A novel quinoline derivative, DFIQ, sensitizes NSCLC cells to ferroptosis by promoting oxidative stress accompanied by autophagic dysfunction and mitochondrial damage.

BACKGROUND: The development of nonapoptotic programmed cell death inducers as anticancer agents has emerged as a cancer therapy field. Ferroptosis, ferrous ion-driven programmed cell death that is induced by redox imbalance and dysfunctional reactive oxygen species (ROS) clearance, is triggered during sorafenib and PD-1/PD-L1 immunotherapy. DFIQ, a quinoline derivative, promotes apoptosis by disrupting autophagic flux and promoting ROS accumulation. Our pilot experiments suggest that DFIQ participates in ferroptosis sensitization. Thus, in this study, we aimed to reveal the mechanisms of DFIQ in ferroptosis sensitization and evaluate the clinical potential of DFIQ. METHODS: We treated the non-small cell lung cancer (NSCLC) cell lines H1299, A549, and H460 with the ferroptosis inducer (FI) DFIQ and analyzed viability, protein expression, ROS generation, and fluorescence staining at different time points. Colocalization analysis was performed with ImageJ. RESULTS: DFIQ sensitized cells to FIs such as erastin and RSL3, resulting in a decrease in IC50 of at least 0.5-fold. Measurement of ROS accumulation to explore the underlying mechanism indicated that DFIQ and FIs treatment promoted ROS accumulation and SOD1/SOD2 switching. Mitochondria, known ROS sources, produced high ROS levels during DFIQ/FI treatment. RSL3 treatment promoted mitochondrial damage and mitophagy, an autophagy-associated mitochondrial recycling system, and cotreatment with DFIQ induced accumulation of mitochondrial proteins, which indicated disruption of mitophagic flux. Thus, autophagic flux was measured in cells cotreated with DFIQ. DFIQ treatment was found to disrupt autophagic flux, leading to accumulation of damaged mitochondria and eventually inducing ferroptosis. Furthermore, the influence of DFIQ on the effects of clinical FIs, such as sorafenib, was evaluated, and DFIQ was discovered to sensitize NSCLC cells to sorafenib and promote ferroptosis. CONCLUSIONS: This study indicates that DFIQ not only promotes NSCLC apoptosis but also sensitizes cells to ferroptosis by disrupting autophagic flux, leading to accumulation of dysfunctional mitochondria and thus to ferroptosis. Ferroptosis is a novel therapeutic target in cancer therapy. DFIQ shows the potential to enhance the effects of FIs in NSCLC and act as a potential therapeutic adjuvant in ferroptosis-mediated therapy.

Synthesis and Anticancer Evaluation of 4-Anilinoquinolinylchalcone Derivatives.

A series of 4-anilinoquinolinylchalcone derivatives were synthesized and evaluated for antiproliferative activities against the growth of human cancer cell lines (Huh-7 and MDA-MB-231) and normal lung cells (MRC-5). The results exhibited low cytotoxicity against human lung cells (MRC-5). Among them, (E)-3-{4-{[4-(benzyloxy)phenyl]amino}quinolin-2-yl}-1-(4-methoxyphenyl) prop-2-en-1-one (4a) was found to have the highest cytotoxicity in breast cancer cells and low cytotoxicity in normal cells. Compound 4a causes ATP depletion and apoptosis of breast cancer MDA-MB-231 cells and triggers reactive oxygen species (ROS)-dependent caspase 3/7 activation. In conclusion, it is worth studying 4-anilinoquinolinylchalcone derivatives further as new potential anticancer agents for the treatment of human cancers.

Antioxidant, Anti-Inflammation and Antiaging Activities of Artocarpus altilis Methanolic Extract on Urban Particulate Matter-Induced HaCaT Keratinocytes Damage.

