Inhibition effect of procyanidins from lotus seedpod on mouse B16 melanoma invivo and in vitro

Significant growth inhibition effects of procyanidins from lotus (Nelumbo nucifera Gaertn.) seedpod (LSPCs) on mouse melanoma B16 were found both in vivo and in vitro. In vivo treatment with LSPCs inhibited tumour growth in C₅₇BL/6 J mice by 55.3% in terms of average tumour weight. LSPCs can significantly (P < 0.05) decrease lipid peroxidation (LPO) levels and increase the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in liver tissue. In vitro assay of anti-cancer activities suggested that LSPCs (25–100 μg/ml) possessed cytotoxicities against mouse melanoma B16 in a dose-dependent mode. Furthermore, LSPCs had significant (P < 0.05) stimulatory effects on mouse splenocyte proliferation. The prevention of tumour growth was exerted through diverse mechanisms, including cell-cycle arrest, induction of tumour cell death by apoptosis and increase of Ca²⁺ ions, together with stimulation of antioxidant enzyme activities and immunomodulatory activities.     

Purification and characterization of CEP from Lactococcus lactis ssp. lactis

The cell-envelope proteinase (CEP) of Lactococcus lactis ssp. lactis LB12 was released from cells by treatment with lysozyme, purified by ammonium sulfate precipitation and chromatographed on DEAE-Sephadex A-25 and Sephacryl S-300 HR. The purified CEP is a monomer structure and has molecular mass of about 53 kDa. Optimal activity occurred at pH 7.5 and 40 °C. It is a metallopeptidase, activated by Mn²⁺, Mg²⁺, Ca²⁺, inhibited by Co²⁺, Zn²⁺, Ni²⁺ and EDTA, and a serine proteinase which is inhibited by PMSF. The sequence of the first 13 amino acids of the N-terminal of the CEP was determined to be Asp-Val-Phe-Ala-Pro-His-Met-Ala-Asn-Val-Ala-Ala-Val, and the whey protein hydrolysate produced by the CEP displayed ACE-inhibitory activity.     

Identification and structure-activity relationship of gallotannins separated from Galla chinensis

The gallotannins of Galla chinensis (Chinese gallotannins, CGTs) were identified using LC-MS, and their numbers of isomers in different extracts of Galla chinensis were determined. The antioxidant activities of CGTs with different degree of galloylation were evaluated in four antioxidant systems. Their antioxidant activities increased with increasing number of galloyl groups in all four antioxidant tests. CGTs had a dose-response relationship at the low concentrations (15-60 μg/mL) in the β-carotene-linoleic acid system assay. The antibacterial activity of CGTs against Salmonella typhimurium (Gram negative) and Bacillus cereus (Gram positive) was assessed using the paper disc diffusion method. Hexa-hepta-galloylglucopyranoses (6-7GGs) showed the best antibacterial activities. In general, 6-7GGs possessed antioxidant and antibacterial activities greater than BHT, Trolox, or Ethylparaben. Moreover, an insight on the structure-activity relationship of CGTs is discussed.     

Antioxidant phenolic compounds from Smilax sebeana Miq.

Methanol extract and sub-fractions of Smilax sebeana rhizomes and roots were analyzed to evaluate the compounds involved in antioxidant activity. In all separated fractions of the different polarity solvents, ethyl acetate fraction showed the highest antioxidant activity and total phenolic content. This fraction was subjected to the sephadex LH-20 column and preparative HPLC for purification. Six phenolic compounds, chlorogenic acid (1), 4-formylphenol (2), epicatechin (3), cinchonain IIa (4), Ia (5) and Ib (6) were isolated and identified by spectroscopic analyses and further evaluated their potential antioxidant activities by DPPH and superoxide radical scavenging assays. Compared with synthetic antioxidant Trolox, except 4-formylphenol, the other isolated five compounds exhibited excellent antioxidant activities. This is the first report on the chemical constituents of S. sebeana which potentially involved in antioxidant activity. The results suggest that the ethyl acetate extract of S. sebeana might be used as a readily accessible source of natural antioxidant.     

In vitro synergistic anti-oxidant activities of solvent-extracted fractions from Astragalus membranaceus and Glycyrrhiza uralensis

Our study estimated the in vitro anti-oxidant activities of the solvent-extracted fractions from Astragalus membranaceus (AME), Glycyrrhiza uralensis (GU) and the combination of them (AG), using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging assay and ferric reducing anti-oxidant power (FRAP) assay. Different solvent extracts have different anti-oxidant activities. As to the herb pair (AG), the highest anti-oxidant capacity and total phenolic/flavonoid content were observed in the ethyl acetate fraction, which were exhibited in different solvent fractions of the individual herbs. The ethyl acetate extract of herb pair (EA-AG) showed significantly higher anti-oxidant capacity than the theoretical sum of two single herbs, and presented better cytoprotection and induced higher activity of anti-oxidant enzymes than the single herbs. Moreover, there’s a linear correlation between the increment of total phenolics/flavonoids and anti-oxidant capacities, especially between polyphenol content and TEAC values (correlation coefficient = 0.9^∗). These indicated that the phenolic and flavonoid may be the main compounds which caused the synergistic anti-oxidant capacity and cytoprotection in the combination of AME and GU.     

