Fanxin Meng

Investigation on the immunomodulatory activities of Sarcodon imbricatus extracts in a cyclophosphamide (CTX)-induced immunosuppressanted mouse model

Aims: Sarcodon imbricatus, an edible fungus, is widely used in Asian medicine because of its significant pharmacological activities. In the present study, we investigated the immunomodulatory effects of polysaccharide-enriched S. imbricatus extracts (SP) in cyclophosphamide (CTX)-induced immunosuppressed mice. Results: Astragalus polysaccharide (AP) was used as a positive control. Compared with CTX-induced immunosuppressed mice, thirty-day SP treatment strongly enhanced the organ indexes of spleen and thymus and suppressed hind paw swelling. Both AP and SP increased the serum levels of immunoglobulin (IgA, IgG, and IgM), and suppressed the overproduction of interleukin-2 (IL-2). Moreover, SP reduced methane dicarboxylic aldehyde levels, and increased the total antioxidant capacity, superoxide dismutase, and glutathione peroxidase in both serum and liver tissues of CTX-induced immunosuppressed mice. Conclusion: S. imbricatus extracts significantly improved immune function in CTX-induced immunosuppressed mice via modulation of oxidative systems.

37 Optimization of supercritical carbon dioxide extraction conditions of Semen cassiae volatile oil using response surface methodology and antimicrobial activity detection

Objectives The objective of this project was to study the process of extracting Semen cassia. The volatile components of Semen cassia were analyzed using supercritical CO2 extraction (SCDE). Based on a single factor experiment, response surface methodology was used to investigate the extraction of volatile oil. According to the fitted curves under different conditions, the effects of pressure, temperature and time on extraction and interactions between various factors were determined. Antimicrobial activity was also measured. Methods A Box-Behnken central composite design method was used based on single factor experiments. The influence of extraction temperature, extraction time and extraction pressure on extraction yield was studied. The response surface method was employed to analyze the results of experiments. The disk diffusion method was used to detect the antimicrobial activity of Semen cassiae volatile oil. Results The results indicated that the optimum extraction conditions were as follows: extraction temperature 51°C, extraction time 3.22 hours and extraction pressure 25 MPa. Extraction yield reached 2.34%. The volatile oil of Semen cassiae extracted from the tested strains showed antimicrobial activity, with MIC values ranging from 2.5 to 5 mg/mL.Abstract 37 Figure 1 Responsive surfaces and contours Conclusions SCDE is a stable and efficient process. Semen cassiae volatile oil had antimicrobial activity which could provide a theoretical basis for application of this oil.

16 Discrimination of Brazilian green propolis and Chinese propolis based on high-performance liquid chromatographic fingerprints and multivariate statistical analysis

Objectives The determination of chemical components is usually used in the quality control of propolis. However, chemical components from different types of propolis are similar. The objective of this investigation was to establish a method based on a specific chemical fingerprint profile and a multivariate mixed model statistical analysis which could easily distinguish propolis of different origins and promote the quality control of propolis. Methods A novel approach using high performance liquid chromatography (HPLC) coupled with multivariate statistical analysis was established for profiling and distinguishing Chinese and Brazilian green propolis. A batch of 22 propolis samples was analyzed, and the datasets on retention time, peak area and sample codes were subjected to mixed multivariate statistical analysis consisting of principal component analysis (PCA) and a self-organization mapping net (SOM). Results The fingerprints were profiled. PCA score plots showed Chinese and Brazilian green propolis clearly classified into two groups. The visualized SOM results showed data from the two groups projected to the adjacent neurons clearly separated from each other. Artepillin C, which contributed greatly to the differentiation, was screened out and identified as the reference compound. Artepillin C is the characteristic component in Brazilian propolis which can be used as chemical marker to distinguish propolis of different origins. Conclusions In this study, fingerprints coupled with multivariate statistical analysis have been successfully applied to distinguish Chinese from Brazilian green propolis. The research identified a chemical marker, and thus helps to investigate and promote the quality control of propolis.

46 Sandwich-type ethylcellulose films for controlled release of anti-restenosis drugs

Objectives Restenosis is a response of the vessel wall to balloon-induced injury and is characterized primarily by elastic recoil of the vessel wall and a series of pathological processes including thrombus, inflammation and vascular smooth muscle cell (VSMC) proliferation. To treat restenosis, appropriate drug delivery vehicles are needed which can release therapeutic agents targeting different symptoms into blood vessels in a controlled manner. The main objective of the present study was to prepare sandwich-type ethyl cellulose films with high performance for efficient drug loading and controlled drug release for restenosis treatment. Methods Sandwich-type ethyl cellulose films loaded with probucol for treating coronary artery disease, or aspirin as an antithrombotic drug, were prepared by casting three individual layers in sequence using an ethyl cellulose/toluene solution. On a glass plate, the first ethyl cellulose layer (bottom layer) was cast without drugs, on to which the middle layer containing probucol or aspirin was then cast. After solvent evaporation at room temperature, a third top layer was cast on to the middle layer. The obtained drug-loading films were further dried at room temperature under vacuum. Results The sandwich-type ethyl cellulose films exhibited a drug loading content (DLC) of 12.1 ± 0.9% and a drug loading efficiency (DLE) of 73.5 ± 3.6% for aspirin, and a DLC of 11.0 ± 0.8% and a DLE of 69.3 ± 3.4% for probucol. Under physiological conditions (37°C, pH 7.4), the release half-life of aspirin from the films was 2.7 ± 0.2 hours, while that of probucol was 7.1 ± 0.6 days. The two drugs showed totally different release behaviors, which can be employed in combination to treat restenosis. Conclusion Sandwich-type ethylcellulose films loaded with probucol or aspirin were successfully prepared and showed ability to release the two drugs in different ways: rapid release of aspirin to treat thrombus and inflammation typical of early-stage restenosis, and sustained release of probucol for inhibition of VSMC proliferation frequently seen in the later stage of restenosis. These drug-loaded ethylcellulose films provide new insight into restenosis therapy.

