Hydroazulene Diterpenes from a Dictyota Brown Alga and Their Antioxidant and Neuroprotective Effects Against Cerebral Ischemia-Reperfusion Injury.

Five new diterpenes, including four new hydroazulenes, (8R,11R)-8,11-diacetoxypachydictyol A (1), (8R*,11R*)-6-O-acetyl-8-acetoxy-11-hydroxypachydictyol A (2), (8R*,11S*)-8-acetoxy-11-hydroxypachydictyol A (3), and (8R*,11S*)-6-O-acetyl-8,11-dihydroxypachydictyol A (4), and a secohydroazulene derivative, named 7Z-7,8-seco-7,11-didehydro-8- acetoxypachydictyol A (5), were isolated from a South China Sea collection of a Dictyota sp. nov. brown alga, together with five known analogues (6-10). Structure elucidation was achieved by extensive spectroscopic analysis and comparison with reported data. All compounds showed potent antioxidant effects against H2O2-induced oxidative damage in neuron-like PC12 cells at a low concentration of 2 µM. The antioxidant property of dictyol C (9) was associated with activation of the Nrf2/ARE signaling pathway; it also showed neuroprotective effects against cerebral ischemia-reperfusion injury (CIRI) in a rat model of transient middle cerebral artery occlusion. As such, hydroazulene diterpenes could serve as lead structures for the development of novel neuroprotective agents against CIRI.

A Steroid-Type Antioxidant Targeting the Keap1/Nrf2/ARE Signaling Pathway from the Soft Coral Dendronephthya gigantea.

Four new steroids, named 7-dehydroerectasteroid F (1), 11α-acetoxyarmatinol A (2), 22,23-didehydroarmatinol A (3), and 3-O-acetylhyrtiosterol (4), together with 11 previously described analogues, were isolated from a South China Sea collection of the soft coral Dendronephthya gigantea. The structures of the new steroids were elucidated by comprehensive spectroscopic analysis and by comparison with previously reported data. Compound 1 showed potent protection against H2O2-induced oxidative damage in neuron-like PC12 cells by promoting nuclear translocation of Nrf2 and enhancing the expression of HO-1. 1 represents the first steroid-type antioxidant from marine organisms.

A novel non-ATP competitive FGFR1 inhibitor with therapeutic potential on gastric cancer through inhibition of cell proliferation, survival and migration.

Fibroblast growth factor receptor 1 (FGFR1), belonging to receptor tyrosine kinases (RTKs), possesses various biological functions. Over-expression of FGFR1 has been observed in multiple human malignancies. Hence, targeting FGFR1 is an attractive prospect for the advancement of cancer treatment options. Here, we present a novel small molecular FGFR1 inhibitor L16H50, which can inhibit FGFR1 kinase in an ATP-independent manner. It potently inhibits FGFR1-mediated signaling in a gastric cancer cell line, resulting in inhibition of cell growth, survival and migration. It also displays an outstanding anti-tumor activity in a gastric cancer xenograft tumor model by targeting FGFR1 signaling. These results show that L16H50 is a potent non-ATP-competitive FGFR1 inhibitor and may provide strong rationale for its evaluation in gastric cancer patients.

Novel antioxidants' synthesis and their anti-oxidative activity through activating Nrf2 signaling pathway.

Novel structure compounds (WS) containing 3,4,5-trimethoxyphenyl and acyl pyrazole were designed and synthesized based combination principles. Among them, WS13 was screened out to possess desirable anti-oxidative activity in vitro. Cell survival assay and apoptosis experiment in H2O2 induced PC12 cells injury model all showed that its cytoprotection exhibited a concentration-effect manner. WS13 at 10µM could remove ROS with equal effiency to edaravone. Further, it clearly activated Nrf2 nuclear translocation and upregulated GCLC mRNA transcription and protein expression in dose-dependent manner, and its cytoprotection was reversed by GCLC protein inhibitor. In total, WS13 with further promotion can serve as Nrf2-GCLC activator in anti-oxidative therapy.

