<p>In vivo Screening of Natural Products Against Angiogenesis and Mechanisms of Anti-Angiogenic Activity of Deoxysappanone B 7,4ʹ-Dimethyl Ether</p>

The Role of SLIT3-ROBO4 Signaling in Endoplasmic Reticulum Stress-Induced Delayed Corneal Epithelial and Nerve Regeneration

Purpose

In the present study, we aim to elucidate the underlying molecular mechanism of endoplasmic reticulum (ER) stress induced delayed corneal epithelial wound healing and nerve regeneration.

Methods

Human limbal epithelial cells (HLECs) were treated with thapsigargin to induce excessive ER stress and then RNA sequencing was performed. Immunofluorescence, qPCR, Western blot, and ELISA were used to detect the expression changes of SLIT3 and its receptors ROBO1-4. The role of recombinant SLIT3 protein in corneal epithelial proliferation and migration were assessed by CCK8 and cell scratch assay, respectively. Thapsigargin, exogenous SLIT3 protein, SLIT3-specific siRNA, and ROBO4-specific siRNA was injected subconjunctivally to evaluate the effects of different intervention on corneal epithelial and nerve regeneration. In addition, Ki67 staining was performed to evaluate the proliferation ability of epithelial cells.

Results

Thapsigargin suppressed normal corneal epithelial and nerve regeneration significantly. RNA sequencing genes related to development and regeneration revealed that thapsigargin induced ER stress significantly upregulated the expression of SLIT3 and ROBO4 in corneal epithelial cells. Exogenous SLIT3 inhibited normal corneal epithelial injury repair and nerve regeneration, and significantly suppressed the proliferation and migration ability of cultured mouse corneal epithelial cells. SLIT3 siRNA inhibited ROBO4 expression and promoted epithelial wound healing under thapsigargin treatment. ROBO4 siRNA significantly attenuated the delayed corneal epithelial injury repair and nerve regeneration induced by SLIT3 treatment or thapsigargin treatment.

Conclusions

ER stress inhibits corneal epithelial injury repair and nerve regeneration may be related with the upregulation of SLIT3-ROBO4 pathway.

Predictive insights into plant-based compounds as fibroblast growth factor receptor 1 inhibitors: a combined molecular docking and dynamics simulation study

The discovery of novel therapeutic agents with potent anticancer activity remains a critical challenge in drug development. Natural products, particularly bioactive phytoconstituents derived from plants, have emerged as promising sources for anticancer drug discovery. In this study, we used virtual screening techniques to explore the potential of bioactive phytoconstituents as inhibitors of fibroblast growth factor receptor 1 (FGFR1), a key signaling protein implicated in cancer progression. We used virtual screening techniques to analyze phytoconstituents extracted from the IMPPAT 2.0 database. Our primary objective was to discover promising inhibitors of FGFR1. To ensure the selection of promising candidates, we initially filtered the molecules based on their physicochemical properties. Subsequently, we performed binding affinity calculations, PAINS, ADMET, and PASS filters to identify nontoxic and highly effective hits. Through this screening process, one phytocompound, namely Mundulone, emerged as a potential lead. This compound demonstrated an appreciable affinity for FGFR1 and exhibited specific interactions with the ATP-binding site residues. To gain further insights into the conformational dynamics of Mundulone and the reference FGFR1 inhibitor, Lenvatinib, we conducted time-evolution analyses employing 200 ns molecular dynamics simulations (MDS) and essential dynamics. These analyses provided valuable information regarding the dynamic behavior and stability of the compounds in complexes with FGFR1. Overall, the findings indicate that Mundulone exhibits promising binding affinity, specific interactions, and favorable drug profiles, making it a promising lead candidate. Further experimental analysis will be necessary to confirm its effectiveness and safety profiles for therapeutic advancement in the cancer field.Communicated by Ramaswamy H. Sarma.

Topical Application of Baicalin Combined with Echinacoside Ameliorates Psoriatic Skin Lesions by Suppressing the Inflammation-Related TNF Signaling Pathway and the Angiogenesis-Related VEGF Signaling Pathway

