Pharmacokinetics, Efficacy, and Safety Evaluation of Docetaxel/Hydroxypropyl-Sulfobutyl-β-Cyclodextrin Inclusion Complex

Hydroxypropyl-sulfobutyl-β-cyclodextrin (HP-SBE-β-CD) inclusion complex was developed and used as a drug delivery system for DTX (DTX/HP-SBE-β-CD). The objective of the present study was to evaluate and compare the biological properties of DTX/HP-SBE-Β-CD with Taxotere®. The pharmacokinetics, biodistribution, antitumor efficacy in vivo and in vitro, and safety evaluation of DTX/HP-SBE-β-CD were studied. The most significant finding was that it was possible to prepare a Polysorbate-80-free inclusion complex for DTX. Studies based on pharmacokinetics, biodistribution, and antitumor efficacy indicated that DTX/HP-SBE-β-CD had similar pharmacokinetic properties and antitumor efficacy both in vitro and in vivo as Taxotere®. Fortunately, this new drug delivery system attenuated the side effects when used in vivo. As a consequence, DTX/HP-SBE-β-CD may be a promising alternative to Taxotere® for cancer chemotherapy treatment with reduced side effects. The therapeutic potential against a variety of human tumors and low toxicity demonstrated in a stringent study clearly warrant clinical investigation of DTX/HP-SBE-β-CD for possible use against human tumors.Key words: antitumor efficacy, biodistribution, DTX/HP-SBE-β-CD, pharmacokinetics, safety evaluation     

Investigation of aggregation and assembly of alkali lignin using iodine as a probe

Molecular iodine has been introduced into the alkali lignin (AL) solutions to adjust the π-π aggregation, and the effect of lignin-iodine complexes on the aggregation and assembly characteristics of AL have been investigated by using fluorescence, UV-vis spectroscopy, light scattering, and viscometric techniques. Results show that AL form π-π aggregates (i.e., J-aggregates) in THF driven by the π-π interaction of the aromatic groups in AL, and the π-π aggregates undergo disaggregation in THF-I(2) media because of the formation of lignin-iodine charge-transfer complexes. By using iodine as a probe to investigate the aggregation behaviors and assembly characteristics, it is estimated that about 18 mol % aromatic groups of AL form π-π aggregates in AL molecular aggregates. When molecular iodine is introduced into the AL solutions, lignin-iodine complexes occur with charge-transfer transition from HOMO of the aromatic groups of AL to the LUMO of iodine. The formation of lignin-iodine complexes reduces the affinity of the aromatic groups approaching each other due to the electrostatic repulsion and then eliminates the π-π interaction of the aromatic groups. The disaggregation of the π-π aggregates brings a dissociation behavior of AL chains and a pronounced molecular expansion. This dissociation behavior and molecular expansion of AL in the dipping solutions induce a decrease in the adsorbed amount and an increase in the adsorption rate, when AL is transferred from the dipping solution to the self-assembled adsorbed films. Consequently, the adsorption behavior of AL can be controlled by adjusting the π-π aggregation. Above observations give insight into the occurrence of J-aggregation of the aromatic groups in the AL molecular aggregates and the disaggregation mechanism of AL aggregates induced by the lignin-iodine complexes for the first time. The understanding can provide an academic instruction in the efficient utilization of the alkali lignin from the waste liquor and also leads to further development in expanding functionalities of the aromatic compounds through manipulation of the π-π aggregation.     