Particulate matter (PM) is one of the reasons that exacerbate skin diseases. Impaired barrier function is a common symptom in skin diseases, including atopic dermatitis, eczema and psoriasis. Herbal extracts rich in antioxidants are thought to provide excellent pharmacological activities; however, the anti-pollution activity of Artocarpus altilis extract (AAM) has not been investigated yet. The present study demonstrated that 5 µg/mL of AAM was considered to be a safe dose for further experiments without cytotoxicity. Next, we evaluated the anti-pollution activity of AAM through the PM-induced keratinocytes damage cell model. The results showed that AAM could reduce PM-induced overproduction of intracellular ROS and the final product of lipid peroxidation, 4-hydroxynonenal (4HNE). In addition, AAM not only reduced the inflammatory protein expressions, including tumor necrosis factor α (TNFα), TNF receptor 1 (TNFR1) and cyclooxygenase-2 (COX-2), but also balanced the aging protein ratio of matrix metalloproteinase (MMPs) and tissue inhibitors of metalloproteases (TIMPs) through downregulating the phosphorylation of mitogen-activated protein kinase (MAPK) signaling. For skin barrier protection, AAM could repair PM-induced barrier function proteins damage, including filaggrin, loricrin and aquaporin 3 for providing anti-aging bioactivity. In conclusion, AAM has the potential to be developed as an anti-pollution active ingredient for topical skin products to prevent skin oxidation, inflammation and aging, and restore the skin barrier function.

Inhibition of gut microbial ß-glucuronidase effectively prevents carcinogen-induced microbial dysbiosis and intestinal tumorigenesis.

The bidirectional interaction between carcinogens and gut microbiota that contributes to colorectal cancer is complicated. Reactivation of carcinogen metabolites by microbial ß-glucuronidase (ßG) in the gut potentially plays an important role in colorectal carcinogenesis. We assessed the chemoprotective effects and associated changes in gut microbiota induced by pre-administration of bacterial-specific ßG inhibitor TCH-3511 in carcinogen azoxymethane (AOM)-treated APCMin/+ mice. AOM induced intestinal ßG activity, which was reflected in increases in the incidence, formation, and number of tumors in the intestine. Notably, inhibition of gut microbial ßG by TCH-3511 significantly reduced AOM-induced intestinal ßG activity, decreased the number of polyps in both the small and large intestine to a frequency that was similar in mice without AOM exposure. AOM also led to lower diversity and altered composition in the gut microbiota with a significant increase in mucin-degrading Akkermansia genus. Conversely, mice treated with TCH-3511 and AOM exhibited a more similar gut microbiota structure as mice without AOM administration. Importantly, TCH-3511 treatment significant decreased Akkermansia genus and produced a concomitant increase in short-chain fatty acid butyrate-producing gut commensal microbes Lachnoospiraceae NK4A136 group genus in AOM-treated mice. Taken together, our results reveal a key role of gut microbial ßG in promoting AOM-induced gut microbial dysbiosis and intestinal tumorigenesis, indicating the chemoprotective benefit of gut microbial ßG inhibition against carcinogens via maintaining the gut microbiota balance and preventing cancer-associated gut microbial dysbiosis. Thus, the bacterial-specific ßG inhibitor TCH-3511 is a potential chemoprevention agent for colorectal cancer.

Enhancement of Anticancer Potential of Pterostilbene Derivative by Chalcone Hybridization.

Pterostilbene, a natural metabolite of resveratrol, has been indicated as a potent anticancer molecule. Recently, several pterostilbene derivatives have been reported to exhibit better anticancer activities than that of the parent pterostilbene molecule. In the present study, a series of pterostilbene derivatives were designed and synthesized by the hybridization of pterostilbene, chalcone, and cinnamic acid. The cytotoxic effect of these hybrid molecules was determined using two oral cancer cell lines, HSC-3 and OECM-1. (E)-3-(2-((E)-4-Hydroxystyryl)-4,6-dimethoxyphenyl)-1-(2-methoxyphenyl)prop-2-en-1-one (4d), with IC50 of 16.38 and 18.06 µM against OECM-1 and HSC-3, respectively, was selected for further anticancer mechanism studies. Results indicated that compound 4d effectively inhibited cell proliferation and induced G2/M cell cycle arrest via modulating p21, cyclin B1, and cyclin A2. Compound 4d ultimately induced cell apoptosis by reducing the expression of Bcl-2 and surviving. In addition, cleavage of PARP and caspase-3 were enhanced following the treatment of compound 4d with increased dose. To conclude, a number of pterostilbene derivatives were discovered to possess potent anticancer potentials. Among them, compound 4d was the most active, more active than the parent pterostilbene.

