Active volatile components of the preferred hosts are potential attractants to Hyphantria cunea adults.

The extraordinary adaptability and dispersal abilities have allowed Hyphantria cunea to expand its range, posing a great threat to urban landscapes and natural ecosystems. Searching for safe, efficient, and low-cost control methods may provide new strategies for pest management in H. cunea spread areas. In this study, based on the attraction of insects by preferred hosts, it was found that the response rates of virgin H. cunea female adults to Salix matsudana, Juglans mandshurica and Ulmus pumila were 89.17%, 97.92% and 93.98%, respectively. It was further found that this significant preference was mainly related to the volatiles m-xylene, o-xylene, dodecane and tetradecane found in the three species. Even though all four compounds at 10 µL/mL and 100 µL/mL had significant attractive effects on the virgin H. cunea female adults, m-xylene and dodecane at 100 µL/mL elicited significant EAG responses and tending behaviors by stimulating the olfactory receptor neurons (ORN A) of females, with response rates of 83.13% and 84.17%, while also having significant attractive effects on virgin male adults with rates of 65.74% and 67.51%. Therefore, both m-xylene and dodecane which at concentrations of 100 µL/mL had strong attractions to adults, could be used as the first choice of attractants for both sexes of H. cunea. This has important practical significance in reducing the frequency of H. cunea generations, limiting their population, controlling their spread range, and improving the efficiency of pest management in epidemic areas.

ML365 inhibits TWIK2 channel to block ATP-induced NLRP3 inflammasome.

Dysregulation of NLRP3 inflammasome results in uncontrolled inflammation, which participates in various chronic diseases. TWIK2 potassium channel mediates potassium efflux that has been reported to be an essential upstream mechanism for ATP-induced NLRP3 inflammasome activation. Thus, TWIK2 potassium channel could be a potential drug target for NLRP3-related inflammatory diseases. In the present study we investigated the effects of known K2P channel modulators on TWIK2 channel expressed in a heterologous system. In order to increase plasma membrane expression and thus TWIK2 currents, a mutant channel with three mutations (TWIK2I289A/L290A/Y308A) in the C-terminus was expressed in COS-7 cells. TWIK2 currents were assessed using whole-cell voltage-clamp recording. Among 6 known K2P channel modulators tested (DCPIB, quinine, fluoxetine, ML365, ML335, and TKDC), ML365 was the most potent TWIK2 channel blocker with an IC50 value of 4.07 ± 1.5 µM. Furthermore, ML365 selectively inhibited TWIK2 without affecting TWIK1 or THIK1 channels. We showed that ML365 (1, 5 µM) concentration-dependently inhibited ATP-induced NLRP3 inflammasome activation in LPS-primed murine BMDMs, whereas it did not affect nigericin-induced NLRP3, or non-canonical, AIM2 and NLRC4 inflammasomes activation. Knockdown of TWIK2 significantly impaired the inhibitory effect of ML365 on ATP-induced NLRP3 inflammasome activation. Moreover, we demonstrated that pre-administration of ML365 (1, 10, 25 mg/kg, ip) dose-dependently ameliorated LPS-induced endotoxic shock in mice. In a preliminary pharmacokinetic study conducted in rats, ML365 showed good absolute oral bioavailability with F value of 22.49%. In conclusion, ML365 provides a structural reference for future design of selective TWIK2 channel inhibitors in treating related inflammatory diseases.

Identification and characterization of a series of novel HCN channel inhibitors.

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels play a critical role in controlling pacemaker activity in both heart and nervous system. Developing HCN channel inhibitors has been proposed to be an important strategy for the treatment of pain, heart failure, arrhythmias, and epilepsy. One HCN channel inhibitor, ivabradine, has been clinically approved for the treatment of angina pectoris and heart failure. In this study, we designed and synthesized eight alkanol amine derivatives, and assessed their effects on HCN channels expressed in COS7 cells using a whole-cell patch clamp method. Among them, compound 4e displayed the most potent inhibitory activity with an IC50 of 2.9 ± 1.2 µM at - 120 mV on HCN2 channel expressed in COS7 cells. Further analysis revealed that application of compound 4e (10 µM) caused a slowing of activation and a hyperpolarizing shift (ΔV1/2 = - 30.2 ± 2.9 mV, n = 5) in the voltage dependence of HCN2 channel activation. The inhibitory effect of compound 4e on HCN1 and HCN4 channel expressed in COS7 cells was less potent with IC50 of 17.2 ± 1.3 and 7.3 ± 1.2 µM, respectively. Besides, we showed that application of compound 4e (10 µM) inhibited Ih and action potential firing in acutely dissociated mouse small dorsal root ganglion neurons. Our study provides a new strategy for the design and development of potent HCN channel inhibitors.

Cestrum nocturnum Flower Extracts Attenuate Proliferation and Induce Apoptosis in Malignant Cells through Inducing DNA Damage and Inhibiting Topoisomerase II Activity.

Most of the existing chemotherapeutic drugs have plenty of side effects. Chinese herbal medicine has been used for pharmaceutical and dietary therapy for thousands of years with more effective and fewer side effects. Cestrum nocturnum (CN) has long been used to treat digestive diseases for centuries in China. Our previous study first proved that the n-butanol part isolated from the flowers of CN produced an inhibitory effect on the proliferation of malignant cells. However, the fractions responsible for the antiproliferation effect of n-butanol part from CN flowers and related mechanisms remain unknown. Thus, in this study, we extracted fractions C4 and C5 from n-butanol part of CN flowers and investigated their immune toxicity and antitumor activities. It was found that fractions C4 and C5 exhibited great cytotoxicity to cancer cell lines but had low immune toxicity towards T and B lymphocytes in vitro. The tested fractions also attenuated proliferation and induced apoptosis at G0/G1 and G2/M phases in Bel-7404 cells through inducing DNA damage and inhibiting topoisomerase II relaxation activity. These results suggest that fractions C4 and C5 may represent important sources of potential antitumor agents due to their pronounced antitumor effects and low immune toxicity.

