Molecular weight-dependent antitumor effects of prunes-derived type I arabinogalactan on human and murine triple wild-type melanomas.

The regulation of metastasis-related cellular aspects of two structurally similar AGIs from prunes tea infusion, with different molar masses, was studied in vitro against Triple Wild-Type metastatic melanoma (TWM) from murine and human origin. The higher molar mass AGI (AGI-78KDa) induced TWMs cells death and, in murine cell line, it decreased some metastasis-related cellular processes: invasiveness capacity, cell-extracellular matrix interaction, and colonies sizes. The lower molar mass AGI (AGI-12KDa) did not induce cell death but decreased TWMs proliferation rate and, in murine cell line, it decreased cell adhesion and colonies sizes. Both AGIs alter the clonogenic capacity of human cell line. In spite to understand why we saw so many differences between AGIs effects on murine and human cell lines we performed in silico analysis that demonstrated differential gene expression profiles between them. Complementary network topological predictions suggested that AGIs can modulate multiple pathways in a specie-dependent manner, which explain differential results obtained in vitro between cell lines. Our results pointed to therapeutic potential of AGIs from prunes tea against TWMs and showed that molecular weight of AGIs may influence their antitumor effects.

Dietary polysaccharides from guavira pomace, a co-product from the fruit pulp industry, display therapeutic application in gut disorders.

Inflammatory bowel disease (IBD) includes two distinct diseases: Crohn's disease (CD) and ulcerative colitis (UC). IBD is a chronic systemic disease of the gastrointestinal tract, characterized by an inflammatory process. The mechanisms by which diseases develop are still unknown, but it is known that it results from a complex interaction between genetic variability, the host's immune system, and environmental factors. One of the main complaints of patients is abdominal pain, which may be associated with the release of inflammatory mediators, changes in the normal motility of the digestive tract, and increased intestinal permeability. Currently available drugs for abdominal pain are not satisfactory, therefore, it is extremely necessary to seek new therapeutic options for the treatment of abdominal pain. Polysaccharides extracted from fruits have attracted interest, as these molecules protect the intestinal mucosa and promote wound healing, attenuating inflammation, pain, and altered intestinal motility. In this study, we investigated the ability of pectic polysaccharides obtained from guavira pomace, named CPW to reduce visceral hypersensitivity, regulate intestinal motility, and control diarrhea in mice. Acetic acid, capsaicin, or mustard oil were used to assess visceral pain in normal mice. CPW reduced abdominal writhing, cell migration, and capsaicin-induced visceral nociception. Furthermore, it regulated intestinal motility and all measured parameters of castor oil-induced diarrhea. CPW treatment reversed the increase in mucosal permeability, TEER, and tissue weight caused by acetic acid. In addition, molecular docking analysis showed that specific the CPW units binds to the 3N8V, 5COX, 2J67 and 6RBF proteins. Thus, the results suggest that CPW has attractive therapeutic characteristics for the treatment of abdominal pain and ulcerative colitis.

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.

ß-L-Araf-containing arabinan and glucuronoxylan from guavira fruit pomace.

Guavira is a plant that belongs to Myrtaceae family, being widespread in the Brazilian Cerrado. In this study, pectic and hemicellulosic polysaccharides from guavira pomace, an agroindustry residue from pulp production, were structurally characterized using GPC, monosaccharide composition, methylation and NMR experiments. The absolute configurations of monosaccharides and the nature of uronic acids were attributed according to numerous data on the composition of related plant arabinogalactans and hemicelluloses present in the literature. An arabinan was purified, presenting Ara (85.0%), Rha (3.3%), Gal (7.7%) and GalA (4.0%). Mono and bidimensional NMR analyses of this arabinan demonstrated the presence of terminal ß-L-Araf units, whose occurrence has been scarcely reported in the literature. Hemicellulosic fraction contained a glucuronoxylan, with α-D-GlcpA/4-O-methyl-α-D-GlcpA group linked to O-2 of a (1 → 4)-ß-D-xylan, presenting one uronic acid residue for every six xylose units. These findings about guavira pomace polysaccharides could contribute to develop future nutraceutical and technological uses for this industrial waste.