Microbial transformation of tectoridin from Pueraria flos by Lactobacillus and bifidobacteria

Tectoridin could be hydrolyzed to tectorigenin by β-glucosidase-producing intestinal bacteria. In this study, nine strains of Lactobacillus and bifidobacteria were screened for high levels of β-glucosidase activity. We investigated their ability to transform tectoridin from Pueraria flos to tectorigenin. Lactobacillus reuteri DSM20016 showed the highest cell-envelope associated β-glucosidase activity, whereas the intracellular β-glucosidase activity from Bifidobacterium adolescentis ATCC15703 was higher than the other screened bacterial strains. L. reuteri DSM20016, Lactobacillus rhamnosus GGB41031 and B. adolescentis ATCC15703 showed high bioconversion rate of tectoridin. L. reuteri DSM20016 showed the highest bioconversion efficiency of tectoridin, 100% tectoridin was hydrolyzed and there was an approximate 185-fold increase in the concentration of tectorigenin after 24 h. The present study suggests that L. reuteri DSM20016, L. rhamnosus GGB41031 and B. adolescentis ATCC15703 have great potential for converting tectoridin from Pueraria flos to more bioactive tectorigenin.     

Immunomodulatory and anticancer activities of phenolics from Garcinia mangostana fruit pericarp

The methanolic extract of Garciniamangostana fruit pericarp was partitioned into butanol and water fractions in this work. Three major phenolics were purified and identified as P₁ [1,3,6,7-tetrahydroxy-2,8-(3-methyl-2-butenyl) xanthone], P₂ [1,3,6-trihydroxy-7-methoxy-2,8-(3-methyl-2-butenyl) xanthone] and P₃ (epicatechin). Strong antioxidant activities were detected for P₁–P₃. In vitro cell proliferation trials indicated that P₁ and P₃ exhibited good immunomodulatory activities when 7.5 μg/ml was used. Furthermore, P₁ and P₃ showed good cytotoxicities against human breast cancer cells (MCF-7) and human colon cancer cells (LOVO). P₁ exhibited the maximal cytotoxicity of 73.06% against MCF-7 cells and of 46.27% against LOVO cells when 62.5 μg/ml was used. The cytotoxicities of P₁, P₂, P₃ and paclitaxel against normal embryonic lung fibroblast cells (HELF) were in a decreasing order: paclitaxel > P₃ > P₁ > P_2. These results suggested that P₁ and P₃ could be used as a potential anticancer agent.     

Phenolic composition and biological activities of Salvia halophila and Salvia virgata from Turkey

The aerial parts of Salvia halophila and Salvia virgata were subjected to Soxhlet extraction with different solvents such as n-hexane, ethyl acetate, methanol, and aqueous methanol (50%). Plants were also extracted with water under reflux. The effects of the extracts were studied in p-benzoquinone-induced abdominal constriction test for the assessment of antinociceptive activity and carrageenan-induced hind paw edema and 12-O-tetradecanoyl-13-acetate (TPA)-induced ear edema models in mice for the anti-inflammatory activity. The extracts were analysed using a HPLC–PDA method. Results showed that methanol extract of S. virgata significantly inhibited carrageenan-induced paw edema and p-benzoquinone-induced abdominal constriction at 100 mg/kg dose, while it showed no effect in the TPA-induced ear edema. On the other hand, the other extracts did not show any inhibitory antinociceptive and anti-inflammatory activities in these in vivo models. Rosmarinic acid was found as main constituent in the extracts, while caffeic acid and luteolin derivatives were also detected.     

Structural characterisation of polysaccharides from Tricholoma matsutake and their antioxidant and antitumour activities

In this study, polysaccharides from Tricholoma matsutake (TM-P) were purified using a DEAE-Sepharose fast flow column and three polysaccharide fractions (TM-P1, TM-P2 and TM-P3) were obtained. The chemical composition and structural characteristics of TM-P2 were quite different from those of TM-P1 and TM-P3. TM-P2 consisted of glucose, galactose and mannose with a molar ratio of 5.9:1.1:1.0. The glycosidic linkages were mainly composed of 1,6- and 1-linked glucose. Furthermore, TM-P2 showed the strongest in vitro antioxidant and antitumour activities. The oxygen radical absorbance capacity (ORAC) of TM-P2 was 2100.44 μmol Trolox/g. The antiproliferative activities of TM-P2 (4.0 mg/ml) on the growth of HepG2 and A549 cells were 67.98% and 59.04%, respectively.     

Novel modified furanoeremophilane-type sesquiterpenes and benzofuran derivatives from Ligularia veitchiana

Three new compounds, 2-acetyl-5-isopentenyl-6-methylbenzofuran (1), 1,3-dimethoxy-4,6-dimethylnaphthofuran (2), and 3,4,5-trimethoxycinnamyl angelic acid ester (3), along with 13 known compounds were isolated from the roots of Ligularia veitchiana, which are commonly used as a folk medicine and food supplement in China. Their structures were elucidated by spectroscopic techniques. Biological screening studies indicated that compound 2 displayed a moderate activity against Staphylococcus aureus, which may be due to the existence of a modified eremophilane skeleton, whilst compounds 11, 12 and 15 exhibited potent activity against HL-60 and HeLa cell lines.     

