Roxarsone inhibits hepatic stellate cell activation and ameliorates liver fibrosis by blocking TGF-ß1/Smad signaling pathway.

Hepatic fibrosis is a pathological change caused by chronic liver injury and self-repair, and it is the inevitable stage of the development of chronic liver disease to cirrhosis or even liver cancer. Activation of hepatic stellate cells (HSCs) is a core event in the development of liver fibrosis and blockage of the activation of HSCs has been shown to alleviate liver fibrosis. Roxarsone, an organoarsenic additive, with antibiotic effect, growth promotion and improving feed efficiency, is widely used in livestock and animal production. The purpose of this study was to evaluate the therapeutic effect of Roxarsone on liver fibrosis and explore the possible mechanism. We found that Roxarsone could inhibit transforming growth factor-ß1 (TGF-ß1) induced the activation of HSCs and weaken the migration ability. Moreover, Roxarsone administration significantly ameliorated CCl4-induced liver fibrosis in mice with improvement of liver function and decreases of deposition of extracellular matrix (ECM). Mechanism investigations revealed that Roxarsone specifically inhibited the activation of TGF-ß1/Smad signaling pathway, but had no effect on MAPK and PI3K/AKT pathways. These results suggest that Roxarsone has a protective effect on liver fibrosis which provides a new candidate for the treatment of liver fibrosis.

Rational drug design of CB2 receptor ligands: from 2012 to 2021.

Cannabinoid receptors belong to the large family of G-protein-coupled receptors, which can be divided into two receptor types, cannabinoid receptor type-1 (CB1) and cannabinoid receptor type-2 (CB2). Marinol, Cesamet and Sativex are marketed CB1 drugs which are still in use and work well, but the central nervous system side effects caused by activation CB1, which limited the development of CB1 ligands. So far, no selective CB2 ligand has been approved for marketing, but lots of its ligands in the clinical stage and pre-clinical stage have positive effects on the treatment of some disease models and have great potential for development. Most selective CB2 agonists are designed and synthesized based on non-selective CB2 agonists through the classical med-chem strategies, e.g. molecular hybridization, scaffold hopping, bioisosterism, etc. During these processes, the balance between selectivity, activity, and pharmacokinetic properties needs to be achieved. Hence, we summarized some reported ligands on the basis of the optimization strategies in recent 10 years, and the limitations and future directions.

Peramivir, an Anti-Influenza Virus Drug, Exhibits Potential Anti-Cytokine Storm Effects.

Coronavirus Disease 2019 (COVID-19) infected by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has been declared a public health emergency of international concerns. Cytokine storm syndrome (CSS) is a critical clinical symptom of severe COVID-19 patients, and the macrophage is recognized as the direct host cell of SARS-CoV-2 and potential drivers of CSS. In the present study, peramivir was identified to reduce TNF-α by partly intervention of NF-κB activity in LPS-induced macrophage model. In vivo, peramivir reduced the multi-cytokines in serum and bronchoalveolar lavage fluid (BALF), alleviated the acute lung injury and prolonged the survival time in mice. In human peripheral blood mononuclear cells (hPBMCs), peramivir could also inhibit the release of TNF-α. Collectively, we proposed that peramivir might be a candidate for the treatment of COVID-19 and other infections related CSS.

Novel dual-mode antitumor chlorin-based derivatives as potent photosensitizers and histone deacetylase inhibitors for photodynamic therapy and chemotherapy.

The combination of photodynamic therapy (PDT) and chemotherapy is a prospective strategy to improve antitumor efficacy. Herein, a series of novel cytotoxic chlorin-based derivatives as dual photosensitizers (PSs) and histone deacetylase inhibitors (HDACIs) were synthesized and investigated for biological activity. Among them, compound 15e showed definite HDAC2 and 10 inhibitory activities by up-regulating expression of acetyl-H4 and highest phototoxicity and dark-toxicity, which was more phototoxic than Talaporfin as a PS while with stronger dark-toxicity compared to vorinostat (SAHA) as a HDACI. The biological assays demonstrated that 15e was liable to enter A549 cells and localized in mitochondria, lysosomes, golgi and endoplasmic reticulum (ER) etc. multiple organelles, resulting in higher cell apoptosis rate and ROS production compared to Talaporfin. Moreover, it could induce tumor cell autophagy as a dual PS and HDACI. All results suggested that compound 15e could be applied as a potential dual cytotoxic drug for PDT and chemotherapy.

