Isolation, structural characterization and anti-oxidant activity of a novel polysaccharide from garlic bolt.

Allium sativum L. is a widely distributed plant used as a spice, vegetable and medicine. In this study, one novel water-soluble polysaccharide (GBP-1a), with a molecular weight of 15.0 kDa, was isolated from the scape of A. sativum (garlic bolt). GBP-1a consists of galactose, glucose and arabinose at a ratio of 73.29:4.36:1.70. It has a backbone, which is composed of 1,4-linked Galp, with 1,2,6-linked Galp branches and 1-linked Glcp residue. In addition, the anti-oxidant activities of GBP-1a, as well as the two main polysaccharide fractions on ABTS radicals, metal ions and superoxide anion radicals, were evaluated in vitro. This study added new data to the study of polysaccharides from garlic bolt.

Influences of different pectins on the emulsifying performance of conjugates formed between pectin and whey protein isolate.

The effects of different pectins on the conjugates formed between pectin and whey protein isolate (WPI) under the dry-heating condition (80 °C, 79% relative humidity) were investigated in this study. The different pectin samples were sugar beet pectin (SBP), high methyl-esterified citrus pectin (HMCP) and low methyl-esterified citrus pectin (LMCP). The covalent linkage between pectin and WPI was proved by SDS-PAGE. As the incubation time was prolonged, the degree of glycosylation (DG) of WPI-pectin conjugate gradually increased, but its solubility decreased gradually. The glycosylated speed between WPI and SBP was the fastest, while the DG between WPI and LMCP was the highest. Even so, the 24 h-incubated WPI-HMCP conjugate sample had the best emulsifying properties in all of the prepared conjugates. All the results revealed that the HMCP was the most suitable pectin sample for preparing the WPI-pectin conjugate with a superior emulsifying performance.

Anti-inflammatory, antioxidant and antitumor activities of ingredients of Curcuma phaeocaulis Val.

Curcuma phaeocaulis Val. is used in Chinese Pharmacopoeia as health food and folk medicine for removing blood stasis, alleviating pain and tumor therapy. This research was aimed to explore and compare three main bioactivities including anti-oxidant, antitumor and anti-inflammatory activities between the ethanol extract of C. Phaeocaulis and its fractions using different in vitro models. Firstly, 70 % ethanol was used to extract C. Phaeocaulis, and then the crude extract was re-extracted, resulting in petroleum ether (EZ-PE), ethyl acetate (EZ-EA), and water fractions (EZ-W), respectively, and then a series of index was detected. Results showed that all the extracts had medium DPPH radical scavenging activity when the concentration was 200 µg/ml and their DPPH radical scavenging activity was in a concentration-dependent manner. The extracts except ethanol extract of C. Phaeocaulis had almost no cytotoxicity to the survival of RAW264.7 cell when the concentration reached 80 µg/ml, and all of them had medium inhibitory effect on nitrite release. Extracts of C. Phaeocaulis had medium intensity antitumor activity, EZ-PE and EZ-EA fractions significantly inhibited the proliferation of four tumor cells (SMMC-7721 cell lines, HepG-2 cell lines, A549 cell lines and Hela cell lines). C. Phaeocaulis had antioxidant and anti-inflammatory activities, which did not carry out centralized phenomenon when re-extracted. EZ-PE and EZ-EA were active antitumor sites of C. Phaeocaulis.

Isolation and identification of ingredients inducing cancer cell death from the seeds of Alpinia galanga, a Chinese spice.

This study was carried out to isolate ingredients from the seeds of a Chinese spice (Alpinia galangal) and to evaluate their cytotoxic activity on cancer cell lines. Isolation and purification of the phytochemical constituents were conducted using silica gel, Sephadex LH-20 and ODS columns. After extraction using 95% ethanol, the total extracts were re-extracted, resulting in petroleum ether (PE), ethyl acetate (EA) and water fractions, respectively. Activity tests showed that the EA fraction exhibited obvious (p < 0.05) protective effects on H2O2 damaged PC-12 cells at 20 µg mL(-1), and showed much higher (p < 0.05) cytotoxic activity on cancer cell lines than other fractions. Five compounds, 1'-S-1'-acetoxyeugenol acetate (I), 1'-S-1'-acetoxychavicol acetate (II), 2-propenal, 3-[4-(acetyloxy)-3-methoxyphenyl] (III), isocoronarin D (IV) and caryolane-1, 9ß-diol (V), were obtained from the EA fraction and identified by HPLC, UV, MS, and NMR spectroscopic analyses. Compounds III and V were isolated from A. galangal for the first time. Moreover, compounds I, II, IV and V were the main active ingredients for inducing death of the tested cancer cells, and their IC50 values ranged from 60 to 90 µg mL(-1), indicating that these compounds possessed a wide anti-cancer capability. Therefore, A. galangal seeds could be a potential source of healthy food for tumor prevention.

Application of fluorescently labeled tracer technique for detection of natural active macromolecules in Chinese medicine.

Active substances in traditional Chinese Medicine (TCM) contain not only a variety of small molecules, but also many other macromolecules (TCMMs), such as proteins, peptides and polysaccharides. Active TCMM can achieve good therapeutic effects by regulating the body's overall function with lower side effects. This review summarized the literatures published in recent years on the application of fluorescently labeled tracer technique for detection of natural active macromolecules in TCM. Classified by fluorescent markers, applications of fluorescein, rhodamine, and quantum dots (QDs) in TCMM active tracer are reviewed, and the methods and principles of TCMM fluorescent marker are illustrated. Studies on active TCMMs and their action mechanism are quite difficult due to a multitarget, multicomponent, and multipath system of TCM. However, the development of fluorescently labeled active tracer technique (FLATT) provides this research with new tools. Traditional fluorescent markers have many deficiencies, such as easily quenched, short luminous cycle, and intrinsic toxicity. Relatively, FLATT has many obvious advantages, and its application in TCMM is still at the early stage. In order to improve the overall level of fluorescence labeling in TCMM active tracer, the improvement on FLATT's detection sensitivity and biological affinity is urgent and critical to allow study of these interesting molecules.

Antioxidant and anticomplement functions of flavonoids extracted from Penthorum chinense Pursh.

Penthorum chinense Pursh is rich in flavonoids, which have strong antioxidant and anticomplement activities. In order to optimize their extraction conditions, various extraction parameters were chosen to identify their effects on flavonoids extraction. Single factor and Box-Behnken experimental designs consisting of 24 experimental runs and five replicates at zero point were applied to obtain the optimal extraction yield. The optimization conditions for flavonoids extraction were determined as follows: ethanol concentration 60.89%, extraction time 68.15 min, temperature 52.89 °C and liquid/solid ratio 19.70 : 1. The corresponding flavonoids content was 7.19%. The regression equation was found to fit well with the actual situation. Furthermore, the antioxidant activity (the free radical scavenging ability and ferric reducing/antioxidant power) and anticomplement ability of the flavonoids from P. chinense were determined. Results showed that the flavonoids of P. chinense displayed significant antioxidant and anticomplement activities. Its antioxidant activity can compete with ascorbic acid (Vc), whereas its anticomplement activity (IC50 = 111.6 µg ml(-1)) surpassed the effect of heparin (IC50 = 399.7 µg ml(-1)) which was used as the positive control, suggesting that P. chinense flavonoids and their related products could potentially be used as a promising natural agent in the treatment of humoral effector inflammation.