Fluorine-Modified Rutaecarpine Exerts Cyclooxygenase-2 Inhibition and Anti-inflammatory Effects in Lungs

In Vitro COX Inhibitory Activity, LC-MS Analysis and Molecular Docking Study of Silene vulgaris and Stellaria media

Silene vulgaris (Moench) Garcke and Stellaria media (L.) Vill is a perennial wild weed species belonging to the Caryophyllaceae family and is widely available and abundant in the environment. The present study has aimed to evaluate the anti-inflammatory potential of two underutilized wild edible plants, Silene vulgaris (Moench) Garcke and Stellaria media (L.) Vill. fractions employing in-vitro COX inhibitory assay. Invitro COX-2 inhibitory potential of MESV and MESM fractions was carried out using BioVisionR "COX Activity Assay Kit (Fluorometric)". LC-MS analysis of selected fractions was conducted to identify bioactive compounds that were further validated for their affinity determination toward target enzymes employing molecular docking studies using the LibDock program. In-vitro COX inhibitory assay revealed that hexane fraction of S. vulgaris (HFSV) and hexane fraction of S. media (HFSM) caused impressive inhibition of COX-2 enzyme with IC50 values 1.38 µg/mL and 1.51 µg/mL respectively. Further, LC-MS analysis revealed the presence of 46 compounds in HFSV and 44 compounds in HFSM respectively. Amongst identified bioactive compounds in HFSV and HFSM, sinapinic acid and syringic acid showed good docking scores with COX-2 i.e., 89.256, and 82.168 respectively. Also, the availability of chrysin in HFSM and rhamnetin in HFSV exhibited good docking scores i.e., 115.092, and 112.341 with a selective affinity towards COX-2. The findings of in-vitro COX Inhibitory Activity and molecular docking studies highlighted the impressive anti-inflammatory properties of S. vulgaris and S. media, and require further investigations to establish them as therapeutic candidates in the management of inflammation and related issues.

Comprehensive Analysis of 11 Species of Euodia (Rutaceae) by Untargeted LC-IT-TOF/MS Metabolomics and In Vitro Functional Methods

The Euodia genus comprises numerous untapped medicinal plants that warrant thorough evaluation for their potential as valuable natural sources of herbal medicine or food flavorings. In this study, untargeted metabolomics and in vitro functional methods were employed to analyze fruit extracts from 11 significant species of the Euodia genus. An investigation of the distribution of metabolites (quinolone and indole quinazoline alkaloids) in these species indicated that E. rutaecarpa (Euodia rutaecarpa) was the most widely distributed species, followed by E. compacta (Euodia compacta), E. glabrifolia (Euodia glabrifolia), E. austrosinensis (Euodia austrosinensis), and E. fargesii (Euodia fargesii). There have been reports on the close correlation between indole quinazoline alkaloids and their anti-tumor activity, especially in E. rutaecarpa fruits which exhibit effectiveness against various types of cancer, such as SGC-7901, Hela, A549, and other cancer cell lines. Additionally, the E. rutaecarpa plant contains indole quinazoline alkaloids, which possess remarkable antibacterial properties. Our results offer novel insights into the utilization of Euodia resources in the pharmaceutical industry.

Promising derivatives of rutaecarpine with diverse pharmacological activities

Rutaecarpine (RUT) is a natural pentacyclic indolopyridoquinazolinone alkaloid first isolated from one of the most famous traditional Chinese herbs, Evodia rutaecarpa, which is used for treating a variety of ailments, including headaches, gastrointestinal disorders, postpartum hemorrhage, amenorrhea, difficult menstruation, and other diseases. Accumulating pharmacological studies showed that RUT possesses a wide range of pharmacological effects through different mechanisms. However, its poor physicochemical properties and moderate biological activities have hampered its clinical application. In this regard, the modification of RUT aimed at seeking its derivatives with better physicochemical properties and more potency has been extensively studied. These derivatives exhibit diverse pharmacological activities, including anti-inflammatory, anti-atherogenic, anti-Alzheimer's disease, antitumor, and antifungal activities via a variety of mechanisms, such as inhibiting cyclooxygenase-2 (COX-2), acetylcholine (AChE), phosphodiesterase 4B (PDE4B), phosphodiesterase 5 (PDE5), or topoisomerases (Topos). From this perspective, this paper provides a comprehensive description of RUT derivatives by focusing on their diverse biological activities. This review aims to give an insight into the biological activities of RUT derivatives and encourage further exploration of RUT.

