The anti-inflammation and pharmacokinetics of a novel alkaloid from Portulaca oleracea L.

Abstract Objectives This study was to elucidate the pharmacokinetics of a novel alkaloid, 6-acetyl-2,2,5-trimethyl-2,3-dihydrocyclohepta[b]pyrrol-8(1H)-one, named oleracone isolated from Portulaca oleracea L., and to examine the anti-inflammatory ability with lipopolysaccharide (LPS) stimulated macrophages. Methods The novel alkaloid, oleracone, was isolated from Portulaca oleracea L., and its structure was determined by spectroscopic analysis including HRESIMS, 2D NMR spectroscopic data and single-crystal X-ray diffraction. The activity of anti-inflammation was assayed via the test with RAW 264.7 activated by LPS, and the pharmacokinetics of oleracone in rat plasma after intravenous and oral administration at dose of 2.5 mg/kg was, respectively, investigated by a rapid and sensitive ultra high-performance liquid chromatography (UHPLC) method with bergapten as internal standard. Key findings Oleracone was a novel alkaloid first isolated from Portulaca oleracea L. and possessed unique structure in natural products, whose anti-inflammatory effecting on nitrite oxide production and several pivotal pro-inflammatory cytokines was found at the concentration of 50 μm, and the pharmacokinetic results indicated that oleracone was rapidly distributed with Tmax of 15.7 min after oral administration and presented a higher oral absolute bioavailability to be 74.91 ± 10.7%. Conclusions Oleracone as novel alkaloid presented remarkably anti-inflammatory effect, which was rapid distributed in rat with high bioavailability of 74.91 ± 10.7%.