DNA-encoded libraries (DELs): a review of on-DNA chemistries and their output.

A DNA-encoded library is a collection of small molecules covalently linked to DNA that has unique information about the identity and the structure of each library member. A DNA-encoded chemical library (DEL) is broadly adopted by major pharmaceutical companies and used in numerous drug discovery programs. The application of the DEL technology is advantageous at the initial period of drug discovery because of reduced cost, time, and storage space for the identification of target compounds. The key points for the construction of DELs comprise the development and the selection of the encoding methods, transfer of routine chemical reaction from off-DNA to on-DNA, and exploration of new chemical reactions on DNA. The limitations in the chemical space and the diversity of DEL were reduced gradually by using novel DNA-compatible reactions based on the formation and the cleavage of various bonds. Here, we summarized a series of novel DNA-compatible chemistry reactions for DEL building blocks and analysed the druggability of screened hit molecules via DELs in the past five years.

Design, synthesis and biological evaluation of novel 31-hexyloxy chlorin e6-based 152- or 131-amino acid derivatives as potent photosensitizers for photodynamic therapy.

This study aimed to improve the biological effectiveness and pharmacokinetic properties of chlorin e6, a second-generation photosensitizer (PS), for tumor photodynamic therapy (PDT). Herein, the novel 31-hexyloxy chlorin e6-based 152- or 131-amino acid derivatives 3a, 3b, 3c and 8 were synthesized and their photophysical properties and in vitro bioactivities such as phototoxicity against A549, HeLa and melanoma B16-F10 cells, reactive oxygen species (ROS) production and subcellular localization were evaluated. In addition, preferred target compounds were also investigated for their in vivo pharmacokinetic in SD rats and in vivo antitumor efficacies in C57BL/6 mice bearing melanoma B16-F10 cells. Apparently, simultaneous introduction of amino acid residue and n-hexyloxy chain in chlorin e6 made a significant improvement in photophysical properties, ROS production, in vitro and in vivo PDT efficacy. Encouragingly, all target compounds showed higher in vitro phototoxicity than Talaporfin, and that 3c (152-Lys) exhibited strongest phototoxicity and highest dark toxicity/phototoxicity ratio, followed by 8 (131-Asp), 3a (152-Asp) and 3b (152-Glu). Moreover, in vivo PDT antitumor efficacy of 3a, 3c and 8 was all better than that of Talaporfin, and that both 3c and 8 had stronger PDT antitumor efficiency than 3a. The overall results suggested that these novel 31-hexyloxy chlorin e6-based 152- or 131-amino acid derivatives, especially 3c and 8, might be potential antitumor candidate drugs for clinical treatment of melanoma by PDT.

Drug repurposing of anti-infective clinical drugs: Discovery of two potential anti-cytokine storm agents.

Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2) has been widely spread in the world with a high mortality. Cytokine storm syndrome (CSS) and acute lung injury caused by SARS-CoV-2 infection severely threaten the patients. With the purpose to find effective and low-toxic drugs to mitigate CSS, entecavir and imipenem were identified to reduce TNF-α using a LPS-induced macrophage model from the anti-infective drug library. Entecavir and imipenem efficiently suppressed the release of inflammatory cytokines by partly intervention of NF-κB activity. The acute lung injury was also alleviated and the survival time was prolonged in mice. In addition, entecavir and imipenem inhibited the release of TNF-α and IL-10 in human peripheral blood mononuclear cells (hPBMCs). Collectively, we proposed that entecavir and imipenem might be candidates for the treatment of CSS.

Trans-cinnamaldehyde protected PC12 cells against oxygen and glucose deprivation/reperfusion (OGD/R)-induced injury via anti-apoptosis and anti-oxidative stress.

