Does 3-pentadecylcatechol, an urushiol derivative, get absorbed in the body? A rat oral administration experiment

Urushiols are important active compounds foundin the sap of the lacquer tree (Rhus verniciflua Stokes). Recently, various biological effects of urushiols, such asantioxidant, antimicrobial, and anticancer activities, havebeen reported. However, urushiols can also induce skinallergies. Nevertheless, the lacquer tree has traditionallybeen used in Korea as a folk medicine. In this study, weevaluated the absorption and metabolism of 3-pentadecylcatechol(PDC), a natural urushiol. PDC (48.0 mg/kg bodywt.) in 1 mL propylene glycol was orally administered torats (Sprague-Dawley, male, 6 weeks old). Blood plasma,urine, and feces were collected, separately. PDC was notdetected in the extracts from rat blood plasma and urine. However, 89.4 ± 5.2% of the orally administered PDCwas detected in the feces extracts, indicating that PDC waspredominantly excreted and not absorbed.