Ni/Mn-Complex-Tethered Tetranuclear Polyoxovanadates: Crystal Structure and Inhibitory Activity on Human Hepatocellular Carcinoma (HepG-2).

Polyoxometalates (POMs) exhibit unique structural characteristics and excellent physical and chemical properties, which have attracted significant attention from scholars in the fields of anticancer research and chemotherapy. Herein, we successfully synthesized and structurally characterized two novel polyoxovanadates (POVs), denoted as POVs-1 and POVs-2, where [M(1-vIM)4]2[VV4O12]·H2O (M: NiII and MnII, 1-vinylimidazole abbreviated as 1-vIM) serve as ligands. The two POVs are isomeric and consist of fundamental structural units, each comprising one [V4O12]4- cluster, two [M(1-vIM)4]2+ cations, and one water molecule. Subsequently, we evaluated the cell viability of human hepatocellular carcinoma (HepG-2) cells treated with the synthesized POVs using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazoliumbromide) assay. And the changes in cell nucleus morphology, mitochondrial membrane potential (Δψm), and reactive oxygen species levels in HepG-2 exposed to POVs were monitored using specific fluorescent staining techniques. Both hybrid POVs showed potent inhibitory activities, induing apoptosis in HepG-2 cells along with significant mitochondria dysfunction and a burst of reactive oxygen species. Notably, the inhibitory effects of POVs-2 were more pronounced than those of POVs-1, which is primarily attributed to the different transition metal ions present. These findings underscore the intricate relationship between the metal components, structural characteristics, and the observed antitumor activities in HepG-2 cells.

A Semi-Synthetic Diet and the Potential Important Chemicals for Mythimna separata (Lepidoptera: Noctuidae).

Armyworm feeding in large, destructive groups is hugely difficult to control and the oriental armyworm, Mythimna separata (Walk), is one such pest. In this study, we reported a semisynthetic artificial diet for the oriental armyworm. This diet is based on Ritter's diet, a formula developed for Heliothis zea. The survival of M. separata was extremely low and only around 2% insects can reach the adult stage on Ritter's diet. But, it can reach up to 100% if corn leaf powder (CLP) was mixed, and insects grew faster and gained more mass. After testing a set of mixtures of Ritter's diet and CLP, we found that 14.3% was the optimal proportion of CLP for making the artificial diet. We then used chloroform to extract CLP. Insect performance was still much better on Ch-extracted CLP diets than that on Ritter's diet, but it was poorer than that on the diets containing unprocessed CLP, suggesting that the essential factor(s) was only partially extracted from corn leaf. We then used methanol and dichloromethane, two solvents differing in their polarity, to process the extractions and analyzed the extracted chemicals using gas chromatography-mass spectrometry (GC-MS). Insects had a better performance on dichloromethane-extracted CLP diet in comparison to methanol-extracted one, indicating that the important factor(s) is more prone to methanol extraction. The reported recipe here is useful for the research on M. separata and possibly other grain-crop eating armyworms. The functions of the chemicals extracted from corn leaf tissue can be investigated in the future studies.

Transcription of four Rhopalosiphum padi (L.) heat shock protein genes and their responses to heat stress and insecticide exposure.

