The copper (II) complex of salicylate phenanthroline induces immunogenic cell death of colorectal cancer cells through inducing endoplasmic reticulum stress.

BACKGROUND: In our previous study, Cu(sal)phen was found to have anti-tumor effects, yet its precise mechanism remains unknown. Research has shown that dying tumor cells release damage-associated molecular patterns (DAMPs) to promote anti-tumor immune response. Therefore, we have further explored the effects and potential molecular mechanisms of Cu(sal)phen-induced immunogenic cell death (ICD) in colorectal cancer (CRC). METHODS: ELISA and flow cytometry were used to detect the effects of Cu(sal)phen treatment on ICD markers. The molecular mechanisms of Cu(sal)phen-induced ICD were investigated through the detection of endoplasmic reticulum stress (ERS) and reactive oxygen species (ROS) in vitro using Western blot and flow cytometry. Additionally, a mouse model was constructed to study the effects of Cu(sal)phen on immune cells and anti-tumor-related cytokines in vivo. RESULTS: Cu(sal)phen induced the release of calreticulin (CRT), adenosine triphosphate (ATP) and high mobility group box 1 (HMGB1), the main molecular markers of ICD, by promoting the accumulation of ROS and inducing ERS. Furthermore, Cu(sal)phen promoted the maturation of dendritic cells (DCs) and activation of CD8+T cells, as well as the secretion of interleukin-12 (IL-12) and interferon-γ (IFN-γ), while downregulating transforming growth factor-ß (TGF-ß) levels, thereby activating the anti-tumor immune response. CONCLUSION: Cu(sal)phen has the potential to induce ICD in tumors and activate the adaptive immune response to achieve anti-tumor effects. This makes Cu(sal)phen a promising candidate for the treatment of CRC.

Salubrinal promotes phospho-eIF2α-dependent activation of UPR leading to autophagy-mediated attenuation of iron-induced insulin resistance.

Identification of new mechanisms mediating insulin sensitivity is important to allow validation of corresponding therapeutic targets. In this study, we first used a cellular model of skeletal muscle cell iron overload and found that endoplasmic reticulum (ER) stress and insulin resistance occurred after iron treatment. Insulin sensitivity was assessed using cells engineered to express an Akt biosensor, based on nuclear FoxO localization, as well as western blotting for insulin signaling proteins. Use of salubrinal to elevate eIF2α phosphorylation and promote the unfolded protein response (UPR) attenuated iron-induced insulin resistance. Salubrinal induced autophagy flux and its beneficial effects on insulin sensitivity were not observed in autophagy-deficient cells generated by overexpressing a dominant-negative ATG5 mutant or via knockout of ATG7. This indicated the beneficial effect of salubrinal-induced UPR activation was autophagy-dependent. We translated these observations to an animal model of systemic iron overload-induced skeletal muscle insulin resistance where administration of salubrinal as pretreatment promoted eIF2α phosphorylation, enhanced autophagic flux in skeletal muscle and improved insulin responsiveness. Together, our results show that salubrinal elicited an eIF2α-autophagy axis leading to improved skeletal muscle insulin sensitivity both in vitro and in mice.

Structural basis for specific inhibition of salicylate synthase from Mycobacterium abscessus.

Blocking iron uptake and metabolism has been emerging as a promising therapeutic strategy for the development of novel antimicrobial compounds. Like all mycobacteria, M. abscessus (Mab) has evolved several countermeasures to scavenge iron from host carrier proteins, including the production of siderophores, which play a crucial role in these processes. In this study, we solved, for the first time, the crystal structure of Mab-SaS, the first enzyme involved in the biosynthesis of siderophores. Moreover, we screened a small, focused library and identified a compound exhibiting a potent inhibitory effect against Mab-SaS (IC50 ≈ 2 µM). Its binding mode was investigated by means of Induced Fit Docking simulations, performed on the crystal structure presented herein. Furthermore, cytotoxicity data and pharmacokinetic predictions revealed the safety and drug-likeness of this class of compounds. Finally, the crystallographic data were used to optimize the model for future virtual screening campaigns. Taken together, the findings of our study pave the way for the identification of potent Mab-SaS inhibitors, based on both established and unexplored chemotypes.

Salicylate induces AMPK and inhibits c-MYC to activate a NRF2/ARE/miR-34a/b/c cascade resulting in suppression of colorectal cancer metastasis.

