Non-alcoholic fatty liver disease (NAFLD) is a very common chronic liver disease in clinic, which can further develop into liver fibrosis, cirrhosis, eventually hepatocellular carcinoma and liver failure. Limonin is a natural triterpenoid compound containing furan rings. Previous studies have found that limonin has good anti-inflammatory, analgesic and liver protective functions. However, the mechanism of action of limonin on NAFLD has not been clarified. Based on the background, C57BL/6J male mice were fed with high fat diet (HFD) to establish NAFLD model (the experiment was approved by the Animal Ethics Committee of Hefei University of Technology, the approval number is HFUT20220429001), and limonin was added to the mice for administration by intragastric administration (i.g.). The results showed that HFD can induce typical NAFLD phenotypes, including impaired liver function, increased fat accumulation, and increased serum aspartate amino transferase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) levels in mice. Mice were treated with limonin (50 and 100 mg·kg^-1) for 10 weeks, and it was found that limonin could restore dyslipidemia and improve fat accumulation in liver cells of mice. In addition, we conducted in vitro experiments with human hepatoma cell line HepG2 cells, and found that limonin can promote the expression of oxidative metabolism and autophagy related genes and inhibit apoptosis in HepG2 cells. Mechanistically, limonin improves high-fat food-induced NAFLD by promoting the expression of oxidative metabolism genes transcriptional coactivator of peroxisome proliferator activating receptor γ (PPARγ) (PGC1α) and carnitine palmitoyl transferase 1 alpha (CPT1α) through peroxisome proliferator activates receptor alpha (PPARα). These results indicate that limonin can inhibit apoptosis, promote autophagy and improve NAFLD by promoting oxidative metabolism of fatty acids through PPARα.

The medicinal history of Pien Tze Huang is long, and it is the only "double top secret" variety of technology and formula at present. It has the effects of clearing heat and detoxifying, detumescence and pain, cooling blood and removing blood stasis. At present, researchers have analyzed and identified some compounds in Pien Tze Huang and its precious medicinal materials, such as Panax notoginseng, calculus bovis, snake gall and musk, and conducted activity screening, pharmacokinetics and pharmacological related studies on these chemical components. It was found that Pien Tze Huang had a significant effect on the treatment of acute and chronic hepatitis, ulcer, colon cancer, liver cancer and other diseases. The purpose of this paper is to systematically discuss the research achievements of researchers in recent years on the material basis, pharmacological effects and clinical application of Pien Tze Huang, with a view to providing ideas for the further research of Pien Tze Huang.

The global incidence rate of nonalcoholic steatohepatitis (NASH) continues to rise. The pathogenesis of NASH is complex, and there is no effective clinical treatment. Previous study has shown that DEAD box protein 5 (DDX5) can significantly alleviate the NASH process in mice. This study screened the natural product library of the research group and found that the active compound hypercalin B (HB) in Hypericum beanii N. Robson, a traditional Chinese medicine, can upregulate the expression of DDX5 protein in a dose-dependent manner. In this study, an in vitro model of NASH stimulated by palmitic acid (PA) and an animal model of NASH induced by the methionine- and choline-deficient diet (MCD) were constructed. Different concentrations of HB were used to investigate the effect and mechanism of HB in alleviating NASH progression. All animal experiments in this paper were approved by the Ethics Committee of China Pharmaceutical University (NO: 2021-02-003). In vitro model results showed that HB significantly reduced the intracellular lipid deposition induced by free fatty acid (FFA). Animal experiments showed that HB improved liver injury by significantly reducing lipid accumulation in the liver of NASH mice, and reducing serum aspartate transaminase (AST) and alanine transaminase (ALT) levels. Moreover, HB could inhibit liver inflammation by reducing the mRNA levels of liver pro-inflammatory cytokines including interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor α (TNFα). Further research showed that HB could reduce the phosphorylation level of the mechanical target of rapamycin (mTOR) and reduce the expression of sterol regulatory element binding protein 1 (SREBP1) and fatty acid synthase (FASN), thereby improving lipid metabolism and alleviating NASH progression, and the effects of HB against NASH were dependent on DDX5. In conclusion, HB can improve lipid metabolism and inhibit inflammatory activation by suppressing mTORC1 pathway via upregulating DDX5 protein, and showed promising anti-NASH activity in vitro and in vivo.