The therapeutic potential of a novel non-ATP-competitive fibroblast growth factor receptor 1 inhibitor on gastric cancer.

Previous studies showed that fibroblast growth factor receptor 1 (FGFR1) is an attractive target in gastric cancer therapy. In the current study, we aimed to investigate whether the compound L6123, a novel non-ATP-competitive FGFR1 inhibitor, could show better antitumor activity than the leading compound, nordihydroguaiaretic acid (NDGA), in FGFR1-overexpressing gastric cancer cells. Using an MTT assay, we investigated the inhibitory effect of L6123 on the viability of three gastric cancer cells (MGC-803, SGC-7901, and BGC-823) overexpressing FGFR1, wild-type mouse embryonic fibroblast (MEF), and MEF expressing FGFR1, FGFR2, and FRS2α gene knockout (MEF). We studied the antitumor mechanism of L6123 against the gastric cancer cell line SGC-7901 by western blot analysis. The antitumor effects of L6123 on the gastric cancer cell line SGC-7901 were detected by flow cytometry, Hoechst staining, western blot analysis, and Transwell invasion assay. L6123 had lower IC50 in all three gastric cancer cells than NDGA and showed better inhibitory activity against MEF cells than against MEF cells. In the SGC-7901 gastric cell, L6123 inhibited the FGF2-induced phosphorylation of FGFR1/FRS2α/ERK1/2 in a dose-dependent manner, induced the activation of the apoptosis-related proteins, cleaved-PARP and cleaved-caspase-3, decreased the expression of pro-caspase-3 and Bcl-2, and induced tumor cell apoptosis. L6123 also dose-dependently reduced cell invasion ability, and showed better activity than NDGA at the same concentration. A novel non-ATP-competitive inhibitor L6123 showed excellent antigastric cancer activity by inhibiting the FGFR1 signaling pathway. Thus, we discovered a potential agent for the treatment of FGFR1-overexpressing gastric cancer.

Synthetic chalcones with potent antioxidant ability on H2O2-induced apoptosis in PC12 cells.

Chalcone derivatives (E)-3-(4-hydroxy-3-methoxyphenyl)-1-(4-methoxyphenyl) prop-2-en-1-one and (E)-3-(4-hydroxyphenyl)-1-(4-methoxyphenyl) prop-2-en-1-one (Compounds 1 and 2) have been demonstrated to be potent anti-inflammatory agents in our previous study. In light of the relationship of intracellular mechanisms between anti-inflammatories and antioxidants, we further designed and synthesized a series of chalcone derivatives based on 1 and 2, to explore their antioxidant efficacy. The majority of the derivatives exhibited strong protective effects on PC12 (PC12 rat pheochromocytoma) cells exposed to H2O2, and all compounds were nontoxic. A preliminary structure-activity relationship was proposed. Compounds 1 and 1d ((E)-2-methoxy-4-(3-(4-methoxyphenyl)-3-oxoprop-1-en-1-yl) phenyl acrylate) exerted the action in a good dose-dependent manner. Quantitative RT-PCR (qRT-PCR) and western blot analysis showed that 1 and 1d significantly improve the expression of nuclear factor erythroid 2 p45-related factor 2 (Nrf2)-dependent antioxidant genes g-Glutamylcysteine Ligase Catalytic Subunit (GCLC) and heme oxygenase-1 (HO-1) and their corresponding proteins (γ-glutamyl cysteine synthase (γ-GCS) and HO-1) in PC12 cells. Inhibition of GCLC and HO-1 by specific inhibitors, L-buthionine-S-sulfoximine (BSO) and zinc protoporphyrin (ZnPP), respectively, partially reduce the protective effect of 1 and 1d. These data present a series of novel chalcone analogs, especially compounds 1 and 1d, as candidates for treating oxidative stress-related disease by activating the Nrf2-antioxidant responsive element (ARE) pathway.