Aspirin and its active metabolite salicylate have emerged as promising agents for the chemoprevention of colorectal cancer (CRC). Moreover, aspirin suppresses the progression of established CRCs. However, the underlying molecular mechanisms are not completely understood. Here we found that salicylate induces the expression of the miR-34a and miR-34b/c genes, which encode tumor suppressive microRNAs, in a p53-independent manner. Salicylate activated AMPK, thereby activating NRF2, which directly induced miR-34a/b/c expression via ARE motifs. In addition, salicylate suppressed c-MYC, a known repressor of NRF2-mediated transactivation, via activating AMPK. The suppression of c-MYC by salicylate was necessary for NRF2-mediated activation of miR-34a/b/c. Inactivation of miR-34a/b/c largely abrogated the inhibitory effects of salicylate on migration, invasion and metastasis formation by CRC cells. In the future, aspirin and its derivates may be used therapeutically to activate miR-34a and miR-34b/c in tumors that have lost p53.

Lipophilic modification of salirasib modulates the antiproliferative and antimigratory activity.

Salirasib, or farnesylthiosalicylic acid (FTS), is a salicylic acid derivative with demonstrated antineoplastic activity. While designed as a competitor of the substrate S-farnesyl cysteine on Ras, it is a potent competitive inhibitor of isoprenylcysteine carboxymethyl transferase. In this study, the antiproliferative activity on six different solid tumor cell lines was evaluated with a series of lipophilic thioether modified salirasib analogues, including those with or without a 1,2,3-triazole linker. A combination of bioassay, cheminformatics, docking, and in silico ADME-Tox was also performed. SAR analysis that analogues with three or more isoprene units or a long aliphatic chain exhibited the most potent activity. Furthermore, three compounds display superior antiproliferative activity than salirasib and similar potency compared to control anticancer drugs across all tested solid tumor cell lines. In addition, the behavior of the collection on migration and invasion, a key process in tumor metastasis, was also studied. Three analogues with specific antimigratory activity were identified with differential structural features being interesting starting points on the development of new antimetastatic agents. The antiproliferative and antimigratory effects observed suggest that modifying the thiol aliphatic/prenyl substituents can modulate the activity.

Copper (II) complex of salicylate phenanthroline induces the apoptosis of colorectal cancer cells, including oxaliplatin­resistant cells.

Oxaliplatin (Oxa) is one of the most effective chemotherapeutic drugs used in the treatment of colorectal cancer (CRC). However, the use of this drug is associated with severe side­effects and patients eventually develop resistance to Oxa. In recent years, copper complexes have been extensively investigated as substitutes for platinum­based drugs. Therefore, a number of copper complexes have also been developed for cancer therapy, such as copper (II) complex of salicylate phenanthroline [Cu(sal)(phen)]. In the present study, the antitumor activity and the related molecular mechanisms of Cu(sal)(phen) were examined in CRC cells. As compared with the chemotherapeutic drug, Oxa, Cu(sal)(phen) was more effective in inducing apoptosis and reactive oxygen species (ROS) production, and in decreasing mitochondrial membrane potential in the CRC cell lines, HCT116 and SW480. In addition, the expression of the apoptosis­related proteins, Bcl­2 and survivin, and those of the upstream regulators, p­JAK2 and p­STAT5, were significantly decreased in the two cell lines following treatment with Cu(sal)(phen). Furthermore, the efficacy of the complex against CRC was found to be excellent in an animal model. The results of immunohistochemical analysis revealed that the expression levels of Bcl­2, survivin and Ki­67 in tumor tissues were decreased following Cu(sal)(phen) treatment. The antitumor mechanisms underlying Cu(Sal)(phen) treatment were the induction of ROS generation, the inhibition of the JAK2/STAT5 signaling pathway and the downregulation of the expression of anti­apoptotic proteins, such as Bcl­2 and survivin. On the whole, the findings of the present study indicated that Cu(sal)(phen) effectively inhibited the viability and proliferation of HCT116 and SW480 CRC cells; in the future, the authors aim to conduct further experiments in future studies to provide more evidence that supports the development of Cu(sal)(phen) as a therapeutic agent for CRC.

UV filter ethylhexyl salicylate affects cardiovascular development by disrupting lipid metabolism in zebrafish embryos.

