Incomplete lineage sorting and gene flow within Allium (Amayllidaceae).

The phylogeny and systematics of the genus Allium have been studied with a variety of diverse data types, including an increasing amount of molecular data. However, strong phylogenetic discordance and high levels of uncertainty have prevented the identification of a consistent phylogeny. The difficulty in establishing phylogenetic consensus and evidence for genealogical discordance make Allium a compelling test case to assess the relative contribution of incomplete lineage sorting (ILS), gene flow and gene tree estimation error on phylogenetic reconstruction. In this study, we obtained 75 transcriptomes of 38 Allium species across 10 subgenera. Whole plastid genome, single copy genes and consensus CDS were generated to estimate phylogenetic trees both using coalescence and concatenation methods. Multiple approaches including coalescence simulation, quartet sampling, reticulate network inference, sequence simulation, theta of ILS and reticulation index were carried out across the CDS gene trees to investigate the degrees of ILS, gene flow and gene tree estimation error. Afterward, a regression analysis was used to test the relative contributions of each of these forms of uncertainty to the final phylogeny. Despite extensive topological discordance among gene trees, we found a fully supported species tree that agrees with the most of well-accepted relationships and establishes monophyly of the genus Allium. We presented clear evidence for substantial ILS across the phylogeny of Allium. Further, we identified two ancient hybridization events for the formation of the second evolutionary line and subg. Butomissa as well as several introgression events between recently diverged species. Our regression analysis revealed that gene tree inference error and gene flow were the two most dominant factors explaining for the overall gene tree variation, with the difficulty in disentangling the effects of ILS and gene tree estimation error due to a positive correlation between them. Based on our efforts to mitigate the methodological errors in reconstructing trees, we believed ILS and gene flow are two principal reasons for the oft-reported phylogenetic heterogeneity of Allium. This study presents a strongly-supported and well-resolved phylogenetic backbone for the sampled Allium species, and exemplifies how to untangle heterogeneity in phylogenetic signal and reconstruct the true evolutionary history of the target taxa.

Phylotranscriptomic discordance is best explained by incomplete lineage sorting within Allium subgenus Cyathophora and thus hemiplasy accounts for interspecific trait transition.

The transition of traits between genetically related lineages is a fascinating topic that provides clues to understanding the drivers of speciation and diversification. Much can be learned about this process from phylogeny-based trait evolution. However, such inference is often plagued by genome-wide gene-tree discordance (GTD), mostly due to incomplete lineage sorting (ILS) and/or introgressive hybridization, especially when the genes underlying the traits appear discordant. Here, by collecting transcriptomes, whole chloroplast genomes (cpDNA), and population genetic datasets, we used the coalescent model to turn GTD into a source of information for ILS and employed hemiplasy to explain specific cases of apparent "phylogenetic discordance" between different morphological traits and probable species phylogeny in the Allium subg. Cyathophora. Both concatenation and coalescence methods consistently showed the same phylogenetic topology for species tree inference based on single-copy genes (SCGs), as supported by the KS distribution. However, GTD was high across the genomes of subg. Cyathophora: ∼27%-38.9% of the SCG trees were in conflict with the species tree. Plasmid and nuclear incongruence was also present. Our coalescent simulations indicated that such GTD was mainly a product of ILS. Our hemiplasy risk factor calculations supported that random fixation of ancient polymorphisms in different populations during successive speciation events along the subg. Cyathophora phylogeny may have caused the character transition, as well as the anomalous cpDNA tree. Our study exemplifies how phylogenetic noise can be transformed into evolutionary information for understanding character state transitions along species phylogenies.

Mucus-penetrating dendritic mesoporous silica nanoparticle loading drug nanocrystal clusters to enhance permeation and intestinal absorption.

