Dual mutations in the whitefly nicotinic acetylcholine receptor ß1 subunit confer target-site resistance to multiple neonicotinoid insecticides.

Neonicotinoid insecticides, which target insect nicotinic acetylcholine receptors (nAChRs), have been widely and intensively used to control the whitefly, Bemisia tabaci, a highly damaging, globally distributed, crop pest. This has inevitably led to the emergence of populations with resistance to neonicotinoids. However, to date, there have been no reports of target-site resistance involving mutation of B. tabaci nAChR genes. Here we characterize the nAChR subunit gene family of B. tabaci and identify dual mutations (A58T&R79E) in one of these genes (BTß1) that confer resistance to multiple neonicotinoids. Transgenic D. melanogaster, where the native nAChR Dß1 was replaced with BTß1A58T&R79E, were significantly more resistant to neonicotinoids than flies where Dß1 were replaced with the wildtype BTß1 sequence, demonstrating the causal role of the mutations in resistance. The two mutations identified in this study replace two amino acids that are highly conserved in >200 insect species. Three-dimensional modelling suggests a molecular mechanism for this resistance, whereby A58T forms a hydrogen bond with the R79E side chain, which positions its negatively-charged carboxylate group to electrostatically repulse a neonicotinoid at the orthosteric site. Together these findings describe the first case of target-site resistance to neonicotinoids in B. tabaci and provide insight into the molecular determinants of neonicotinoid binding and selectivity.

Novel_miR-1517 mediates CYP6CM1 to regulate imidacloprid resistance in Bemisia tabaci (Hemiptera: Gennadius).

Bemisia tabaci (Hemiptera: Gennadius) is a notorious pest that is capable of feeding on >600 kinds of agricultural crops. Imidacloprid is critical in managing pest with sucking mouthparts, such as B. tabaci. However, the field population of B. tabaci has evolved resistance because of insecticide overuse. The overexpression of the detoxification enzyme cytochrome P450 monooxygenase is considered the main mechanism of imidacloprid resistance, but the mechanism underlying gene regulation remains unclear. MicroRNAs are a type of endogenous small molecule compounds that is fundamental in regulating gene expression at the post-transcriptional level. Whether miRNAs are related to the imidacloprid resistance of B. tabaci remains unknown. To gain deep insight into imidacloprid resistance, we conducted on miRNAs expression profiling of two B. tabaci Mediterranean (MED) strains with 19-fold resistance through deep sequencing of small RNAs. A total of 8 known and 1591 novel miRNAs were identified. In addition, 16 miRNAs showed significant difference in expression levels between the two strains, as verified by quantitative reverse transcription PCR. Among these, novel_miR-376, 1517, and 1136 significantly expressed at low levels in resistant samples, decreasing by 36.9%, 60.2%, and 15.6%, respectively. Moreover, modulating novel_miR-1517 expression by feeding with 1517 inhibitor and 1517 mimic significantly affected B. tabaci imidacloprid susceptibility by regulating CYP6CM1 expression. In this article, miRNAs related to imidacloprid resistance of B. tabaci were systematically screened and identified, providing important information for the miRNA-based technological innovation for this pest management.

Over-expression of UDP-glycosyltransferase UGT353G2 confers resistance to neonicotinoids in whitefly (Bemisia tabaci).

The whitefly, Bemisia tabaci, comes up high metabolic resistance to most neonicotinoids in long-term evolution, which is the key problem of pest control. UGT glycosyltransferase, as a secondary detoxification enzyme, plays an indispensable role in detoxification metabolism. In this study, UGT inhibitors, 5-nitrouracil and sulfinpyrazone, dramatically augmented the toxic damage of neonicotinoids to B. tabaci. A UGT named UGT353G2 was identified in whitefly, which was notably up-regulated in resistant strain (3.92 folds), and could be induced by most neonicotinoids. Additionally, the using of RNA interference (RNAi) suppresses UGT353G2 substantially increased sensitivity to neonicotinoids in resistant strain. Our results support that UGT353G2 may be involved in the neonicotinoids resistance of whitefly. These findings will help further verify the functional role of UGTs in neonicotinoid resistance.