Increased risk of reflux esophagitis in non-obese individuals with nonalcoholic fatty liver disease: a cross-sectional study.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) and gastroesophageal reflux disease (GERD) are both associated with obesity. However, the relationship of NAFLD with reflux esophagitis (RE) is still unclear in non-obese individuals. METHODS: Individuals with a body mass index (BMI) of 28 kg/m2 or higher, as well as waist circumference (WC) no less than 90 cm for men and no less than 85 cm for women were excluded. After controlling for other factors, 1905 eligible adult subjects were included. The components related to metabolic syndrome and the prevalence of NAFLD in the RE group as well as the non-RE group were analyzed. Risk factors for RE were determined using logistic regression. RESULTS: In non-obese individuals, the prevalence of RE and NAFLD increased with increasing WC and BMI (p < 0.001). Based on the results of logistic regression analysis, NAFLD was found to increase the risk of RE with statistical significance. Even after adjusting for metabolic syndrome and other related factors, NAFLD remained an independent influencing factor for the risk of RE (OR = 2.029; 95% CI 1.459-2.821, p < 0.001). CONCLUSIONS: The prevalence of NAFLD was significantly higher in patients with RE compared to those without RE. These results indicate that NAFLD has a potential as an independent risk factor for RE, even in non-obese individuals.

Erratum: Author correction to 'Design, synthesis and biological evaluation of chalcone analogues with novel dual antioxidant mechanisms as potential anti-ischemic stroke agents' [Acta Pharmaceutica Sinica B 9 (2019) 335-350].

[This corrects the article DOI: 10.1016/j.apsb.2019.01.003.].

Design and Synthesis of Novel Nordihydroguaiaretic Acid (NDGA) Analogues as Potential FGFR1 Kinase Inhibitors With Anti-Gastric Activity and Chemosensitizing Effect.

Aberrant fibroblast growth factor receptor-1 (FGFR1), a key driver promoting gastric cancer (GC) progression and chemo-resistance, has been increasingly recognized as a potential therapeutic target in GC. Hereon, we designed and synthesized a series of asymmetric analogues using Af23 and NDGA as lead compounds by retaining the basic structural framework (bisaryl-1,4-dien-3-one) and the unilateral active functional groups (3,4-dihydroxyl). Thereinto, Y14 showed considerable inhibitory activity against FGFR1. Next, pharmacological experiments showed that Y14 could significantly inhibit the phosphorylation of FGFR1 and its downstream kinase AKT and ERK, thus inhibiting the growth, survival, and migration of gastric cancer cells. Furthermore, compared with 5-FU treatment alone, the combination of Y14 and 5-FU significantly reduced the phosphorylation level of FGFR1, and enhanced the anti-cancer effect by inhibiting the viability and colony formation in two gastric cancer cell lines. These results confirmed that Y14 exerted anti-gastric activity and chemosensitizing effect by inhibiting FGFR1 phosphorylation and its downstream signaling pathway in vitro. This work also provides evidence that Y14, an effective FGFR1 inhibitor, could be used alone or in combination with chemotherapy to treat gastric cancer in the future.

Design, synthesis and biological evaluation of chalcone analogues with novel dual antioxidant mechanisms as potential anti-ischemic stroke agents.

Scavenging reactive oxygen species (ROS) by antioxidants is the important therapy to cerebral ischemia-reperfusion injury (CIRI) in stroke. The antioxidant with novel dual-antioxidant mechanism of directly scavenging ROS and indirectly through antioxidant pathway activation may be a promising CIRI therapeutic strategy. In our study, a series of chalcone analogues were designed and synthesized, and multiple potential chalcone analogues with dual antioxidant mechanisms were screened. Among these compounds, the most active 33 not only conferred cytoprotection of H2O2-induced oxidative damage in PC12 cells through scavenging free radicals directly and activating NRF2/ARE antioxidant pathway at the same time, but also played an important role against ischemia/reperfusion-related brain injury in animals. More importantly, in comparison with mono-antioxidant mechanism compounds, 33 exhibited higher cytoprotective and neuroprotective potential in vitro and in vivo. Overall, our findings showed compound 33 could emerge as a promising anti-ischemic stroke drug candidate and provided novel dual-antioxidant mechanism strategies and concepts for oxidative stress-related diseases treatment.

