Pharmacokinetics of niazirin from Moringa oleifera Lam in rats by UPLC‐MS/MS: Absolute bioavailability and dose proportionality

Niazirin is a nitrile glycoside isolated from the pods and leaves of Moringa oleifera and possesses antidiabetic activity. However, its pharmacokinetic properties have not been well studied yet. The present study aims to establish a specific, rapid, and simple method for the determination of niazirin in rat plasma and apply it to evaluate its absolute bioavailability and dose proportionality. MS/MS detection was performed in multiple reaction monitoring modes with negative electrospray ionization. The precursor–product ion transitions were m/z 278.1 [M‐H]− → 130.8 for niazirin and m/z 316.9 [M‐H]− → 271.0 for IS. The intra‐ and inter‐day precision (RSD) was <11.53% and the accuracy (RE) ranged from 6.20% to 9.68%. The extraction recoveries ranged from 87.92% to 91.82%. Absolute bioavailability in rats was assessed by comparing pharmacokinetic results after the oral (5, 20, and 40 mg/kg) and intravenous (5 mg/kg) administration. The results indicated that the absolute bioavailability of niazirin in rats was 46.78%, 52.61%, and 48.28%, respectively, and the equations of AUC0−∞ and Cmax at the three doses were y = 177.39x + 99.716 (r2 = 0.9962), and y = 63.152x + 19.531 (r2 = 0.9961), respectively. The study provides a scientific basis for safety evaluation and new clinical research on niazirin.