Baicalin (BAI), the main active component of Scutellaria baicalensis, has significant anti-inflammatory and antibacterial effects. Echinacoside (ECH), an active component from Echinacea purpurea, has significant antiangiogenesis and antioxidant effects. In previous studies, BAI or ECH has been used for some skin inflammation problems by topical treatment. Psoriasis (PSO) is a common inflammatory skin disease with typical features such as excessive inflammatory response and vascular proliferation in skin lesions. Because of the anti-inflammatory effect of BAI and the antiangiogenic activity of ECH, it is proposed that the combination of BAI and ECH can ameliorate psoriatic skin lesions better than a single component. This study aims to explore the effects and potential mechanisms of BAI combined with ECH on imiquimod (IMQ)-induced psoriatic skin lesions by topical treatment. Transcriptome analysis first showed that the TNF signaling pathway and the VEGF signaling pathway were significantly enriched in IMQ-induced psoriatic skin lesions. Topical application of BAI combined with ECH could ameliorate IMQ-induced skin lesions in mice, especially the better effects of B2-E1 (BAI/ECH = 2:1). Network pharmacology analysis and molecular docking indicated that BAI-treated PSO on the skin by regulating the TNF signaling pathway, and ECH treated PSO on the skin by regulating the VEGF signaling pathway. Meanwhile, the ELISA test and the qPCR assay showed that BAI combined with ECH could inhibit the expression of key cytokines and genes related to the TNF signaling pathway and the VEGF signaling pathway. Zebrafish experiments demonstrated the anti-inflammatory and antiangiogenic effects of BAI combined with ECH and revealed the potential mechanisms associated with regulating the inflammation-related TNF signaling pathway and the angiogenesis-related VEGF signaling pathway. This suggested that BAI combined with ECH may be a promising topical agent to ameliorate psoriatic skin lesions in the future.

Arrest of mouse preterm labor until term delivery by combination therapy with atosiban and mundulone, a natural product with tocolytic efficacy

There is a lack of FDA-approved tocolytics for the management of preterm labor (PL). In prior drug discovery efforts, we identified mundulone and mundulone acetate (MA) as inhibitors of in vitro intracellular Ca2+-regulated myometrial contractility. In this study, we probed the tocolytic potential of these compounds using human myometrial samples and a mouse model of preterm birth. In a phenotypic assay, mundulone displayed greater efficacy, while MA showed greater potency and uterine-selectivity in the inhibition of intracellular-Ca2+ mobilization. Cell viability assays revealed that MA was significantly less cytotoxic. Organ bath and vessel myography studies showed that only mundulone exerted inhibition of myometrial contractions and that neither compounds affected vasoreactivity of ductus arteriosus. A high-throughput combination screen identified that mundulone exhibits synergism with two clinical-tocolytics (atosiban and nifedipine), and MA displayed synergistic efficacy with nifedipine. Of these combinations, mundulone+atosiban demonstrated a significant improvement in the in vitro therapeutic index compared to mundulone alone. The ex vivo and in vivo synergism of mundulone+atosiban was substantiated, yielding greater tocolytic efficacy and potency on myometrial tissue and reduced preterm birth rates in a mouse model of PL compared to each single agent. Treatment with mundulone after mifepristone administration dose-dependently delayed the timing of delivery. Importantly, mundulone+atosiban permitted long-term management of PL, allowing 71% dams to deliver viable pups at term (>day 19, 4-5 days post-mifepristone exposure) without visible maternal and fetal consequences. Collectively, these studies provide a strong foundation for the development of mundulone as a single or combination tocolytic for management of PL.

Arrest of mouse preterm labor until term delivery by combination therapy with atosiban and mundulone, a natural product with tocolytic efficacy

Currently, there is a lack of FDA-approved tocolytics for the management of preterm labor (PL). In prior drug discovery efforts, we identified mundulone and its analog mundulone acetate (MA) as inhibitors of in vitro intracellular Ca 2+ -regulated myometrial contractility. In this study, we probed the tocolytic and therapeutic potential of these small molecules using myometrial cells and tissues obtained from patients receiving cesarean deliveries, as well as a mouse model of PL resulting in preterm birth. In a phenotypic assay, mundulone displayed greater efficacy in the inhibition of intracellular-Ca 2+ from myometrial cells; however, MA showed greater potency and uterine-selectivity, based IC 50 and E max values between myometrial cells compared to aorta vascular smooth muscle cells, a major maternal off-target site of current tocolytics. Cell viability assays revealed that MA was significantly less cytotoxic. Organ bath and vessel myography studies showed that only mundulone exerted concentration-dependent inhibition of ex vivo myometrial contractions and that neither mundulone or MA affected vasoreactivity of ductus arteriosus, a major fetal off-target of current tocolytics. A high-throughput combination screen of in vitro intracellular Ca 2+ -mobilization identified that mundulone exhibits synergism with two clinical-tocolytics (atosiban and nifedipine), and MA displayed synergistic efficacy with nifedipine. Of these synergistic combinations, mundulone + atosiban demonstrated a favorable in vitro therapeutic index (TI)=10, a substantial improvement compared to TI=0.8 for mundulone alone. The ex vivo and in vivo synergism of mundulone and atosiban was substantiated, yielding greater tocolytic efficacy and potency on isolated mouse and human myometrial tissue and reduced preterm birth rates in a mouse model of PL compared to each single agent. Treatment with mundulone 5hrs after mifepristone administration (and PL induction) dose-dependently delayed the timing of delivery. Importantly, mundulone in combination with atosiban (FR 3.7:1, 6.5mg/kg + 1.75mg/kg) permitted long-term management of PL after induction with 30 μg mifepristone, allowing 71% dams to deliver viable pups at term (> day 19, 4-5 days post-mifepristone exposure) without any visible maternal and fetal consequences. Collectively, these studies provide a strong foundation for the future development of mundulone as a stand-alone single- and/or combination-tocolytic therapy for management of PL.

