Single-dose comparative pharmacokinetic/pharmacodynamic study of a micellar formulation versus a native Boswellia serrata dry extract in healthy volunteers

Extracts of oleogum resins of Boswellia trees possess anti-inflammatory activities. Micellar formulations have been developed to increase the oral bioavailability of bioactive boswellic and lupeolic acids. The current single-dose crossover clinical trial compares for the first time pharmacokinetics/pharmacodynamics of two Boswellia serrata nutraceuticals, native Biotikon® BS-85 and micellar Boswellia-Loges®. After oral administration of the study preparations (800 mg) to 20 healthy volunteers, plasma concentrations of 8 boswellic and lupeolic acids were measured by using HPLC-MS/MS for up to 48 h Blood samples collected 2 and 5 h after drug administration were stimulated for 24 h with endotoxic lipopolysaccharide. The release of proinflammatory cytokines analyzed by flow cytometry was used as readout of the pharmacodynamic properties of the preparations. Registration: German Clinical Trials Register (DRKS) No. DRKS00027369. Administration of the micellar extract significantly increased Cmax, AUC0–48, and shortened Tmax for all boswellic and lupeolic acids compared to native extract. Accordingly, their relative bioavailability increased to 1,720-4,291 % with the highest difference for acetyl-11-keto-β-boswellic acid (AKBA). Both preparations reduced the release of TNF-α and the native formulation diminished also IL-1β and IL-6. However, no significant differences were observed between the preparations, except for a higher decrease in IL-1β by the native formulation Biotikon® BS-85. In a lymphocytic gene reporter cell line, both nutraceuticals similarly inhibited the NF-κB transcription factor activity as well as the TNF-α release, yet the native formulation Biotikon®BS-85 was more efficient in inhibiting TNF-α. Administration of the micellar Boswellia serrata nutraceutical increased the oral bioavailability of boswellic and lupeolic acids. Yet, the increase in plasma concentration did not enhance the anti-inflammatory efficacy of the micellar extract compared to the native extract in this ex vivo model.