Amazoniac
Member
- From 1989 to 2001: What Have We Learned About the “Biological Actions of Beta-Carotene”?
- Carotenoid Action on the Immune Response
- Vitamin A and b-Carotene on Host Defense
"Cohen and Elin (30) reported that mice injected with retinyl palmitate showed increased resistance against gram-positive and gram-negative bacterial and fungal infections. Similarly, Hof and Emerling (60) showed that rats fed retinyl acetate had a 100-fold increase in resistance to Listeria infection. In a germ-free environment, vitamin A-deficient rats were able to survive for long periods (96), again demonstrating the importance of vitamin A on disease resistance."
"The lymphoid organs play a central role in the function of the immune system. Both poison/"vitamin" A and b-carotene influence cellularity and function of the lymphoid organs. Vitamin A-deficient rats and chickens show increased involution of the spleen and thymus (8, 21, 36, 68, 77, 121). Butera and Krakowka (19) recently reported that rats fed a diet deficient in vitamin A showed decreased cellularity in the bursal (B)-cell germinal centers and the periarteriolar thymal (T)-cell sheaths of the spleen and also showed decreased cellularity in the cortex of the thymus as compared with pair-fed controls. Similarly, vitamin A-deficient mice showed decreased cellularity in the regional lymph nodes (109)."
"b-Carotene supplementation [] seems to be beneficial to the development of the lymphoid organs. Mice fed b-carotene showed increased thymic size and increased number of small thymic lymphocytes (98). Therefore, through their effects on growth and cell differentiation, vitamin A and b-carotene seem to influence the cellularity and function of lymphoid organs."
"b-Carotene behaves in opposition to vitamin A in its effect on IFN action. b-Carotene potentiates the stimulatory action of IFN on monocyte FcT-receptor and inhibits the cytostatic action of IFN (93). Therefore, the net effect of b-carotene in this study was to potentiate both cellular activation and proliferation while the reverse effects were true for retinoic acid. These opposing effects between vitamin A and b-carotene may represent specific responses according to the specific needs of the host animal."
Regardless of applications of the orange parts, I think that it's interesting for you to start searching for how preformed poison A differentially affects immunity when compared to propoison A carotteners.
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- Novel Action of Carotenoids on Non-Alcoholic Fatty Liver Disease: Macrophage Polarization and Liver Homeostasis
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- 9-Cis-13,14-dihydroretinoic acid, a new endogenous mammalian ligand of retinoid X receptor and the active ligand of a potential new vitamin A category: vitamin A5 (!)
"[b-Carotene] could enhance lymphocyte proliferation independent of its pro-vitamin A function (38). It is entirely possible that all of the subsequent actions described [] are a consequence of the antioxidant/singlet oxygen quenching capacity of beta-carotene; however, that specific link has not been made in all studies of immune function."
"Delayed type hypersensivity (DTH)2 skin test responses, a well accepted index of overall immune function, also were unaffected by supplementation in nonimmune-stressed populations, but DTH responses were maintained when beta-carotene supplements were taken prior to UV exposure in both young and senior men (20,21). Thus, when UV or cancer stresses the immune system, there may be a role for beta-carotene as an immunoenhancer. There are also three reports of enhanced Natural Killer (NK) cell cytotoxicity in seniors (9,10,22). NK cells are considered to be critical in recognizing and killing malignant cells in the body."
"Delayed type hypersensivity (DTH)2 skin test responses, a well accepted index of overall immune function, also were unaffected by supplementation in nonimmune-stressed populations, but DTH responses were maintained when beta-carotene supplements were taken prior to UV exposure in both young and senior men (20,21). Thus, when UV or cancer stresses the immune system, there may be a role for beta-carotene as an immunoenhancer. There are also three reports of enhanced Natural Killer (NK) cell cytotoxicity in seniors (9,10,22). NK cells are considered to be critical in recognizing and killing malignant cells in the body."
- Carotenoid Action on the Immune Response
"Many earlier studies focused on β-carotene (6). Seifter et al. (7) reported a marked stimulatory action of β-carotene on the growth of the thymus gland and a large increase in the number of thymic small lymphocytes."
"Besides cell-mediated and humoral immune responses, β-carotene has been shown to regulate nonspecific cellular host defense. Blood neutrophils isolated from cattle fed β-carotene had higher killing ability during the peripartum period (19). The increased bacterial killing could be accounted for partly by increased myeloperoxidase activity in the neutrophils. Tjoelker et al. (20) reported that dietary β-carotene stimulated phagocytic and bacterial killing ability of neutrophils from dairy cows during the stressful drying off period. In contrast, retinol and retinoic acid generally decreased phagocytosis and had no effect on killing activity."