Application of Zebrafish as a Model for Anti-Cancer Activity Evaluation and Toxicity Testing of Natural Products

Developing natural product-based anti-cancer drugs/agents is a promising way to overcome the serious side effects and toxicity of traditional chemotherapeutics for cancer treatment. However, rapid assessment of the in vivo anti-cancer activities of natural products is a challenge. Alternatively, zebrafish are useful model organisms and perform well in addressing this challenging issue. Nowadays, a growing number of studies have utilized zebrafish models to evaluate the in vivo activities of natural compounds. Herein, we reviewed the application of zebrafish models for evaluating the anti-cancer activity and toxicity of natural products over the past years, summarized its process and benefits, and provided future outlooks for the development of natural product-based anti-cancer drugs.

Ethanol extract from Artemisia argyi leaves inhibits HSV-1 infection by destroying the viral envelope

Herpes simplex virus type 1 (HSV-1) is a widely disseminated virus that establishes latency in the brain and causes occasional but fatal herpes simplex encephalitis. Currently, acyclovir (ACV) is the main clinical drug used in the treatment of HSV-1 infection, and the failure of therapy in immunocompromised patients caused by ACV-resistant HSV-1 strains necessitates the requirement to develop novel anti-HSV-1 drugs. Artemisia argyi, a Traditional Chinese Medicine, has been historically used to treat inflammation, bacterial infection, and cancer. In this study, we demonstrated the antiviral effect and mechanism of ethanol extract of A. argyi leaves (hereafter referred to as 'AEE'). We showed that AEE at 10 μg/ml exhibits potent antiviral effects on both normal and ACV-resistant HSV-1 strains. AEE also inhibited the infection of HSV-2, rotavirus, and influenza virus. Transmission electron microscopy revealed that AEE destroys the membrane integrity of HSV-1 viral particles, resulting in impaired viral attachment and penetration. Furthermore, mass spectrometry assay identified 12 major components of AEE, among which two new flavones, deoxysappanone B 7,3'-dimethyl ether, and 3,7-dihydroxy-3',4'-dimethoxyflavone, exhibited the highest binding affinity to HSV-1 glycoprotein gB at the surface site critical for gB-gH-gL interaction and gB-mediated membrane fusion, suggesting their involvement in inactivating virions. Therefore, A. argyi is an important source of antiviral drugs, and the AEE may be a potential novel antiviral agent against HSV-1 infection.

Proangiogenesis effects of compound danshen dripping pills in zebrafish

Background

The compound Danshen Dripping Pill (CDDP), which is a mixture of extracts from Radix Salviae and Panax notoginseng, is a patented traditional Chinese medicine that is widely used in multiple countries for relieving coronary heart disease (CHD), but its pharmacological mechanism has not been fully elucidated. In this study, we screened the key pharmacological pathways and targets of CDDP that act on CHD using a network pharmacology-based strategy, and the angiogenic activity of CDDP was directly visually investigated in zebrafish embryos in vivo.

Methods

The potential therapeutic targets and pathways were predicted through a bioinformatics analysis. The proangiogenic effects of CDDP were examined using vascular sprouting assays on subintestinal vessels (SIVs) and optic arteries (OAs) as well as injury assays on intersegmental vessels (ISVs). Pharmacological experiments were applied to confirm the pathway involved.

Results

Sixty-five potential therapeutic targets of CDDP on CHD were identified and enriched in the PI3K/AKT and VEGF/VEGFR pathways. An in vivo study revealed that CDDP promoted angiogenesis in SIVs and OAs in a dose-dependent manner and relieved the impairments in ISVs induced by lenvatinib, a VEGF receptor kinase inhibitor (VRI). In addition, Vegfaa and Kdrl expression were significantly upregulated after CDDP treatment. Furthermore, the proangiogenic effect of CDDP could be abolished by PI3K/AKT pathway inhibitors.

Conclusions

CDDP has a proangiogenic effect, the mechanism of which involves the VEGF/VEGFR and PI3K/AKT signaling pathways. These results suggest a new insight into the cardiovascular protective effect of CDDP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03589-y.