Wenjuan Cong

Investigation on the interactions between pirarubicin and phospholipids

Differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy and quantum calculation based on molecular modeling were applied to investigate the interaction between pirarubicin (THP), an anthracycline antibiotic frequently used in chemotherapy, and zwitterionic distearoylphosphatidylcholine (DSPC) or anionic distearoylphosphatidylglycerol (DSPG). DSC and FTIR studies suggested that DSPG bilayers were less perturbed by THP than those of DSPC, and this might be due to the strong interactions between NH(3)(+) of THP and the phosphate (PO(2)(-)) group in the polar head of DSPG, which limit the further access of THP into its bilayers. Quantum calculation results based on molecular modeling could further confirm the DSC and FTIR conclusions. Meanwhile, it could well translate the calorimetric and spectroscopic phenomena into the underlying physical knowledge. Interactions between THP and phospholipids can play a critical role in the liposomal drug delivery system, especially in the safety mechanism elucidation and rational formulation design.

Effect of metformin on the urinary metabolites of diet-induced-obese mice studied by ultra performance liquid chromatography coupled to time-of-flight mass spectrometry (UPLC-TOF/MS)

Obesity is becoming a health concern worldwide and metformin, a first line anti-diabetic drug, was associated with weight loss under different backgrounds. However, most researches focused on the anti-diabetic mechanism and less attention has been paid on the mechanism of weight loss of metformin. Therefore, we established a metabonomic method to evaluate metformin action in preventing obesity in a high fat diet-induced-obesity (DIO) mice model. 36 male C57BL/6 mice (8-week old) were randomly divided into control group (n=12, normal chow), model group (n=12, high fat chow) and metformin group (n=12, high fat chow and dosed with metformin) over 16 weeks. A urinary metabonomic study using UPLC-TOF/MS was performed in combination with multivariate statistical analysis. In addition, indices of body weight and food intake as well as fasting blood glucose, fed blood glucose, oral glucose tolerance test (OGTT) and plasma insulin were collected. Significant weight loss in metformin-treated mice was achieved and 21 potential biomarkers were identified. Decreased glucose, myristic acid, stearidonic acid, lysoPC (16:0), lysoPC (18:0), L-glutamic acid, L-methionine, L-threonine, L-phenylalanine, L-histidine, L-carnitine, L-malic acid and pantothenic acid in urine indicated that metformin may have exerted effects on energy metabolism. Further, based on the biomarkers, we cautiously propose that tricarboxylic acid cycle (TCA) may have been compromised by metformin and might contribute to the activation of adenosine monophosphate kinase (AMPK), then AMPK activation led to more β-oxidation of certain fatty acids and augmented lipolysis and thus induced weight loss. Related cellular and molecular studies are being considered to further investigate the underlying mechanism.

Metabonomic study on the cumulative cardiotoxicity of a pirarubicin liposome powder.

Pirarubicin (THP) is an anthracycline frequently used in the chemotherapy against acute leukemia, malignant lymphoma and several solid tumors. However, its clinical use is severely limited by the development of a progressive dose-dependent cardiomyopathy that results in irreversible congestive heart failure. To provide a strategy for constraining or minimizing the cumulative cardiotoxicity of THP, a pirarubicin liposome powder (L-THP) was appropriately prepared, and the cumulative cardiotoxicity of L-THP and free THP (F-THP) were investigated on Sprague-Dawley rats after 3 successive doses. Urinary samples for metabonomic study, serum samples for biochemical assay, and heart samples for histopathology test were collected. As a result, the metabonomics-based findings such as PLS-DA plotting showed minimal metabolic alterations in L-THP as compared to F-THP, and correlated with the changes of serum biochemical assay and cardiac histopathology as measurements of damage to heart tissue. Our results confirm that when encapsulated into liposomes, the cumulative cardiotoxicity of THP can be greatly ameliorated. Lipophilic aglycone metabolites of THP associated with redox cycling are cardiotoxic for the possibility of reactive oxygen species (ROS) formation. Also, metabonomic analysis shows that the successive doses of THP will lead to severe metabolic pathways disturbances in the cell energy production. Further, the preliminary efficacy study of L-THP on lung cancer was evaluated in the approach of in vitro cytotoxicity on A549 cells by high content screening (HCS) analysis, and L-THP was found to exhibit better therapeutic index against lung cancer than THP.

Microemulsion-based patch for transdermal delivery of huperzine A and ligustrazine phosphate in treatment of Alzheimer’s disease

The aim of the present study was to construct an innovative microemulsion-based patch for simultaneously transdermal delivery of huperzine A (HA) and ligustrazine phosphate (LP). The pseudo-ternary phase diagrams for microemulsion region were developed using oleic acid as oil, Cremophor RH40 as a surfactant, and ethanol as a cosurfactant. 1,8-cineole was added to the microemulsion as a penetration enhancer. The microemulsion-based transdermal patches were prepared by the lamination technique. The permeation studies were performed in vitro to evaluate the abilities of various microemulsions and transdermal patches to deliver HA and LP across the rat abdominal skin, showing that microemulsions increased the permeation rates of HA and LP compared with the control, and the penetration kinetics of the transdermal patch was in a zero order process. The results of the pharmacodynamic studies indicated that the transdermal combination therapy of HA and LP showed more benefits for fighting against amnesia in comparison with monotherapy. The anti-amnesic effects were also confirmed in scopolamine-induced amnesia rats after transdermal administration at multiple doses for 9 consecutive days, and the efficacy exhibited a dose-dependent manner. As a conclusion, the microemulsion-based transdermal patch containing HA and LP might provide a feasible strategy for the prevention of Alzheimer’s disease.