Design and Green Synthesis of Piperlongumine Analogs and Their Antioxidant Activity against Cerebral Ischemia-Reperfusion Injury.

The supplementation of exogenous antioxidants to scavenge excessive reactive oxygen species (ROS) is an effective treatment for cerebral ischemia-reperfusion injury (CIRI) in stroke. Piperlongumine (PL), a natural alkaloid, has a great potential as a neuroprotective agent, but it also has obvious toxicity. Moreover, its neuroprotective effects remain to be improved. In this study, we designed a series of novel PL analogs by hybridizing the screened low-toxicity diketene skeleton with antioxidant effect and the 3,4,5-trimethoxyphenyl group, which may increase the antioxidant activity of PL. The intermediate was synthesized by a novel green synthesis method, and 34 compounds were obtained. The compounds without obvious cytotoxicity have remarkable antioxidant effects, especially compared with diketene skeletons and PL. The cytoprotection of the active compound decreased significantly by reduction of the carbon-carbon double bonds of the Michael acceptor in the diketene skeleton. More importantly, further study revealed that compound A9, which has the best activity, can confer protection for cells against oxidative stress and attenuate brain injury in vivo. Overall, this study provided a promising drug candidate for the treatment of CIRI and guided the further development of drug research in oxidative stress-mediated diseases.

Simultaneous determination of five toxic alkaloids in body fluids by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

A novel analytical method was developed and validated for the rapid and simultaneous analysis of five toxic alkaloids: Brucine, Strychnine, Ephedrine, Aconitine and Colchicine, in blood and urine using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (HPLC-ESI-MRM) mode. The linear range was 0.05-50.0 ng mL(-1) for Brucine, 0.1-50.0 ng mL(-1) for Strychnine and Ephedrine, 0.01-10.0 ng mL(-1) for Aconitine and Colchicine. The limits of quantification for Brucine, Strychnine, Ephedrine, Aconitine and Colchicine were found to be 0.03, 0.05, 0.20, 0.05, 0.01 ng mL(-1), respectively. The average extraction recoveries in urine ranged from 96.0 to 114.0% and in whole blood were 94.0 to 113.0%. The intra-day and inter-day RSDs were less than 8.3 and 10.6%, respectively. The five alkaloids could be well separated within 7 min in a single run. The established method should be suitable for the determination of trace alkaloids in body fluids.

Design, synthesis, anti-lung cancer activity, and chemosensitization of tumor-selective MCACs based on ROS-mediated JNK pathway activation and NF-κB pathway inhibition.

EF24 and F35 both were effective monocarbonyl curcumin analogues (MCACs) with excellent anti-tumor activity, however, drug defect such as toxicity may limit their further development. To get anti-lung cancer drugs with high efficiency, low toxicity and chemosensitization, a series of analogues based on EF24 and F35 were designed and synthesized. A number of compounds were found to exhibit cytotoxic activities selectively towards lung cancer cells compared to normal cells. Among these compounds, 5B was considered as an optimal anti-tumor agent for lung cancer cells with IC50 values ranging from 1.0 to 1.7 µM, selectivity index (SI, as a logarithm of a ratio of IC50 value for normal and cancer cells) were all above 1.1, while the SI of EF24 and F35 were less than 0.8. Consistent with selectivity in vitro, 5B was observed to show lower toxicity in acute toxicity experiment than EF24 and F35 respectively. Further, 5B was found to exert anti-tumor effects through ROS-mediated activation of JNK pathway and inhibition of NF-κB pathway. 5B could significantly enhance the sensitivity of A549 cells to cisplatin or 5-Fu. These findings suggested that 5B was an effective and less toxic MCAC and provided a promising candidate for anti-tumor drugs.

Design, synthesis, and evaluation of chalcone analogues incorporate α,ß-Unsaturated ketone functionality as anti-lung cancer agents via evoking ROS to induce pyroptosis.