The bird cherry-oat aphid, Rhopalosiphum padi (L.), a worldwide destructive pest, is more heat tolerant than other wheat aphids, and it has developed resistance to different insecticides. Heat shock proteins (HSPs) play an important role in coping with environmental stresses. To investigate Hsp transcriptional responses to heat and insecticide stress, four full-length Hsp genes from R. padi (RpHsp60, RpHsc70, RpHsp70-1, and RpHsp70-2) were cloned. Four RpHsps were expressed during all R. padi developmental stages, but at varying levels. The mRNA levels of RpHsps were increased under thermal stress and reached maximal induction at a lower temperature (36°C) in the alate morph than in the apterous morph (37°C or 38°C). RpHsp expressions under heat stress suggest that RpHsp70-1 and RpHsp70-2 are inducible in both apterous and alate morphs, RpHsc70 is only heat-inducible in apterous morph, and RpHsp60 exhibits poor sensitivity to heat stress. The pretreatment at 37°C significantly increase both the survival rate and the RpHsps expression level of R. padi at subsequent lethal temperature. Under exposure to two sublethal concentrations (LC10 and LC30) of beta-cypermethrin, both RpHsp70-1 and RpHsp70-2 expressions were induced and reached a maximum 24h after exposure. In contrast, expression of RpHsp60 was not induced by either sublethal concentration of beta-cypermethrin. Moreover, the responses of RpHsp70-1 and RpHsp70-2 to heat shock were more sensitive than those to beta-cypermethrin. These results suggest that induction of RpHsp expression is related to thermal tolerance, and that RpHsp70-1 and RpHsp70-2 are the primary genes involved in the response to both heat and pesticide stress.

The Survival and Reproduction of Rhopalosiphum padi (Hemiptera: Aphididae) on Different Plants: Exploring the Possible Host Range for a Serious Wheat Pest.

Rhopalosiphum padi (L.) is one of the most economically important pests of wheat worldwide; however, the host ranges of R. padi remain unclear. Particularly, it is unknown which plants R. padi can survive and reproduce on after the harvest of crops. The results revealed that the survival, developmental times, longevity, and fecundity of the aphid varied among the 13 Gramineae weeds, with the life-history parameters significantly differing. The virginoparae could survive long-term and reproduce on 11 of the 13 weeds. Gramineae weeds can possibly play a significant role in the buildup of R. padi populations as reservoirs. The virginoparae could survive long term and reproduce on Iris lactea Pall. var. chinensis (Fisch.) Koidz (Liliflorae: Iridaceae), Iris tectorum Maxim. (Liliflorae: Iridaceae), Cyperus rotundus L. (Cyperales: Cyperaceae), and Brassica oleracea L. var. capitata (Rhoeadales: Cruciferae), but not on Fagopyrum esculentum Moench (Polygonales: Polygonaceae), F. tataricum (L.) Gaertn. (Polygonales: Polygonaceae), Chlorophytum comosum (Thunb.) Baker (Liliflorae: Liliaceae), and Ophiopogon japonicas (Thunb.) Ker-Gawl (Liliflorae: Liliaceae). Rhopalosiphum padi can survive and reproduce on non-Gramineae plants of different families. Detailed host range information would be helpful for more effective control of insect pests. The design and implementation of sustainable pest management strategies should consider the aphid population on weeds and other host plants.

Geographical Variations in the Life Histories of Rhopalosiphum padi (Hemiptera: Aphididae) in China.

Population dynamics of an insect can be affected by its life-history traits. Understanding of the life-history variations among geographical populations of an insect pest is important for developing the corresponding control strategies in different regions. Rhopalosiphum padi is a cosmopolitan cereal pest, and life-history traits identification of R. padi from different geographical regions is rare. Here, we experimentally evaluated variations in the life histories and life-table parameters of R. padi populations from six widely ranging geographical regions, including Baoding (HB), Xianyang (SX), Nanyang (HN), Wuhan (HW), Beibei (CB), and Guiyang (GG), in China. Total longevity was similar for HB, CB, and GG populations and generally shorter than that of the SX, HN, and HW populations. The age at first reproduction of HB and HW populations was significantly different from that of the other four populations. Mean fecundity of the SX population was significantly higher than that of the other five populations, and the mean fecundity of the GG population was the lowest. Principal component analysis (PCA) also showed that the life-history and life-table parameters of R. padi differed among the six geographical populations. According to PCA results, the HW population was in one cluster; the GG population was in another cluster; the SX, HN, and CB populations were in one cluster; and the HB population differed from the above three clusters. The complexity of local genetic adaptation in aphids was discussed. The current results will likely be of importance to management practices and population dynamics forecasting of R. padi.