DeltAMT: a statistical algorithm for fast detection of protein modifications from LC-MS/MS data

Identification of proteins and their modifications via liquid chromatography-tandem mass spectrometry is an important task for the field of proteomics. However, because of the complexity of tandem mass spectra, the majority of the spectra cannot be identified. The presence of unanticipated protein modifications is among the major reasons for the low spectral identification rate. The conventional database search approach to protein identification has inherent difficulties in comprehensive detection of protein modifications. In recent years, increasing efforts have been devoted to developing unrestrictive approaches to modification identification, but they often suffer from their lack of speed. This paper presents a statistical algorithm named DeltAMT (Delta Accurate Mass and Time) for fast detection of abundant protein modifications from tandem mass spectra with high-accuracy precursor masses. The algorithm is based on the fact that the modified and unmodified versions of a peptide are usually present simultaneously in a sample and their spectra are correlated with each other in precursor masses and retention times. By representing each pair of spectra as a delta mass and time vector, bivariate Gaussian mixture models are used to detect modification-related spectral pairs. Unlike previous approaches to unrestrictive modification identification that mainly rely upon the fragment information and the mass dimension in liquid chromatography-tandem mass spectrometry, the proposed algorithm makes the most of precursor information. Thus, it is highly efficient while being accurate and sensitive. On two published data sets, the algorithm effectively detected various modifications and other interesting events, yielding deep insights into the data. Based on these discoveries, the spectral identification rates were significantly increased and many modified peptides were identified.     

MtDNA haplogroups M7 and B in southwestern Han Chinese at risk for acute mountain sickness

We conducted a case-control study to investigate the association of mitochondrial DNA (mtDNA) haplogroups with acute mountain sickness (AMS) in Han Chinese from southwestern (SW) China. Pearson's chi-square test or Fisher's exact test revealed significant reduction of mtDNA haplogroups D and M9, while a significant increase of haplogroup M7 in AMS subjects compared with non-AMS subjects. The multivariate logistic regression analysis after adjustment for body mass index (BMI), a risk factor of AMS in the present study, showed that both D and M9 were associated with significantly decreased risk of AMS, while M7 was associated with a significantly increased risk of AMS (OR=0.605, p=0.000; OR=0.037, p=0.001, and OR=2.419, p=0.001, respectively). In addition, further analysis stratified by the AMS severities indicated that haplogroup B was correlated with a 2.41-folds increased risk of developing severe AMS (95%C.I=1.288-4.514, p=0.006). Our findings provide evidence that, in SW Han Chinese, mtDNA haplogroups D and M9 are related to individual tolerance to AMS, while haplogroups M7 and B are risk factors for AMS.     

The altered activity of complex III may contribute to the high penetrance of Leber's hereditary optic neuropathy in a Chinese family carrying the ND4 G11778A mutation

The ND4 G11778A mutation is the most common mitochondrial DNA mutation leading to Leber's hereditary optic neuropathy (LHON). Despite considerable clinical evidences, the modifier role of nuclear background and mitochondrial haplotypes in phenotypic manifestation of LHON remains poorly understood. We investigated the effect of these modifiers on bioenergetics in lymphoblastoid cell lines derived from five affected subjects of one Chinese family carrying the G11778A mutation and five Chinese controls. Significant reductions in the activities of complexes I and III were observed in mutant cell lines from the Chinese family, whereas the mutant cell lines from other families carrying the same mutation exhibited only reduced activity of complex I. The reduced activities of complexes I and III caused remarkably higher reductions of ATP synthesis in mutant cell lines from the Chinese family than those from other families. The deficient respiration increased generation of reactive oxygen species. The defect in complex III activity, likely resulting from the mitochondrial haplotype or nuclear gene alteration, worsens mitochondrial dysfunction caused by the G11778A mutation, thereby causing extremely high penetrance and expressivity of optic neuropathy in this Chinese family. Our data provide the first experimental evidence that altered activity of complex III modulates the phenotypic manifestation of LHON-associated G11778A mutation. Thus, our findings may provide new insights into the pathophysiology of LHON.     