Ischemia stroke is the major cause of mortality and permanent neurological disability with little definitive therapeutic options. This cerebral ischemic injury leads to the oxidative stress and eventually cell death. We hypothesized that treatment of this condition with the trans-cinnamaldehyde(TC) could protect cells from ischemic and reperfusion injury. Oxygen and glucose deprivation/reperfusion (OGD/R) was used as an in vitro model of hypoxic ischemic injury in present study. MTT was used to evaluate the protective effects of TC. Next, we tested whether TC reduced the production of reactive oxygen species (ROS). Besides, experiments were performed to determine whether or not the mitochondrial membrane potential was affected. Furthermore, the inhibiters of NO and PI3 K were used to determine the initial mechanisms. TC treatment improved cell viability, reduced intracellular ROS, and increased MMP. Further, the inhibition of NO or PI3 K significantly reduced TC's protective effects. These findings suggest that TC might be a promising agent for ischemic stroke.

[Identification of Volatile Chemical Constituents from Hui Formula "Ha Hei Lili" by GC-MS].

OBJECTIVE: The volatile components of the Hui formula "Ha Hei Lili" were extracted by steam distillation extraction (SD) and supercritical CO2 fluid extraction, and the structures were analyzed and identified by GC-MS. METHODS: The GC-MS conditions were set as follows: Rxi-5Sil MS quartz capillary column (30 m x 0.25 mm, 0.25 µm), the initial temperature of 50 degrees C to keep 1 min, to 10 degrees C/min heating to 120 degrees C, maintained 3 min, then to 3 degrees C/min heating to 200 degrees C, maintained 3 min, and then to 5 degreesC/min heating to 290 degrees C, maintained until completion of analysis; helium as the carrier gas, column flow rate 1.0 ml/min, split ratio 25: 1, inlet temperature 250 degrees C, EI ionization source 70 eV, ion source temperature 230 degrees C, scan range of m/z 35 - 500. RESULTS: Yield of volatile oil were 0.21% and 5.44% extracted by SD and SFE methods, respectively; and for SD method, 36 kinds of compounds were identified, accounted for 87.02% of total mass of volatile oil; for SFE method, 38 kinds of constituents were identified, accounted for 97.47% of total mass of volatile oil. CONCLUSION: The type of constituents contained in the volatile oil extracted by SD and SFE methods are totally different; and GC-MS can be used to identify the structures and relative content of volatile components, the results of this study can provide an experimental basis for development and utilization of Hui formula "Ha Hei Lili".

[Recent advances in the study of new antifungal lead compounds].

In recent years, the incidence and mortality rate of invasive fungal infection have increased dramatically, and it is of great significance to develop novel antifungal agents with new chemical structure and new mode of action. In this review, novel antifungal lead compounds reported from 2007 to 2009 are reviewed. Moreover, their chemical structures, antifungal activities and structure-activity relationships have been summarized, which can provide useful information for future study of antifungal agents.

In vivo effects of Pain Relieving Plaster on closed soft tissue injury in rabbit ears.

BACKGROUND: Soft tissue injury imposes major public health burdens worldwide. The positive effect of China's Tibetan medicine and the Lamiophlomis rotata-based herbal Pain Relieving Plaster (PRP) on healing closed soft tissue injury (CSTI) has been reported. The herbs contained in Plaster are also referred as 'blood-activating and stasis-dispelling' in herbal medicine. The formula of the plaster contains four China's Tibetan medical herbs, including Lamiophlomis rotata, Oxytropis falcate Bunge, Curcuma longa Linn, and Myricaria bracteata. Two of these herbs (Lamiophlomis rotate; Curcuma longa Linn) are commonly used in different formulae of Chinese medicine. The objective of this study is to use an interdisciplinary approach to test the hypothesis that the formula and its components influence the process of CSTI. METHODS: In vivo models have been established in 30 rabbit ear pinnae and studied for: (1) blood flow velocity (BFV) which was affected by pressure of 21.2 kg/cm2 for 30 second over the local rabbit ear tissue; (2) edema formation of the closed soft tissue injury; (3) in vivo local temperature change. RESULTS: The results of in vivo studies indicated that CSTI significantly increased the velocity of blood flow and increased edema formation within the control group. The PRP extracts for 5 hours significantly slowed down the BFV of CSTI in rabbit ears, markedly decreased the elevated edema level from the 3rd to the 5th day. CONCLUSION: The ingredients contained in the formula have positive effects in healing CSTI and further study is worth exploring.

