Anti-inflammatory potential of a lipid-based formulation of a rotenoid-rich fraction prepared from Boerhavia diffusa

Abstract

Context: Boerhavia diffusa L. (Nyctaginaceae) roots are used in Ayurveda for treating inflammatory diseases. Generally poor oral bioavailability is a major problem associated with herbal drugs.Objective: To develop a phospholipid complex of rotenoid-rich fraction (RRF) and evaluate its in vivo anti-inflammatory activity and pharmacokinetic study.Materials and methods: RRF was prepared from a 70% ethanol extract of B. diffusa roots. This RRF was complexed with phosphatidylcholine by refluxing in 70% ethanol. In vivo anti-inflammatory activity of RRF-PC and RRF was determined using the carrageenan-induced rat paw edema method, at a dose equivalent to 100 mg/kg p.o. of RRF. Edema volume was calculated at 3 and 5 h. The plasma concentration of boeravinone B was estimated in rats at a same dose level. Blood samples were collected at 1, 2, 4, 6, 8, 10, 12, 24, and 36 h.Results: 1H and 31P NMR spectra of RRF-PC showed up-field shift of protons of the +N(CH3)3 group (3.37 → 3.23) and the phosphorus atom (−1.26 → −1.57 ppm), respectively, which confirmed phospholipid complex formation between phosphatidylcholine [PO4 and +N(CH3)3 groups] and phytoconstituents by hydrogen bonding. The RRF-PC showed significantly enhanced in vivo anti-inflammatory activity (64%) as compared with RRF (48%) and ibuprofen (50%) at 5 h (p < 0.001). Furthermore, detected plasma concentration of boeravinone B was two times higher in RRF-PC (75 ng/mL) as compared with RRF (40 ng/mL).Conclusion: The present study demonstrated an increased anti-inflammatory potential and higher plasma level of boeravinone B in lipid-based formulation (RRF-PC) as compared with RRF.