Modulatory Effects of Tea Components with Different Fermentation Degrees on Fluoride Bioavailability in Rats

TL;DR

This study shows how different tea components can reduce fluoride absorption in rats, potentially helping prevent fluorosis.

Contribution

The study identifies specific tea compounds that modulate fluoride bioavailability in rats.

Findings

High-dose EGCG reduced plasma fluoride levels and increased fecal excretion.

Theabrownin delayed fluoride absorption and reduced peak concentration.

Tea polysaccharides and calcium/aluminum also significantly reduced fluoride bioavailability.

Abstract

Tea offers health benefits, but some teas accumulate high fluoride (F), posing fluorosis risks. However, the roles of individual tea components in regulating F bioavailability remain unclear. This study investigated the effects of major tea constituents on F metabolism in male rats (n = 5/group) administered F (40 mg/L) alone or with graded doses of epigallocatechin gallate (EGCG, 150–450 mg/kg); theaflavins, thearubigins, and theabrownin (TFs, TRs, TB, 200–800 mg/kg each); tea polysaccharides (TPSs, 25–250 mg/kg); and calcium and aluminum (Ca, Al, 800–3200 µg/kg each) via gavage. Pharmacokinetic analysis of plasma F (0–480 min) and fecal F excretion were assessed. The result showed that high-dose EGCG (450 mg/kg) reduced Cmax by 61.76% and total exposure (AUC0–t) by 37.48% compared to the control, while significantly increasing fecal F by 26.79% (p < 0.05). TB (800 mg/kg) delayed F absorption by prolonging Tmax from 18 to 30 min and reduced Cmax by 35.38% (p < 0.05). TPS (250 mg/kg) decreased Cmax by 51.72% and AUC0–t by 24.38% (p < 0.05). Ca and Al (800–3200 µg/kg) reduced Cmax by 39.19–69.62%, and low-dose aluminum (800 µg/kg) increased fecal F by 35.58% (p < 0.05). These findings elucidate distinct roles of tea constituents in mitigating F bioavailability, providing a scientific basis for tea safety assessment and dietary interventions against F overexposure.

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