Identification of Y118 amino acid residue in Candida albicans sterol 14alpha-demethylase associated with the enzyme activity and selective antifungal activity of azole analogues.

Our previous publication established a model to predict that the phenyl group of the C-3 side chain of azole antifungal compounds interacts with the phenol group of Tyr118 through the formation of pi-pi face-to-edge interaction. To verify this prediction, wild type and three site-directed mutants of the Y118 residue of Candida albicans sterol 14alpha-demethylase P450 (CACYP51) were constructed and heterologously expressed in Saccharomyces cerevisiae with deletion of the CYP51 gene. With the strains obtained and microsome enzymes separated, cell susceptibility and CACYP51 activity were examined with the 5 novel azole compounds based on the molecular modeling in comparison with fluconazole. After alteration of Y118 with Y118A, Y118F, and Y118T by a single base substitution, the expression levels of CACYP51 protein were not affected. However, these mutations markedly decreased its catalytic activity respectively; the mutation changes also decreased azole susceptibility, indicating the structural importance of the Y118 residue in maintaining CACYP51 activity and in determining azole susceptibility. In addition, our synthetic compounds with the phenyl group side chain attached to C3 produced higher susceptibility against S. cerevisiae with expression of CACYP51 and exhibited more potent inhibitory effects on CACYP51 activity in comparison with fluconazole, suggesting that the phenyl group of C3 side chain substitutes is also important for selective binding to target enzymes.

[Evolutionary trace analysis of N-myristoyltransferase family].

To clarify the important functional residues in the active site of N-myristoyltransferase (NMT), a novel antifungal drug target, and to guide the design of specific inhibitors, multiple sequence alignments were performed on the NMT family and thus evolutionary trace was constructed. The important functional residues in myristoyl CoA binding site, catalytic center and inhibitor binding site of NMT family were identified by ET analysis. The trace residues were mapped onto the active site of CaNMT. Trpl26, Asn175 and Thr211 are highly conserved trace residues and do not interact with current NMT inhibitors, which are potential novel drug binding sites for the novel inhibitor design. Pro338, Leu350, Ile352 and Ala353 are class-specific trace residues, which are important for the optimization of current NMT inhibitors. The trace residues identified by ET analysis are of great importance to study the structure-function relationship and also to guide the design of specific inhibitors.

Synthesis of novel triazole derivatives as inhibitors of cytochrome P450 14alpha-demethylase (CYP51).

A series of 1-(1H-1,2,4-triazol-1-yl)-2-(2,4-difluorophenyl)-3-[(4-substitutedphenyl)-piperazin-1-yl]-propan-2-ols have been designed and synthesized on the basis of the structure-activity relationships and antimycotic mechanism of azole antifungal agents. Their structures were confirmed by elemental analysis, IR, MS and (1)H NMR. Results of preliminary antifungal tests against eight human pathogenic fungi (Candida albicans, Candida parapsilosis, Candida tropicalis, Cryptococcus neoformans, Aspergillus fumigatus, Trichophyton rubrum, Fonsecaea compacta, and Microsporum gypseum) in vitro showed that all title compounds exhibited activity against fungi tested to some extent. Among the compounds tested, all compounds showed higher activity against C. albicans than fluconazole in vitro. Compounds 3, 6-8, 28, 29, and 32 exhibited the same activities against C. albicans as voriconazole (with the MIC value of 0.0152microg/mL). Compounds 3, 6, and 7 showed higher activity against C. parapsilosis than all five positive controls.

