Latest ArticlesInductively coupled plasma mass spectrometry (ICP-MS) was applied to determine the concentrations of lead (Pb), cadmium (Cd) and arsenic (As) in Lindera aggregata (Sims) Kosterm. The physiologically based extraction test (PBET) digestion in vitro/Caco-2 cell model was established to investigate the bioaccessible contents of Pb, Cd and As in decoction of Lindera aggregata (Sims) Kosterm. The target-organ toxicity dose modification of HI method (TTD) was used to evaluate the cumulative risk caused by the combined exposure of the total levels of Pb, Cd and As in Lindera aggregata (Sims) Kosterm. and the bioaccessible contents in the decoction. The results showed that the total contents of Pb, Cd and As in 4 batches of samples were in the range of 2.901-3.872, 1.299-1.800 and 0.062-0.216 mg·kg-1, respectively. After transportation by Cacco-2 cells, the bioaccessible contents of Pb, Cd, and As in the decoction were in the range of 0.045-0.080, 0.070-0.112 and 0.004-0.018 mg·kg-1. The results of risk assessment showed that calculated by the total amounts of heavy metals in the Lindera aggregata (Sims) Kosterm., for the end points of nervous system, the cumulative risks of co-exposure of heavy metals in 3 batches of samples were of concern. After decoction and transportation by Caco-2 cells, for the end points of cardiovascular system, blood, nervous system, kidney and testis, the TTD modification of HI values of all batches of samples were less than 1, and the health risks were acceptable. The study provided methodology basis for a more objective assessment of the health risks of heavy metals and harmful elements in traditional Chinese medicine and for a more scientific limit standard of heavy metals and harmful elements.
Dengzhan Shengmai capsule, as a compound Chinese patent medicine, consists of four herbs: Herba Erigerontis, Ginseng, Ophiopogon, and Schisandrae Chinensis Fructus, and contains significant components of flavonoids, lignans, saponins, and organic acids. It is widely used clinically to treat cerebrovascular diseases such as chronic cerebral hypoperfusion and dementia with remarkable efficacy. This study proposes a research strategy for multi-component traditional Chinese medicine metabolites based on prediction databases and unfolds the analysis using Dengzhan Shengmai capsule as an example. Using the UPLC-Q-TOF/MS method, the analytical method was established and detected biological samples such as urine, feces, and bile of rats before and after administration based on the prediction of theoretical metabolites of Dengzhan Shengmai capsule. The possible secondary fragment ion information of metabolites was identified by comparing the detected results with prediction databases. The metabolites were identified based on the archetypal component mass spectrometric cleavage law and multistage mass spectrometric data. 51 metabolites, mainly flavonoid, organic acid, and lignan constituents, were finally identified from rat biosamples based on 306 theoretical metabolites of Dengzhan Shengmai capsule. This study provides a new strategy for the identification of metabolites in vivo and the analysis of metabolic pathways of TCM. The study complied with the procedures established by the Animal Experiment Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences and passed the animal experiment ethics examine (No. 00003645).
Polysaccharides and free monosaccharides are important active components in Cistanches Herba, which have functions of anti-aging and immunological activity regulation. The study of monosaccharide composition in polysaccharide and free monosaccharide can lay a foundation for the study of primary structure, spatial structure of Cistanche polysaccharide and biological activity of Cistanches Herba. In this study, a method of water extraction and alcohol precipitation was used to extract Cistanche polysaccharide. Trifluoroacetic acid was selected as the hydrolytic acid for polysaccharide hydrolysis. An orthogonal experimental method is established. Three levels of acid concentration, hydrolysis temperature and hydrolysis time were selected to investigate the optimal hydrolysis condition. The optimal hydrolysis condition was 0.08 mol·L-1 trifluoroacetic acid hydrolysis at 100 ℃ for 3 h. The free monosaccharides of Cistanches Herba were extracted by water extraction. The established ion chromatogram integrated pulsed amperometry method can efficiently separate 11 monosaccharides in a short time. The method has good repeatability and high sensitivity, methodological experiment results meet the requirements of quantitative determination. It can accurately determine the monosaccharide composition of Cistanche polysaccharide and free monosaccharide content. Ion chromatography does not require derivatization operation and the pre-treatment steps are simple. This method can measure fructose, but PMP derivation-HPLC method can't. The monosaccharide composition of Cistanche polysaccharide include fucose, arabinose, rhamnose-galactose, glucose, xylose, mannose, fructose, ribose and glucuronic acid, among which the contents of glucose and fructose are relatively high. The free monosaccharides in the water extract of Cistanches Herba include glucose, fructose and mannose.