In Vitro and In Silico Investigation of Polyacetylenes from Launaea capitata (Spreng.) Dandy as Potential COX-2, 5-LOX, and BchE Inhibitors

Diverse secondary metabolites are biosynthesized by plants via various enzymatic cascades. These have the capacity to interact with various human receptors, particularly enzymes implicated in the etiology of several diseases. The n-hexane fraction of the whole plant extract of the wild edible plant, Launaea capitata (Spreng.) Dandy was purified by column chromatography. Five polyacetylene derivatives were identified, including (3S,8E)-deca-8-en-4,6-diyne-1,3-diol (1A), (3S)-deca-4,6,8-triyne-1,3-diol (1B), (3S)-(6E,12E)-tetradecadiene-8,10-diyne-1,3-diol (2), bidensyneoside (3), and (3S)-(6E,12E)-tetradecadiene-8,10-diyne-1-ol-3-O-β-D-glucopyranoside (4). These compounds were investigated for their in vitro inhibitory activity against enzymes involved in neuroinflammatory disorders, including cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), and butyrylcholinesterase (BchE) enzymes. All isolates recorded weak-moderate activities against COX-2. However, the polyacetylene glycoside (4) showed dual inhibition against BchE (IC₅₀ 14.77 ± 1.55 μM) and 5-LOX (IC₅₀ 34.59 ± 4.26 μM). Molecular docking experiments were conducted to explain these results, which showed that compound 4 exhibited greater binding affinity to 5-LOX (-8.132 kcal/mol) compared to the cocrystallized ligand (-6.218 kcal/mol). Similarly, 4 showed a good binding affinity to BchE (-7.305 kcal/mol), which was comparable to the cocrystallized ligand (-8.049 kcal/mol). Simultaneous docking was used to study the combinatorial affinity of the unresolved mixture 1A/1B to the active sites of the tested enzymes. Generally, the individual molecules showed lower docking scores against all the investigated targets compared to their combination, which was consistent with the in vitro results. This study demonstrated that the presence of a sugar moiety (in 3 and 4) resulted in dual inhibition of 5-LOX and BchE enzymes compared to their free polyacetylenes analogs. Thus, polyacetylene glycosides could be suggested as potential leads for developing new inhibitors against the enzymes involved in neuroinflammation.

The Anti-Proliferative and Apoptotic Effects of Rutaecarpine on Human Esophageal Squamous Cell Carcinoma Cell Line CE81T/VGH In Vitro and In Vivo

The overall five-year survival rate for patients with esophageal cancer is low (15 to 25%) because of the poor prognosis at earlier stages. Rutaecarpine (RTP) is a bioalkaloid found in the traditional Chinese herb Evodia rutaecarpa and has been shown to exhibit anti-proliferative effect on tumor cells. However, the mechanisms by which RTP confer these effects and its importance in esophageal squamous cell carcinoma treatment remain unclear. Thus, in the present study, we first incubated human esophageal squamous cell carcinoma cell line, CE81T/VGH, with RTP to evaluate RTP’s effects on tumor cell growth and apoptosis. We also performed a xenograft study to confirm the in vitro findings. Furthermore, we determined the expression of p53, Bax, bcl-2, caspase-3, caspase-9, and PCNA in CE81T/VGH cells or the tumor tissues to investigate the possible mechanisms. All the effects of TRP were compared with that of cisplatin. The results showed that RTP significantly inhibits CE81T/VGH cell growth, promotes arrest of cells in the G₂/M phase, and induces apoptosis. Consistently, the in vivo study showed that tumor size, tumor weight, and proliferating cell nuclear antigen protein expression in tumor tissue are significantly reduced in the high-dose RTP treatment group. Furthermore, the in vitro and in vivo studies showed that RTP increases the expression of p53 and Bax proteins, while inhibiting the expression of Bcl-2 in cancer cells. In addition, RTP significantly increases the expression of cleaved caspase-9 and cleaved caspase-3 proteins in tumor tissues in mice. These results suggest that RTP may trigger the apoptosis and inhibit growth in CE81T/VGH cells by the mechanisms associated with the regulation of the expression of p53, Bax, Bcl-2, as well as caspase-9 and caspase-3.