Discovery of an Orally Efficacious MYC Inhibitor for Liver Cancer Using a GNMT-Based High-Throughput Screening System and Structure-Activity Relationship Analysis.

Glycine-N-methyl transferase (GNMT) downregulation results in spontaneous hepatocellular carcinoma (HCC). Overexpression of GNMT inhibits the proliferation of liver cancer cell lines and prevents carcinogen-induced HCC, suggesting that GNMT induction is a potential approach for anti-HCC therapy. Herein, we used Huh7 GNMT promoter-driven screening to identify a GNMT inducer. Compound K78 was identified and validated for its induction of GNMT and inhibition of Huh7 cell growth. Subsequently, we employed structure-activity relationship analysis and found a potent GNMT inducer, K117. K117 inhibited Huh7 cell growth in vitro and xenograft in vivo. Oral administration of a dosage of K117 at 10 mpk (milligrams per kilogram) can inhibit Huh7 xenograft in a manner equivalent to the effect of sorafenib at a dosage of 25 mpk. A mechanistic study revealed that K117 is an MYC inhibitor. Ectopic expression of MYC using CMV promoter blocked K117-mediated MYC inhibition and GNMT induction. Overall, K117 is a potential lead compound for HCC- and MYC-dependent cancers.

Discovery of 4-Anilinoquinolinylchalcone Derivatives as Potential NRF2 Activators.

Activation of nuclear factor erythroid-2-related factor 2 (NRF2) has been proven to be an effective means to prevent the development of cancer, and natural curcumin stands out as a potent NRF2 activator and cancer chemopreventive agent. In this study, we have synthesized a series of 4-anilinoquinolinylchalcone derivatives, and used a NRF2 promoter-driven firefly luciferase reporter stable cell line, the HaCaT/ARE cells, to screen a panel of these compounds. Among them, (E)-3-{4-[(4-acetylphenyl)amino]quinolin-2-yl}-1-(4-fluorophenyl)prop-2-en-1-one (13b) significantly increased NRF2 activity in the HaCaT cell with a half maximal effective concentration (EC50) value of 1.95 µM. Treatment of compound 13b upregulated HaCaT cell NRF2 expression at the protein level. Moreover, the mRNA level of NRF2 target genes, heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and glucose-6-phosphate dehydrogenase (G6PD) were significantly increased in HaCaT cells upon the compound 13b treatment. The molecular docking results exhibited that the small molecule 13b is well accommodated by the bound region of Kelch-like ECH-associated protein 1 (Keap1)-Kelch and NRF2 through stable hydrogen bonds and hydrophobic interaction, which contributed to the enhancement of affinity and stability between the ligand and receptor. Compound 13b has been identified as the lead compound for further structural optimization.

Facile skin targeting of a thalidomide analog containing benzyl chloride moiety alleviates experimental psoriasis via the suppression of MAPK/NF-κB/AP-1 phosphorylation in keratinocytes.