Multiple gastrointestinal barriers (mucus clearance and epithelium barrier) are the main challenges in the oral administration of nanocarriers. To achieve efficient mucus penetration and epithelial absorption, a novel strategy based on mesoporous silica nanoparticles with dendritic superstructure, hydrophilicity, and nearly neutral-charged modification was designed. The mPEG covalently grafted dendritic mesoporous silica nanoparticles (mPEG-DMSNs) had a particle size of about 200 nm and a loading capacity of up to 50% andrographolide (AG) as a nanocrystal cluster in the mesoporous structure. This dual strategy of combining with the surface topography structure and hydrophilic modification maintained a high mucus permeability and showed an increase in cell absorption. The mPEG-DMSN formulation also exhibited effective transepithelial transport and intestinal tract distribution. The pharmacokinetics study demonstrated that compared with other AG formulations, the andrographolide nanocrystals-loaded mPEG-DMSN (AG@mPEG-DMSN) exhibited much higher bioavailability. Also, AG@mPEG-DMSN could significantly improve the in vitro and in vivo anti-inflammatory efficacy of AG. In summary, mPEG-DMSN offers an interesting strategy to overcome the mucus clearance and epithelium barriers of the gastrointestinal tract.

Roles of maltodextrin and inulin as matrix formers on particle performance of inhalable drug nanocrystal-embedded microparticles.

The objective of this study was to investigate the influence of inulin (IL) and maltodextrin (MD) as matrix formers on the physical properties of drug nanocrystal-embedded microparticles (NEM) during spray-drying and storage. The redispersibility, aerodynamic performance and phase behaviour of NEM/MD and NEM/IL stored at different water activity (aw) values were evaluated. NEM with 2 g/g (relative to the weight of drug) of IL and MD exhibited the excellent performance after spray-drying. The water activity significantly influenced the redispersibility and aerodynamic performance of NEM/MD and NEM/IL. The NEM/MD presented a higher Tg at all aw values than did NEM/IL. The moisture-induced collapse of the amorphous glassy matrix of IL and MD could be responsible for the poor redispersibility and aerodynamic performance of NEM/IL and NEM/MD, respectively. The NEM/MD exhibited better aerodynamic performance at high aw (0.528) than did NEM/IL. Therefore, MD could be an excellent matrix former for inhalable NEM.

The Shielding Effect of Microcrystalline Cellulose on Drug Nanocrystal Particles During Compaction.

To elucidate the compaction behavior of drug nanocrystals based composite particles (NP) during tabletting, the compaction behavior of binary mixtures of microcrystalline cellulose (MCC) and nanocrystal particles was investigated. The force-displacement correlation of mixtures containing different ratios of MCC and micronized NP was studied in order to explain the nature on densification of NP during compaction, and the resultant compaction curves (pressure as function of in-die thickness) were systemically analyzed to elucidate the most important mechanisms of volume reduction for MCC and NP in different stages of compaction. The results showed that the close compaction of individual MCC was relatively quickly achieved, and the drug NP particles could slide into the intrinsic void spaces between MCC microparticles. This was the reason that the particles size of MCC used in this study was significantly larger compared to that of drug NP. This interstitial rearrangement phenomenon of NP occurred on a typical time scale and was strongly dependent on the speed of compaction. This migration behavior occurred on void spaces of MCC inter-particles might be identified as an elastic stress relaxation mechanism and be helpful to dissolution of NP. MCC can effectively shield the NP from significant aggregation during compaction process.

Solidification drug nanosuspensions into nanocrystals by freeze-drying: a case study with ursodeoxycholic acid.