Knockdown of the Nicotinic Acetylcholine Receptor ß1 Subunit Decreases the Susceptibility to Five Neonicotinoid Insecticides in Whitefly (Bemisia tabaci).

The sweet potato whitefly, Bemisia tabaci, (Gennadius) (Hemiptera:Aleyrodidae) is a global pest of crops. Neonicotinoids are efficient insecticides used for control of this pest. Insecticidal targets of neonicotinoids are insect nicotinic acetylcholine receptors (nAChRs). Here, we characterized and cloned the full length of the nAChR ß1 subunit (BTß1) in B. tabaci and confirmed the consistency of BTß1 in B. tabaci MEAM1 and MED. Expression levels of BTß1 in different developmental stages and body parts of adults were investigated and compared in B. tabaci MED. dsRNA was prepared to knock down BTß1 in adult B. tabaci and significantly decreases the susceptibility to five neonicotinoid insecticides, including imidacloprid, clothianidin, thiacloprid, nitenpyram, and dinotefuran. This study indicated BTß1 as a notable site influencing the susceptibility of B. tabaci to neonicotinoids.

[Systematic analysis on clinical safety of Shuxuetong injection].

OBJECTIVE: To evaluate the clinical adverse drug reactions (ADR) of Shuxuetong Injection (SXTI) comprehensively for its proper use and post-marketing reevaluation. METHOD: Electronic searching of the online Chinese and English medical databases were carried out from their inception to Feb. 2012, studies were screened and data were extracted according to inclusion and exclusion criteria; total number of ADR were calculated by study type respectively, ADR incidence rate was calculated by number of ADRs in experimental arm of clinical trials with control groups divided by total number of experimental groups. RESULT: Eighty and eight papers published concerning ADRs report of SXTI were included, including 65 clinical trials, 20 case reports, and 3 ADRs surveillance or analysis report. 174 ADRs were reported, mainly in circulation system, nervous system, the digestive system, skin and appendages. Adverse reaction type is mainly rash (44.3%) and the digestive system response (23.0%). The incidence rate calculated by data extracted from 65 clinical trials was 4.3%. CONCLUSION: Allergic reaction is the most common ADR type of SXTI. Incidence rate of different studies varies, so a rigorously designed prospectively ADR surveillance study is needed to reevaluate its incidence rate, and analyze reasons of the heterogeneity. Information concerning ADR in literatures is always absent, the quality of reporting is relative poor, thus it is suggested that active, standardized, and systematic ADR reporting should be focused on in clinical trials.

[Development of the theoretical framework and the item pool of the peri-operative recovery scale for integrative medicine].

OBJECTIVE: To study the train of thoughts and procedures for developing the theoretical framework and the item pool of the peri-operative recovery scale for integrative medicine, thus making preparation for the development of this scale and psychometric testing. METHODS: Under the guidance for Chinese medicine theories and the guidance for developing psychometric scale, the theoretical framework and the item pool of the scale were initially laid out by literature retrieval, and expert consultation, etc. RESULTS: The scale covered the domains of physical function, mental function, activity function, pain, and general assessment. Besides, social function is involved, which is suitable for pre-operative testing and long-term therapeutic efficacy testing after discharge from hospital. Each domain should cover correlated Zang-Fu organs, qi, blood, and the patient-reported outcomes. Totally 122 items were initially covered in the item pool according to theoretical framework of the scale. CONCLUSIONS: The peri-operative recovery scale of integrative medicine was the embodiment of the combination of Chinese medicine theories and patient-reported outcome concepts. The scale could reasonably assess the peri-operative recovery outcomes of patients treated by integrative medicine.

Genome-wide identification and analysis of sulfatase and sulfatase modifying factor genes in Bemisia tabaci (Hemiptera: Aleyrodidae).

