Antioxidant properties and subchronic toxicity of the standardized extract of LAMIC, a phytomedicine prototype based on aqueous extracts from trunk bark of Lannea microcarpa Engl and K. Krause

Abstract

Aims: This study investigated the antioxidant activity and the 90 days subchronic toxicity of the standardized LAMIC phytomedicine prototype based on aqueous extracts from Lannea microcarpa trunk bark.

Methods: Three spectrophotometric methods were used to evaluated the antioxidant activity of LAMIC which were 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical, 2,2’-azinobis(3-ethylbenzolin-6-sulphonate) (ABTS) radical scavenging assays and ferric reducing antioxidant power (FRAP) assays. For the standardized LAMIC subchronic toxicity study, male and female Wistar rats were used by daily oral administration at doses of 500, 1000 and 1500 mg/kg bw consecutively for 90 days.

Results: The LAMIC extract exhibit better inhibitory activity against DPPH radical than ABTS radical with respective IC₅₀ values of 45.38±3.21 µg/mL and 66.45±18.76 µg/mL, while FRAP assay exhibit antioxidant activity of 211.34±15.92 mmol EAA/g.

Subchronic oral administration of LAMIC was well-tolerated at all tested doses. No behavioral and physiological changes and mortality were observed. The LAMIC extract did not present any impact on general hematological parameters and biochemical parameters. Moreover, no significant changes were raised in organ and body weight of treated groups compared to the Control group.

Conclusion: These results support that LAMIC prototype was a valuable source of natural antioxidants and no toxicity was associated to its long terms oral consumption in rats indicating a potential application as a cardiovascular protective formulation.

Keywords: LAMIC–Lannea microcarpa–Standardization–Antioxidant–Subchronic toxicity.