Development and Characterization of Modified Gelatin-Based Cling Films with Antimicrobial and Antioxidant Activities and Their Application in the Preservation of Cherry Tomatoes.

The utilization of functional cling films presents a promising approach to alleviate post-harvest spoilage caused by microbial activity, oxidative metabolism, and moisture loss in agricultural products. To overcome the environmental problems of conventional packaging materials, in this study, we developed functional fruit and vegetable cling films based on glycidyltrimethylammonium chloride and rosemarinic acid cross-linked gelatin (RQ-GEL). The results indicate that the prepared RQ-GEL film possesses excellent UV light barrier properties and mechanical performance. RQ-GEL inhibited S. aureus and E. coli by 93.79% and 92.04%, respectively. DPPH and ABTS free radical scavenging activities were as high as 87.69% and 84.6%. In the cherry tomato preservation experiment, when compared to uncovered samples, the RQ-GEL group had a 29.77% reduction in weight loss and a significant 26.92% reduction in hardness. Meanwhile, the RQ-GEL group delays the decline of fruit total soluble solids and titratable acidity content, and prolongs the preservation period of cherry tomatoes. Hence, RQ-GEL cling film is poised to emerge as a promising packaging material for the post-harvest preservation of agricultural products.

Identification of cuticular protein genes and analysis of their roles in phosphine resistance of the rusty grain beetle Cryptolestes ferrugineus.

The rusty grain beetle, Cryptolestes ferrugineus (Stephens) is one of the most economically important stored grain pests, and it has evolved the high resistance to phosphine. Cuticular proteins (CPs) are the major structural components of insect cuticle, and previous studies have confirmed that CPs were involved in insecticide resistance. However, the CPs of C. ferrugineus are still poorly characterized, and thus we conducted transcriptome-wide identification of CP genes and analyze their possible relationships with phosphine resistance in this pest. In this study, a total of 122 putative CPs were annotated in the C. ferrugineus transcriptome data by blasting with the known CPs of Tribolium castaneum. The analysis of conserved motifs revealed these CPs of C. ferrugineus belonging to 9 different families, including 87 CPR, 13 CPAP1, 7 CPAP3, 3 Tweedle, 1 CPLCA, 1 CPLCG, 5 CPLCP, 2 CPCFC, and 3 CPFL proteins. The further phylogenetic analysis showed the different evolutionary patterns of CPs. Namely, we found some CPs (CPR family) formed species-specific protein clusters, indicating these CPs might occur independently among insect taxa, and while some other CPs (CPAP1 and CPAP3 family) shared a closer correlation based on the architecture of protein domains. Subsequently, the previous RNA-seq data were applied to establish the expression profiles of CPs in a phosphine susceptible and resistant populations of C. ferrugineus, and a large amount of CP genes were found to be over-expressed in resistant insects. Lastly, an up-regulated CP gene (CPR family) was selected for the further functional analysis, and after this gene was silenced via RNA interference (RNAi), the sensitivity to phosphine was significantly enhanced in C. ferrugineus. In conclusion, the present results provided us an overview of C. ferrugineus CPs, and which suggested that the CPs might play the critical roles in phosphine resistance.

Abscisic acid-generating bacteria can reduce Cd concentration in pakchoi grown in Cd-contaminated soil.

Contamination of vegetable plants with cadmium (Cd) has become a serious issue in recent years. In the present study, pakchoi (Brassica chinensis L.) grown in Cd-contaminated soil inoculated with abscisic acid (ABA)-generating bacteria, Azospirillum brasilense and Bacillus subtilis, showed 28%-281% and 26%-255% greater biomass, and 40%-79% and 43%-77% lower Cd concentrations, respectively, than those of the controlbacteria-free plants. These treatments also alleviated the Cd-induced photosynthesis inhibition and oxidative damage (indicated by malondialdehyde [MDA], H2O2, and O2• -). Furthermore, the application of bacteria also remarkably improved the levels of antioxidant-related compounds (total phenolics, total flavonoids, ascorbate, and 2,2-diphenyl-1-picrylhydrazyl [DPPH] activity) and nutritional quality (soluble sugar and soluble protein) in the Cd-supplied plants. Based on these results, we conclude that the application of ABA-generating bacteria might be an alternative strategy for improving the biomass production and quality of vegetable plants grown in Cd-contaminated soil.

