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%.

Keywords: anti-inflammation; oleracone; pharmacokinetics; rat plasma; ultra high-performance liquid chromatography.