BACKGROUND: Thalidomide can be a TNF-α inhibitor for treating skin inflammation. This drug exhibits a strong toxicity that limits its application. OBJECTIVE: We synthesized a thalidomide analog containing the benzyl chloride group (2-[1-(3-chlorobenzyl)-2,6-dioxopiperidin-3-yl]isoindoline-1,3-dione, CDI) to examine anti-inflammatory activity against psoriasis. METHODS: The evaluation was conducted by the experimental platforms of in vitro TNF-α- or imiquimod (IMQ)-stimulated HaCaT cells and in vivo IMQ-induced psoriasiform plaque. RESULTS: Using the in vitro keratinocyte model, we demonstrated a greater inhibition of IL-1ß, IL-6, and IL-24 by CDI than by thalidomide. No significant cytotoxicity was observed at 100 µM. CDI delivered facilely into the skin with a cutaneous targeting ability 228-fold greater than thalidomide. CDI caused a negligible irritation on healthy mouse skin. We showed that topically applied CDI reduced IMQ-induced red scaly lesions, hyperplasia, microabscesses, and cytokine expression in the mouse model. The skin-barrier function measured by transepidermal water loss (TEWL) could be partially recovered from 50.6-36.3 g/m2/h by CDI. The mechanistic study showed that CDI suppressed cytokine production by inhibiting the phosphorylation of NF-κB and AP-1 via MAPK pathways. CONCLUSION: CDI would be beneficial for the development of a therapeutic agent against psoriasis.

DFIQ, a Novel Quinoline Derivative, Shows Anticancer Potential by Inducing Apoptosis and Autophagy in NSCLC Cell and In Vivo Zebrafish Xenograft Models.

Lung cancer is one of the deadliest cancers worldwide due to chemoresistance in patients with late-stage disease. Quinoline derivatives show biological activity against HIV, malaria, bacteriuria, and cancer. DFIQ is a novel synthetic quinoline derivative that induces cell death in both in vitro and in vivo zebrafish xenograft models. DFIQ induced cell death, including apoptosis, and the IC50 values were 4.16 and 2.31 µM at 24 and 48 h, respectively. DFIQ was also found to induce apoptotic protein cleavage and DNA damage, reduce cell cycle-associated protein expression, and disrupt reactive oxygen species (ROS) reduction, thus resulting in the accumulation of superoxide radicals. Autophagy is also a necessary process associated with chemotherapy-induced cell death. Lysosome accumulation and lysosome-associated membrane protein-2 (LAMP2) depletion were observed after DFIQ treatment, and cell death induction was restored upon treatment with the autophagy inhibitor 3-methyladenine (3-MA). Nevertheless, ROS production was found to be involved in DFIQ-induced autophagy activation and LAMP2 depletion. Our data provide the first evidence for developing DFIQ for clinical usage and show the regulatory mechanism by which DFIQ affects ROS, autophagy, and apoptosis.

Discovery of 3-Arylquinoxaline Derivatives as Potential Anti-Dengue Virus Agents.

We designed and synthesized a series of novel 3-arylquinoxaline derivatives and evaluated their biological activities as potential dengue virus (DENV) replication inhibitors. Among them, [3-(4-methoxyphenyl)quinoxalin-2-yl](phenyl)methanol (19a), [6,7-dichloro-3-(4-methoxyphenyl)quinoxalin-2-yl](phenyl)methanol (20a), and (4-methoxyphenyl)(3-phenylquinoxalin-2-yl)methanone (21b) were found to significantly inhibit the DENV RNA expression in Huh-7-DV-Fluc cells with a potency better than that of ribavirin. Compound 19a reduced DENV replication in both viral protein and messenger RNA (mRNA) levels in a dose-dependent manner and exhibited no significant cell cytotoxicity. Notably, compound 19a exhibited a half maximal effective concentration (EC50) value at 1.29 ± 0.74 µM. We further observed that the inhibitory effect of 19a on DENV replication was due to suppression of DENV-induced cyclooxygenase-2 (COX-2) expression. Docking studies also showed that 19a caused hydrophobic interactions at the active sites with Arg29, Glu31, Tyr116, Leu138, Pro139, Lys454, Arg455, and Gln529. The calculated lowest binding energy between the 19a and COX-2 was -9.10 kcal/mol. In conclusion, compound 19a might be a potential lead compound for developing an anti-DENV agent.

