Studies of the Toxicological Potential of Capsinoids XIV: A 26-week Gavage Toxicity Study of Dihydrocapsiate in Rats

To further evaluate the safety of dihydrocapsiate (4-hydroxy-3-methoxybenzyl 8-methylnonanoate, CAS No. 205687-03-2), a 26-week gavage toxicity study was conducted in Sprague-Dawley rats (20/sex/group). Test animals received either dihydrocapsiate, 100, 300, or 1000 mg/kg/day, or vehicle (medium-chain triglyceride) by gavage and were observed for antemortem and postmortem signs of toxicity including changes in clinical signs, body weights, food consumption, water intake, ophthalmology, clinical pathology (clinical chemistry, hematology, urinalysis), tissue findings (macroscopic and microscopic examination), as well as organ weights. After the end of the dosing period, reversibility was assessed (10/sex/group for the control and 1000 mg/kg groups) following a 4-week recovery period. There were no adverse or toxicological changes observed in clinical signs, body weight, food consumption, water intake, ophthalmology, urinalysis, hematology, blood chemistry, organ weights, or histopathology. It was concluded that the no observable adverse effect level (NOAEL) of dihydrocapsiate was 1000 mg/kg/day for both sexes in this 26-week gavage study.