50 Synthesis, characterization and stability of five tavaborole-based pharmaceutical cocrystals

Objectives Pharmaceutical cocrystals have received attention in the pharmaceutical industry due to their potential for readily changing the physicochemical and biological properties of free active pharmaceutical ingredients (API). Tavaborole is an antifungal agent with strong moisture absorption leading to poor stability. The objective of this investigation was to prepare five pharmaceutical tavaborole cocrystals and to optimize their stability. Methods The five novel pharmaceutical cocrystals with tavaborole as the API were synthesised using the grinding method, with p-aminobenzoic acid (cocrystal 1), m-aminobenzoic acid (cocrystal 2), 2,3’-dihydroxybenzoic acid (cocrystal 3), salicylic acid (cocrystal 4) and 2,6’-pyridinedicarboxylic acid (cocrystal 5). Characterization with XRD and TGA further identified a new phase. The thermal stability, chemical stability and moisture absorption rate of API and cocrystals were also measured and discussed. Results The thermal stability of the five cocrystals was significantly improved compared to the API alone. Chemical degradation and a hydration reaction of cocrystals did not occur in 43%, 58%, 75% and 92% relative humidity at 25°C. The moisture absorption rate of API and cocrystals decreased in the order: API>cocrystal 2>cocrystal 1>cocrystal 4>cocrystal 3>cocrystal 5. Conclusions In this study, we used the grinding method to synthesize pharmaceutical cocrystals of tavaborole. The thermal stability, chemical stability and hygroscopic stability of cocrystals were significantly better than those of API alone. Acknowledgments We are grateful to the Major International (Regional) Joint Research Project of NSFC (Grant No. 21120102034).

44 Core-shell nanospheres for pH-responsive release of anticancer drugs and near-infrared imaging

Objectives Nanoscaled drug carriers with pH-responsiveness have attracted extensive interest in view of the acidic environment in cancerous cells. Rapid response to pH changes plays a key role in efficient intracellular drug release. In addition, real-time tracking of drug carriers is important for understanding distribution and targeted accumulation of the drug carriers. This work aims at developing silver selenide quantum dots (Ag2Se QDs)@carboxymethyl chitosan (CMCS) core-shell nanospheres with encapsulated paclitaxel (PTX) for cancer therapy and bioimaging. Methods Oleic acid-capping Ag2 Se QDs were synthesized by a one-pot strategy, washed with ethanol, and obtained by centrifugation. The as-synthesized Ag2Se QDs were reacted with N-hydroxysuccinimide and conjugated with CMCS at the amino sites. In an aqueous solution of PTX, the hydrophobic oleoyl groups tended to aggregate locally and entrap PTX by hydrophobic interaction, spontaneously producing Ag2Se QDs (PTX)@CMCS nanospheres. Results By conjugating the oleic acid-capping Ag2 Se QDs with pH-sensitive CMCS at a degree of substitution (DS) of 13%, biocompatible core-shell nanospheres loaded with PTX were successfully prepared, which had an average size of 36.3 ± 0.2 nm. The drug loading content (DLC) and drug loading efficiency (DLE) for the PTX was 5.01 ± 0.8% and 52.4 ± 3.2%, respectively. The PTX release half-life was 4.1 hours under conditions resembling the intracellular environment of cancerous cells (37°C, pH 5.0). Conclusions Core-shell structured Ag2Se QDs (PTX)@CMCS nanospheres capable of releasing PTX in an acidic environment and emitting NIR fluorescence under NIR laser excitation were synthesized and characterized. The hydrophobic oleoyl groups entrapped PTX via hydrophobic interaction and the oleoyl-CMCS chains were extended at lowered pH to release the otherwise encaged drug. In addition, the encapsulated Ag2Se QDs can emit bright NIR fluorescence for bioimaging by which nanosphere distribution in a patient can be monitored. This study provides a new approach for developing nanocomposite drug carriers for cancer therapy.

5 Fermentation and extraction conditions optimization for the production of polysaccharides of Lepista sordida

Objectives Lepista sordida (Schum.: Fr.) Sing. is a type of edible Agaricus mushroom. It exhibits several activities including immunomodulation, and antioxidant and anti-fungal properties. The objective of this investigation was to investigate the fermentation and extraction conditions of polysaccharides from the mycelium of L. sordida. Methods This single parameter experiment was performed to identify the optimal culture conditions including culture temperature, culture cycle and initial pH. Furthermore, an orthogonal experimental design L9 (34) was used to evaluate the combination effects of carbon sources, nitrogen and minerals on the extracts from mycelia. Extraction conditions optimization including the ratio of water to material (v/w), temperature and extraction time based on response surface methodology was employed to identify the optimum conditions. Results The maximum mycelium dry weight was obtained when cultured in an optimal composition of sucrose 30 g/L, yeast extract 6 g/L, KH2PO4 0.1 g/L and MgSO4 1 g/L at temperature 28° C, culture cycles of 7 days and initial pH 7.0. The optimum conditions for polysaccharide extraction from L. sordida mycelia were a ratio of water to material of 72.1:1, temperature 92.6° C and time 2.9 hours. Under these conditions, the predictive and practical extraction efficiency was 16.5% and 16.5±0.1%, respectively. Conclusions The results are helpful for building an efficient and controllable model to improve the extraction efficiency for industrial production of bioactive polysaccharides from L. sordida. Acknowledgments This study as supported by the Guangdong Provincial College Students Innovation and Entrepreneurship Training Program (Nos. DC2016062 and DC2016063).