The invasive pest whitefly (Bemisia tabaci) is a complex species, of which Middle East-Minor Asia 1 (MEAM1) and Mediterranean (MED) are the two most damaging members. Previous research showed that cabbage is frequently infested with MEAM1 but seldomly with MED, and this difference in performance is associated with glucosinolate (GS) content. Some insects can modify GS using glucosinolate sulfatase (SULF), the activity of which is regulated by sulfatase modifying factor 1 (SUMF1); therefore, to increase our understanding of different performances of MEAM1 and MED on cabbage plants, we identified and compared nine putative SULFs and one SUMF in MEAM1 and MED. We found that the lengths of two genes, BtSulf2 and BtSulf4, differed between MEAM1 and MED. The messenger RNA levels of BtSulf4 increased more than 20-fold after MEAM1 and MED adults were exposed to GS, but BtSulf2 expression was only induced by GS in MEAM1. Knockdown of BtSulf2 and BtSulf4 in MEAM1 resulted in a substantial increase in the mortality of GS-treated adults but not in MED. These results indicate that differences in BtSulf2 and BtSulf4 sequences and/or expression may explain why MEAM1 performs better than MED on cabbage. Our results provide a basis for future functional research on SULF and SUMF in B. tabaci.

Chemical constituents from Daphne tangutica and their cytotoxicity against nasopharyngeal carcinoma cells.

Two new sesquiterpenoids (1-2), together with 30 known compounds including one sesquiterpenoid (3), six diterpenoids (4-9), fourteen lignans (10-23), and nine other kinds of compounds (24-32), were isolated from the stems of Daphne tangutica Maxim. Their structures were determined through extensive spectroscopic analyses, and the absolute configuration of daphnoid A (1) and B (2) were determined by the experimental and calculated electron circular dichroism (ECD) spectra. All the isolates were evaluated against two human nasopharyngeal carcinoma cells (HONE-1 and SUNE-1). Compound 25 (daphnenone) showed potent cytotoxicity toward HONE-1 and SUNE-1with IC50 values of 2.23 and 1.43 µM, respectively. Further studies indicated that compound 25 exhibited cytotoxic effects by inducing tumor cell apoptosis and arresting the cell cycle at G2/M phases in HONE-1 cells.

Diterpenoids with diverse scaffolds from Vitex trifolia as potential topoisomerase I inhibitor.

Eleven new compounds, including six labdane (1-6), three halimane (7-9), and two clerodane (10-11) diterpenoids and 16 known analogues (12-27), were isolated from the leaves of Vitex trifolia. The structures of 1-11 were established by extensive 1D- and 2D-NMR and HRMS spectroscopic data. The absolute configurations of compounds 3, 7, and 10 were assigned using X-ray diffraction. Compounds 1-27 were evaluated for DNA topoisomerases I (Top1) inhibitory activity and cytotoxicity against HCT 116 cells. Compounds 8 and 11 exhibited equipotent Top1 inhibitory activity to the positive control, camptothecin (CPT), at 100µM. Compounds 8, 9, 16, and 27 showed moderate cytotoxicity at low micromolar concentrations.

Euphomilones A and B, ent-Rosane Diterpenoids with 7/5/6 and 5/7/6 Skeletons from Euphorbia milii.

Three highly modified ent-rosane diterpenoids, euphomilones A (1) and B (2) and euphomianol A (3), were isolated from the aerial parts of Euphorbia milii. The structures were elucidated from physical, spectroscopic, and X-ray diffraction data, as well as experimental and calculated electronic circular dichroism (ECD) analysis. Plausible biogenetic pathways to 1-3 are proposed. Also, compound 1 exhibited inhibition of receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclast formation (IC50 = 12.6 µM).

Natural phosphodiesterase-4 (PDE4) inhibitors from Crotalaria ferruginea.

Bioassay-guided fractionation of the ethanol extract of the Chinese folk medicine Crotalaria ferruginea led to the isolation of a new isoflavonoid, 4'-hydroxy-2'-methylalpinum-isoflavone (1), and eight known analogs (2-9). Their structures were elucidated by spectroscopic analysis. Compounds 1, 2, 5, and 8 showed inhibitory activities against phosphodiesterase-4 (PDE4), a therapeutic target of asthma, with IC50 values ranging from 2.57 to 8.94 µM. The possible action mechanism and the structure-activity relationship (SAR) of the active isoflavonoids were explored by using molecular docking and molecular dynamics (MD) simulation methods. Our study herein may explain the anti-inflammatory function of this plant in Chinese folk medicine.