Ethylhexyl salicylate (EHS) is an organic UV filter commonly used in sunscreens to protect people from the UV radiation. The widespread use of EHS will enter the aquatic environment along with human activities. EHS readily accumulates in adipose tissue as a lipophilic compound, but its toxic effects on lipid metabolism and cardiovascular system of aquatic organisms have not been studied. This study investigated the effects of EHS on lipid metabolism and cardiovascular development during zebrafish embryogenesis. The results showed that EHS caused defects such as pericardial edema, cardiovascular dysplasia, lipid deposition, ischemia, and apoptosis in zebrafish embryos. In addition, qPCR and whole-mount in situ hybridization (WISH) results indicated that EHS treatment significantly altered the expression of genes related to cardiovascular development, lipid metabolism, erythropoiesis, and apoptosis. The hypolipidemic drug rosiglitazone was able to alleviate the cardiovascular defects caused by EHS, indicating that EHS affected cardiovascular development by disrupting lipid metabolism. In addition, severe ischemia caused by cardiovascular abnormalities and apoptosis were observed in the EHS-treated embryos, which was likely to be the main cause of embryonic mortality. In conclusion, this study shows that EHS has toxic effects on lipid metabolism and cardiovascular formation. Our findings provide new evidence for assessing UV filter EHS toxicity and contribute to raising awareness of the safety risks of EHS.

The copper (II) complex of salicylate phenanthroline inhibits proliferation and induces apoptosis of hepatocellular carcinoma cells.

In the present study, we investigated the antitumor effect and associated molecular mechanisms of the copper (II) complex of salicylate phenanthroline [Cu(sal)(phen)] against hepatocellular carcinoma (HCC). Cu(sal)(phen) inhibited the proliferation of HCC cells (HepG2 and HCC-LM9) and induced apoptosis of HCC cells in a dose-dependent manner by upregulating mitochondrial reactive oxygen species (ROS) production. The expression of the antiapoptotic proteins survivin and Bcl-2 was decreased, while the expression of the DNA damage marker γ-H2 AX and the apoptotic marker cleaved PARP was upregulated with Cu(sal)(phen) treatment. In vivo, the growth of HepG2 subcutaneous xenograft tumors was greatly attenuated by Cu(sal)(phen) treatment. Immunohistochemistry staining showed that the expression of survivin, Bcl-2, and Ki67 in the tumor was downregulated by Cu(sal)(phen). Toxicity experiments with BALB/c mice revealed that Cu(sal)(phen) is a relatively safe drug. Our results indicate that Cu(sal)(phen) possesses great potential as a therapeutic drug for HCC.

Evaluation of scolicidal potential of salicylate coated zinc nanoparticles against Echinococcus granulosus protoscoleces.

Echinococcosis is a zoonotic disease caused by larval stages of the Echinococcus genus (metastasis). In this study, salicylate-coated Zinc oxide nanoparticles (SA-ZnO-NPs) were fabricated and characterized by SEM, FTIR and XRD analytical techniques. After that, different doses of SA-ZnO-NPs, SA and ZnO-NPs were taken to assess scolicidal potency. Scanning electron microscopy (SEM) micrographs were also used to evaluate the morphological deformities of treated protoscoleces. Furthermore, Caspase-3&7 inductions were examined in protoscoleces cysts treated with all formulations. Based on SEM and DLS analyses, the size of SA-ZnO-NPs was between 30 and 40 nm, with a spherical shape. The FTIR spectrum verified the presence of SA functional groups on the ZnO coating. At 20 min, SA-ZnO-NPs at 2000 µg/ml exhibited the greatest activity on protoscolices with 100% mortality, followed by ZnO-NPs at 1500 µg/ml at 10 min and SA alone at 2000 µg/ml at 30 min. The activation of Caspase-3&7 apoptotic enzyme was determined for 2000 µg/ml of SA-ZnO-NPs, ZnO-NPs and SA to be 16.4, 31.4, and 35.7%, respectively. The SEM image revealed apoptogenic alterations and the induction of tegument surface wrinkles, as well as abnormalities in rostellum protoscolices. According to the current study, SA-ZnO-NPs have a high mortality rate against hydatid cyst protoscolices. As a result, further studies on the qualitative assessment of these nanoformulations in vivo and preclinical animal trials seem to be required. Furthermore, the adoption of nano-drugs potentially offers alternative therapeutic approaches to combat hydatid cysts.