Although small molecule drugs (SMD) are still mainstream for the treatment of diseases, large molecule biologicss of many advantages, pose a challenge to the further discovery and use of SMD. The advantages of SMD are the convenience of oral administration and good patient compliance. However, the challenge with SMD is to integrate the PD, PK, selectivity and safety into a chemical structure. Because of their small size and surface area they often bind to various proteins, and off-target actions can cause adverse reactions. In this sense, selectivity is critical. Based upon target as the core to construct a chemical structure, it is necessary to consider the requirements of all the attributes, but achievement of the full-dimensional optimization is difficult. Modern drug discovery has been greatly enhanced by molecular biology and structural biology, and new strategies and technologies have emerged, which have created many successful medicines. For example, under the guidance of structural biology, covalent binding drugs connect moderate "electrophilic warheads" to the appropriate positions of molecules, and upon binding to their targets the electrophiles are irreversibly linked to the target by covalent bonds. Molecular biology can be directly applied to the development of antibody-coupled drugs (ADC). The antibody (A) acts as a carrier and a guide (for PK), and carries toxic molecules (D) into cancer cells, thus playing a killing role (for PD). The separate pharmacodynamic and pharmacokinetic entities are coupled (C) by linkers. PROTACs are also bifunctional molecules, which recruit a target protein and ubiquitin ligase E3 to form a ternary complex, which then acts as a catalyst to ubiquitinate the target protein and lead to degradation by the proteasome. In addition, in recent years, the combination of two fixed-dose drugs has improved selectivity, safety, and long-term benefit with many severe diseases, and can be regarded as an innovative strategy of physical combination. This review discusses some successful examples to briefly present the principles from the perspective of medicinal chemistry and therapeutic application.

Toll like receptors (TLRs) are the earliest discovered natural immune pattern recognition receptors (PRRs). The abnormality of TLR signal transduction pathway is the key factor leading to chronic inflammatory, cancer, nervous system disease and cardiovascular diseases. The development of TLR agonists and inhibitors has attracted much attention. Currently known TLR2 agonists, such as lipopeptides or their derivatives, have certain limitations in drug development due to their difficult synthesis, easy hydrolysis, and triggering inflammatory cytokine storms, while inhibitors have been rarely reported. New small molecule TLR2 agonists or inhibitors with higher stability are more likely to be developed as tumor immunotherapy or anti-inflammatory drugs.

Gouty arthritis is a type of metabolic rheumatic disease caused by autoimmune abnormalities. Currently, the use of Western medicine in the clinical treatment of gouty arthritis has been associated with a high risk of adverse reactions. Therefore, there is a growing interest in exploring therapeutic drugs from traditional Chinese medicine as a potential alternative. According to the theory of traditional Chinese medicine, gouty arthritis has been classified as damp-heat arthralgia syndrome. Shirebi granules has been found to have good clinical efficacy in treating gouty arthritis. However, its underlying pharmacological mechanisms remain unclear. To address this problem, the study first established the interaction network of candidate targets for Shirebi granules, which is used to treat damp-heat syndrome of gouty arthritis. Then, the key candidate targets of Shirebi granules for treating gouty arthritis with damp-heat syndrome were screened by calculating the topological features of the network nodes. Then, the functional mining of the key candidate targets revealed that the candidate targets of Shirebi granules may intervene in the biological process of inflammatory response and lipid metabolism through the crosstalk of Wnt/β-catenin signaling. To verify the effectiveness of Shirebi granules in treating gouty arthritis with damp-heat syndrome, a rat model was established. The results demonstrated that the granules significantly improved the severity of arthritis in rats with this condition, reduced joint inflammation, gait score, swelling index, increased mechanical pain threshold (P < 0.05), and reduced the content of serum inflammatory factors IL-1β, IL-6, and TNF-α in gouty arthritis rats with damp-heat syndrome (P < 0.01) gouty. It was also found that Shirebi granules effectively alleviated the symptoms of dampness heat syndrome such as local joint fever and dry mouth by reducing the temperature of the joints in acute gouty arthritis with damp-heat syndrome (AD) rats, increasing the threshold of heat pain, increasing water intake (P < 0.01), and inhibiting abnormal changes in the content of fatty acid oxidation related enzymes (P < 0.01). Western blot analysis showed that Shirebi granules increased the protein expression levels of Wnt and β-catenin (P < 0.01) while decreasing the protein expression of p65, p-p65 and PPARγ (P < 0.01) in rats with gouty arthritis and damp-heat syndrome. The results showed that Shirebi granules may reverse the "inflammation-immune" imbalance and lipid metabolism disorder by regulating the crosstalk of Wnt/β-catenin signaling, and play a role in alleviating the severity of the disease. This study provides a methodological reference for elucidating the pharmacological mechanisms of traditional Chinese medicine formulas. It also presents research ideas for the appropriate clinical use of Chinese patent medicines and the development of new clinical drugs for gouty arthritis therapy. The animal welfare and experiment procedures of this study were performed in accordance with the regulations of the Experimental Animal Ethics Committee of Experimental Research Center, China Academy of Chinese Medical Sciences (grant No. ERCCACMS11-2302-08).

