G protein-coupled receptors (GPCRs) represent the largest family of membrane proteins and are the target of approximately half of all therapeutic drugs. There are ~300 orphan GPCRs, which have great potential in drug development. G protein-coupled receptor 35 (GPR35), a rhodopsin-like orphan GPCR, is widely involved in immune regulation, gastrointestinal disorders, cardiovascular diseases, cancer, as well as other diseases, suggesting its great potential as a therapeutic target in a variety of diseases. However, the current research on GPR35 is insufficient, including the true endogenous ligand has not been confirmed, the molecular mechanism of its role in disease is not fully understood, and there is a lack of effective intervention strategies targeting GPR35. This article summarizes the deorphatization of GPR35, GPR35-related signaling pathways and their association with various diseases, in order to provide a reference for in-depth study of GPR35 in diseases and development of drugs targeting GPR35.

Apoptosis, or programmed cell death, is a common phenomenon which involved in a variety of physiological and pathological conditions in humans, such as neurodegenerative diseases, ischemic injury, autoimmune diseases and cancers. Apoptosis can be detected in vitro by morphology, biochemistry, molecular biology, immunology, and other techniques. Probes for cell apoptosis detection in vivo are still under research and various reagents and methods are constantly emerging. However, none of apoptosis detection methods or reagents are perfect and they all have advantages and disadvantages, as well as suitable scope of application. With the increasing application of apoptosis detection techniques, researchers will be confused about how to choose a suitable method to detect apoptosis and define the application range of each apoptosis detection method. Therefore, it is necessary to compare the benefits and drawbacks of existing apoptosis detection techniques as well as their applicable conditions. This article reviews morphological characteristics, molecular mechanism and specific biochemical changes in apoptotic cells. We summarized various apoptosis-detection methods based on these characteristics that can be used in vitro and in vivo, the advantages and disadvantages of each method and the scope of application. Also, we highlighted the existing tracers that have been used in apoptosis detection in vivo, their potentialities and limitations as well as the clinical applications of apoptosis imaging in multiple disease fields.

Inductively 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.

In this study, the flow injection (FI) technology combined with the unique step wise multiple ions monitoring scanning (step-wise MIM) mode of Qtrap-MS was first established for the identification and discrimination of eight Murraya species. It only takes 5 min for each sample to detect approximate 600 compounds. The characteristic MS chromatograms of eight Murraya plants were analyzed by Analyst and SIMCA-P. The results of PCA showed that sect. Murraya and sect. Bergera were clearly divided into two categories, suggesting that there is difference in the chemical compositions between these two groups. Further detail analysis of the MS data could realize the preliminary structure elucidation of the component types contained in different plants. The main components in M. exotica and M. alata are coumarins, and polymethoxyflavones are rich in M. paniculata, while carbazole alkaloids are the major ones in sect. Bergera plants. The results are consistent with our previous comprehensive analysis of the chemical components of Murraya species. In conclusion, our research confirmed that FI-Qtrap-MS technology can be used for rapid identification and differentiation of similar plant species, providing reference for chemical taxonomy and a new method for the quality evaluation of medicinal materials.

Target identification and verification of natural products is an important and challenging work in the field of chemical biology. It is also an important job for researchers to apply chemical proteomics technology to biomedicine in order to identify target proteins of natural products. Target identification is critical to understanding its mechanisms and developing natural products as molecular probes and potential therapeutic drugs. Traditional approaches of small molecule target identification based on affinity have been shown to be successful, such as click-chemical probes, radioisotope labeling or photosensitized small-molecule probes. Nevertheless, these technologies require purified candidate target proteins, and modified small molecules with probes or linkers, such as adding agarose beads, biotin labels, fluorescent labeling or photo-affinity labeling. Many structure-activity relationship studies should be performed to ensure that the addition of small molecule labels undisturbed the original biological activity of the small molecules. Unfortunately, all these modifications are likely to alter their biological activity or binding specificity. To overcome the bottleneck of "target recognition", researchers have developed a series of new techniques for unmodified drug target identification. In this article, we reviewed the target identification techniques of natural product without structural modification in order to provide reference for the development of natural products.