Protective Effect of Resveratrol in an Experimental Model of Salicylate-Induced Tinnitus.

To date, the effect of resveratrol on tinnitus has not been reported. The attenuative effects of resveratrol (RSV) on a salicylate-induced tinnitus model were evaluated by in vitro and in vivo experiments. The gene expression of the activity-regulated cytoskeleton-associated protein (ARC), tumor necrosis factor-alpha (TNFα), and NMDA receptor subunit 2B (NR2B) in SH-SY5Y cells was examined using qPCR. Phosphorylated cAMP response element-binding protein (p-CREB), apoptosis markers, and reactive oxygen species (ROS) were evaluated by in vitro experiments. The in vivo experiment evaluated the gap-prepulse inhibition of the acoustic startle reflex (GPIAS) and auditory brainstem response (ABR) level. The NR2B expression in the auditory cortex (AC) was determined by immunohistochemistry. RSV significantly reduced the salicylate-induced expression of NR2B, ARC, and TNFα in neuronal cells; the GPIAS and ABR thresholds altered by salicylate in rats were recovered close to their normal range. RSV also reduced the salicylate-induced NR2B overexpression of the AC. These results confirmed that resveratrol exerted an attenuative effect on salicylate-induced tinnitus and may have a therapeutic potential.

The Osteosarcoma Stem Cell Activity of a Gallium(III)-Phenanthroline Complex Appended to Salicylate.

We report the synthesis, characterisation, and anti-osteosarcoma properties of a gallium(III) complex (1) comprising of two 1,10-phenanthroline ligands and salicylate, a non-steroidal anti-inflammatory drug. The gallium(III) complex 1 displays micromolar potency towards bulk osteosarcoma cells and osteosarcoma stem cells (OSCs). Notably, the gallium(III) complex 1 exhibits significantly higher toxicity towards OSCs grown in monolayer and three-dimensional cultures than cisplatin, a frontline anti-osteosarcoma drug. Nuclei isolation and immunoblotting studies show that the gallium(III) complex 1 enters osteosarcoma cell nuclei and induces DNA damage. Flow cytometry and cytotoxicity studies (in the presence of prostaglandin E2) indicate that the gallium(III) complex 1 downregulates cyclooxygenase-2 (COX-2) expression and kills osteosarcoma cells in a COX-2-dependent manner. Further, the mode of osteosarcoma cell death evoked by the gallium(III) complex 1 is characterised as caspase-dependent apoptosis.

Lobaric acid prevents the adverse effects of tetramethrin on the estrous cycle of female albino Wistar rats.

Tetramethrin (Tm) is a commonly used pesticide that has been reported to exert estrogen-antagonistic effects selectively on female rats. The present study was undertaken to assess the protective role of lobaric acid (La) on estrous cycle in Tm-treated female Wistar rats. Female rats were exposed to Tm (50 mg/kg b.w/day) only or in combination with La at low (50 mg/kg b.w/day) or high (100 mg/kg b.w/day) dose for 30 days. The results showed that Tm altered the estrous cycle of female rats by decreasing the levels of luteinizing hormone, follicular-stimulating hormone, progesterone, estrone, and estradiol while increasing testosterone level. The morphology of vaginal smears of Tm-treated female rats showed the presence of abnormal cells and/or structures at different phases of estrus cycle. Strikingly, in (Tm + La)-treated rats, all the observed adverse effects of Tm on the hormonal parameters, cell morphology, and the length of each phase of estrous cycle were significantly diminished in a dose-dependent manner. The docking results showed that La competes with Tm for Gonadotropin-Releasing Hormone (GnRH) receptor, thereby reducing the toxicity of Tm but did not cancel the response of GnRH receptor completely. In conclusion, our results designated that La could be used as a potential candidate in the management of insecticide-induced alterations of the reproductive cycle of rodents.

Hydrazide-hydrazones as Small Molecule Tropomyosin Receptor Kina se A (TRKA) Inhibitors: Synthesis, Anticancer Activities, In silico ADME and Molecular Docking Studies.

