundation for continued research of and quality control of Astragali Radix.
To investigate the antitumor activity of shikonin against human colorectal cancer, the IC50 value towards four different human colon cancer cells was detected by MTT assay. In addition, a SW620 xenograft model was established and both the tumor volume and tumor inhibitory rate were calculated to evaluate the antitumor activity of shikonin in vivo. To further explore the mechanism of shikonin, metabolomics combined with multivariate statistical analysis was performed to analyse the profile of metabolites in mouse serum. The results show that shikonin can significantly inhibit the proliferation of four different colon cancer cell lines and exerted a high antitumor activity in vivo. The tumor inhibitory rate at low dose and high dose were 38.35% and 42.16%, respectively. In addition, a total of 38 potential biomarkers related to the antitumor effects of shikonin were identified through metabolomics analysis, including tryptophan, proline and methionine. The study revealed that the mechanism was related to disordered amino acid metabolism in colon cancer, especially in tryptophan metabolism. Our study suggests that shikonin could exert an antitumor effect by regulating amino acid metabolism in colon cancer and provides a theoretical foundation for further exploration and the eventual clinical application of shikonin.
One of pathological features of Alzheimer's disease (AD) is extracelluar aggregation of amyloid-β protein (Aβ) forming senile plaques. Investigation on inhibition of Aβ aggregation can be crucial for designing effective drugs against AD. Previous studies have demonstrated that the deamidation at Asn27, a type of post translation modification, significantly prevented the polymerization of Aβ monomers. But the underlying mechanism is still unclear. Therefore, we investigated the possible effect of Asn27 deamidation on structure and aggregation of Aβ42 monomer using molecular dynamics simulation. The results showed that the deamidation of Asn27 can directly disrupt the salt bridge formed between D23 and K28, and effectively decrease the content of β-sheet that is important for aggregation of Aβ. Moreover, the inability at C-terminal region (CTR) and N-terminal region (NTR) to form antiparallel β-sheets further weakens the intra-peptide interaction of Aβ42 monomer. These changes caused by Asn27 deamidation lead to the decline of the aggregated trend of Aβ42 monomer, which is consistent with the experimental observation. According to these results, the salt bridge formed between D23 and K28 plays an important role in promoting the polymerization process between Aβ42 monomers, and disrupting this interaction may be a potential direction for further designing drugs to inhibit aggregation of Aβ42. In summary, this study shows a potential affected site that can efficiently inhibit aggregation of Aβ42.
Oligosaccharides play important roles in many biological processes and have great medicinal potential. The structure-activity study of oligosaccharides is complicated by the diversity and complexity of their structures. This review summarizes the state of oligosaccharide structural analysis in recent years. The ionization methods and dissociation rule of acid oligosaccharides, neutral oligosaccharides and glycopeptides in mass spectrometry are discussed and the methods of extraction and purification of oligosaccharides, the suitable mass spectrometry models for different types of oligosaccharides, and the advantages and disadvantages of different mass spectrometry models are introduced. We believe that this review will be helpful for the further investigation of these important biological substances.
The aim of this study was to determine whether the anti-fibrotic effects of pirfenidone (Pirf) and nintedanib (Nint) associated with the regulation of the alveolar epithelial type 2 cell (AEC II)-mediated lung alveolar regeneration in single- and multiple-dosage animal models of bleomycin-induced pulmonary fibrosis. All procedures involving animal treatment were approved according to the Committee on the Ethics of Animal Experiments of the Institute of Materia Medica, Chinese Academy of Medical Sciences. We found that the Pirf and Nint treatment of mice decreased the lung weight index, inflammation level, and the content of hydroxyproline compared with nontreated fibrotic mice in the single dosage model. Also, Pirf and Nint increased the oxygen saturation level and improved the lung functions in fibrotic mice, indicating that both drugs have anti-fibrotic effects in this model. However, the anti-fibrotic effects of Pirf and Nint were not observed in the multiple-dosage model. Further studies showed that Pirf and Nint decreased the expression of β-catenin, Axin2, c-Myc, Cyclin D1, and inhibited the Wnt/β-catenin signaling pathway, suggesting that Pirf and Nint did not produce anti-fibrotic effects in the multiple-dosage model due to their inhibiting the Wnt/β-catenin pathway and suppressing the stemness of AEC II, namely, suppressing AEC II-mediated lung alveolar regeneration.
ACK1 (activated Cdc42-associated kinase) is a non-receptor tyrosine kinase, originally identified by its binding to the GTP-binding small GTPase Cdc42. It is widely expressed in human tissues and activated by various extracellular growth factors such as EGF, PDGF and TGF-β. The activated ACK1 mediates the signaling cascade by interacting with downstream effectors followed by their phosphorylation. In recent years, researchers have investigated the biological functions of ACK1 and its roles in cancer research. The gene amplification and overexpression of ACK1 is associated with a poor prognosis and metastasis in a variety of cancers including lung, ovarian and prostate cancers. Therefore, the development of small molecule inhibitors of ACK1 provides promising opportunities for cancer-targeted therapy. In this review, we briefly describe recent advances in understanding the activation and biological function of ACK1 and introduce its novel inhibitors with potential therapeutic activities in preclinical studies.
Long noncoding RNAs (lncRNAs) are a class of RNAs that are more than 200 nucleotides in length with no protein coding property. LncRNAs are involved in almost every cellular process through multiple mechanisms. LncRNAs can directly bind to molecules in cells such as proteins, RNA, and DNA, to regulate cellular functions by influencing processes including transcription, translation, and molecular transporting. Recent researches showed lncRNAs are key regulators of serious cardiac diseases, especially in development and progression of cardiac ischemia, arrhythmia, cardiac fibrosis, and heart failure. This article mainly summarizes the function and mechanism of lncRNAs in cardiac diseases and gives reasonable prospect of lncRNAs in the future.
We evaluate the therapeutic effects of baicalein on chemotherapy-induced intestinal mucositis (CIM) in mice. The role of gut microflora regulation in the therapeutic effects of baicalein was investigated meanwhile. Male Balb/c mice were randomly divided into three groups including normal control group, model group and experimental group. Except for normal control group, mice were injected with 5-fluorouracil and irinotecan to induce CIM. Animal welfare and experimental procedures comply follow the rules of the Animal Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences. Baicalein significantly reduced disease activity index (DAI) of CIM mice and decreased the content of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) in serum. There were significant differences in the composition of the gut microbiota among groups according to the analysis of α diversity, β diversity, and the species differences. Compared with the normal control group, the Ruminococcaceae_UCG_014 and unclassified_f_Lachnospiraceae in mice of model group were significantly decreased while Bacteroides, Escherichia_Shigella, Enterococcus, Parabacteroides, Clostridium_sensu_stricto_1, and Lactococcus were significantly increased. Baicalein significantly decreased the abundance of Bacteroides, Escherichia_Shigella, Parabacteroides, Enterococcus, Clostridium_sensu_stricto_1, and Lactococcus. Meantime, norank_f_Muribaculaceae was notably increased by baicalein. The content of IL-6 and TNF-α in the serum of the three groups were positively correlated with the abundance of Clostridium_sensu_stricto_1, Lactococcus, Bacteroides, and Enterococcus according to correlation analysis. This study suggested the potential therapeutic effect of baicalein on CIM in mice. Regulation of gut microbiota probably plays a critical role in the therapeutic effects of baicalein.