Jian-Guo Jiang

Advancing oleaginous microorganisms to produce lipid via metabolic engineering technology

With the depletion of global petroleum and its increasing price, biodiesel has been becoming one of the most promising biofuels for global fuels market. Researchers exploit oleaginous microorganisms for biodiesel production due to their short life cycle, less labor required, less affection by venue, and easier to scale up. Many oleaginous microorganisms can accumulate lipids, especially triacylglycerols (TAGs), which are the main materials for biodiesel production. This review is covering the related researches on different oleaginous microorganisms, such as yeast, mold, bacteria and microalgae, which might become the potential oil feedstocks for biodiesel production in the future, showing that biodiesel from oleaginous microorganisms has a great prospect in the development of biomass energy. Microbial oils biosynthesis process includes fatty acid synthesis approach and TAG synthesis approach. In addition, the strategies to increase lipids accumulation via metabolic engineering technology, involving the enhancement of fatty acid synthesis approach, the enhancement of TAG synthesis approach, the regulation of related TAG biosynthesis bypass approaches, the blocking of competing pathways and the multi-gene approach, are discussed in detail. It is suggested that DGAT and ME are the most promising targets for gene transformation, and reducing PEPC activity is observed to be beneficial for lipid production.

Application of metabonomic analytical techniques in the modernization and toxicology research of traditional Chinese medicine

In the recent years, a wide range of metabonomic analytical techniques are widely used in the modern research of traditional Chinese medicine (TCM). At the same time, the international community has attached increasing importance to TCM toxicity problems. Thus, many studies have been implemented to investigate the toxicity mechanisms of TCM. Among these studies, many metabonomic‐based methods have been implemented to facilitate TCM toxicity investigation. At present, the most prevailing methods for TCM toxicity research are mainly single analysis techniques using only one analytical means. These techniques include nuclear magnetic resonance (NMR), gas chromatography‐mass spectrometry (GC‐MS), and liquid chromatography‐mass spectrometry (LC‐MS), etc.; with these techniques, some favourable outcomes have been gained in the toxic reaction studies of TCM, such as the action target organs assay, the establishment of action pattern, the elucidation of action mechanism and the exploration of action material foundation. However, every analytical technique has its advantages and drawbacks, no existing analytical technique can be versatile. Multi‐analysed techniques can partially overcome the shortcomings of single‐analysed techniques. Combination of GC‐MS and LC‐MS metabolic profiling approaches has unravelled the pathological outcomes of aristolochic acid‐induced nephrotoxicity, which can not be achieved by single‐analysed techniques. It is believed that with the further development of metabonomic analytical techniques, especially multi‐analysed techniques, metabonomics will greatly promote TCM toxicity research and be beneficial to the modernization of TCM in terms of extending the application of modern means in the TCM safety assessment, assisting the formulation of TCM safety norms and establishing the international standards indicators.

Optimum extraction Process of polyphenols from the bark of Phyllanthus emblica L. based on the response surface methodology

Phyllanthus emblica L. is an economic plant used in Chinese medicine for the treatment of various diseases. The bark of P. emblica is rich in polyphenols and its extractions have shown strong antioxidative and radical scavenging activity. Response surface methodology (RSM) was used to assess the optimal extraction of polyphenols from P. emblica bark. Various extraction parameters including ethanol concentration, extraction time, temperature, solid-liquid ratio, and extraction times were chosen to identify their effects on polyphenols extraction. Among these parameters, extraction times and solvent concentration were found to have significant effect on polyphenols extraction. RSM was applied to obtain the optimal combination of solvent concentration, extraction time, temperature, and extraction time for maximum rate of extraction. The most suitable condition for the extraction of polyphenols was at ethanol concentration 75%, extraction time 25 min, extraction temperature 45 degrees C, and extraction times 3. At these optimal extraction parameters, the maximum extraction of polyphenols obtained experimentally was found to be very close to its predicted value. The extraction rate of polyphenols was 19.78% at the optimum conditions. The mathematical model developed was found to fit with the experimental data of polyphenols extraction.

