Recommended Daily Dose of Sesame Lignans Has No Influence on Oral Absorption of P-Glycoprotein Substrates in Rats

Sesamin (SM) and episesamin (ESM) are constituents of sesame seeds, which are used in health foods and considered to have various beneficial effects in the prevention of lifestyle-related diseases. P-Glycoprotein (P-gp) is an ATP-binding cassette transporter involved in drug absorption in the human gastrointestinal tract. A recent report indicated that SM influences P-gp-mediated drug transport. In the present study, we investigated whether SM and ESM inhibit P-gp in vitro, using Caco-2 cells and the typical P-gp substrates rhodamine123 (Rho123) and fexofenadine. SM and ESM showed no effect on accumulation of these compounds, indicating that SM and ESM do not influence P-gp function. In addition, an in vivo study using Rho123 indicated that SM and ESM do not affect absorption of P-gp substrates. Overall, these results suggest that health foods containing SM and ESM are unlikely to interact with P-gp substrates.