Deciphering the anti-angiogenic effect of endostatin/cyclophosphamide to normalize tumor micrangium through notch signaling pathway in colon cancer.

BACKGROUND: The invasion of colon cancer is associated with the tumor angiogenesis. Endostatin is an important anti-angiogenic agent, and the additive effect of endostatin with a chemotherapeutic agent, cyclophosphamide, on micrangium has not been established. METHODS: Male BALB/c strain nude mice were injected with human colorectal carcinoma cells (HCT-116). The mice were divided into four groups (n=15, each group) and were treated with different concentrations of endostatin (15, 10, and 5 mg/kg/day), cyclophosphamide (20, 10, and 5 mg/kg/day), and combination of endostatin/cyclophosphamide (15+20, 15+10, and 15+5 mg/kg/day). The tumor inhibition rate was evaluated, followed by the quantification of messenger ribonucleic acid (mRNA) and protein expression of notch signaling components NOTCH-1, NOTCH-3, NOTCH-4, JAG-1, DLL-4, Hes-1, and Hey-1 using quantitative polymerase chain reaction (qPCR). The protein expression of NOTCH-3, JAG-1, and DLL-4 was confirmed using western blotting. Microvessel density (MVD) was evaluated to detect micrangium following the treatment. RESULTS: The endostatin/cyclophosphamide-treated samples exhibited an additive effect on the tumor inhibition rate and the microvessel count. NOTCH-1, NOTCH-3, NOTCH-4, JAG-1, Hes-1, and Hey-1 expression levels were highly correlated and downregulated in the treated samples, whereas DLL-4 expression was upregulated that accounted for its anti-angiogenic property. CONCLUSIONS: The combination treatment of colon cancer with endostatin and a chemotherapeutic agent, cyclophosphamide proves to be an efficient therapeutic strategy to inhibit the rapid vasculature formation confirmed by the differential expression of notch signaling components.

Analysis of mutation of the c-Kit gene and PDGFRA in gastrointestinal stromal tumors.

The aim of the present study was to investigate mutation status of the c-Kit gene (KIT) and PDGFRA in patients with a gastrointestinal stromal tumor (GIST). In total, 93 patients with a GIST were included in the study, in which polymerase chain reaction amplification and gene sequencing were used to detect the sequences of exons 9, 11, 13 and 17 in KIT and exons 12 and 18 in PDGFRA. KIT mutations were detected in 64 cases (68.82%), of which exon 11 mutations were detected in 56 cases (60.22%), exon 13 mutations were detected in three cases (3.23%) and one case (1.08%) was shown to have a mutation in exon 17. The most common mutation in exon 11 was a deletion, which accounted for 55.36% (31/56) of the cases, followed by a point mutation observed in 26.79% (15/56) of the cases, while an insertion (tandem repeats) was identified in 14.29% (8/56) of the cases, and 3.57% (2/56) of the exon 11 mutations were deletions associated with a point mutation. The majority of the mutations were heterozygous, with only a few homozygous mutations. Mutational analysis revealed the mutations to be more concentrated in the classic hot zone at the 5'-end, followed by the tandem repeat frame at the 3'-end. In four cases, a mutation was detected in exon 18 of PDGFRA, of which one was associated with a mutation in KIT. The remaining three cases (10.34%, 3/29) were not associated with mutations in KIT and accounted for 37.5% (3/8) of the CD117-negative GIST cases. Therefore, the majority of the GIST cases were characterized by mutations in KIT or PDGFRA, which were directly associated with the disease. Pairs of different mutations in the same exon of KIT, or KIT mutations coupled with pairs of mutations in PDGFRA, were detected in a small number of patients. Imatinib is a small molecule tyrosine kinase inhibitor and is the first line targeted treatment for GIST, resulting in markedly improved survival rates. Thus, gene mutation genotyping may provide inspiration and guidance for imatinib-based targeted cancer therapy.

[Experimental study on antitumor effect of extracts from Cestrum nocturnum in vivo].

OBJECTIVE: To observe the antitumor effects of extracts from Cestrum nocturnum (CN) in vivo. METHODS: The S180-mice model was used to observe the tumor-inhibition rate of CN and the H22-mice model was used to test the survival time. RESULTS: The experiment in S180-mice demonstrated that the n-butanol and polysaccharides extracts from CN had obvious effects on tumor inhibition. Its inhibitory rates were 52.30%, 46.75%, 42.28%, 43.19%, 37.96% and 31.82% respectively in the mice administrated the n-butanol and polysaccharides extracts from CN with 30 mg/kg, 20 mg/kg and 15 mg/kg weight dosage. It was noted that tumor formation postponed in mice treated with the n-butanol and polysaccharides extracts from CN compared with the control panel and tumor growth became slower; The n-butanol and polysaccharides extracts from CN could also greatly enhance the life span of mice with H22 ascitic tumors by 116.43%, 44.52%, 20.54%, 109.52%, 112.61% and 115.01%, respectively. The inhibit effects of n-butanol fraction extracts from CN had direct relationship with dose, while the polysaccharides fraction extracts from CN had no obvious relationship with dose. CONCLUSION: The n-butanol and polysaccharides extracts of CN are able to inhibit tumor growth and prolong the lifetime of the tumor-bearing mice in a dose-dependent pattern.