Autophagy often occurs after cells are attacked by oxidative stress, where damaged structures are phagocytic and degraded into nutrients, thereby reducing oxidative damage, promoting the survival of cancer cells and reducing the therapeutic effect of photodynamic therapy (PDT). However, excessive activation of autophagy can promote cell apoptosis. In this paper, the photosensitizer pyropheophorbide-a (Ppa) was used to produce a large amount of reactive oxygen species (ROS) to achieve the effect of killing cancer cells. At the same time, icaritin (Ica), an autophagy inducer, was used to over-activate autophagy, which transformed the protection of cancer cells into the promotion of cancer cell apoptosis, so as to improve the effect of photodynamic therapy. In this study, the interaction force between Ica and Ppa was exploited to successfully construct a self-assembled nanomedicine IP with good stability and high drug load. The synthesis method is simple, through using the drug itself as a carrier, and the loading capacity (LA) of Ica and Ppa can be increased to 83.53% and 16.45% without introducing potential biosafety risks of nanocarriers. Compared with free Ppa, self-assembled nanomedicine IP showed superior performance in cellular uptake and reactive oxygen species production. In addition, the self-assembled nanomedicine IP can reverse the protective autophagy induced by PDT by activating the autophagy of tumor cells, and facilitate apoptosis and antitumor coordination, which significantly improves the antitumor activity of PDT.
Radiation enteritis (RE) is a common syndrome in the radiotherapy of abdominal and pelvic malignant tumors, heavy influencing living quality, but no specific clinical regimens are available. Long oil (LO) is composed of the fat components from cuttlebone, safflower, walnut oil and rapeseed oil and has been clinically used for wound healing. In this study, oral LO was applied for the prevention and treatment of RE and the mechanisms were explored. Animal experiments were approved by the Ethics Committee of the Beijing Institute of Radiation Medicine, Academy of Military Medical Sciences, and the experiments were conducted in accordance with relevant guidelines and regulations. An RE mouse model was established after single whole abdominal γ-ray radiation of 13 Gy. LO (8 mL·kg-1) was intragastrically administered to the mice 1 h pre-radiation. Compared to the models, the mice of the LO group had more regenerated intestinal crypts and longer villus on day 3.5, and remarkable increase in the abundance of gut microbiota on day 7, especially the amounts of probiotics including Eubacterium and Lactobacillus. Moreover, the mice of the LO group showed longer total movement distance, shorter immobility time, and higher speed than the model mice on day 7. On day 14, the mice of the LO group showed the high descending of proinflammatory factors including tumor necrosis factor-α and interleukin-6, close to the normal levels. Therefore, oral LO can alleviate the inflamed syndromes of RE and improve the repair of damaged intestinal tissues. Moreover, the mice of the LO group had highly low permeability of intestinal mucosa according to the fluorescence labeling experiment, which was close to the normal level. Oral LO can protect intestine mucosa and prevent RE by modification of the intestinal microenvironment, alleviation of the inflammatory response, and promotion of tissue repair.
Most drugs need to interact with cell membrane to reach the biological target, so that membrane affinity assay is an important early screening step in drug discovery. However, at present, the traditional oil-water distribution method is still used, a new, simple and accurate method for membrane affinity assay is urgently needed. In this study, according to the colorimetric principle, a new assay model based on polydiacetylene vesicles was optimized through a series of experiments including different concentrations of vesicle solution, temperature, or pH reaction environment. On this basis, tetracaine hydrochloride, 2-methylimidazole and histamine were used as model drugs to measure the membrane affinity constants and verify the between-batch precision of the optimized assay model (relative standard deviation less than 5%). In addition, polydiacetylene vesicles were stable for up to 180 days, demonstrating the potential application of the assay model. This strategy is simple, stable, reliable, with high reproducibility, low cost and easy to promote, which provided a new tool and a new direction for the high-throughput assay of membrane affinity.