Improvement of Skin Penetration, Antipollutant Activity and Skin Hydration of 7,3',4'-Trihydroxyisoflavone Cyclodextrin Inclusion Complex.

As is known, many antioxidants from plant extracts have been used as additives in skincare products to prevent skin damage following overexposure to environmental pollutants. 7,3',4'-trihydroxyisoflavone (734THIF), an isoflavone compound, possesses various biological activities, including antioxidant, antityrosinase, photodamage protection, and anticancer effects. Unfortunately, 734THIF has poor water solubility, which limits its skin penetration and absorption, and subsequently influences its biological activity. The aim of the present study was to investigate the mechanisms for the improvement in water solubility and skin penetration of 2-hydroxypropyl-ß-cyclodextrin (HPBCD) inclusion complex with 734THIF (5-7HP). We also determined its photostability, antipollutant activity in HaCaT keratinocytes, and moisturizing effect in human subjects. Our results showed that 734THIF was embedded into the lipophilic inner cavity of HPBCD and its water solubility and skin penetration were thereby improved through amorphous transformation, surface area enhancement, and hydrogen bonding formation between 734THIF and HPBCD. In addition, 5-7HP inhibited PM-induced ROS generation and then downregulated ROS-mediated COX-2 and MMP9 production and AQP-3 consumption by inhibiting the phosphorylation of MAPKs. Consequently, we suggest that 5-7HP is a safe and photostable topical ingredient to enhance the skin penetration of 734THIF and skin hydration, and therefore 5-7HP may be used as an antipollutant additive in skin care products.

Liposomal Avicequinone-B formulations: Aqueous solubility, physicochemical properties and apoptotic effects on cutaneous squamous cell carcinoma cells.

BACKGROUND: Avicequinone-B (Naphtho[2,3-b]furan-4,9-dione) is a furanonaphthoquinone derivative. It is a hydrophobic compound with poor aqueous solubility, which may restrict its potential pharmaceutical and biomedical applications. PURPOSE: We synthesized different liposomal formulations of Avicequinone-B, and measured their particle size, aqueous solubility, and physicochemical properties. In addition, we investigated the anticancer activity of liposomal Avicequinone-B in human cutaneous squamous cell carcinoma (SCC) cells. METHODS: Liposomal Avicequinone-B formulations were synthesized using the thin-film hydration method. Drug yield, encapsulation efficiency and aqueous solubility were determined by high performance liquid chromatography. Particle size and polydispersity index were measured by submicron particle size analyzer, and ultrastructural morphology was visualized by transmission electron microscopy. Thermal transitions were determined by differential scanning calorimetry. Anti-skin cancer activity was determined in HSC-1 cells (human cutaneous SCC cell line) using the MTS cytotoxicity assay, apoptosis was assessed by caspase-3/7 activity assay, mitochondrial membrane potential was determined by JC-10 assay, and signal transduction pathways were evaluated by Western blot analysis. RESULTS: Liposomal Avicequinone-B formulations showed adequate yield and high encapsulation efficiency. These liposomal formulations produced small, uniformly sized nanoparticles, and greatly increased the aqueous solubility of Avicequinone-B. Differential scanning calorimetry showed loss of thermal phase transitions. In addition, liposomal Avicequinone-B showed significant cytotoxic effect on HSC-1 cells, through reduction of mitochondrial membrane potential, increased cytosolic cytochrome-c level, increased cleaved caspase 8 level, and induction of apoptosis. This was mediated through activation of ERK, p38 and JNK signaling pathways. CONCLUSION: Liposomal Avicequinone-B demonstrated improved aqueous solubility and physicochemical characteristics, and induced apoptosis in cutaneous SCC cells. Therefore, liposomal Avicequinone-B may have potential uses as a topical anti-skin cancer drug formulation in the future.

Discovery of 2-Substituted 3-Arylquinoline Derivatives as Potential Anti-Inflammatory Agents Through Inhibition of LPS-Induced Inflammatory Responses in Macrophages.