Comparison of the effects of rutaecarpine on molecular subtypes of breast cancer

Objective

Natural compounds have gained considerable attention in recent years due to disadvantages and properties of current chemotherapy drugs in cancer therapy. In addition, the impact of these compounds is specific for each type and/or subtypes of cancer due to different treatment response. Rutaecarpine, an alkaloid obtained from Evodia Rutaecarpa Chinese herb, has anticancer activity by inhibiting topoisomerase and/or cyclo-oxygenase-2 levels. However, the effectiveness of rutaecarpine has not been well known in breast cancer in terms of subtype. Therefore, we investigated the potential therapeutic effects of rutaecarpine on two different subtypes of breast cancer cells.

Materials and Methods

The cytotoxic and apoptotic effects of rutaecarpine on MCF-7 and MDA-MB-231 cells were analyzed by WST-1, Annexin V, cell cycle, and acridine orange staining.

Results

WST-1 results indicated that rutaecarpine significantly inhibited the growth of both cancer cells for 48 h (P < 0.05). In addition, rutaecarpine treatment caused apoptotic cell death through chromatin condensation and nuclear blebbing and G0/G1 arrest in both breast cancer cells. However, the efficacy of rutaecarpine was more profound in MCF-7 cells than MDA-MB-231 cells.

Conclusions

Consequently, rutaecarpine has a potential therapeutic effect on breast cancer. However, the effectiveness of rutaecarpine is dependent on the subtype of breast cancer.

Synthesis and Biological Evaluation of Salicylic Acid Analogues of Celecoxib as a New Class of Selective Cyclooxygenase-1 Inhibitor

A series of salicylic acid analogues of celecoxib where the phenylsulfonamide moiety in the structure of celecoxib is replaced by salicylic acid moiety was synthesized and tested for in vitro cyclooxygenase (COX)-1 and COX-2 enzyme inhibition. Among the series, 5-substituted-2-hydroxy-benzoic acid analogues (7a-7h) generally showed better inhibitory activities on both enzymes than 4-substituted-2-hydroxy-benzoic acid analogues (12a-12h). In particular, the chloro analogue 7f which had the highest inhibitory effect (IC₅₀ = 0.0057 µM) to COX-1 with excellent COX-1 selectivity (SI = 768) can be classified as a new potent and selective COX-1 inhibitor. The high inhibitory potency of 7f was rationalized through the docking simulation of this analogue in the active site of COX-1 enzyme.

3-B-RUT, a derivative of RUT, protected against alcohol-induced liver injury by attenuating inflammation and oxidative stress

Alcoholic liver disease (ALD) is the most common chronic liver disease worldwide. Currently, there is no definitive treatment for alcohol-induced liver injury (ALI). Inflammatory response and oxidative stress play a crucial role in ALI. Cyclooxygenase 2 (COX-2) can be induced by inflammation and it has been reported that the enhanced expression of COX-2 in alcoholic liver injury. Rutaecarpine (RUT) was extracted from evodia rutaecarpa. RUT has a wide range of pharmacological activities. In order to increase its anti-inflammatory activity, our group introduced sulfonyl group to synthesized the 3-[2-(trifluoromethoxy)benzenesulfonamide]-rutaecarpine (3-B-RUT). In this study, we explored the protective effect of 3-B-RUT on alcoholic liver injury in vivo and in vitro and preliminarily explore its mechanism. Mice ALI model was established according to the chronic-plus-binge ethanol model. Results showed that 3-B-RUT (20 μg/kg) attenuated alcohol-induced liver injury and suppressed liver inflammation and oxidative stress, and the effect was comparable to RUT (20 mg/kg). In vitro results are consistent with in vivo results. Mechanistically, the 3-B-RUT might suppress inflammatory response and oxidative stress by regulating activation of NF-κB/COX-2 pathway. In summary, 3-B-RUT, a derivative of RUT, may be a promising clinical candidate for ALI treatment.