The trace chemical components in functional Monascus rice were studied to explore the potential bioactive substances. MCI column, Sephadex LH-20 gel, and preparative liquid chromatography were used to purified the ethyl acetate extract from functional Monascus rice. Two novel pyridine Monascus pigments were isolated and identified, named monascopyridine G (1) and monascopyridine H (2), respectively based on extensive mass spectrometry (MS), infrared radiation (IR), and nuclear magnetic resonance (NMR) analysis. The molecular docking experiments between compounds 1 and 2 and peroxisome proliferators-activated receptor-gamma (PPARγ) showed that they exhibited obvious binding force with the receptor protein. Besides, the biosynthetic pathways of the two compounds were proposed, which provide a valuable reference for the selective production of these potential bioactive substances.

Astragalus, which was first documented in Shennong Bencao Jing, is the dried root of Astragalus membranaceus (Fisch.) Bge. or Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao. The active ingredients astragalus membranaceus saponins (AMS), astragalus polysaccharides (APS) and astragalus flavonoids (AFS) have pharmacological effects such as anti-tumor properties, lowering blood sugar, regulating lipid metabolism, cardiovascular protection, anti-oxidation, bone protection, anti-fibrosis, etc. Fibrosis affects almost all organs, particularly vital organs such as the lungs, liver, heart and kidneys. The primary pathological changes of fibrosis involve abnormal increase of myofibroblasts and excessive deposition of extracellular matrix (ECM) components, which lead to the formation of scar tissue, ultimately resulting in fibrosis and even functional loss or failure of organs, which seriously threatens human health and life. Recent, studies have shown that Astragalus membranaceus has a good therapetuic effect on organ fibrosis. This article reviews the current advances of Astragalus in the prevention and treatment of fibrosis of lungs, liver, heart, kidneys and other important organs.

Small interfering RNA (siRNA) is the initiator of RNA interference and inhibits gene expression by targeted degradation of specific messenger RNA. siRNA-mediated gene regulation has high efficiency and specificity and exhibits great significance in the treatment of diseases. However, the naked or unmodified siRNA has poor stability, easy to degrade by nuclease, short half-life, and low intracellular delivery. As an emerging non-viral nucleic acid delivery system, ionizable lipid nanoparticles play an important role in improving the druggability of siRNA. At present, one siRNA drug based on ionizable lipid nanoparticles has been approved for the treatment of rare disease. This review introduces the research progress in ionizable lipid nanoparticles for siRNA delivery, focusing on the effect of each component of lipid nanoparticles on the efficiency of siRNA-mediated gene silencing, which provides new references for the studies on ionizable lipid nanocarriers for siRNA delivery.

Cancer seriously threatens human life and health, it is urgent for the development of rapid detection, precise localization and effective treatment of tumors. Chemical fluorescent probes that are sensitive to tumor-specific microenvironments have important significance in tumor theranostics and a variety of such probes have been developed. In this review, we classified chemical fluorescent probes that are sensitive to tumor microenvironments according to biological characteristics and microenvironmental changes while combining spectroscopy or response mechanisms, and systematically introduced the research progress of chemical fluorescent probes with sensitivity to hypoxia, low polarity, high viscosity, abnormal pH values and abundant reactive oxygen species in tumor microenvironments, in order to provide references for the development and applications of these probes.

Intracerebral delivery of drugs for the treatment of central nervous system disorders is usually limited by the blood-brain barrier (BBB). Transdermal drug delivery systems (TDDS) have the advantage of improving patient compliance and avoiding first-pass effects compared to intravenous, oral and intranasal drug delivery, and are an emerging non-invasive drug delivery route that facilitates long-term drug delivery to patients. The discovery of direct subcutaneous targeting of lymphatic pathways to brain tissue has made TDDS a new brain-targeted drug delivery strategy. At the same time, the development of nano-delivery technology has further facilitated the application of TDDS for targeted drug delivery to the brain. This review summarizes the mechanism of transdermal drug delivery into the brain and the application of TDDS in the treatment of brain diseases, providing new ideas and methods for the treatment of central nervous system diseases.