Light-sensitive features of seed germination in the invasive species Ageratina adenophora (syn. Eupatorium adenophorum) in China

Ageratina adenophora (Crofton weed) is a noxious invasive plant in several countries and its germination features favor its invasiveness. The aim of this study was to characterize the light-sensitive seed germination of this weed. Two to five-fold higher germination was observed under light conditions than under dark conditions. Dormancy-breaking methods of low temperature pre-treatment, pre-soaking with KNO3 solution, polyethylene glycol, and salicylic acid did not influence germination under either light or dark conditions. Very low light (39 μmol·m-2·s-1, 25% light transmittance) tripled seed germination from 22.3 to 66.7%, when compared to no light. Germination under violet, blue and green glass papers was significantly lower than that under yellow, orange, and red ones. Significant correlations between red-light intensity, red/far-red ratio and germination indicated that these 2 types of light may be responsible for the germination differences. Experiments under narrow band filters also proved this; red light at 630 nm could induce germination, while far-red light 740 nm could prevent germination. Thus, red/far-red light was effective in the photoblastic germination of Crofton weed, while other treatments could not replace light during germination. This photoblastic germination could favor the fast colonization of this weed when the seeds in deep soil approach the surface.Keywords: Crofton weed, plant invasiveness, light quality, light quantity, red/far-red ratio, biological contro

Microwave-Assisted Simultaneous Extraction of Luteolin and Apigenin from Tree Peony Pod and Evaluation of Its Antioxidant Activity

An efficient microwave-assisted extraction (MAE) technique was employed in simultaneous extraction of luteolin and apigenin from tree peony pod. The MAE procedure was optimized using response surface methodology (RSM) and compared with other conventional extraction techniques of macerate extraction (ME) and heat reflux extraction (HRE). The optimal conditions of MAE were as follows: employing 70% ethanol volume fraction as solvent, soaking time of 4 h, liquid-solid ratio of 10 (mL/g), microwave irradiation power of 265 W, microwave irradiation time of 9.6 min, and 3 extraction cycles. Under the optimal conditions, 151 μg/g luteolin and 104 μg/g apigenin were extracted from the tree peony pod. Compared with ME and HRE, MAE gave the highest extraction efficiency. The antioxidant activities of the extracts obtained by MAE, ME, and HRE were evaluated using a 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) free radical-scavenging assay, a ferric reducing antioxidant power assay (FRAP), and a reducing power assay. Meanwhile, the structural changes of the unprocessed and processed tree peony pod samples were analyzed by scanning electron microscopy

Nanocrystallization of the Pharmaceutically Active Agent Genipin by an Emulsion Solvent Evaporation Method

To improve the water solubility and dissolution rate, genipin was nanocrystallized by an emulsion solvent evaporation method, followed by freeze-drying. The optimization condition of nanocrystallization process was carried out by single-factor experiment. The effects of five experimental parameters, such as concentration of surfactants the proportion of water to organic phase, homogenate speed and time, homogenization pressure and times, and the proportion of genipin to lyoprotectants on the mean particle size (MPS) of genipin nanoparticles, were investigated. Under the optimum conditions by single-factor experiments, genipin nanoparticles with an MPS of 59.8 nm were obtained. The genipin nanoparticles were characterized by SEM, FTIR, XRD, DSC, solvent residue, drug purity test, dissolution testing, and bioavailability analysis. The analysis results indicated that the chemical structure of genipin nanoparticles was unchanged, but the crystallinity was reduced. The solubility of genipin nanoparticles was 9.05 times of the raw drug. In addition, the residual amounts of chloroform and ethanol were separately less than the ICH limit for class II, and the oral bioavailability of the genipin nanoparticles powder was 7.99 times of raw genipin. According to the results above, genipin nanoparticles show the potential application value of its oral absorption

Investigation of Various Cross-Linking Methods for the Immobilization of Cytosine Arabinoside on Bacterial Magnetosomes

Bacterial magnetosomes (BMs) have emerged as potential drug delivery vehicles, possessing an iron oxide or iron sulfide core surrounded by a natural lipid membrane shell. In this study, we immobilized cytosine arabinoside (Ara-C) effectively on BMs by using various methods such as direct absorption (ABMs), and others include different cross-linkers such as genipin (GP) and glutaraldehyde (G). A well-dispersed Ara-C coupled bacterial magnetosomes resulted in significantly higher negative charge than that of naked BMs (−11.5±0.3 mV) confirming the drug loading. Out of all methods, direct absorption process led to the highest encapsulation efficiency and drug loading of 88.2±4.3% and 46.9±1.2%, respectively. These designs have shown the long-term drug release behavior without an initial burst release. Our results indicate that BMs-based nanoconjugates will potentially find widespread applications in pharmaceutical field

Preparation, characterization and targeting of micronized 10-hydroxycamptothecin-loaded folate-conjugated human serum albumin nanoparticles to cancer cells

Qingyong Li, Chen Liu, Xiuhua Zhao, Yuangang Zu, Ying Wang, Baoyou Zhang, Dongmei Zhao, Qi Zhao, Lin Su, Yang Gao, Baihe SunKey Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang, People's Republic of ChinaBackground: The purpose of this study was to develop a method for targeted delivery of 10-hydroxycamptothecin (HCPT)-loaded nanoparticles (NPs) to cancer cells.Methods: We first used a supercritical antisolvent process to prepare micronized HCPT (nHCPT), and then folate-conjugated human serum albumin (HSA) nHCPT-loaded NPs (FA-HSA-nHCPT-NPs) were prepared using a NP-coated method combined with a desolvation technique. The amount of folate conjugation was 16 µg · mg-1 HSA.Results: The particle size of the spherical nHCPT microparticles obtained was 118.5 ± 6.6 nm. The particle size and zeta potential of the FA-HSA-nHCPT-NPs were 233.9 ± 1.2 nm and -25.23 ± 2.98 mV, respectively. The FA-HSA-nHCPT-NPs exhibited a smooth surface and a distinct spherical shape, and the results of differential scanning calorimetry and X-ray diffraction indicated that the FA-HSA-nHCPT-NPs presented in a nanostructured amorphous state. The FA-HSA-nHCPT-NPs showed sustained-release characteristics for 120 hours in vitro, with a drug-loading content of 7.3% and an encapsulating efficiency of 79.1%.Conclusion: The FA-NPs were effective delivery systems for uptake by SGC7901 cells compared with folate-free NPs. These results suggest that a NP-coated method combined with a desolvation technique is effective for preparing NPs with drugs having poor solubility in water and most organic solvents, using albumin as the wall material. FA-HSA-NPs are a stable delivery system and have the potential for targeted delivery of anticancer drugs.Keywords: nanoparticle-coated, desolvation technique, 10-hydroxycamptothecin, human serum albumin, folate, targeted delivery&nbsp

Ultrafine Resveratrol Particles: Supercritical Antisolvent Preparation and Evaluation In Vitro and In Vivo

Ultrafine resveratrol (u-Res) particles were prepared through the SAS process. The orthogonal method was used to optimize the factors of the SAS process. The size of u-Res reached 0.68 μm under the optimum conditions. The characterization of the u-Res particles was tested by many analysis methods. The chemical structure of Res was unaffected by the SAS process. The degree of crystallinity of the u-Res particles greatly reduced. The purity of the u-Res particles increased from 98.5% to 99.2% during the SAS process. The u-Res particles had greater saturation solubility and dissolution rate than the raw-Res (r-Res) particles. The radical scavenging activity and bioavailability of the u-Res in vivo were 1.9 times of the r-Res