Effect of silicon-rich water intake on the systemic and peritoneal inflammation of rats with chronic low levels of aluminum ingestion.

BACKGROUND AND OBJECTIVES: Study evaluated effect of silicon-rich water intake on systemic inflammation and functional characteristics of peritoneal macrophages (PMs) of rats that were chronically exposed to dietary aluminum.

METHODS: One month-old female Wistar Albino rats were administered aluminum chloride dissolved in distilled water (1.6mg/kg body weight in 0.5mL) by gavage for 90days. The rats were then given standard (6mg/L) or silicon-rich water (19mg/L silicon) (n=7/group). Control rats underwent sham gavage and received standard or silicon-rich water (n=7/group). Blood was assessed for cytokine levels. Unstimulated and lipopolysaccharide (LPS)-stimulated PMs were assessed in terms of phagocytic activity and cytokine secretion in vitro.

RESULTS: Chronic exposition to dietary aluminum and silicon-rich drinking water did not change serum TNF-α levels. Aluminum increased serum IL-2 and this was reversed by silicon-rich water. The aluminum-exposed rats had higher serum sICAM-1 than sham-gavaged, unrelated to type of water. LPS-stimulated PMs from aluminum-intoxicated animals exhibited low phagocytic activity and release of TNF-α, this was significantly improved by silicon-rich water intake. In the presence of silicon-rich water, LPS-stimulated and unstimulated PMs from aluminum-exposed rats produced significantly more IL-10.

CONCLUSIONS: Chronic ingestion of aluminum, increases systemic and peritoneal inflammation and PM dysfunction. The presence of high levels of the natural aluminum antagonist silicon in the drinking water restored IL-10 and TNF-α PM secretion, preventing prolonged inflammation. Thus, silicon intake can decrease the immunotoxicity of aluminum.