Association of genetic variants in complement factor H and factor H-related genes with systemic lupus erythematosus susceptibility

Systemic lupus erythematosus (SLE), a complex polygenic autoimmune disease, is associated with increased complement activation. Variants of genes encoding complement regulator factor H (CFH) and five CFH-related proteins (CFHR1-CFHR5) within the chromosome 1q32 locus linked to SLE, have been associated with multiple human diseases and may contribute to dysregulated complement activation predisposing to SLE. We assessed 60 SNPs covering the CFH-CFHRs region for association with SLE in 15,864 case-control subjects derived from four ethnic groups. Significant allelic associations with SLE were detected in European Americans (EA) and African Americans (AA), which could be attributed to an intronic CFH SNP (rs6677604, in intron 11, P _meta = 6.6×10⁻⁸, OR = 1.18) and an intergenic SNP between CFHR1 and CFHR4 (rs16840639, P _meta = 2.9×10⁻⁷, OR = 1.17) rather than to previously identified disease-associated CFH exonic SNPs, including I62V, Y402H, A474A, and D936E. In addition, allelic association of rs6677604 with SLE was subsequently confirmed in Asians (AS). Haplotype analysis revealed that the underlying causal variant, tagged by rs6677604 and rs16840639, was localized to a ∼146 kb block extending from intron 9 of CFH to downstream of CFHR1. Within this block, the deletion of CFHR3 and CFHR1 (CFHR3-1Δ), a likely causal variant measured using multiplex ligation-dependent probe amplification, was tagged by rs6677604 in EA and AS and rs16840639 in AA, respectively. Deduced from genotypic associations of tag SNPs in EA, AA, and AS, homozygous deletion of CFHR3-1Δ (P _meta = 3.2×10⁻⁷, OR = 1.47) conferred a higher risk of SLE than heterozygous deletion (P _meta = 3.5×10⁻⁴, OR = 1.14). These results suggested that the CFHR3-1Δ deletion within the SLE-associated block, but not the previously described exonic SNPs of CFH, might contribute to the development of SLE in EA, AA, and AS, providing new insights into the role of complement regulators in the pathogenesis of SLE.     

Identification of hyperoside metabolites in rat using ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry

In this paper, ultra performance liquid chromatography (UPLC)/quadrupole-time-of-flight mass spectrometry (QTOF) with automated data analysis software (Metabolynx?) were applied for fast analysis of hyperoside metabolites in rat after intravenous administration. MS(E) was used for simultaneous acquisition of precursor ion information and fragment ion data at high and low collision energy in one analytical run, which facilitated the fast structural characterization of 12 metabolites in rat plasma, urine and bile. The results indicated that methylation, sulfation and glucuronidation were the major metabolic pathways of hyperoside in vivo, and among them, 3'-O-methyl-hyperoside was confirmed by matching its fragmentation patterns with standard compound. The present study provided important information about the metabolism of hyperoside which will be helpful for fully understanding the mechanism of this compound's action. Furthermore, this work demonstrated the potential of the UPLC/QTOFMS approach using Metabolynx for fast and automated identification of metabolites of natural product.     

Screening for in vitro metabolites of Abelmoschus manihot extract in intestinal bacteria by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

Abelmoschus manihot has drawn much attention recently due to its potential beneficial health effects after oral administration. However, the metabolic fate of A. manihot in intestinal flora is not well understood. In this paper, we describe a strategy using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF MS) with automated data analysis software (MetaboLynx?) for fast analysis of the metabolic profile of flavonoids from A. manihot in intestinal flora. The human and rat incubated samples collected 72 h in the anaerobic incubator were analyzed by UPLC-Q-TOF MS within 10 min. A total of 14 metabolites were identified in human and rat incubated solution compared with blank samples. The results indicated that hydrolysis, hydroxylation and acetylation were the major metabolic pathways of flavonoids in A. manihot extract in vitro. MS(E) was used for simultaneous acquisition of precursor ion information and fragment ion data at high and low collision energy in one analytical run, which facilitated the fast structural characterization of metabolites. This work demonstrated the potential of the UPLC-Q-TOF MS approach using Metabolynx for fast and automated identification of metabolites of natural product in intestinal flora.