Chemical Evaluation of Liquidambar styraciflua L. Fruits Extracts and Their Potential as Anticancer Drugs.

Liquidambar styraciflua L. is an aromatic species, popularly used in traditional Chinese medicine to treat diarrhea, dysentery, coughs, and skin sores. The present study was designed to investigate the chemical composition and biological potential of extracts obtained from the fruits of this plant. For the chemical evaluation, it was used mainly liquid and gas chromatography, plus NMR, and colorimetric methods. The aqueous extract (EA) originated two other fractions: an aqueous (P-EA) and an ethanolic (S-EA). The three extracts were composed of proteins, phenolic compounds, and carbohydrates in different proportions. The analyses showed that the polysaccharide extract (P-EA) contained pectic polysaccharides, such as acetylated and methyl esterified homogalacturonans together with arabinogalactan, while the fraction S-EA presented phenolic acids and terpenes such as gallic acid, protocathecuic acid, liquidambaric acid, combretastatin, and atractyloside A. EA, P-EA, and S-EA showed antioxidant activity, with IC50 values of 4.64 µg/mL, 16.45 µg/mL, and 3.67 µg/mL, respectively. The cytotoxicity followed the sequence S-EA > EA > P-EA, demonstrating that the toxic compounds were separated from the non-toxic ones by ethanol precipitation. While the fraction S-EA is very toxic to any cell line, the fraction P-EA is a promising candidate for studies against cancer due to its high toxicity to tumoral cells and low toxicity to normal cells.

An α-D-galactan and a ß-D-glucan from the mushroom Amanita muscaria: Structural characterization and antitumor activity against melanoma.

Polysaccharides α-D-galactan (GAL-Am) and ß-D-glucan (GLC-Am) were obtained from Amanita muscaria fruiting bodies. They were purified using different methodologies, such as Fehling precipitation (for both fractions), freeze-thawing process and ultrafiltration (for GLC-Am). Results showed that the GAL-Am has (1 â†’ 6)-linked Galp main chain branched at O-2 by terminal Galp units and has not been previously reported. Besides, GLC-Am has (1 â†’ 3)-linked Glcp in the main chain, substituted at O-6 by (1 â†’ 6)-linked ß-Glcp units. Both are water-soluble, with 9.0 × 103 g/moL and 1.3 × 105 g/moL, respectively. GAL-Am and GLC-Am presented a selective proliferation reduction against B16-F10 melanoma cell line, not affecting non tumoral BALB/3T3 fibroblast cell line. Furthermore, both fractions reduced clonogenic capacity of melanoma cell line over an extended period of time. These results were obtained without modulations in B16-F10 cell adhesion, reinforcing the biological activities towards cell proliferation impairment and eliciting these polysaccharides as promising compounds to further exploration of their antimelanoma properties.

Polysaccharides from Pleurotus eryngii: Selective extraction methodologies and their modulatory effects on THP-1 macrophages.

Polysaccharides from P. eryngii mushroom were selectively extracted using low-cost technologies (water at different conditions of temperature and pressure). Mannogalactan was the main polysaccharide in cold-water extracted fraction (CWEF), while a linear (1→6)-ß-d-glucan was the main polymer in hot-water extracted fraction (HWEF). Autoclave-extracted fraction (AEF) contained a mixture of at least four different α- and ß-glucans. The report of linear (1→6)-ß-glucan and linear (1→3)-ß-glucan is a new finding for P. eryngii fruiting bodies. The immunostimulatory properties of the fractions on THP-1 macrophages were studied. All fractions at 50, 250 and 500 µg/mL were not cytotoxic and produced different stimulus on NO, IL-1ß and IL-10 secretion by the cells. Thus, our results showed that it is possible to concentrate different P. eryngii polysaccharides in selected fractions using a simple and low-cost procedure. Since biological effects depends on the polysaccharide structure, this technique allows the obtainment of fractions with distinct immunomodulatory activities.

Polysaccharides from green sweet pepper increase the antineoplastic effect of methotrexate on mammary tumor cells.

This study investigated the antineoplastic effects and toxicity of long-term treatment with polysaccharides from sweet green pepper (Capsicum annuum [CAP]), and concomitant treatment with CAP + methotrexate (MTX) on mammary tumor cells in vivo and in vitro. Ehrlich tumor cells were subcutaneously inoculated in female Swiss mice. The long-term treatment (31 days) with CAP (100 mg kg-1, p.o.) reduced the tumor growth and did not induce toxicity. The combined treatment protocol of 100 mg kg-1 CAP (p.o.) + 1 mg kg-1 MTX (i.p.) for 21 days inhibited the tumor growth in 95%, higher than the inhibition induced by MTX alone (1.0 or 2.5 mg kg-1, i.p.). In tumors, both CAP and CAP + MTX decreased the gene expression of Vegf, vessel area, and IL-4 and IL-10 levels, and increased IL-6 levels and the degree of necrosis. Treatment with CAP + MTX also increased TNF-α levels in tumors. Additionally, CAP + MTX treatment reduced the viability of human MDA-MB-231 and MDA-MB-436 mammary tumor cells in culture. In fact, CAP exerted antineoplastic effects in vivo and in vitro against mammary tumor cells, possibly by modulating inflammation and angiogenesis. CAP may be a promising adjunct chemotherapy with lower toxicity.