Chalcone, a natural structure, demonstrates many pharmacological activities including anticancer, and one promising mechanism is to modulate the generation of ROS. It has been known that pyroptosis is associated with anticancer effects, whereas there is fewer researches about ROS-mediated pyroptosis triggered by chemotherapy drugs. Moreover, incorporation of a α,ß-unsaturated ketone unit into chalcone may be an effective strategy for development of chemotherapy drugs. Hence, a number of chalcone analogues bearing a α,ß-unsaturated ketone were synthesized from chalcone analogues 1 with modest anticancer activities as the lead compound. Structure-activity relationship (SAR) studies confirmed the function of α,ß-unsaturated ketone to improve anticancer activity. Notably, compound 8, bearing a α,ß-unsaturated ketone, is the most potent inhibitor of cancer, with IC50 values on NCI-H460, A549 and H1975 cells of 2.3 ±â€¯0.3, 3.2 ±â€¯0.0 and 5.7 ±â€¯1.4 µM, respectively. Besides, 8 showed antiproliferative ability against NCI-H460 cells in a time- and concentration-dependent manner through modulating ROS to induce caspase-3-mediated pyroptosis, and displayed a better safety profile in vivo. Overall, these results demonstrated that compound 8 is a candidate agent and a potential lead compound for development of chemotherapy drugs, and can be used as a probe to further examine the mechanism of ROS-dependent pyroptosis.

Design, synthesis, and evaluation of NDGA analogues as potential anti-ischemic stroke agents.

Exogenous supplementation of antioxidants with ROS scavenging activity would be a potential therapy to cerebral ischemia-reperfusion injury in stroke. In the present study, a series of NDGA analogues with attenuation oxidative stress by directly scavenging ROS and indirectly through keap1/Nrf2/ARE pathway activation were designed and synthesized. All analogues were found to effectively remove ROS directly by DPPH radical scavenging assay, and compound 3a conferred potent protection from the oxidative injury in PC12 cells via promoting Nrf2 to translocate into nucleus and increasing expression of heme oxygenase-1(HO-1), where strongly reduced intracellular ROS level indirectly. More importantly, 3a significantly reduced brain infarction after cerebral ischemia-reperfusion injury in rats subjected to transient middle cerebral artery occlusion (MCAO). Overall, our findings shown compound 3a could serve as a promising compound for the treatment of stroke.

Design, synthesis and QSAR study of novel isatin analogues inspired Michael acceptor as potential anticancer compounds.

Molecular hybridization is considered as an effective tactic to develop drugs for the treatment of cancer. A series of novel hybrid compounds of isatin and Michael acceptor were designed and synthesized on the basis of association principle. These hybrid compounds were tested for cytotoxic potential against human cancer cell lines namely, BGC-823, SGC-7901 and NCI-H460 by MTT assay. Most compounds showed good anti-growth activities in all tested human cancer cells. SAR and QSAR analysis may provide vital information for the future development of novel anti-cancer inhibitors. Notably, compound 6a showed potent growth inhibition on BGC-823, SGC-7901 and NCI-H460 with the IC50 values of 3.6 ±â€¯0.6, 5.7 ±â€¯1.2, 3.2 ±â€¯0.7 µM, respectively. Besides, colony formation assays, wound healing assays and flow cytometry analysis indicated 6a exhibited a potent anti-growth and anti-migration ability in a concentration-dependence manner through arrested cells in the G2/M phase of cell cycle. Moreover, 6a significantly repressed tumor growth in a NCI-H460 xenograft mouse model. Overall, our findings suggested isatin analogues inspired Michael acceptor may provide promising lead compounds for the development of cancer chemotherapeutics.

Synthesis and anti-tumor activity of EF24 analogues as IKKß inhibitors.