Characterization and pharmacokinetics of a novel pirarubicin liposome powder.

Background: Pirarubicin (THP), an analogue of doxorubicin, has exhibited promising activities against acute leukemia, malignant lymphoma, and several solid tumors. However, the cumulative cardiotoxicity limits its wide application in chemotherapy. Method: To provide an alternative strategy for reducing the cardiotoxicity, a novel THP liposome powder (L-THP), comprising distearoylphosphatidylcholine, distearoylphosphatidylglycerol, cholesterol, and lactose was appropriately prepared based on the physicochemical properties of THP. And L-THP was characterized and evaluated. Comparative studies on pharmacokinetic and biodistribution behaviors between L-THP and commercialized THP injection were performed in normal mice through intravenous administration. Results: When L-THP was reconstituted in a proper amount of normal saline for injection, it had a mean diameter of around 220.0 nm, a zeta potential of about −33.0 mV, and a high THP entrapment efficiency of more than 93.1%. Pharmacokinetics study showed that heart accumulation of THP could be reduced by 81.2% for L-THP. Conclusion: These results suggest that our L-THP might greatly reduce the cardiotoxicity, thus improving the therapeutic index of THP. Meanwhile, further preclinical studies are warranted to define the cardiotoxicity and the therapeutic efficacy of L-THP.

Polyphenols and health: Interactions between fibre, plant polyphenols and the gut microbiota

Abstract A high‐fibre diet and one rich in fruit and vegetables have long been associated with lower risk of chronic disease. There are several possible mechanisms underpinning these associations, but one likely important factor is the production of bioactive molecules from plant‐based foods by the bacteria in the colon. This links to our growing understanding of the role of the gut microbiome in promoting health. Polyphenolic‐rich plant foods have been associated with potential health effects in many studies, but the bioavailability of polyphenol compounds, as eaten, is often very low. Most of the ingested molecules enter the large intestine where they are catabolised to smaller phenolic acids that may be the key bioactive effectors. Dietary fibres, present in plant foods, are also fermented by the bacteria to short‐chain fatty acids, compounds associated with several beneficial effects on cell turnover, metabolism and eating behaviour. Polyphenols and fibre are often eaten together, but there is a lack of research investigating the interaction between these two groups of key substrates for the colonic bacteria. In a project funded by the Biotechnology and Biological Sciences Research Council Diet and Health Research Industry Club, we are investigating whether combining different fibres and polyphenol sources can enhance the production of bioactive phenolic acids to promote health. This could lead to improved dietary recommendations and to new products with enhanced potential health‐promoting actions.

A simple HPLC method for simultaneous analysis of 7 bioactive constituents for Liuwei Dihuang Pill and its application in quality consistency evaluation

A combinative method using HPLC fingerprinting and quantitative analysis was developed and validated for manufacturer-to-manufacturer quality consistency evaluation of Liuwei Dihuang pills (LDP). Seven bioactive constituents of LDP, including gallic acid, 5-hydroxymethyl furfural, morroniside, paeoniflorin, sweroside, loganin and paeonal, were selected as markers to evaluate the similarities of 20 samples from 16 manufacturers. The similarity values for the 20 LDP samples were all greater than 0.92, indicating that there is a general quality consistency for different manufacturers. Additionally, the 7 selected bioactive compounds were in accordance with the compatibility principle of “the monarch drug, the ministerial drug, the adjunctive drug and the messenger drug” of Traditional Chinese Medicine (TCM) prescription and the multi components quality evaluation requirements of TCM as well. The detection and quantification limits for these 7 bioactive components were all less than 0.11 μg mL−1 and 0.38 μg mL−1, respectively. The mean recovery for all the investigated constituents was acceptable with an accuracy of 98–102%. The intra- and inter-day precisions of this method were less than 4.73%, and stability and repeatability were less than 3.23%. This method is simple and reliable, and also shows that the combination of the chromatographic fingerprint and quantitative analysis offers an efficient solution to quality consistency evaluation of herbal preparations.

Identification of fukinolic acid from Cimicifuga heracleifolia and its derivatives as novel antiviral compounds against enterovirus A71 infection

Human enterovirus 71 (EV-A71) infections cause a wide array of diseases ranging from diarrhoea and rashes to hand-foot-and-mouth disease and, in rare cases, severe neurological disorders. No specific antiviral drug therapy is currently available. Extracts from 75 Chinese medicinal plants selected for antiviral activity based on the Chinese pharmacopeia and advice from traditional Chinese medicine clinicians were tested for activity against EV-A71. The aqueous extract of the rhizome of Cimicifuga heracleifolia (Sheng Ma) and Arnebia euchroma (Zi Cao) showed potent antiviral activity. The active fractions were isolated by bioassay-guided purification, and identified by a combination of high-resolution mass spectrometry and nuclear magnetic resonance. Fukinolic acid and cimicifugic acid A and J, were identified as active anti-EV-A71 compounds for C. heracleifolia, whereas for A. euchroma, two caffeic acid derivatives were tentatively deduced. Commercially available fukinolic acid analogues such as L-chicoric acid and D-chicoric also showed in vitro micromolar activity against EV-A71 lab-strain and clinical isolates.