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

Area of Science:

• Nutritional Science
• Toxicology
• Pharmacokinetics

Background:

• Tea consumption is widespread, offering health benefits.
• Some teas contain high fluoride levels, posing a risk of fluorosis.
• The impact of individual tea components on fluoride bioavailability is not well understood.

Purpose of the Study:

• To investigate the effects of major tea constituents on fluoride metabolism in rats.
• To elucidate the distinct roles of tea components in mitigating fluoride bioavailability.

Main Methods:

• Male rats were administered fluoride alone or with varying doses of epigallocatechin gallate (EGCG), theaflavins, thearubigins, theabrownin (TB), tea polysaccharides (TPSs), calcium (Ca), and aluminum (Al).
• Pharmacokinetic analysis of plasma fluoride levels over 480 minutes was performed.
• Fecal fluoride excretion was measured to assess absorption and elimination.

Main Results:

• High-dose EGCG significantly reduced peak plasma fluoride concentration (Cmax) and total exposure (AUC0-t), while increasing fecal fluoride excretion.
• Theabrownin (TB) delayed fluoride absorption and reduced Cmax.
• Tea polysaccharides (TPSs) decreased Cmax and AUC0-t, and both calcium (Ca) and aluminum (Al) reduced Cmax, with low-dose aluminum increasing fecal fluoride.

Conclusions:

• Epigallocatechin gallate (EGCG), theabrownin (TB), and tea polysaccharides (TPSs) play distinct roles in reducing fluoride bioavailability.
• Calcium (Ca) and aluminum (Al) also influence fluoride absorption.
• These findings provide a scientific basis for assessing tea safety and developing dietary strategies to prevent fluoride overexposure.