AIM: The aim of the study was to search for new anticancer agents as TRKA inhibitors. BACKGROUND: A series of new salicylic acid hydrazide hydrazones were synthesized and evaluated for their in vitro anticancer activities against lung (A549), ovarian (SK-OV-3), skin (SK-MEL-2), and colon (HCT15) cancer cell lines, and tropomyosin receptor kinase A (TRKA) inhibitory activities. OBJECTIVE: In this study, we focused on the synthesis and anticancer properties evaluation of salicylic acid hydrazide hydrazones as TRKA inhibitors. The in vitro anticancer activities of hydrazone analogs were measured against four cancer cell lines, and the TRKA inhibitory properties were investigated using an enzyme assay to determine their modes of action. In silico molecular docking was conducted using the crystal structure of the TRKA receptor to study the interactions and modes of binding at its active site, and ligand-based target predictions were used to identify putative secondary enzymatic targets of the synthesized compounds. Additionally, pharmacokinetic properties, toxicity effects, and drug scores of the studied molecules were also assessed. METHODS: A series of hydrazide hydrazones were prepared by means of a facile and straight-forward two-step reaction under soft reflux conditions from a methyl ester of substituted aromatic acids and hydrazine hydrate followed by the condensation with substituted aldehydes. In vitro cytotoxic properties of the synthesized compounds were screened against four human cancer cells using the SRB (sulforhodamine-B) colorimetric method. The TRKA inhibitory activity was measured by enzymatic assay. In silico ADME, drug score properties, docking studies, and ligand-based target prediction analyses were performed using Osiris Cheminformatics and AutoDock Vina, and SwissTargetPrediction bioinformatics software. RESULTS: In vitro bioassays revealed that compound 6 exhibited the most potent broad-spectrum anticancer activities with IC50 values of 0.144, <0.001, 0.019, and 0.022 µM against A549, SK-OV-3, SK-MEL-2, and HCT15 cancer cells, respectively, followed by compounds 11, 3a, and 9. In TRKA inhibitory assays, compounds 3e and 11 demonstrated the highest potency with IC50 values of 111 and 614 nM, respectively. The results of docking studies on 3e and 11 with the active site of the TRKA receptor revealed that both compounds interacted as previously reported TRKA inhibitors with high docking scores. CONCLUSION: New salicylic acid hydrazide hydrazones were synthesized, and the most active compounds exhibited significant anticancer properties against A549, SK-OV-3, SK-MEL-2, and HCT15 cancer cells, suggesting to be good candidates for in vivo studies. The results obtained in the present study would help in the design and preparation of new hydrazidehydrazone analogs as potential TRKA inhibitors for cancer treatment.

The Effect of Standardised Leaf Extracts of Gaultheria procumbens on Multiple Oxidants, Inflammation-Related Enzymes, and Pro-Oxidant and Pro-Inflammatory Functions of Human Neutrophils.

The leaves of Gaultheria procumbens are polyphenol-rich traditional medicines used to treat inflammation-related diseases. The present study aimed to optimise the solvent for the effective recovery of active leaf components through simple direct extraction and verify the biological effects of the selected extract in a model of human neutrophils ex vivo. The extracts were comprehensively standardised, and forty-one individual polyphenols, representing salicylates, catechins, procyanidins, phenolic acids, and flavonoids, were identified by UHPLC-PDA-ESI-MS3. The chosen methanol-water (75:25, v/v) extract (ME) was obtained with the highest extraction yield and total phenolic levels (397.9 mg/g extract's dw), including 98.9 mg/g salicylates and 299.0 mg/g non-salicylate polyphenols. In biological tests, ME revealed a significant and dose-dependent ability to modulate pro-oxidant and pro-inflammatory functions of human neutrophils: it strongly reduced the ROS level and downregulated the release of pro-inflammatory cytokines and tissue remodelling enzymes, especially IL-1ß and elastase 2, in cells stimulated by fMLP, LPS, or fMLP + cytochalasin B. The extracts were also potent direct scavengers of in vivo relevant oxidants (O2•-, •OH, and H2O2) and inhibitors of pro-inflammatory enzymes (cyclooxygenase-2, hyaluronidase, and lipoxygenase). The statistically significant correlations between the tested variables revealed the synergic contribution of individual polyphenols to the observed effects and indicated them as useful active markers for the standardisation of the extract/plant material. Moreover, the safety of ME was confirmed in cytotoxicity tests. The obtained results might partially explain the ethnomedicinal application of G. procumbens leaves and support the usage of the standardised leaf extract in the adjuvant treatment of oxidative stress and inflammation-related chronic diseases.