Dietary fibres from guavira pomace, a co-product from fruit pulp industry: Characterization and cellular antioxidant activity.

Exotic fruits and their co-products may be valuable sources of antioxidant dietary fibres (DF) which are useful for food industry and human health. In this study, we aimed to characterize DF obtained from guavira fruit pomace and investigate its antioxidant potential employing TEAC assay as well as a cell model. The DF were chemically characterized as containing arabinan, highly-methoxylated homogalacturonan and arabinogalactan. The DF-containing fraction (CPW) presented ABTS free radical scavenger activity. MTT and DCFH-DA assay were performed to assess, respectively, changes in cell viability and the potential intracellular antioxidant activity against H2O2-induced oxidative stress in murine NIH 3T3 fibroblast. CPW exhibited no effects on cell viability, moreover, when administered 48 h prior the induction of H2O2 toxic effects, it protected the cells, significantly increasing the cell viability compared to control. This protection may be related to the observed reduction of reactive oxygen species levels. Thus, the pre-treatment of cells with guavira DF for 48 h remarkably induced a cytoprotection against pro-oxidant conditions, and may be a valuable functional compound recovered from an unexploited agroindutrial waste.

Structural features of polysaccharides from edible jambo (Syzygium jambos) fruits and antitumor activity of extracted pectins.

Jambo is a tropical fruit cultivated in Southeast Asia and tropical regions of America and Africa. After extraction, its polysaccharides were structurally characterized. Water soluble polysaccharides (WSP) were composed of GalA:Ara:Gal:Glc:Rha in 51:22:16:5:6 molar ratio, indicating the presence of pectic polysaccharides. Methylation analysis and NMR spectroscopy indicated the presence of homogalacturonan (HG), type II arabinogalactan and type I rhamnogalacturonan (RG-I). The HG/RG-I ratio was 88%, indicating greater amounts of smooth than hairy pectic regions. Hemicellulosic polysaccharides were extracted from the residue and fractionated by freeze-thaw procedure in two fractions (ASP-S and ASP-I). ASP-S was composed of Glc:Gal:Xyl:Ara:Man:Fuc:UA in a 45:16:20:3:8:5:2 molar ratio. Methylation analysis and 13C NMR spectroscopy indicated xyloglucan, xylan and mannan. Their relative proportion estimated on sugar linkage was 89%, 6% and 3%, respectively. ASP-I was composed mainly of xylose (99.5%) and its 13C NMR indicated a linear (1 → 4)-ß-D-xylan. The biological activity of WSP was tested in Ehrlich tumor-bearing mice. After 21 days of oral treatment, the doses of 150 and 250 mg/kg WSP reduced expressively the tumor growth, similarly to the positive control methotrexate, and improved the body weight of tumor-bearing mice. Further studies are necessary to investigate the mechanisms of the WSP antitumor effect.

Antineoplastic effect of pectic polysaccharides from green sweet pepper (Capsicum annuum) on mammary tumor cells in vivo and in vitro.

The present study investigated the antineoplastic effects of pectic polysaccharides that were extracted from green sweet pepper (Capsicum annuum [CAP]) in the Ehrlich carcinoma in mice and in human mammary tumor lineages. After the subcutaneous inoculation of 2 × 106 Ehrlich tumor cells, Female Swiss mice received 50, 100, or 150 mg/kg CAP or vehicle orally once daily or methotrexate (2.5 mg/kg, i.p., every 5 days) for 21 days. CAP dose-dependently reduced Ehrlich tumor growth. It also reduced the viability of MCF-7, MDA-MB-231, and MDA-MB-436 human mammary cell lineages. Treatment with CAP reduced the gene expression of vascular endothelial growth factor in vivo and in vitro, reduced vessel areas of the tumors, and induced necrosis in Ehrlich solid tumors. CAP treatment significantly increased Interleukin-6 in tumors. The antineoplastic effect of CAP appears to depend on the regulation of inflammation and angiogenesis. Further studies are encouraged to better understand the CAP potential for the treatment of breast tumors.

Gastroprotective activity of a pectic polysaccharide fraction obtained from infusion of Sedum dendroideum leaves.

BACKGROUND: Sedum dendroideum, popularly known in Brazil as balsam, is traditionally used as a wound healing agent, to treat gastritis, and several other health problems. Some studies have shown that plant polysaccharides may have gastroprotective properties. PURPOSE: Considering the popular use of S. dendroideum and the gastroprotective activity of polysaccharides, the objective of this work was to obtain, to characterize, and to evaluate the gastroprotective activity of a polysaccharide fraction from this plant. METHODS: Polysaccharides of S. dendroideum were extracted with water by infusion, fractionated by freeze-thawing process and dialyzed at a 100 kDa cut-off membrane, and characterized by monosaccharide composition and NMR analysis. The gastroprotective activity of the pectic polysaccharide fraction RSBAL was evaluated in the ethanol-induced ulcer model in rats, followed by determination of the mucus and glutathione levels in the gastric tissue. RESULTS: RSBAL was constituted by a homogalacturonan and a homogalacturonan branched by side chains of arabinans and type II arabinogalactans. It reduced ethanol-induced gastric ulcers in rats, preserving mucus and glutathione levels in the stomach. CONCLUSION: This study demonstrated that polysaccharides could be related to the pharmacological activity of S. dendroideum.