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Polysaccharides isolated from Açaí fruit induce innate immune responses.

Holderness J, Schepetkin IA, Freedman B, Kirpotina LN, Quinn MT, Hedges JF, Jutila MA - PLoS ONE (2011)

Bottom Line: Similar polyphenol and polysaccharide fractions are found in Acai fruit.Contrary to previous reports, we did not identify agonist activity in the polyphenol fraction; however, the Acai polysaccharide fraction induced robust γδ T cell stimulatory activity in human, mouse, and bovine PBMC cultures.When delivered in vivo, Acai polysaccharide induced myeloid cell recruitment and IL-12 production.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America.

ABSTRACT
The Açaí (Acai) fruit is a popular nutritional supplement that purportedly enhances immune system function. These anecdotal claims are supported by limited studies describing immune responses to the Acai polyphenol fraction. Previously, we characterized γδ T cell responses to both polyphenol and polysaccharide fractions from several plant-derived nutritional supplements. Similar polyphenol and polysaccharide fractions are found in Acai fruit. Thus, we hypothesized that one or both of these fractions could activate γδ T cells. Contrary to previous reports, we did not identify agonist activity in the polyphenol fraction; however, the Acai polysaccharide fraction induced robust γδ T cell stimulatory activity in human, mouse, and bovine PBMC cultures. To characterize the immune response to Acai polysaccharides, we fractionated the crude polysaccharide preparation and tested these fractions for activity in human PBMC cultures. The largest Acai polysaccharides were the most active in vitro as indicated by activation of myeloid and γδ T cells. When delivered in vivo, Acai polysaccharide induced myeloid cell recruitment and IL-12 production. These results define innate immune responses induced by the polysaccharide component of Acai and have implications for the treatment of asthma and infectious disease.

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γδ T cell stimulatory activity in Acai is concentrated in the polysaccharide fraction and effective in all species tested.A) Aqueous extract of Acai was separated via EtOH precipitation or Kupchan fractionation. The resulting fractions were lyophilized, re-suspended in water, and tested in bovine PBMC culture for γδ T cell agonist activity. Data represent mean and SD from triplicate cultures from the same calf. EtOH precipitant (ppt.) responses are representative of cultures from three calves and three separate preparations. B) Human cells were cultured for 48 h with Acai-PS or medium prior to analysis for cell activation (CD69 expression) using flow cytometry. Values represent the average response of duplicate cultures from a single donor. Data are representative of two experiments. C) CFSE-labeled TCRα−/− splenocytes were cultured in X-VIVO with PBS, Yam-PS (9 µg/mL), or Acai-PS (10 µg/mL) for 24 h, then medium was replaced with fresh medium containing IL-2 and cultured for an additional 72 h. Percent cell proliferation was determined as the percent of γδ T cells (lymphocyte, GL3+ gates) or others (lymphocyte, GL3- gates) divided at least once and are representative of two Acai-PS preparations.
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pone-0017301-g001: γδ T cell stimulatory activity in Acai is concentrated in the polysaccharide fraction and effective in all species tested.A) Aqueous extract of Acai was separated via EtOH precipitation or Kupchan fractionation. The resulting fractions were lyophilized, re-suspended in water, and tested in bovine PBMC culture for γδ T cell agonist activity. Data represent mean and SD from triplicate cultures from the same calf. EtOH precipitant (ppt.) responses are representative of cultures from three calves and three separate preparations. B) Human cells were cultured for 48 h with Acai-PS or medium prior to analysis for cell activation (CD69 expression) using flow cytometry. Values represent the average response of duplicate cultures from a single donor. Data are representative of two experiments. C) CFSE-labeled TCRα−/− splenocytes were cultured in X-VIVO with PBS, Yam-PS (9 µg/mL), or Acai-PS (10 µg/mL) for 24 h, then medium was replaced with fresh medium containing IL-2 and cultured for an additional 72 h. Percent cell proliferation was determined as the percent of γδ T cells (lymphocyte, GL3+ gates) or others (lymphocyte, GL3- gates) divided at least once and are representative of two Acai-PS preparations.

Mentions: Acai fruit pulp was obtained from two sources: Acai 100 (Genesis Today; Austin, TX) and Acai Berry Pure (Acai Berry Pure Bulk; Carlsbad, CA). The Acai 100 preparation consisted of 100% pure, liquid-format Acai fruit and was used to obtain preliminary results (data not shown) as well as to prepare the preliminary EtOH precipitation and Kupchan fractionation [39] products assayed in Figure 1A (prepared by contract: PhytoMyco Research Corporation; Greenville, North Carolina).


Polysaccharides isolated from Açaí fruit induce innate immune responses.