"A specific role of carotenoids on immune response was first reported by Bendich and Shapiro (8). They showed that rats fed canthaxanthin, a carotenoid with no provitamin A activity, had a heightened mitogen-induced lymphocyte proliferation; dietary β-carotene showed similar action. Subsequent studies have similarly reported the immuno-enhancing action of carotenoids without provitamin A activity, notably lutein, lycopene, astaxanthin and canthaxanthin. Canthaxanthin enhanced the expression of activation markers for Th and NK cells in human PBMC in vitro (21). Jyonouchi et al. (22) reported that lutein and astaxanthin increased the ex vivo antibody response of mouse splenocytes to T-cell antigens. Schwartz et al. (23) reported increased cytochrome oxidase and peroxidase activities in macrophages incubated with canthaxanthin, β-carotene, and α-carotene compared with incubation with 13-cis retinoic acid. The stimulatory activity of canthaxanthin was greater than that observed with β-carotene and α-carotene. Phagocytosis also was stimulated by these carotenoids, even though to a lower degree. All of these changes indicate increased respiratory bursts by the macrophages when they are exposed to carotenoids."
"The domestic dog and cat have recently been used in parallel studies using similar experimental designs to compare the immuno-modulatory role of carotenoids. These studies thus provide direct comparisons between carotenoids with (β-carotene) or without (lutein) provitamin A activity, and also between species that can (dogs) or that are very inefficient converters (cats) of β-carotene to vitamin A. Dietary β-carotene (24) and lutein (25) stimulated DTH response, the number of CD4+Th cells, and IgG production in dogs, thus demonstrating that lutein, a carotenoid without provitamin A activity, exerts a similar immuno-modulating action as β-carotene."
"In contrast, lutein but not β-carotene enhanced mitogen-induced lymphocyte proliferation in dogs, indicating species differences in the lymphocyte proliferation response to a given dietary carotenoid. Cats fed β-carotene (unpublished data, Park et al.) or lutein (26) also showed heightened DTH response, higher Th and B cell subpopulations, and increased plasma IgG concentrations. It can be concluded that the actions of both β-carotene and lutein in cats are not due to their prior conversion to vitamin A because cats are poor converters of β-carotene to vitamin A."
"Besides cell-mediated and humoral immune responses, β-carotene has been shown to regulate nonspecific cellular host defense. Blood neutrophils isolated from cattle fed β-carotene had higher killing ability during the peripartum period (19). The increased bacterial killing could be accounted for partly by increased myeloperoxidase activity in the neutrophils. Tjoelker et al. (20) reported that dietary β-carotene stimulated phagocytic and bacterial killing ability of neutrophils from dairy cows during the stressful drying off period. In contrast, retinol and retinoic acid generally decreased phagocytosis and had no effect on killing activity."
"A specific role of carotenoids on immune response was first reported by Bendich and Shapiro (8). They showed that rats fed canthaxanthin, a carotenoid with no provitamin A activity, had a heightened mitogen-induced lymphocyte proliferation; dietary β-carotene showed similar action. Subsequent studies have similarly reported the immuno-enhancing action of carotenoids without provitamin A activity, notably lutein, lycopene, astaxanthin and canthaxanthin. Canthaxanthin enhanced the expression of activation markers for Th and NK cells in human PBMC in vitro (21). Jyonouchi et al. (22) reported that lutein and astaxanthin increased the ex vivo antibody response of mouse splenocytes to T-cell antigens. Schwartz et al. (23) reported increased cytochrome oxidase and peroxidase activities in macrophages incubated with canthaxanthin, β-carotene, and α-carotene compared with incubation with 13-cis retinoic acid. The stimulatory activity of canthaxanthin was greater than that observed with β-carotene and α-carotene. Phagocytosis also was stimulated by these carotenoids, even though to a lower degree. All of these changes indicate increased respiratory bursts by the macrophages when they are exposed to carotenoids."
"The domestic dog and cat have recently been used in parallel studies using similar experimental designs to compare the immuno-modulatory role of carotenoids. These studies thus provide direct comparisons between carotenoids with (β-carotene) or without (lutein) provitamin A activity, and also between species that can (dogs) or that are very inefficient converters (cats) of β-carotene to vitamin A. Dietary β-carotene (24) and lutein (25) stimulated DTH response, the number of CD4+Th cells, and IgG production in dogs, thus demonstrating that lutein, a carotenoid without provitamin A activity, exerts a similar immuno-modulating action as β-carotene."
