Fumigant Toxicity in Myzus persicae Sulzer (Hemiptera: Aphididae): Controlled Release of (E)-anethole from Microspheres

Design, Synthesis, and Biological Evaluation of Pyrido [1,2-α] Pyrimidinone Mesoionic Derivatives Bearing Propenylbenzene as the Vector Control Insecticide

A series of novel pyrido [1,2-α] pyrimidinone mesoionic derivatives bearing a propenylbenzene group at the 1-position were synthesized on the basis of the structure of mesoionic insecticides triflumezopyrim and dicloromezotiaz via a rationally conceived pharmacophore model and evaluated for their insecticidal activities against three insect vectors. The bioassay results showed that some compounds exerted remarkable insecticidal activities against M. domestica, Ae. albopictus, and B. germanica. Particularly, compound 26l displayed outstanding insecticidal activity against Ae. Albopictus, with an LC50 value of 0.45 μg/mL, far superior to that of imidacloprid (LC50 = 1.82 μg/mL) and equivalent to that of triflumezopyrim (0.35 μg/mL). Meanwhile, compound 34l presented a broad insecticidal spectrum, with LC50 values of 1.51 μg/g sugar, 0.52 μg/mL and 0.14 μg/adult, which were about 2.88, 3.50, and 1.50 times better than that of imidacloprid (LC50 = 4.35 μg/g sugar, 1.82 μg/mL and 0.21 μg/adult against M. domestica, Ae. albopictus, and B. germanica, respectively) and equivalent to that of triflumezopyrim against M. domestica (1.13 μg/g sugar) and Ae. albopictus (0.35 μg/mL) but lower than the potency against B. germanica (0.06 μg/g sugar). The molecular docking study by energy minimizations revealed that introducing propenylbenzene at the 1-position of compounds 26l and 34l could embed into the binding pocket of nicotinic acetylcholine receptors and form pi-alkyl interaction with LEU306. These results demonstrated that compounds 26l and 34l could be promising candidates for vector control insecticides, which deserved further investigation.

In Vivo Bioassay of the Repellent Activity of Caraway Essential Oil against Green Peach Aphid

An in vivo dual choice bioassay with white cabbage as a host plant was used to determine the repellent effect of three different accessions of caraway (Carum carvi L.) essential oils (EOs) against the green peach aphid Myzus persicae (Sulzer). The dominant components of the EO were D-Carvone (47.3-74.4%) and D-limonene (25.2-51.9%), which accounted for 99.2-99.5% of the EOs determined by GC/MS. The EO with the highest D-limonene content (51.9%) showed the highest repellence (Repellency Index (RI) = +41%), which was stable up to 330 min. The incorporation of several surfactants with different hydrophilic-lipophilic balance values (from 12.4 to 16.7) with caraway EO caused a general inhibition of the repellent effect during the testing period (RI from +41% to -19%). Overall, the findings indicate that caraway EO could be used as a green peach aphid repellent, but more work is needed to formulate the EO into a ready-to-use product.

Trans-anethole ameliorates LPS-induced inflammation via suppression of TLR4/NF-κB pathway in IEC-6 cells

This study was undertaken to investigate the protective role of trans-anethole (TA) in lipopolysaccharide (LPS)-induced rat intestinal epithelial cells (IEC-6) injury and the potential mechanisms. The cells were pretreated with TA (0 and 1 mM) for 24 h, prior to stimulation by LPS (1 mg/mL) for 24 h. Compared with the control group (CON), LPS stimulus resulted in decreased cell viability, intestinal barrier injury, increased cell apoptosis and cell cycle arrest at the G2/M phase. These effects triggered by LPS were reversed by TA. In order to reveal the main genes and pathways involved among the groups, transcriptome analysis was performed to identify the differential expression genes (DEGs) among the treatment groups. There were a total of 493 DEGs (275 upregulated and 218 downregulated) that were identified between the LPS and CON group. Meanwhile, a total of 361 DEGs (103 regulated and 258 downregulated) were identified in the LPS+TA group compared with the LPS group. The results showed that the DEGs were mostly enriched in immune related pathways, such as tumor necrosis factor (TNF) signaling pathway, cytokine-cytokine receptor interaction, complement and coagulation cascades, interleukin-17 (IL-17) signaling pathway, NF-kappa B (NF-κB) signaling pathway, antigen processing and presentation, and NOD-like receptor signaling pathway. Based on the results of RNA-sequencing, further investigation of the signaling pathway involved revealed that TA could inhibit the activation of toll like receptor 4 (TLR4)/NF-κB signaling pathway and NLR family pyrin domain containing 3 (NLRP3) inflammasome in LPS-induced IEC-6 cells. In conclusion, this finding demonstrated a functional role of TA in intestinal epithelial cells injury and indicated that TA may be a potential strategy for treatment of inflammatory intestinal diseases.