Salicylate activates KATP channels and reduces spontaneous firing in glycinergic cartwheel neurons in the dorsal cochlear nucleus of rats.

High doses of salicylate induce tinnitus in humans and experimental animals. The Dorsal Cochlear Nucleus is implicated with the genesis of tinnitus, and increased activity in this nucleus is seen in animal models of tinnitus. Incubation of brainstem slices containing the DCN with millimolar salicylate reduces the spontaneous firing of glycinergic cartwheel neurons and glycinergic neurotransmission on fusiform neurons, the principal neuron of this nucleus. However, the mechanism of salicylate mediating this effect is not known. Recently, we have shown that KATP channels strongly modulate the spontaneous firing of cartwheel neurons. We tested if KATP channels could mediate the effects of salicylate on cartwheel neurons. Perfusion of 1.4 mM salicylate hyperpolarizes the membrane of cartwheel neurons and stops firing. Salicylate produces an outward current similar to the KATP current seen in quiet cartwheel neurons. Activation of this current is occluded by the KATP agonist diazoxide, which is produced by the opening of KATP channels. The antagonist of AMP-kinase (AMPK), dorsomorphim, inhibited salicylate effects, suggesting that they could be mediated by activation of this kinase. Still, the AMPK agonist, AICAR, did not reproduce salicylate effects but occluded them. Additionally, inhibiting mitochondrial ATP synthesis with the protonophore CCCP reproduced, albeit with less efficacy, and inhibited the effects of salicylate. We concluded that salicylate in millimolar concentrations opens KATP channels in DCN cartwheel neurons, inhibiting spontaneous firing of these neurons, probably by activating AMPK and reducing mitochondrial ATP synthesis.

Zinc complex of 3,5-di-tert-butyl salicylate inhibits viability, migration, and invasion in triple-negative breast cancer cells.

The zinc complex of 3,5-di-tert-butyl salicylate (Zn{[CH3)3C]2Sal}22-) is a zinc ion chelate of salicylate. In this study, we found that this compound inhibits viability, invasion, and migration and induces apoptosis in triple-negative breast cancer 4T1 cells. RNA-seq showed that the expression of 17 genes was upregulated and 26 genes were downregulated significantly by Zn{[CH3)3C]2Sal}22- treatment. Further GO and KEGG analysis showed that the activity of Zn{[CH3)3C]2Sal}22- against triple-negative breast cancer cells may be involved in the JAK-STAT3, HIF-1, and TNF signaling pathways. The expression of key genes was verified by RT-PCR. The phosphorylation of STAT3 and its upstream SRC decreased drastically upon Zn{[CH3)3C]2Sal}22- treatment, as demonstrated by western blot. Our results indicate that Zn{[CH3)3C]2Sal}22- inhibits the activity of TNBC cells by downregulating the STAT3 signaling through the SRC pathway.

Lecanoric acid mediates anti-proliferative effects by an M phase arrest in colon cancer cells.

Lichen extracts containing, among other compounds, depsides such as evernic acid, atranorin, and lecanoric acid possess anti-proliferative effects. We aimed to identify lichen metabolites that are responsible for the observed anti-proliferative effects. We performed cytotoxicity, cell colony, cell cycle and apoptosis assays in various cell lines or primary immune cells. We analyzed several cell cycle proteins and apoptosis-related proteins to gain insights into the underlying mechanism. All depsides reduced the viability of the tested cell lines (HCT-116, HEK293T, HeLa, NIH3T3, RAW246.7) in a cell line-dependent manner with lecanoric acid being the most effective. Atranorin did not influence the cell cycle or colony formation in HCT-116 cells, but induced apoptosis in HCT-116 cells. Evernic acid showed no anti-proliferative effects. Lecanoric acid inhibited cell colony formation already at 0.03 µg/ml in HCT-116 cells and induced a G2 cell cycle block in several cell lines. Moreover, lecanoric acid arrested the cell cycle, presumably in the M phase, since expression of cyclin B1 and phosphorylated histone H3 was upregulated, whereas the inactive cyclin-dependent kinase 1 (CDK1) was reduced in HCT-116 cells. Most importantly, cell death induced by lecanoric acid was more prominent in cancer cells than in primary human immune and endothelial cells. In conclusion, lecanoric acid seems to mediate its anti-proliferative effects via arrest of cells in the M phase. Our data suggest lecanoric acid may be a potential new candidate for anti-cancer therapy, because it has anti-proliferative effects on cancer cell lines, and does not affect primary immune cells.

