Does aluminium stimulate the immune system in male rats after oral exposure?

Hematological and immunological impairment following in-utero and postnatal exposure to aluminum sulfate in female offspring of albino rats

Aim: Aluminum (Al) is a ubiquitous element extensively utilized in many products like food additives, pharmaceuticals, and vaccines, but its hematotoxic and immunotoxic effects are not entirely clarified. The present study explored the developmental hematotoxic and immunotoxic properties of aluminum sulfate (AS) in rats' offspring. Methods: Forty female offspring (10 rats each) were given three incremental AS doses plus a control group, from conception through lactation and after weaning until reached eight weeks old (near adults). Spleen relative weights along with total and differential blood counts were evaluated. Spectroscopic Al levels in spleen and brain were analyzed. Three immunoglobulins (IgG, IgM, and IgE) and two cytokines, interferon-γ and tumor necrosis factor-α, were measured through the ELISA technique. Results: The results revealed a significant relative increase in splenic weights mostly observed in the highest AS dose treated group. Reduction in the total leukocytic count was noticed in the three AS treated groups with relative lymphocytosis. Additionally, a significant decline in RBCs counts and hemoglobin concentrations were recorded. Tumor necrosis factor-α was significantly elevated in the three Al treated groups, while, interferon- γ showed a non-significant reduction compared to the control group. A significant increment in IgG and decline in IgE concentrations with no change in IgM level among groups were observed. Conclusion: Perinatal AS exposure caused mostly non-linear dose-dependent hematotoxicity and immunological impairment especially for the acquired immunity either cellular or humoral. Further studies can examine the immunotoxic effect of Al on male offspring during different stages of immune development.

impact of aluminum exposure on the immune system: a mini review

Aluminum (Al) is widely used in daily life and will lead to environmental release and exposure. The toxicity of Al had been documented, and which attracted a growing concern on human and animal health. The immune system appears to be sensitive to Al exposure. But few studies focused on the potential immunological responses induced by Al. It is imperative to study the effects of Al on the immune function and this review discusses the effects of Al on autoimmunity, oral tolerance, expression of the immune cells, hypersensitivity and erythrocyte immune function. It will provide evidence to study the association between Al and immune function.

Effects of aluminum on immune functions of cultured splenic T and B lymphocytes in rats

The effects of Aluminum (Al) exposure on immune functions of cultured splenic T and B lymphocytes of rats were studied. The lymphocytes were isolated from spleen of healthy male Wistar rats weighing 110-120 g. The cultured cells in RPMI-1640 medium were exposed to 0 (control group), 0.035 (low-dose group), 0.07 (medial-dose group), and 0.14 (high-dose group) mg/mL Al(3+) as aluminum trichloride (AlCl(3)) in an incubator under 5% CO(2) at 37°C for 24 h. The T and B lymphocyte proliferation was measured with a tetrazolium dye colorimetric assay. The levels of interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α were determined by iodine [(125)I] IL-2, IL-6, and TNF-α radioimmunoassay kits, respectively. The proportions of CD3(+), CD4(+), and CD8(+) T lymphocytes were measured with a flow cytometer. The results showed that the T and B lymphocyte proliferation, the levels of IL-2, IL-6, TNF-α, the proportions of CD3(+) and CD4(+) T lymphocytes, and the ratio of CD4(+)/CD8(+) T lymphocytes were lowered by Al treatments, while the proportion of CD8(+) T lymphocytes was increased. These findings indicate that Al exposure can inhibit the immune functions of splenic T and B lymphocytes of rats in vitro.

Suppressive effects of aluminum trichloride on the T lymphocyte immune function of rats

Aluminum (Al) has increasingly been used in the daily life, and could cause the change of human health because it can accumulate in the organs. A rat model was thus used to examine potential effect of Al on the immune function. Forty male Wistar rats (5 weeks old) weighed 110-120 g were randomly allocated into four groups and were orally exposed to 0, 64.18, 128.36, and 256.72 mg/kg body weight aluminum trichloride (AlCl3) in drinking water for 120 days. The levels of CD3+, CD4+, CD8+ T lymphocyte, acid non-specific activity esterase (ANAE+) in blood, and interleukin-2 (IL-2) and tumor necrosis factor-α (TNF-α) in serum were determined at the end of experiment. The results showed that the proportions of CD3+, CD4+ T lymphocyte, the ratio of CD4+/CD8+, and the levels of ANAE+, IL-2, and TNF-α were significantly reduced in AlCl3-treated rats, while the proportion of CD8+ T lymphocyte was increased in an AlCl3-dose dependent manner. Our findings indicate that a long term exposure of AlCl3 could suppress the T lymphocyte immune function of rats.

Cytotoxicity of environmentally relevant concentrations of aluminum in murine thymocytes and lymphocytes

The effects of low concentrations of aluminum chloride on thymocytes and lymphocytes acutely dissociated from young mice were studied using flow cytometry with a DNA-binding dye. We demonstrate a rapid and dose-dependent injury in murine thymocytes and lymphocytes resulting from exposure to aluminum, as indicated by an increase in the entry into the cell of the DNA-binding dye, propidium iodine. A 60-minute exposure to 10 μM AlCl₃ caused damage of about 5% of thymocytes, while 50% were injured after 10 minutes at 20 μM. Nearly all thymocytes showed evidence of damage at 30 μM AlCl₃ after only 5 minutes of incubation. In lymphocytes, injury was observed at 15 μM AlCl₃ and less than 50% of cells were injured after a 60-minute exposure to 20 μM. Injury only rarely proceeded to rapid cell death and was associated with cell swelling. These results suggest that aluminum has cytotoxic effects on cells of the immune system.

Aluminium cycling in the soil-plant-animal-human continuum

A critical review of the literature on Al toxicity in plants, animals and humans reveals a similar mode of Al action in all living organisms, namely interference with the secondary messenger system (phosphoinositide and cytosolic Ca2+ signalling pathways) and enhanced production of reactive oxygen species resulting in oxidative stress. Aluminium uptake by plants is relatively quick (across the intact plasma membrane in < 30 min and across the tonoplast in < 1 h), despite huge proportion of Al being bound in the cell wall. Aluminium absorption in the animal/human digestive system is low (only about 0.1% of daily Al intake stays in the human body), except when Al is complexed with organic ligands (eg. citrate, tartarate, glutamate). Aluminium accumulates in bones and brain, with Al-citrate and Al-transferrin complexes crossing the blood-brain barrier and accumulating in brain cells. Tea plant and other Al-accumulator plant species contain large amounts of Al in the form of non-toxic organic complexes.