EF24 is an IKKß inhibitor (IC50: 72 µM) containing various anti-tumor activities. In this study, a series of EF24 analogs targeting IKKß were designed and synthesized. Several IKKß inhibitors with better activities than EF24 were screened out and B3 showed best IKKß inhibitory (IC50: 6.6 µM). Molecular docking and dynamic simulation experiments further confirmed this inhibitory effect. B3 obviously suppressed the viability of Hela229, A549, SGC-7901 and MGC-803 cells. Then, in SGC-7901 and MGC-803 cells, B3 blocked the NF-κB signal pathway by inhibiting IKKß phosphorylation, and followed arrested the cell cycle at G2/M phase by suppressing the Cyclin B1 and Cdc2 p34 expression, induced the cell apoptosis by down-regulating Bcl-2 protein and up-regulating cleaved-caspase3. Moreover, B3 significantly reduced tumor growth and suppressed the IKKß-NF-κB signal pathway in SGC-7901 xenograft model. In total, this study present a potential IKKß inhibitor as anti-tumor precursor.

Design, synthesis, and evaluation of asymmetric EF24 analogues as potential anti-cancer agents for lung cancer.

The nuclear factor-kappa B (NF-κB) signaling pathway has been targeted for the therapy of various cancers, including lung cancer. EF24 was considered as a potent inhibitor of NF-κB signaling pathway. In this study, a series of asymmetric EF24 analogues were synthesized and evaluated for their anti-cancer activity against three lung cancer cell lines (A549, LLC, H1650). Most of the compounds exhibited good anti-tumor activity. Among them, compound 81 showed greater cytotoxicity than EF24. Compound 81 also possessed a potent anti-migration and anti-proliferative ability against A549 cells in a concentration-dependent manner. Moreover, compound 81 induced lung cancer cells death by inhibiting NF-κB signaling pathway, and activated the JNK-mitochondrial apoptotic pathway by increasing reactive oxygen species (ROS) generation resulting in apoptosis. In summary, compound 81 is a valuable candidate for anti-lung cancer therapy.

Synthesis and evaluation of asymmetric curcuminoid analogs as potential anticancer agents that downregulate NF-κB activation and enhance the sensitivity of gastric cancer cell lines to irinotecan chemotherapy.

NF-κB is a critical target for cancer treatment due to its central role in facilitating cancer progression and desensitizing cancer cells to chemotherapeutic drugs. In this study, a series of chemically modified asymmetric curcuminoid analogs named S01-S15 were synthesized and evaluated for NF-κB inhibitory activity in gastric cancer cell lines. Cell growth inhibition assays revealed that most of these analogs effectively inhibited the growth of BGC-823, SGC-7901, and MFC cells. S06 was selected for further research. MTT assay, clonogenic assay, Hoechst 33258 staining assay, and western blotting revealed that S06 could exert anti-gastric cancer effects by downregulating NF-κB activity. Moreover, via its effects on NF-κB, S06 effectively enhanced the sensitivity of the gastric cancer cells to irinotecan. Together, this study provide a series of new curcuminoid analogs as promising cancer therapeutic agents.

[Inclusion Bodies are Formed in SFTSV-infected Human Macrophages].

The severe fever with thrombocytopenia syndrome virus (SFTSV) is a new member in the genus Phlebovirus of the family Bunyaviridae identified in China. The SFTSV is also the causative pathogen of an emerging infectious disease: severe fever with thrombocytopenia syndrome. Using immunofluorescent staining and confocal microscopy, the intracellular distribution of nucleocapsid protein (NP) in SFTSV-infected THP-1 cells was investigated with serial doses of SFTSV at different times after infection. Transmission electron microscopy was used to observe the ultrafine intracellular structure of SFTSV-infected THP-1 cells at different times after infection. SFTSV NP could form intracellular inclusion bodies in infected THP-1 cells. The association between NP-formed inclusion bodies and virus production was analyzed: the size of the inclusion body formed 3 days after infection was correlated with the viral load in supernatants collected 7 days after infection. These findings suggest that the inclusion bodies formed in SFTSV-infected THP-1 cells could be where the SFTSV uses host-cell proteins and intracellular organelles to produce new viral particles.