We describe herein the preparation of certain 2-substituted 3-arylquinoline derivatives and the evaluation of their anti-inflammatory effects in LPS-activated murine J774A.1 macrophage cells. Among these newly synthesized 2-substituted 3-arylquinoline derivatives, 2-(4-methoxy- benzoyl)-3-(3,4,5-trimethoxyphenyl)quinoline (18a) and 2-(4-fluorobenzoyl)-3-(3,4,5-trimethoxy- phenyl)quinoline (18b) are two of the most active compounds which can inhibit the production of NO at non-cytotoxic concentrations. Our results have also indicated that compounds 18a and 18b significantly decrease the secretion of pro-inflammatory cytokines (TNF-á and IL-6), inhibit the expression of iNOS, suppress the phosphorylation of MAPKs, and attenuate the activity of NF-êB by LPS-activated macrophages. Through molecular docking analysis, we found that 18b could fit into the middle of the TNF-á dimer and form hydrophobic interactions with Leu55, Leu57 chain A and B, Tyr59, Val123 chain B and D, Ile 155. These results suggest that both 18a and 18b are potential lead compounds in inhibiting LPS-induced inflammatory responses. Further structural optimization to discover novel anti-inflammatory agents is ongoing.

Phytochemical naphtho[1,2-b] furan-4,5­dione induced topoisomerase II-mediated DNA damage response in human non-small-cell lung cancer.

BACKGROUND: Phytochemical naphtho[1,2-b] furan-4,5­dione (NFD) presenting in Avicennia marina exert anti-cancer effects, but little is known regarding about DNA damage-mediated apoptosis in non-small-cell lung carcinoma (NSCLC). PURPOSE: To examine whether NFD-induced apoptosis of NSCLC cells is correlated with the induction of DNA damage, and to investigate its underlying mechanism. STUDY DESIGN: The anti-proliferative effects of NFD were assessed by MTS Assay Kit FACS assay, and in vivo nude mice xenograft assay. The DNA damage related proteins, the Bcl-2 family and pro-apoptotic factors were examined by immunofluorescence assay, q-PCR, and western blotting. The activity of NF-κB p65 in nuclear extracts was detected using a colorimetric DNA-binding ELISA assay. The inhibitory activity of topoisomerase II (TOPO II) was evaluated by molecular docking and TOPO II catalytic assay. RESULTS: NFD exerted selective cytotoxicity against NSCLC H1299, H1437 and A549 cells rather than normal lung-embryonated cells MRC-5. Remarkably, we found that NFD activated the hull marker and modulator of DNA damage repairs such as γ-H2AX, ATM, ATR, CHK1, and CHK2 probably caused by the accumulation of intracellular reactive oxygen species (ROS) and inhibition of TOPO II activity. Furthermore, the suppression of transcription factor NF-κB by NFD resulted in significantly decreased levels of pro-survival proteins including Bcl-2 family Bcl-2, Bcl-xL and Mcl-1 and the endogenous inhibitors of apoptosis XIAP and survivin in H1299 cells. Moreover, the nude mice xenograft assay further validated the suppression of H1299 growth by NFD, which is the first report for evaluating the anti-cancer effect of NFD in vivo. CONCLUSION: These findings provide a novel mechanism indicating the inhibition of TOPO II activity and NF-κB signaling by NFD, leading to DNA damage and apoptosis of NSCLC tumor cells.

Pharmacological inhibition of bacterial ß-glucuronidase prevents irinotecan-induced diarrhea without impairing its antitumor efficacy in vivo.

