Biological activities of three nigerian spices – Laurus nobilis linn, Murraya koenigii (L) spreng and Thymus vulgaris linn

Abstract

Purpose: To evaluate the biological properties of polyphenol extracts of three spices–Laurus nobilis (bay), Murayya koenigii (curry) and Thymus vulgaris (thyme) from Lagos, Nigeria. Methods: Acetone extracts of these spices were subjected to bovine serum albumin (BSA)-glucose antiglycation, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion radical scavenging assays. Brine-shrimp lethality and phytotoxicity tests were also performed on the extracts (10–1000 μg/mL). Results: The extract of T. vulgaris had the highest antiglycation effect with 50% inhibitory concentration (IC50) of 0.02 mg/mL, as well as antioxidant potential with IC50 of 0.10 and 0.06 mg/mL for DPPH and superoxide anion radical scavenging assays, respectively (p < 0.05). On the other hand, all the extracts exhibited weak cytotoxicity with 50% lethal dose (LD50) ranging from 1000–2000 μg/mL, and for phytotoxicity, LD50 ranged from 640–1640 μg/mL). Conclusion: Acetone extracts of bay, curry and thyme displayed good antiglycation as well as antioxidant potential and are safe for consumption. However, of all the spices, thyme exhibited the best activity as an antioxidant and antiglycation agent.