To elucidate the effect of solidification processes on the redispersibility of drug nanocrystals (NC) during freeze-drying, ursodeoxycholic acid (UDCA) nanosuspensions were transformed into UDCA-NC via different solidification process included freezing and lyophilization. The effect of different concentrations of stabilizers and cryoprotectants on redispersibility of UDCA-NC was investigated, respectively. The results showed that the redispersibility of UDCA-NC was RDI-20 °C < RDI-80 °C < RDI-196 °C during freezing, which indicated the redispersibility of UDCA-NC at the conventional temperature was better more than those at moderate and rigorous condition. Compared to the drying strengthen, the employed amount and type of stabilizers more dramatically affected the redispersibility of UDCA-NC during lyophilization. The hydroxypropylmethylcellulose and PVPK30 were effective to protect UDCA-NC from damage during lyophilization, which could homogeneously adsorb into the surface of NC to prevent from agglomerates. The sucrose and glucose achieved excellent performance that protected UDCA-NC from crystal growth during lyophilization, respectively. It was concluded that UDCA-NC was subjected to agglomeration during solidification transformation, and the degree of agglomeration suffered varied with the type and the amounts of stabilizers used, as well as different solidification conditions. The PVPK30-sucrose system was more effective to protect UDCA-NC from the damage during solidification process.

Combination of submicroemulsion and phospholipid complex for novel delivery of ursodeoxycholic acid.

The objective of this study was to prepare and characterize ursodeoxycholic acid submicron emulsion (UA-SME) loaded with ursodeoxycholic acid phytosomes (UA-PS) and optimize the process variables. A screening experiment with response surface methodology with Box-Behnken design (BBD) was used to optimize the process parameters of UA-SME. The blood concentrations of UA after oral administration of UA-SME and UA coarse drug were assayed. The optimum process conditions were finally obtained by using a desirability function. It was found that stirring velocity, homogenization pressure and homogenization cycles were the most important variables that affected the particles size, polydispersity index and entrapment efficiency of UA-SME. Results showed that the optimum stirring velocity, homogenization pressure and cycles were 16 000 rpm, 60 MPa and 10 cycles, respectively. The mean diameter, polydispersity index and entrapment efficiency of UA-SME were 251.9 nm, 0.241 and 74.36%, respectively. Pharmacokinetic parameters of UA and UA-SME in rats were Tmax 2.215 and 1.489 h, Cmax 0.0364 and 0.1562 µg/mL, AUC0-∞ 3.682 and 13.756 µg h/mL, respectively. The bioavailability of UA in rats was significantly different (p < 0.05) after oral administration of UA-SME compared to those of UA coarse drug. This was due to improvement of the hydrophilicity and lipophilic property of UA-SME.

The study on the entrapment efficiency and in vitro release of puerarin submicron emulsion.

The entrapment efficiency (EE) and release in vitro are very important physicochemical characteristics of puerarin submicron emulsion (SME). In this paper, the performance of ultrafiltration (UF), ultracentrifugation (UC), and microdialysis (MD) for determining the EE of SME were evaluated, respectively. The release study in vitro of puerarin from SME was studied by using MD and pressure UF technology. The EE of SME was 86.5%, 72.8%, and 55.8% as determined by MD, UF, and UC, respectively. MD was not suitable for EE measurements of puerarin submicron oil droplet, which could only determine the total EE of submicron oil droplet and liposomes micelles, but it could be applied to determine the amount of free drug in SMEs. Although UC was the fastest and simplest to use, its results were the least reliable. UF was still the relatively accurate method for EE determination of puerarin SME. The release of puerarin SME could be evaluated by using MD and pressure UF, but MD seemed to be more suitable for the release study of puerarin emulsion. The drug release from puerarin SME at three drug concentrations was initially rapid, but reached a plateau value within 30 min. Drug release of puerarin from the SME occurred via burst release.

[Preparation and characterization of chlorogenic acid complete antigen].

OBJECTIVE: Characterizate the complete antigen of the chlorogenic acid. METHODS: The chlorogenic acid was coupled to BSA as an immunogen and to OVA as a coating antigen using the coupling agent EDC. HCL The immunogen and coating antigen were characterizated by the ultraviolet scanner. The complete antigen was used to immnune the cony pig, detect the antiserum by ELISA. RESULTS: The coupling ratio of the complete antigens was 20. The quinza pig antiserums in 1:128 in OD values were more higher than 2 times of the negative comparison. CONCLUSION: The complete antigen was preparated successfully.