To investigate the crucial role of particle size in the biological effects of nanoparticles, a series of mesoporous silica nanoparticles (MSNs) were prepared with particle size gradients (50, 100, 150, 200 nm) with the traditional Stober method and adjusting the type and ratio of the silica source. The correlation between toxicity and size-caused biological effects were then further examined both in vitro and in vivo. The results indicated that the prepared MSNs had a uniform size, good dispersal, and ordered mesoporous structure. Hemolytic toxicity was found to be independent of particle size. At the cellular level, MSNs with smaller particle sizes were more readily internalized by cells, which initiated to more intense oxidative stress, therefor inducing higher cytotoxicity, and apoptosis rate. In vivo studies demonstrated that MSNs primarily accumulated in the liver and kidneys of mice. Pharmacokinetic analysis revealed that larger MSNs were eliminated more efficiently by the urinary system than smaller MSNs. The mice's body weight monitoring, blood tests, and pathological sections of major organs indicated good biocompatibility for MSNs of different sizes. Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Zhejiang Chinese Medical University. Overall, this study prepared MSNs with a particle size gradient to investigate the correlation between toxicity and particle size using macrophages and endothelial cells. The study also examined the biosafety of MSNs with different particle sizes in vivo and in vitro, which could help to improve the safety design strategy of MSNs for drug delivery systems.
MYB transcription factors are involved in the regulation of various secondary metabolites biosynthesis. Gardenia jasminoides Ellis is the commonly used Chinese herbal medicine, and its main active ingredient is geniposide. Here, leaves and flower buds at different developmental stages of G. jasminoides were used to explore MYB transcription factors related to geniposide biosynthesis based on genome and transcriptome analysis. Transcriptome data analysis showed that, different from the expression of the common pathway genes for terpenoid biosynthesis, the expression level of genes in the specific pathway of geniposide biosynthesis was significantly higher in flower buds than in leaves, which was the same as the organ accumulation pattern of this component. And the promoter regions of geraniol synthase, iridoid synthase and geniposidic acid methyltransferase involved in the specific pathway all contained multiple MYB-binding sites. A total of 105 MYB transcription factors were obtained by annotating the coding genes of G. jasminoides, which were divided into 68 1R-MYB, 33 R2R3-MYB, 3 3R-MYB and 1 atypical MYB transcription factor according to the number of conserved domain. Based on the analysis of phylogenetic tree and quantitative real-time PCR, three candidate MYB transcription factors related to geniposide biosynthesis were selected, including potential positive regulation factor GjMYB23 and negative regulation factors GjMYB31 and GjMYB73. The results of this study will lay a foundation for searching the regulation of geniposide biosynthesis and further analysis of the quality formation mechanism of G. jasminoides, so as to promote the breeding of excellent varieties of G. jasminoides.
There are many multi-original medicinal materials in Chinese Pharmacopoeia, and the mixed use of medicinal materials from different sources is common, which has certain influence on the stability of clinical medication. In this study, pyrosequencing technology was used to screen species-specific single nucleotide polymorphisms (SNP) from commonly used DNA barcode sequences, and a rapid and accurate molecular identification method for original species in mixed medicinal powder of Epimedii Folium was established. Multiple sequence alignment analysis showed that the 176th (C/T) mutation and the 196th (A/G) mutation of ITS, the 123rd (C/G) mutation of matK and the 892nd (A/C) mutation of rbcL could be used as the unique SNPs of E. sagittatum, E. koreanum, E. brevicornu and E. pubescens, respectively. In this study, the applicability of pyrosequencing and Sanger sequencing methods in the sequencing of mixture samples was investigated from the perspective of sensitivity and stability. Pyrosequencing method has higher detection sensitivity than Sanger sequencing method for low content samples in the mixed samples. Stability analysis showed that pyrosequencing technology could still obtain effective sequencing results for the amplified products of template DNA after 45 min of 95 ℃ high temperature water bath, while the critical point of Sanger sequencing method was 30 min. In this study, a new identification technology of Epimedii Folium mixed powder primordial species based on pyrosequencing and specific SNP was developed, which can quickly and accurately identify the mixed use of Epimedii Folium with high sensitivity and stability, and can also support the identification of different primordial species and mixed powder primordial herbs, which is conducive to ensuring the consistency and stability of clinical medication.
Stable isotope tracer metabolomics tracks and analyzes the whole metabolic process of the body through the tracer atoms, which belongs to the frontier technology in the field of biomedicine. This technology is of great significance and value for explaining the pathogenesis of diseases, finding biomarkers of diseases and drug action targets. Taking the mechanism of glucose catabolism disorder in depression as an example, this paper systematically expounds the stable isotope tracer metabolomics technology and its application. The research idea of stable isotope tracer metabolomics based on unmarked metabolomics was put forward, and the research strategy of biological significance interpretation from four dimensions of metabolite isotope abundance, key metabolic enzymes, metabolic flow direction and metabolite flow was given, which broke through the bottleneck of stable isotope tracer metabolomics research technology based on overall animal experiment, and provided scientific basis for the promotion and application of this technology.