Synthesis and evaluation of novel 1-(1H-1,2,4-triazol-1-yl)-2-(2,4-difluorophenyl)-3-[(4-substitutedphenyl)-piperazin-1-yl]-propan-2-ols as antifungal agents.

A series of 1-(1H-1,2,4-triazol-1-yl)-2-(2,4-difluorophenyl)-3-[(4-substitutedphenyl)-piperazin-1-yl]-propan-2-ols have been designed and synthesized on the basis of the structure-activity relationships and antimycotic mechanism of azole antifungal agents. Their structures were confirmed by elemental analysis, IR, MS, (1)H NMR and (13)C NMR. Results of preliminary antifungal tests against six human pathogenic fungi (Candida albicans, Candida parapsilosis, Cryptococcus neoformans, Candida tropicalis, inherently fluconazole-resistant Candida krusei, Candida glabrata) in vitro showed that all title compounds exhibited activity against fungi tested to some extent except against C. tropicalis. Compound 5b showed higher activity against C. albicans, C. parapsilosis and C. krusei than fluconazole, and its MIC values were determined to be 0.5microg/mL, 1microg/mL and 4microg/mL, respectively. Compound 5k showed higher activities against Torulopsis glabrata than fluconazole (with the MIC value of 2microg/mL). Compounds 5a, 5c, 5f, 5g, 5i exhibited higher activities against C. parapsilosis than fluconazole (with the MIC values of 2microg/mL, 2microg/mL, 2microg/mL, 1microg/mL and 2microg/mL, respectively).

[Recent advances in the study of antifungal lead compounds with new chemical scaffolds].

In recent years, the incidence of infections caused by invasive fungal pathogens has increased dramatically. However, most antifungal agents used in clinic have many drawbacks and cannot meet the demand of the clinical use. Therefore, for the development of new generation of antifungal agents, it is of great significance to find antifungal lead compounds with novel chemical scaffolds and new mode of action. Novel antifungal lead compounds reported in recent years are reviewed. Their chemical structures, antifungal activity and structure-activity relationship are discussed in detail, and current problems and trends in future research are also emphasized.

In vitro antifungal activity of ZJ-522, a new triazole restructured from fluconazole and butenafine, against clinically important fungi in comparison with fluconazole and butenafine.

The antifungal activity of ZJ-522, a new triazole antifungal agent restructured from fluconazole and butenafine, was compared to that of fluconazole and butenafine against 43 strains of fungi representing 13 fungal species. MICs were determined by using the National Committee for Clinical Laboratory Standards (NCCLS)-recommended broth microdilution method for yeasts, which was modified for filamentous fungi. ZJ-522 was about 50-fold and 2 to 16-fold more potent than fluconazole against yeasts and filamentous fungi respectively, but it was less active than butenafine against filamentous fungi, although butenafine was inactive against most yeasts. Thus, the fashion of ZJ-522 antifungal activity more similar to that of fluconazole than that of butenafine indicates that ZJ-522 should be an inhibitor of lanosterol 14alpha-demethylase but not of squalene epoxidase, and should be a candidate for clinical development.

[Synthesis and antifungal activity of novel triazole antifungal agents].

AIM: A series of triazole antifungal agents were synthesized to search for novel triazole antifungal agents with more potent activity, less toxicity and broader spectrum. METHODS: Twenty-one 1-(1H-1, 2, 4-triazolyl)-2-(2, 4-diflurophenyl)-3-(4-substituted-1-piperazinyl)-2-propanols were synthesized, on the basis of the three dimensional structure of P450 cytochrome 14alpha-sterol demethylase (CYP51) and their antifungal activities were also evaluated. RESULTS: Results of preliminary biological tests showed that most of title compounds exhibited activity against the eight common pathogenic fungi to some extent and the activities against deep fungi were higher than that against shallow fungi. In general, phenyl and pyridinyl analogues showed higher antifungal activity than that of the phenylacyl analogues. CONCLUSION: Several title compounds showed higher antifungal activities than fluconazole and terbinafine. Compound VIII-1, 4, 5 and IX-3 showed the best antifungal activity with broad antifungal spectrum and were chosen for further study.