Pharmacokinetic, acute toxicity, and pharmacodynamic studies of semen strychni total alkaloid microcapsules

Abstract

Purpose: To investigate the safety and effectiveness of semen strychni total alkaloid microcapsules (SSTAM), compared with semen strychni total alkaloids (SSTA). Methods: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed to assess pharmacokinetics of brucine and strychnine in rats. Acute toxicity was investigated in pre-test and formal experiments in mice. The pharmacodynamics of SSTAM and SSTA were evaluated by their analgesic and anti-inflammatory activities. Results: With respect to brucine, the half-life of SSTA group (1.6 mg/kg), low-dose SSTAM group (6 mg/kg) and high-dose SSTAM group (10 mg/kg) was 5.723, 9.321 and 9.025 h, respectively. With respect to strychnine, the half-life of SSTA group, low-dose SSTAM group and high-dose SSTAM group was 4.065, 8.819 and 8.654 h, respectively. The LD50 values of SSTAM group and SSTA group were 236.59 and 30.27 mg/kg, respectively. The pain inhibition rates of SSTAM groups (25 and 50 mg/kg) were higher than that of SSTA group (p < 0.05) while the pain threshold values of the SSTAM groups (25 and 50 mg/kg) were higher than that of blank control (p < 0.01) and SSTA groups (p < 0.01) at 60 min and 120 min. The inhibition rates of the SSTAM groups (25 and 50 mg/kg) were higher than that of SSTA group based on ear swelling and cotton ball granulation tests. Compared with blank control and SSTA groups, the absorbance values of SSTAM groups (25 and 50 mg/kg) were lower (p < 0.01). Conclusion: SSTAM increases the dosage of administration but reducea the toxicity of the alkaloids in rats, and is thus a potentially safe and effective drug delivery system.