"In contrast, lutein but not β-carotene enhanced mitogen-induced lymphocyte proliferation in dogs, indicating species differences in the lymphocyte proliferation response to a given dietary carotenoid. Cats fed β-carotene (unpublished data, Park et al.) or lutein (26) also showed heightened DTH response, higher Th and B cell subpopulations, and increased plasma IgG concentrations. It can be concluded that the actions of both β-carotene and lutein in cats are not due to their prior conversion to vitamin A because cats are poor converters of β-carotene to vitamin A."
- Vitamin A and b-Carotene on Host Defense
- Vitamin A and b-carotene are required by animals for maintaining the cellularity of the lymphoid organs (thymus, lymph nodes, spleen). Deficiencies also lead to impaired lymphocyte trapping in these organs.
- Vitamin A and b-carotene are immunostimulatory. They enhance mitogen-induced lymphocyte proliferation, delayed-type hypersensitivity, transplant rejection, cell-mediated cytotoxicity, and natural killer cell activity. Vitamin A also stimulates the production of IL-2 by lymphocytes and IL-1 by macrophages but suppresses IFN production by lymphocytes.
- Vitamin A and b-carotene seem to act in opposition in influencing the action of IFN.
- Vitamin A appears to act in the induction phase of immunity. It stimulates T killer cell activity and possibly acts on proliferating helper-type T cells that participate in the inductive phase of T killer sensitization.
- Vitamin A also enhances humoral immunity. It increases serum antibody, number of splenic antibody-forming ceils and local immunity. It is also capable of inhibiting the immunosuppressive effect of hydrocortisone.
- Vitamin A enhances phagocytosis and intracellular kill by PMN and macrophages.
"Cohen and Elin (30) reported that mice injected with retinyl palmitate showed increased resistance against gram-positive and gram-negative bacterial and fungal infections. Similarly, Hof and Emerling (60) showed that rats fed retinyl acetate had a 100-fold increase in resistance to Listeria infection. In a germ-free environment, vitamin A-deficient rats were able to survive for long periods (96), again demonstrating the importance of vitamin A on disease resistance."
"The lymphoid organs play a central role in the function of the immune system. Both poison/"vitamin" A and b-carotene influence cellularity and function of the lymphoid organs. Vitamin A-deficient rats and chickens show increased involution of the spleen and thymus (8, 21, 36, 68, 77, 121). Butera and Krakowka (19) recently reported that rats fed a diet deficient in vitamin A showed decreased cellularity in the bursal (B)-cell germinal centers and the periarteriolar thymal (T)-cell sheaths of the spleen and also showed decreased cellularity in the cortex of the thymus as compared with pair-fed controls. Similarly, vitamin A-deficient mice showed decreased cellularity in the regional lymph nodes (109)."
"b-Carotene supplementation [] seems to be beneficial to the development of the lymphoid organs. Mice fed b-carotene showed increased thymic size and increased number of small thymic lymphocytes (98). Therefore, through their effects on growth and cell differentiation, vitamin A and b-carotene seem to influence the cellularity and function of lymphoid organs."
"b-Carotene behaves in opposition to vitamin A in its effect on IFN action. b-Carotene potentiates the stimulatory action of IFN on monocyte FcT-receptor and inhibits the cytostatic action of IFN (93). Therefore, the net effect of b-carotene in this study was to potentiate both cellular activation and proliferation while the reverse effects were true for retinoic acid. These opposing effects between vitamin A and b-carotene may represent specific responses according to the specific needs of the host animal."
Regardless of applications of the orange parts, I think that it's interesting for you to start searching for how preformed poison A differentially affects immunity when compared to propoison A carotteners.
No doubt, moderator. Also, becoming too wealthy from being toxin-free is boring, we has got to live on the edge.
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- Novel Action of Carotenoids on Non-Alcoholic Fatty Liver Disease: Macrophage Polarization and Liver Homeostasis
"Astaxanthin is well known for its strong antioxidant capacity [113]. It is 100–500-fold more effective than vitamin E at preventing lipid peroxidation." (?)
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- 9-Cis-13,14-dihydroretinoic acid, a new endogenous mammalian ligand of retinoid X receptor and the active ligand of a potential new vitamin A category: vitamin A5 (!)
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