Development of Novel Diclofenac Analogs Designed to Avoid Metabolic Activation and Hepatocyte Toxicity

Diclofenac (DCF) is widely used as a nonsteroidal anti-inflammatory drug; however, it is associated with severe liver injury. This adverse reaction is thought to be related to the reactive quinone imine (QI) and acyl glucuronide (AG) metabolites of DCF, but it remains controversial which reactive metabolites mainly contribute to DCF-induced toxicity. In this study, we synthesized five types of DCF analogs that were designed to mitigate the formation of reactive QI and/or AG metabolites and evaluated their metabolic stability, cyclooxygenase (COX) inhibitory activity, and toxicity to cryopreserved human hepatocytes. Compounds with fluorine at the 5- and 4'-positions of aromatic rings exhibited modest and high metabolic stability to oxidation by cytochrome P450, respectively, but induced cytotoxicity comparable to DCF. Replacing the carboxylic group of DCF with its bioisosteres was effective in terms of stability to oxidative metabolism and glucuronidation; however, sulfonic acid and sulfonamide groups were not preferable for COX inhibition, and tetrazole-containing analogs induced strong cytotoxicity. On the other hand, compounds that have fluorine at the benzylic position were resistant to glucuronidation and showed little toxicity to hepatocytes. In addition, among these compounds, those with hydrogen at the 4'-position (2a and 2c) selectively inhibited the COX-2 enzyme. Throughout these data, it was suggested that compounds 2a and 2c might be novel safer and more efficacious drug candidates instead of DCF.

Evodiamine and rutaecarpine from Tetradium ruticarpum in the treatment of liver diseases

BACKGROUND

Liver is the pivotal organ responsible for plasma protein production, biliary secretion, xenobiotic elimination, glucose and lipid homeostasis. Dysregulation of these functions usually leads to liver diseases and further related complications. The incidence of liver diseases is increasing worldwide, with high morbidity and mortality when at advanced stages, and has become significant public health concern and substential economic burden. Thus, novel therapeutic strategies for managing liver diseases progression are urgently required. T. ruticarpum is one of the most famous and frequently used herbal medicine and has been prescribed in traditional Chinese medicine (TCM) formulas for the treatment of various ailments, including liver diseases. A considerable amount of bioactive ingredients have been isolated and identified from the roots of T. ruticarpum, including alkaloids, saponins, phenols, volatile oils and other compounds. Among these compounds, evodiamine (EVO) and rutaecarpine (RUT) are believed to be the most bioactive compounds.

PURPOSE

To summarize recent findings regarding to the metabolism, pharmacological/toxicological effects of EVO and RUT and to highlight the potential therapeutic effects of them against liver diseases.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "T. ruticarpum", "Wu Zhu Yu", "evodiamine", "rutaecarpine", "liver" and combinations to include published studies of EVO and RUT primarily from 2004-2019. Several critical previous studies beyond this period were also included.

RESULTS

Evodiamine (EVO) and rutaecarpine (RUT) are believed to be the most bioactive alkaloids in T. ruticarpum, having anti-inflammation, anti-fibrosis, anti-lipotoxicity, anti-cancer activities, and thus having potential to improve liver disorders. In the current review, we comprehensively summarized recent progresses in the studies of EVO- and RUT-mediated promising hepatoprotective effects and also provide novel insights regarding the potential use of EVO and RUT as therapeutic options for the treatment of liver diseases.

CONCLUSION

With further in-depth pharmacology and pharmacokinetic studies, we believe that natural products in T. ruticarpum and their derivatives will become promising medicines with improved clinical efficacy for the treatment of liver diseases in the immediate future.