Application of targeted drug delivery system in Chinese medicine

Targeted drug delivery system of traditional Chinese medicine (TCM) refers to those using different carriers to make the effective parts or monomer extracted from TCM or natural medicine into agents which can directly concentrate on the target site. This system is an ideal delivery approach and has became a hot spot in the field of TCM pharmaceutical research since it can improve the pharmacological effects and reduce the adverse reactions. This paper reviews literatures on TCM targeted agents which were published in the past 10 years. In accordance with the different carriers, four types of agents, liposome, nanoparticle, microsphere, and emulsion are analyzed. Liposomes were studied most profoundly and a variety of new types of liposomes was developed on the basis of the traditional liposomes. Using natural or synthetic polymer materials to carry drugs, nanoparticles and microspheres can promote the drug through the blood-brain barrier and enhance its bioavailability. Emulsion has lymphatic affinity and the drug is coated in the internal phase, which can protect the drugs from hydrolysis. All these delivery agents are proved to be effective ways to improve the clinical efficacy of drugs, and each is discussed in detail with examples. At present, TCM targeted agents are still in the exploratory stage and many problems need to be solved. Especially, it is a huge challenge to research the targeted delivery systems for the effective parts of Chinese medicines and compound prescriptions, and the paper gives a particular discussion on this point. In the future, more attention should be paid to the research on the particle agents of TCM effective parts, and the development of new carrier materials in order to enhance the overall quality of TCM targeted agents.

Hydroxytyrosol and Its Potential Therapeutic Effects

As olive oil is the main source of calories in the Mediterranean diet, a large number of studies have been carried out to characterize its role in various diseases and exploitation for the prevention and treatment of hypertension, carcinogenesis, diabetes, atherosclerosis, and other diseases. As one of the major polyphenols present in virgin olive oil, hydroxytyrosol shows a variety of pharmacological activities such as antioxidant properties, anticancer, anti-inflammatory, and neuroprotective activities, and beneficial effects on the cardiovascular system, which show its potentiality for the development of dietary supplements. In the future, more attention should be paid to its action mechanism in vivo and synergistic effect. Further research will be performed to provide the theoretical basis for hydroxytyrosol and its derivatives use as health supplements.

Immunoregulatory actions of polysaccharides from Chinese herbal medicine

Importance of the field: Polysaccharides, one of main classes of bioactive substances from Chinese herbal medicine (CHM), have been indicated to have wide pharmacological activities, especially broad immunomodulatory and antitumour effects. However, their immunoregulatory mechanisms are still not fully understood yet. Areas covered in this review: Polysaccharides from CHM (CHMPS) are reviewed with focus on their immunoregulatory function, describing their immunoregulatory actions on immune organs, immune cells and immune molecules, and discussing their effects on cell surface receptors and cell signaling pathways. What the reader will gain: A better understanding of the immunoregulatory effects of CHMPS and their structure–function relationship. Take home message: CHMPS can active or regulate the immune system including innate and adaptive responses, and have profound effects on different diseases. Through examining the molecular mechanisms of the immunomodulating effects of CHMPS, it can be shown that CHMPS have the potential to be an adjuvant in cancer therapies.

Preparation of a tea polyphenol nanoliposome system and its physicochemical properties.

Tea polyphenol is rich in green tea with diverse biological activities. However, its application in the food industry is limited due to its instability toward oxygen and light. In this study, the preparation of tea polyphenol liposome by the thin film ultrasonic dispersion method was performed in order to enhance the bioavailability of tea polyphenol. The process conditions were optimized using response surface analysis, and the optimal parameters were as follows: ratio of tea polyphenol to lecithin, 0.125:1; ratio of lecithin to cholesterol, 4:1; phosphate buffered saline (PBS) pH, 6.62; ultrasonic time, 3.5 min. The theoretical and practical entrapment efficiency were 60.36% and 60.09 ± 0.69%, respectively. Furthermore, physicochemical properties including size distribution, zeta potential, permeability, infrared spectrum and in vitro release of liposomal formulations were determined. The mean size of tea polyphenol liposome was 160.4 nm, and the ζ-potential value was -67.2. The tea polyphenol liposome was formed by physical interaction, and the in vitro release process followed a first-order equation. The results indicated that the prepared tea polyphenol liposome was stable and suitable for more widespread application.