Dual roles of QOA-8a in antiosteoporosis: a combination of bone anabolic and anti-resorptive effects.

Osteoporotic treatments have largely depended on antiresorptive or anabolic drugs; but the former also suppresses new bone formation, and the latter only includes human parathyroid hormone. There is no drug that has a dual effect to inhibit bone resorption and to stimulate bone formation simultaneously. Here, we report a small molecule, a quinoxaline derivative of oleanolic acid (QOA-8a) that plays such dual roles in osteoblasts and osteoclasts in the treatment of osteoporosis. Osteoclast differentiation was induced by incubation of primary mouse bone marrow-derived macrophages in the presence of RANKL and M-CSF, treatment with QOA-8a dose-dependently inhibited the osteoclast formation with an IC50 value of 0.098 µmol/L. QOA-8a also directly acted on osteoblasts, and stimulated new bone formation in murine calvarial bones in vitro and in vivo. In an OVX rat model, administration of QOA-8a (1, 5 mg·kg-1·d-1, po) for 16 weeks effectively prevented OVX-induced bone loss, accompanied by decreased serum levels of the bone resorption marker CTX-1 and increased serum levels of osteoblast marker N-MID-OT. Meaningfully, our preliminary study revealed that QOA-8a down-regulated the ERK1/2 signal in osteoclasts and up-regulated the signal in osteoblasts. QOA-8a showed dual functions in both animal and human osteoclastogenesis and osteoblastogenesis. Our results demonstrate that QOA-8a might serve as a lead compound with a dual function of bone anabolic and anti-resorptive effects in the development of anti-osteoporosis agents.

Synthesis and biological evaluation of novel sinomenine derivatives as anti-inflammatory agents.

Sinomenine (1) is clinically available for the treatment of rheumatoid arthritis (RA), however, its efficacy is quite weak. In the present study, a library of novel sinomenine-based homodimers and monomers through variable-length linkers were designed and synthesized, and their bioactivities were evaluated using RAW264.7 cells and mice. Among the compounds, 2f and 3b possessed much more potent inhibitory effects on the production of nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) than 1. Preliminary mechanism investigation revealed that 3b inhibited nuclear factor-κB (NF-κB) signaling pathway specifically, 2f suppressed both NF-κB and mitogen-activated protein kinase (MAPK) cascades. Moreover, 3b and 2f significantly alleviated the lipopolysaccharide (LPS)-induced mortality. These two compounds might serve as valuable candidates for anti-inflammatory drug discovery.

Quinoxaline derivative of oleanolic acid inhibits osteoclastic bone resorption and prevents ovariectomy-induced bone loss.

OBJECTIVE: Through bioassay-guided natural product research, it has been discovered that oleanolic acid and its glycosides possess an antibone resorption activity. Quinoxaline derivative of oleanolic acid (QOA-8a), a novel compound, is sourced from a structural modification of oleanolic acid. The aim of the present study was to evaluate the activities of QOA-8a on bone resorption in vitro and its osteoprotective effect in vivo. METHODS: Osteoclast precursors and mature osteoclasts were used to assay antibone resorption activities in vitro. RAW264.7 cells cultured for 2 days in the presence of the receptor activator for nuclear factor κB ligand were used as osteoclast precursors. Mature osteoclasts were generated from either primary cultures of mouse bone marrow-derived macrophages or RAW264.7 cells. Eight-week-old female mice that underwent either ovariectomy or sham surgical operation were used for the evaluation of the osteoprotective effect of QOA-8a at doses of 0.1, 1, and 10 mg kg(-1) day(-1). RESULTS: QOA-8a significantly inhibited the differentiation, formation, and bone resorptive activity of mature osteoclasts without cytotoxicity. QOA-8a selectively induced apoptosis at an early stage of mature osteoclasts at least via increasing the caspase-3 activity, but not osteoclast precursors. Furthermore, QOA-8a significantly prevented bone loss in ovariectomized mice without any hormone-like adverse effects, whereas the mice treated with 1 mg kg(-1) day(-1) kept the same bone mineral density level as that of the sham mice. CONCLUSIONS: QOA-8a inhibits bone resorption without cytotoxicity and prevents bone loss without any hormone-like adverse effects. Although further investigations are necessary to elucidate the detailed molecular mechanisms, QOA-8a demonstrates great potential as a novel agent for the treatment of osteoporosis.