Irinotecan (CPT-11), a first-line chemotherapy for advanced colorectal cancer, causes serious diarrhea in patients receiving treatment. The underlying mechanism has been shown that the active metabolite of CPT-11, SN-38, is metabolized to the inactive metabolite SN-38 glucuronide (SN-38 G) during hepatic glucuronidation, and subsequently is exported into the intestine, where SN-38 G is hydrolyzed by bacterial ß-glucuronidase (ßG) to be SN-38, thus leading to intestinal toxicity. Thus, inhibition of the intestinal bacterial ßG activity is expected to prevent CPT-11-induced diarrhea. However, the effects of such inhibition on serum pharmacokinetics of SN-38, the key determinant of CPT-11 treatment, are uncertain. Here, we determined the effects of a potent E. coli ßG (eßG)-specific inhibitor pyrazolo[4,3-c]quinoline derivative (TCH-3562) for the potential use in preventing CPT-11-induced diarrhea. TCH-3562 exhibited efficacious inhibitory potency of endogenous ßG activity in two anaerobes, Eubacteriumsp. and Peptostreptococcus anaerobius. Oral administration of TCH-3562 also effectively reduced the bacterial ßG activity in mice intestine. Moreover, pharmacokinetic analysis of TCH-3562 revealed a relatively low amount of TCH-3562 was detected in the plasma whereas the majority of TCH-3562 was found in the feces. Importantly, co-treatment of CPT-11 and TCH-3562 did not decrease active SN-38 level in mice plasma. Finally, we established that TCH-3562 as an adjuvant treatment showed protective effects on CPT-11-induced diarrhea and had no negative effects on the therapeutic efficacy of CPT-11 in tumor-bearing mice. Therefore, inhibition of the intestinal bacterial ßG activity by the specific inhibitor, TCH-3562, is promising to prevent CPT-11-induced diarrhea while maintaining its anti-tumor efficacy that may have clinical potentials for the treatment with CPT-11.

Synthesis and Biological Evaluation of Thalidomide Derivatives as Potential Anti-Psoriasis Agents.

Several thalidomide derivatives were synthesized and evaluated for their anti-inflammatory activity. Introduction of the benzyl group to the parent thalidomide is unfavorable in which 2-(1-benzyl-2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (4a) was inactivated. However, the inhibitory activities on TNF-α and IL-6 expression in HaCaT cells were improved by the substitution of a chloro- or methoxy- group at the phenyl position of 4a. The IL-6 inhibitory activity decreased in an order of 5c (69.44%) > 4c (48.73%) > 6c (3.19%) indicating the 3-substituted derivative is more active than the 4-substituted counterpart, which in turn is more active than the 2-substituted counterpart. Among them, 2-[1-(3-chlorobenzyl)-2,6-dioxopiperidin-3-yl]isoindoline-1,3-dione (5c) was found to inhibit TNF-α and IL-6 expression in HaCaT cells with a higher potency than thalidomide and no significant cell cytotoxicity was detected at 10 µM. In psoriasis, Compound 5c reduced IL-6, IL-8, IL-1ß and IL-24 in imiquimod-stimulated models. Our results indicated that compound 5c is a potential lead of novel anti-psoriasis agents. Structural optimization of compound 5c and its in vivo assay are ongoing.

Preparation, characterizations and anti-pollutant activity of 7,3',4'-trihydroxyisoflavone nanoparticles in particulate matter-induced HaCaT keratinocytes.

BACKGROUND: 7,3',4'-Trihydroxyisoflavone (734THI), a secondary metabolite derived from daidzein in soybean, possesses several biological activities, including antioxidant, skin whitening and anti-atopic dermatitis properties, but the poor aqueous solubility of 734THI has limited its application in medicine and cosmetic industry. METHODS: The aim of the present study was to improve the physicochemical properties of 734THI using planetary ball mill preparation under a solvent-free process to improve its solubility and anti-pollutant activity. RESULTS: 734THI nanoparticle powder (734THIN) was successfully prepared by the planetary ball mill technique using polyvinylpyrrolidone K30 as the excipient. 734THIN effectively increased the aqueous solubility and cellular uptake of 734THI by improving its physicochemical properties, including particle size reduction, crystalline-amorphous transformation and intermolecular hydrogen bonding with polyvinylpyrrolidone K30. In addition, 734THIN inhibited the overexpression of COX-2 and MMP-9 by downregulating MAPK pathway signaling in particulate matter-exposed HaCaT keratinocytes, while raw 734THI in PBS with low aqueous solubility did not show any anti-inflammatory or antiaging activity. CONCLUSION: 734THIN may be used as an additive in anti-pollutant skin care products for preventing particulate matter-induced inflammation and aging in skin.