Targeting GRP78-dependent AR-V7 protein degradation overcomes castration-resistance in prostate cancer therapy

Rationale: Androgen receptor splice variant 7 (AR-V7) is a leading cause of the development of castration-resistant prostate cancer (CRPC). However, the regulation and function of AR-V7 at levels of post-translational modifications in prostate cancer therapy remain poorly understood. Here, we conducted a library screen of natural products to identify potential small molecules responsible for AR-V7 protein degradation in human prostate cancer cell lines.

Methods: A natural product library was used to screen the inhibitor of AR-V7. Co-IP and biomass spectrum assays were used to identify the AR-V7-interacting proteins, whereas western blot, confocal microscopy, RNA interfering, and gene transfection were used to validate these interactions. Cell viability, EDU staining, and colony formation assays were employed to detect cell growth and proliferation. Flowcytometry assays were used to detect the distribution of cell cycle. Mouse xenograft models were used to study the anti-CRPC effects in vivo.

Results: This screen identified rutaecarpine, one of the major components of the Chinese medicine Evodia rutaecarpa, as a novel chemical that selectively induces AR-V7 protein degradation via K48-linked ubiquitination. Mechanically, this effect relies on rutaecarpine inducing the formation of a GRP78-AR-V7 protein complex, which further recruits the E3 ligase SIAH2 to directly promote the ubiquitination of AR-V7. Consequently, the genetic and pharmacological activation of the GRP78-dependent AR-V7 protein degradation restores the sensitivity of castration-resistant prostate cancer to anti-androgen therapy in cell culture and animal models.

Conclusions: These findings not only provide a new approach for overcoming castration-resistance in prostate cancer therapy, but also increase our understanding about the interplay between molecular chaperones and ubiquitin ligase in shaping protein stability.

The anti-fibrotic and anti-inflammatory effects of 2,4-diamino-5-(1-hydroxynaphthalen-2-yl)-5H-chromeno[2,3-b] pyriine-3-carbonitrile in corneal fibroblasts

BACKGROUND

Although several studies had addressed the anti-inflammatory effects of derivatives of 4H-chromene and chromeno[2,3-b]pyridine in the different types of cells, whether these derivatives would exert beneficial anti-fibrotic effects during corneal fibrotic scar formation was unclear.

METHODS

We examined the cyclooxygenase-2 (COX-2) expression of 2,4-diamino-5-(1-hydroxynaphthalen-2-yl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile (N1) in the human corneal fibroblasts (HCFs) under the treatment TGF-β1. Signaling pathways underlying the mechanism of the N1 effect on the HCFs were determined.

RESULTS

Application of N1 significantly decreased COX-2 expression after 2 h and 4 h in the HCFs stimulated with TGF-β1. Notably, reduced production of extracellular matrix proteins under N1 treatment was found, including fibronectin, collagen I, and matrix metallopeptidase 9. Immunoblot analysis showed that treatment with N1 significantly attenuated phosphorylation of both STAT3 and Smad 2 in the TGF-β1-stimulated HCFs. Upregulated mRNA of Smad2 and downregulated mRNA of Smad3 were observed using the quantitative real-time polymerase chain reaction. In addition, N1 induced significant increases in HO-1 and Nrf2 expression, but inhibited phosphorylation of NF-κB in the HCFs treated with TGF-β1.

CONCLUSIONS

Our findings show for the first time that N1 exerts anti-fibrotic and anti-inflammatory effects through suppression of COX-2, Smad2, STAT3, iNOS and NF-κB expressions as well as upregulation of Nrf2 and HO-1 expressions, which suggests they are potential therapeutic targets in the treatment of corneal fibrosis.

Catalyst-free cyclization of anthranils and cyclic amines: one-step synthesis of rutaecarpine

An efficient synthesis of a variety of quinazolinone derivatives via a direct cyclization reaction between commercially available anthranils and cyclic amines is described. The developed transformation proceeds with the merits of high step- and atom-efficiency, a broad substrate scope, and good to excellent yields, without additional catalysts, and offers a practical way for the preparation of rutaecarpine and its derivatives with structural diversity.