Editor's Note: This limited study assessed the effect of resveratrol on the pharmacokinetics of diclofenac, the nonsteroidal anti-inflammatory drug, in 12 healthy human volunteers. Resveratrol significantly enhanced maximum plasma concentration, area under the curve, half-life, decreased elimination rate constant, and apparent oral clearance of diclofenac compared to control. The authors suggested that the altered pharmacokinetics might be attributed to resveratrol mediated inhibition of CYP2C9 enzyme.

Phytotherapy Research 

DOI: 10.1002/ptr.5539 

December 3, 2015 

Effect of Resveratrol Treatment on the Pharmacokinetics of Diclofenac in Healthy Human Volunteers

Abstract:

The purpose of the present study was to assess the effect of resveratrol (RSV) treatment on the pharmacokinetics of diclofenac (DIC) in healthy human volunteers. The open-label, two period, sequential study was conducted in 12 healthy human volunteers. A single dose of RSV 500 mg was administered daily for 10 days during treatment phase. A single dose of DIC 100 mg was administered during control and after treatment phases under fasting conditions. The blood samples were collected after DIC dosing and analyzed by HPLC. Treatment with RSV significantly enhanced maximum plasma concentration (C_max) (1.73 to 2.91 µg/mL), area under the curve (AUC) (5.05 to 9.95 µg h/mL), half life (T_1/2) (1.12 to 1.76 h) and significantly decreased elimination rate constant (K_el) (0.71 to 0.41 h⁻¹), apparent oral clearance (CL/F) (14.58 to 6.48 L/h) of DIC as compared to control. The geometric mean ratios for C_max, AUC, T_1/2, K_el and CL/F of DIC were 1.75, 2.12, 1.65, 0.61 and 0.47, respectively were outside the limits of 0.8–1.25, which indicates clinically significant interaction between DIC and RSV. The results suggest that the altered pharmacokinetics of DIC might be attributed to RSV mediated inhibition of CYP2C9 enzyme. Therefore, combination therapy of DIC along with RSV may represent a novel approach to reduce dosage and results in reduced gastrointestinal side effects of DIC.