Obesity is an important risk factor related to osteoarthritis, but it′s role in post-traumatic osteoarthritis on young people need to further study. The internal mechanism except the mechanical loading may be associated with adipose exosomes. To examine the effect of obesity induced by high fat diet and adipose exosomes on knee post-traumatic osteoarthritis caused by destabilization of medial meniscus (DMM) surgery in young mice, 20 6-week-old C57BL/6J mice were randomly assigned to the control diet group (CD, n = 5), the DMM group (n = 5), the high fat diet group (HFD, n = 5) and the HFD plus DMM group (HFD+DMM, n = 5). The CD and DMM group were fed with a control diet, and the HFD and HFD+DMM group were fed with a high fat diet. We did the DMM surgery and the sham surgery on the mice when it was 10 weeks old. Extract obese and normal adipose exosomes, identify exosomes in vitro, and proceed fluorescence imaging in vivo using DiR staining. DMM+HFD-Exo group and DMM+CD-Exo group were injected the exosomes from the tail vain once a week (100 μL per shot with a concentration of 1 μg·μL^-1). Second, 15 6-week-old C57BL/6J mice were randomly assigned to the DMM group (n = 5), the DMM plus obese adipose exosomes group (DMM+HFD-Exo, n = 5), and the DMM plus control diet adipose exosomes group (DMM+CD-Exo, n = 5). Animal welfare and experimental process are in accordance with the regulations of the Experimental Animal Ethics Committee of Nanjing University (IACUC-D2204005). All mice were sacrificed at the age of 18 weeks, the knee joints of the mice were harvested and fixed. We used micro CT to examine the samples and measured the bone volume/tissue volume, trabecular thickness, trabecular number and trabecular separation. Then the samples were decalcified and embedded in paraffin, and 4 μm thickness sections were stained with H&E and safranin O/fast green to observe the histological changes of the knee joint. The results showed compared with the control diet group, high fat diet induced obesity can aggravate the pathological changes of the post-traumatic osteoarthritis caused by DMM surgery, which shows in having a higher Mankin score. The surface of knee articular cartilage in the HFD+DMM group was rough, and the subchondral bone has an increase in bone sclerosis. Compared with the DMM group, obese adipose exosomes can exacerbate the pathological changes of the knee articular cartilage, while not influencing the subchondral bone. In conclusion, high fat diet induced obesity can aggravate the post-traumatic osteoarthritis caused by DMM surgery in young mice. The obese adipose exosomes mainly affect the surface of the knee articular cartilage.

Chinese patent medicine (CPM) is an important part of traditional and Chinese medicine (TCM). Its quality has direct impact on the safety and effectiveness of clinical use. The quality standard is the pivotal approach to guarantee the quality of CPM. Due to the complex material basis, multitudinous quality influencing factors and unveiled active ingredients, dose-effect relationship and action mechanism, the investigation on quality standard faces many difficulties. This paper surveys the current quality status of CPM and the general situation of CPM standards. At present, the dosing problem has the crucial impact on the quality of CPM. The current quality standard system of CPM is confirmed and the limitations are indicated. Based on the above analysis, the principles and considerations on investigation of quality standard are proposed as follows: ① Adhere to safety as the bottom line, strengthen the risk-control ability of the standard of CPM; ② Adhere to theory of TCM and comprehensive quality, improve the integrative control level of the CPM standard; ③ Emphasize technological development and innovation, promote the quality control competence of CPM standard; ④ Facilitate planning and coordination, optimize the management of the CPM standard system; ⑤ Reinforce investigation on evaluation method, develop grade evaluation standard, accelerate high-quality development of CPM. Finally, the future perspective on investigation of CPM quality standard is prospected.

Statins are a class of hydroxymethylglutaryl-CoA reductase inhibitors (HMG-CoA reductase inhibitors), which are widely used to reduce blood lipid in clinic, and are especially important for the prevention and treatment of cardiovascular diseases. In recent years, many studies at home and abroad believe that statins have a unique role in tumor prevention and treatment, and have been widely concerned. In terms of epigenetic regulation mechanism, statins mainly affect the progress of tumor through DNA methylation, histone modification and miRNA regulation. In addition, statins can also achieve their anti-tumor effects by promoting tumor cell autophagy, regulating tumor cell cycle, and promoting tumor cell apoptosis and other signaling pathways. Therefore, the research on statins provides ideas for the discovery of new anti-tumor treatments. In this paper, the role of statins in the prevention and treatment of common tumors is reviewed, including its mechanism of inhibiting the occurrence and development of tumors through epigenetic regulation and other related mechanisms, as well as its clinical research status.

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.