# 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.

## Key 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.