Kinome-Wide Profiling Identifies Human WNK3 as a Target of Cajanin Stilbene Acid from Cajanus cajan (L.) Millsp.

Pigeon Pea (Cajanus cajan (L.) Millsp.) is a common food crop used in many parts of the world for nutritional purposes. One of its chemical constituents is cajanin stilbene acid (CSA), which exerts anticancer activity in vitro and in vivo. In an effort to identify molecular targets of CSA, we performed a kinome-wide approach based on the measurement of the enzymatic activities of 252 human kinases. The serine-threonine kinase WNK3 (also known as protein kinase lysine-deficient 3) was identified as the most promising target of CSA with the strongest enzymatic activity inhibition in vitro and the highest binding affinity in molecular docking in silico. The lowest binding affinity and the predicted binding constant pKi of CSA (-9.65 kcal/mol and 0.084 µM) were comparable or even better than those of the known WNK3 inhibitor PP-121 (-9.42 kcal/mol and 0.123 µM). The statistically significant association between WNK3 mRNA expression and cellular responsiveness to several clinically established anticancer drugs in a panel of 60 tumor cell lines and the prognostic value of WNK3 mRNA expression in sarcoma biopsies for the survival time of 230 patients can be taken as clues that CSA-based inhibition of WNK3 may improve treatment outcomes of cancer patients and that CSA may serve as a valuable supplement to the currently used combination therapy protocols in oncology.

Salicylate Sodium Suppresses Monocyte Chemoattractant Protein-1 Production by Directly Inhibiting Phosphodiesterase 3B in TNF-α-Stimulated Adipocytes.

As a worldwide health issue, obesity is associated with the infiltration of monocytes/macrophages into the adipose tissue causing unresolved inflammation. Monocyte chemoattractant protein-1 (MCP-1) exerts a crucial effect on obesity-related monocytes/macrophages infiltration. Clinically, aspirin and salsalate are beneficial for the treatment of metabolic diseases in which adipose tissue inflammation plays an essential role. Herein, we investigated the effect and precise mechanism of their active metabolite salicylate on TNF-α-elevated MCP-1 in adipocytes. The results indicated that salicylate sodium (SAS) could lower the level of MCP-1 in TNF-α-stimulated adipocytes, which resulted from a previously unrecognized target phosphodiesterase (PDE), 3B (PDE3B), rather than its known targets IKKß and AMPK. The SAS directly bound to the PDE3B to inactivate it, thus elevating the intracellular cAMP level and activating PKA. Subsequently, the expression of MKP-1 was increased, which led to the decrease in p-EKR and p-p38. Both PDE3B silencing and the pharmacological inhibition of cAMP/PKA compromised the suppressive effect of SAS on MCP-1. In addition to PDE3B, the PDE3A and PDE4B activity was also inhibited by SAS. Our findings identify a previously unrecognized pathway through which SAS is capable of attenuating the inflammation of adipocytes.

Anti-Cancer Properties of Ginkgolic Acids in Human Nasopharyngeal Carcinoma CNE-2Z Cells via Inhibition of Heat Shock Protein 90.

Ginkgo biloba L. has been used in traditional Chinese medicine (TCM) for thousands of years. However, the anti-cancer properties of ginkgolic acids (GAS) isolated from G. biloba have not been investigated in human nasopharyngeal carcinoma cells. In this study, GAS exhibited an inhibitory effect on the ATPase activity of heat shock protein 90 (Hsp90) and anti-proliferative activities against four human cancer cell lines, with IC50 values ranging from 14.91 to 23.81 µg·mL-1. In vivo experiments confirmed that GAS inhibited tumor growth in CNE-2Z cell-xenografted nude mice with low hepatotoxicity. We further demonstrated that GAS suppressed migration and invasion and induced the apoptosis of CNE-2Z cells by inducing the degradation of Hsp90 client proteins (MMP-2, MMP-9, Her-2, c-Raf, Akt, and Bcl-2). Together, GAS are new Hsp90 inhibitors by binding to Hsp90 (hydrogen bond and hydrophobic interaction). Thus, GAS from G. biloba might represent promising Hsp90 inhibitors for the development of anti-nasopharyngeal carcinoma agents.