Effects of Aluminum Maltolate Ingestion on the Immune Response of SD Rats

• Main Authors: Kuo,Pei-Jung, 郭姉傛
• Other Authors: Hsu Wang, Guoo-Shyng
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/90935747567679423869

碩士 === 輔仁大學 === 營養科學系 === 100 === The prevalence of allergy has been related to genetic and environmental factors which are responsible for the predisposition and expression of allergy. The allergic reactions are associated with the stronger type 2 T helper cell (Th2) response. Aluminum salts have been used as common adjuvants in vaccines for 80 years. Aluminum salt makes the vaccine more effective, and mainly induces the humoral immunity which activates Th2 response. The aluminum content of infant formula is higher than the breast milk. Although the absorption of dietary Al is low (<0.3%), Al metabolism in the body may be affected in neonates who have immature kidneys. On the other hand, maltol is a legal flavor enhancer and has a high affinity with Al, which may enhance the Al absorption in the gastrointestinal tract. Therefore, the present study aimed to understand the effects of Al on immune system of neonates, and whether those animals with higher plasma and/or tissues Al levels are more susceptible to specific antigen. The purpose of the first experiment is to compare the absorption of aluminum maltolate with aluminum chloride, done by a gavage animal model. Three-day-old pups were divided into four groups with gavage twice a day of 0 (Control, C), 0 (Maltol, M), 1.3 (Al maltolate, ALM) and 1.3 (Al chloride, AlCl3) µg Al/g b.wt/day respectively for 14 days. Then, blood, liver and brain were collected for analysis. Results showed that Al levels in serum and tissues of animals in ALM were the highest among 4 groups. In the second experiment, 3-day-old pups were divided into three groups with gavage of 0 (Control, C), 0 (Maltol, M) and 1.3 (Al maltolate, ALM) µg Al/g b.wt/day respectively. After weaning, animals were continuously fed with semi-purified diet (AIN93G) through drinking water provided DI water, maltol (0.035%) water and aluminum maltolate (25 mg/L) water respectively throughout the experiment period. OVA/TiterMax Gold adjuvant-immunization were intra- peritoneally injected to rats at 7-week of age. Blood samples were collected at the ages of 3, 6 , 12 week respectively. At the age of 12-week, animals were sacrificed, followed by collection of blood, liver, spleen and mesenteric lymph node (MLN) for analysis. Cell proliferation and cytokine concentration of splenocyte and MLN lymphocyte were also measured. Results showed body weight of the rats significantly decreased in ALM group. The ratio of spleen weight/body weight in the ALM group was the highest among 3 groups. The Al concentration of organs and serum in the ALM group were highest among 3 groups. In the systemic immunity, the level of IgG was significantly lowest in ALM group. There was no significant difference of cell proliferation or cytokine concentrations of splenocytes among experimental groups. Meanwhile, the level of IgA in homogenized intestine fluid was significantly lowest in ALM group. There was no significant of cell proliferation or cytokine concentrations of MLN among 3 groups. In conclusions, dietary Al maltolate with Al level equivalents to infant formula seems to be better absorbed than AlCl3 by neonatal pups. Al contents in serum, spleen, liver, and kidney were significantly elevated with dietary Al-maltolate treatment for 12 weeks. In addition, the higher Al content in the body indeed changed the immune responses, however, there was no sign of the immune response toward Th2 under the blood and tissues Al levels in this study.