Holderness J, Schepetkin IA, Freedman B, Kirpotina LN, Quinn MT, Hedges JF, Jutila MA - PLoS ONE (2011)

γδ T cell stimulatory activity in Acai is concentrated in the polysaccharide fraction and effective in all species tested.A) Aqueous extract of Acai was separated via EtOH precipitation or Kupchan fractionation. The resulting fractions were lyophilized, re-suspended in water, and tested in bovine PBMC culture for γδ T cell agonist activity. Data represent mean and SD from triplicate cultures from the same calf. EtOH precipitant (ppt.) responses are representative of cultures from three calves and three separate preparations. B) Human cells were cultured for 48 h with Acai-PS or medium prior to analysis for cell activation (CD69 expression) using flow cytometry. Values represent the average response of duplicate cultures from a single donor. Data are representative of two experiments. C) CFSE-labeled TCRα−/− splenocytes were cultured in X-VIVO with PBS, Yam-PS (9 µg/mL), or Acai-PS (10 µg/mL) for 24 h, then medium was replaced with fresh medium containing IL-2 and cultured for an additional 72 h. Percent cell proliferation was determined as the percent of γδ T cells (lymphocyte, GL3+ gates) or others (lymphocyte, GL3- gates) divided at least once and are representative of two Acai-PS preparations.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3046208&req=5

pone-0017301-g001: γδ T cell stimulatory activity in Acai is concentrated in the polysaccharide fraction and effective in all species tested.A) Aqueous extract of Acai was separated via EtOH precipitation or Kupchan fractionation. The resulting fractions were lyophilized, re-suspended in water, and tested in bovine PBMC culture for γδ T cell agonist activity. Data represent mean and SD from triplicate cultures from the same calf. EtOH precipitant (ppt.) responses are representative of cultures from three calves and three separate preparations. B) Human cells were cultured for 48 h with Acai-PS or medium prior to analysis for cell activation (CD69 expression) using flow cytometry. Values represent the average response of duplicate cultures from a single donor. Data are representative of two experiments. C) CFSE-labeled TCRα−/− splenocytes were cultured in X-VIVO with PBS, Yam-PS (9 µg/mL), or Acai-PS (10 µg/mL) for 24 h, then medium was replaced with fresh medium containing IL-2 and cultured for an additional 72 h. Percent cell proliferation was determined as the percent of γδ T cells (lymphocyte, GL3+ gates) or others (lymphocyte, GL3- gates) divided at least once and are representative of two Acai-PS preparations.
Mentions: Acai fruit pulp was obtained from two sources: Acai 100 (Genesis Today; Austin, TX) and Acai Berry Pure (Acai Berry Pure Bulk; Carlsbad, CA). The Acai 100 preparation consisted of 100% pure, liquid-format Acai fruit and was used to obtain preliminary results (data not shown) as well as to prepare the preliminary EtOH precipitation and Kupchan fractionation [39] products assayed in Figure 1A (prepared by contract: PhytoMyco Research Corporation; Greenville, North Carolina).

Bottom Line: Similar polyphenol and polysaccharide fractions are found in Acai fruit.Contrary to previous reports, we did not identify agonist activity in the polyphenol fraction; however, the Acai polysaccharide fraction induced robust γδ T cell stimulatory activity in human, mouse, and bovine PBMC cultures.When delivered in vivo, Acai polysaccharide induced myeloid cell recruitment and IL-12 production.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology and Infectious Diseases, Montana State University, Bozeman, Montana, United States of America.

ABSTRACT
The Açaí (Acai) fruit is a popular nutritional supplement that purportedly enhances immune system function. These anecdotal claims are supported by limited studies describing immune responses to the Acai polyphenol fraction. Previously, we characterized γδ T cell responses to both polyphenol and polysaccharide fractions from several plant-derived nutritional supplements. Similar polyphenol and polysaccharide fractions are found in Acai fruit. Thus, we hypothesized that one or both of these fractions could activate γδ T cells. Contrary to previous reports, we did not identify agonist activity in the polyphenol fraction; however, the Acai polysaccharide fraction induced robust γδ T cell stimulatory activity in human, mouse, and bovine PBMC cultures. To characterize the immune response to Acai polysaccharides, we fractionated the crude polysaccharide preparation and tested these fractions for activity in human PBMC cultures. The largest Acai polysaccharides were the most active in vitro as indicated by activation of myeloid and γδ T cells. When delivered in vivo, Acai polysaccharide induced myeloid cell recruitment and IL-12 production. These results define innate immune responses induced by the polysaccharide component of Acai and have implications for the treatment of asthma and infectious disease.

Show MeSH
Related in: MedlinePlus