Response surface optimization of ultrasound‐assisted flavonoids extraction from the flower of Citrus aurantium L. var. amara Engl

Citrus aurantium L. var. amara Engl is a member of genus Citrus (Rutaceae) and has been used in Chinese medicine with the effectiveness of digestant and expectorant. Ultrasonic-assisted extraction process for maximum flavonoids from the flower of Citrus aurantium L. var. amara Engl was investigated by response surface methodology. Through single factor experiment, ranges of the main variables (including ethanol concentration, solid/liquid ratio, extraction time and temperature) affecting the extraction yield of flavonoids were confirmed. Box-Behnken central composite design consisting of 24 experimental runs and 5 replicates at zero point was then applied and a regress model was obtained to predict the optimal extraction yield. The ANOVA indicated that the regression equation fits very well with the actual situation, reflecting the relationship between the extraction yield of flavonoids and extraction conditions. The optimal conditions were as follows: extraction temperature 72.11 degrees C, time 51.89 min, ethanol concentration 51.19% and liquid/solid ratio of 40:10. Under the optimal conditions, the maximum response value of yield (1.88%) was consistent with the experimental value (1.87%), indicating the feasibility and validation of response surface methodology in optimizing the extraction of flavonoids from the flower of Citrus aurantium L. var. amara Engl.

Eclipta prostrata L. phytochemicals: isolation, structure elucidation, and their antitumor activity.

Eclipta prostrata L., (Asteraceae), is used in China for both food and medicine purposes. This research is concerned with the isolation and purification of phytochemical constituents from the aerial parts of E. prostrata, using gradient solvent fractionation, macroporous resin, silica gel, Sephadex LH-20 and ODS columns, and TLC analyses. Four fractions (water, 30% ethanol, 60% ethanol and 90% ethanol) were obtained. Four compounds, wedelolactone (I), eclalbasaponin I (II), luteolin (III) and luteolin-7-O-glucoside (IV) were purified and their structures were identified by the interpretation of spectroscopic analyses including MS, (1)H and (13)C NMR. Antitumor activities of extracts (total fraction), four fractions and the isolated compounds were assessed using hepatoma cell smmc-7721 as an in vitro assay system. The 30% ethanol fraction and eclalbasaponin I dose-dependently inhibited the proliferation of hepatoma cell smmc-7721 with IC(50) values of 74.2399 and 111.1703 μg/ml, respectively, more strongly compared with 5-fluorouracil positive control group with the IC(50) value of 195.3131 μg/ml. Antitumor activities of other fractions and compounds were lower than positive control. These results suggested that some specific compounds or extracts from E. prostrata are potential sources of natural anti-tumor materials and worthy of further study.

Analysis of the adverse reactions induced by natural product-derived drugs.

Compared with the therapeutic effects of established medicinal drugs, it is often considered that natural product‐derived drugs are of a more benign nature in side‐effects, which has made natural medicines become a popular form of therapy. Traditional Chinese medicine (TCM) is generally considered as being natural and harmless. TCM has been paid much more attention than before and widely used for the treatment nowadays. However, with the increasing cases of adverse drug reactions (ADRs), the ADRs induced by TCM are becoming more widely recognized. Some ADRs are sometimes even life‐threatening. This article reviews literatures on ADRs induced by TCM which was published in the past 10 years. A total of 3122 cases including complete data are selected for the present analysis. From the data of the 3122 cases, statistics is carried out to the distribution of administration routes and time of the occurrence of ADRs, the prognosis of ADRs, sex and age factors, types and clinical symptoms of ADRs, and drugs involved in ADRs. In addition, occurrence and influencing factors of TCM‐induced diseases are also analysed, which includes spices confusion, processing drugs improperly, toxic components, long‐term medication, improper concerted application, interaction of TCM and Western medicine. It is concluded that the efficacy and toxicity of TCM, often using the compound prescription involving various plants and animals, resulted from a variety of chemical constituents, which lead to a comprehensive response in the human body. The ‘toxicity’ of TCM should be correctly recognized and reasonably utilized.