Antioxidant activity of stilbene glycoside from Polygonum multiflorum Thunb in vivo

Stilbene glycosides were isolated from the ethanol extract of the roots of Polygonum multiflorum Thunb. Two samples were obtained; a fraction separated by macroporous resin and pure crystals of 2,3,5,4′-tetrahydroxystilbene 2-O-β-glucopyranoside. The antioxidant activities of these two samples were evaluated using antioxidant tests of rats in vivo. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of the serum and the organs (liver, heart and brain of rats) of d-galactose induced senile rats which were fed with stilbene glycoside, were increased; however, the content of 2-thiobarbituric acid-reactive substances (TBARS) was decreased. It is concluded that the stilbene glycoside from Polygonum multiflorum Thunb possesses high in vivo antioxidant activity.     

Bioactivity evaluations of ingredients extracted from the flowers of Citrus aurantium L. var. amara Engl

Citrus aurantium L. var. amara Engl, a member of genus Citrus (Rutaceae), widespread in China, is used as folk medicine for the treatment of helping digest, phlegm, enteritidis, stomachic and other deceases. In the present research, silica gel column, Sephadex LH-20, mass spectrometer (MS) and nuclear magnetic resonance (NMR) were used to separate and identify the chemical compounds from the flowers of C. aurantium var. amara, and several bioactivity assays were used to evaluate their antioxidant, anti-inflammatory, anti-virus and antitumour activities. Two major compounds, 5-hydroxy-6,7,3′,4′-tetramethoxyflavone (HTF) and limonexic acid (LA), were isolated and identified from C. aurantium var. amara for the first time. The results of the bioactivity assays showed that HTF and LA displayed significant antioxidant activities and showed significant inhibition effects on the B16 cell lines at a concentration range from 6.25 to 50 μg/ml, and on the SMCC-7721 cell lines from 12.5 to 200 μg/ml. The antitumour effect, anti-inflammatory activity and the inhibiting expression of HBsAg and HBeAg of 2.2.15 cells displayed the tendency in a concentration-dependent manner. These two compounds from C. aurantium var. amara could potentially be used as a promising natural agent in the pharmaceutical industries.     

Preparation,identification and their antitumor activities in vitro of polysaccharides from Chlorella pyrenoidosa

Ultrafiltration membranes of different pore size were applied to fractionate Chlorella pyrenoidosa polysaccharides (CPPS) and the main fraction could be separated by a membrane with nominal molecular weight cut-off (NMWCO) of 30 kDa. Ultrafiltration parameters of 40 °C 14.0 psi were optimized for obtaining the main fraction. The resulting sample was further purified by anion-exchange chromatography and size exclusion chromatography, and two distinctive polysaccharides, CPPS Ia and IIa were recovered. CPPS IIa had infrared spectral characteristic of polysaccharides similar to CPPS Ia, and the symmetrical stretching peak at 1408–1382 cm⁻¹ was an indication of the presence of carboxyl groups. The peak molecular weights were 69658 Da and 109406 Da, for CPPS Ia and CPPS IIa, respectively. Both CPPS Ia and IIa were composed of rhamnose, mannose, glucose, galactose and an unknown monosaccharide. Galactose (relative mass 46.5%) was the predominant monosaccharide of CPPS Ia and in CPPS IIa, rhamnose (37.8%) was predominant. CPPS Ia and IIa presented significantly higher antitumor activity against A549 in vitro than did a blank control, in a dose-dependent manner. Both fractions might be useful for developing natural safe antitumor drugs from C. pyrenoidosa resources.     

Biocontrol of Fusarium species by a novel lectin with low ecotoxicity isolated from Sebastiania jacobinensis

A lectin from Sebastiania jacobinensis bark was isolated using a combination of acetone precipitation, ammonium sulphate fractionation, ion exchange and gel filtration chromatographies. The lectin purified, with a molecular mass of 52.0 kDa and composed of two subunits of 24 kDa, is a glycoprotein with a neutral carbohydrate content of 6.94%. The lectin shows maximum activity over the pH range 4.0–7.5 and heat stability up to 70 °C. Our results show that the lectin is an incompetitive inhibitor for trypsin, with a Ki of 0.39 ± 0.02 μM. Fluorescence spectroscopy indicated the existence of a hydrophobic surface. The percentages of secondary structure are 75% α-helix, 10% β-sheet, 5% β-turn and 10% unordered. Lectin inhibits the mycelial growth of Fusarium moniliforme and Fusarium oxysporum with an IC₅₀ value of 123 ± 0.5 and 303 ± 0.9 μg, respectively. Artemia salina Leach and embryos of Biomphalaria glabrata are not affected by the lectin, indicating low environmental toxicity. Alternative viewpoints are presented that might hopefully help in future efforts to develop safer and more effective microbial control agents.