RESUMO
Hot water extract from biomass of heterotrophic mutant green alga Parachlorella kessleri HY1 (Chlorellaceae) was deproteinised, and three polysaccharidic fractions were obtained by preparative chromatography. The low-molecular fraction (1.5 × 104g mol-1) was defined mainly as branched O-2-ß-xylo-(1â3)-ß-galactofuranan where xylose is partially methylated at O-4. Two high-molecular fractions (3.05 × 105 and 9.84 × 104g mol-1) were complex polysaccharides containing α-l-rhamnan and xylogalactofuranan parts in different ratios. The polysaccharides were well soluble in hot water and, upon cooling, tended to self-segregate. Immunomodulatory activities of the obtained fractions were preliminary tested using ELISA, FACS and ImmunoSpot kits. The polysaccharides increased the TNF-α production in melanoma bearing mice with much higher intensity than in healthy mice. This was in agreement with the FACS results on T and B cells indicating their possibly secondary activation by innate immunity cells.
Assuntos
Linfócitos B/efeitos dos fármacos , Clorófitas/química , Fatores Imunológicos/farmacologia , Polissacarídeos/farmacologia , Linfócitos T/efeitos dos fármacos , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Linfócitos B/imunologia , Linfócitos B/patologia , Sequência de Carboidratos , Regulação da Expressão Gênica/efeitos dos fármacos , Fatores Imunológicos/química , Fatores Imunológicos/isolamento & purificação , Interferon gama/genética , Interferon gama/imunologia , Interleucina-2/genética , Interleucina-2/imunologia , Interleucina-4/genética , Interleucina-4/imunologia , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Melanoma/imunologia , Melanoma/patologia , Metilação , Camundongos , Camundongos Endogâmicos C57BL , Peso Molecular , Extratos Vegetais/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Cultura Primária de Células , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Solubilidade , Linfócitos T/imunologia , Linfócitos T/patologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Água , Xilose/química , Xilose/isolamento & purificaçãoRESUMO
New foods and natural biological modulators have recently become of scientific interest in the investigation of the value of traditional medical therapeutics. Glucans have an important part in this renewed interest. These fungal wall components are claimed to be useful for various medical purposes and they are obtained from medicinal mushrooms commonly used in traditional Oriental medicine. The immunotherapeutic properties of fungi extracts have been reported, including the enhancement of anticancer immunity responses. These properties are principally related to the stimulation of cells of the innate immune system. The discovery of specific receptors for glucans on dendritic cells (dectin-1), as well as interactions with other receptors, mainly expressed by innate immune cells (e.g., Toll-like receptors, complement receptor-3), have raised new attention toward these products as suitable therapeutic agents. We briefly review the characteristics of the glucans from mycelial walls as modulators of the immunity and their possible use as antitumor treatments.