Discovery of Pyrazolo[4,3-c]quinolines Derivatives as Potential Anti-Inflammatory Agents through Inhibiting of NO Production.

The synthesis and anti-inflammatory effects of certain pyrazolo[4,3-c]quinoline derivatives 2a⁻2r are described. The anti-inflammatory activities of these derivatives were evaluated by means of inhibiting nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Among them, 3-amino-4-(4-hydroxyphenylamino)-1H-pyrazolo[4,3-c]-quinoline (2i) and 4-(3-amino-1H-pyrazolo[4,3-c]quinolin-4-ylamino)benzoic acid (2m) exhibited significant inhibition of LPS-stimulated NO production with a potency approximately equal to that of the positive control, 1400 W. Important structure features were analyzed by quantitative structure⁻activity relationship (QSAR) analysis to give better insights into the structure determinants for predicting the inhibitory effects on the accumulation of nitric oxide for RAW 264.7 cells in response to LPS. In addition, our results indicated that their anti-inflammatory effects involve the inhibition of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) protein expression. Further studies on the structural optimization are ongoing.

Discovery of naphtho[1,2-d]oxazole derivatives as potential anti-HCV agents through inducing heme oxygenase-1 expression.

A number of naphtho[1,2-d]oxazole derivatives were synthesized and evaluated for their anti-HCV virus activity. Among them, compound 18 was the most active, exhibited approximately 21-folds more active anti-HCV activity (IC50 of 0.63 µM) than that of ribavirin (IC50 = 13.16 µM). Compound 18 was less cytotoxic than ribavirin, and the selective index (SI) of 18 is approximately 28-folds higher than that of ribavirin (229.10 v.s. 8.08). By using heme oxygenase-1 (HO-1) promoter-based assay and western blotting, compound 18 could induce HO-1 promoter activity, and protein expression. The antiviral effect of compound 18 was attenuated by HO-1 specific inhibitor SnPP treatment, which indicated that compound 18 suppressed HCV replication through inducing HO-1 expression. We further found that compound 18 reduced bach1 expression resulting in increasing the activity of Nrf-2 binding element. Moreover, the induction of HO-1 by compound 18 reduced HCV NS3/4A protease activity and induced the antiviral interferon responses. Therefore, compound 18 can be considered as a supplemental antiviral agent or a lead compound for further developing more effective agents against HCV replication.

Specific Inhibition of Bacterial ß-Glucuronidase by Pyrazolo[4,3-c]quinoline Derivatives via a pH-Dependent Manner To Suppress Chemotherapy-Induced Intestinal Toxicity.

The direct inhibition of bacterial ß-glucuronidase (ßG) activity is expected to reduce the reactivation of glucuronide-conjugated drugs in the intestine, thereby reducing drug toxicity. In this study, we report on the effects of pyrazolo[4,3-c]quinolines acting as a new class of bacterial ßG-specific inhibitors in a pH-dependent manner. Refinement of this chemotype for establishing structure-activity relationship resulted in the identification of potential leads. Notably, the oral administration of 3-amino-4-(4-fluorophenylamino)-1H-pyrazolo[4,3-c]quinoline (42) combined with chemotherapeutic CPT-11 treatment prevented CPT-11-induced serious diarrhea while maintaining the antitumor efficacy in tumor-bearing mice. Importantly, the inhibitory effects of 42 to E. coli ßG was reduced as the pH decreased due to the various surface charges of the active pocket of the enzyme, which may make their combination more favorable at neutral pH. These results demonstrate novel insights into the potent bacterial ßG-specific inhibitor that would allow this inhibitor to be used for the purpose of reducing drug toxicity.