Protective Effects of Aqueous Extract of Bay Leaf (Laurus Nobilis) on Endotoxin-Induced Oxidative Stress in Rabbits

ABSTRACT

The protective effect of oral co-administration of Laurus nobilis on Escherichia coli endotoxin-exposed rabbits was studied. Twenty-five (25) rabbits were randomized into five groups containing five rabbits each – Group A, 500 Endotoxin Unit (EU) kg⁻¹ bw, Group B, 500 EU kg⁻¹ bw + 6.6 mg kg⁻¹ bw extract, Group C, 500 EU kg⁻¹ bw + 3.3 mg kg⁻¹ bw extract, Group D, 500 EU kg⁻¹ bw + Ascorbic acid (100 mg kg⁻¹ bw) and Group E (0 EU kg⁻¹ bw). The rabbits were pre-administered with the bay leaf extract in the first 7 days, then endotoxin oral administration was started and repeated daily for 21 d. At the end of days 7 and 21, assays for the serum superoxide dismutase, glutathione S-transferase, reduced glutathione, catalase, and malondialdehyde were done. The animals were sacrificed to collect kidneys and liver. Histopathological analysis of the liver and kidneys showed that exposure to 500 EU kg⁻¹ bw endotoxin for 21 d + bay leaf extract at 6.6 and 3.3 mg kg⁻¹ bw increased specific activities of superoxide dismutase, glutathione S-transferase, and reduced glutathione and catalase compared to the negative control. There was a decrease in the concentration of malondialdehyde in groups treated with the aqueous extract of bay leaf.

KEYWORDS:

• Ingested endotoxin
• antioxidant potentials
• Laurus nobilis
• food poisoning
• bay leaf

Acknowledgement

The following undergraduate students Dr. M. O. Salawu (2017/2018 session) are hereby acknowledged for their contributions, and the roles played in keeping the rabbits; as well as in the daily administration of test samples to the subjects, during the research:-

Olayinka Dotun ABRAHAM, Zaenab Adeyinka ADEREMI, Blessing Oluwatosin OLORUNFEMI, Taiwo Danvictor ADEOSUN, Sharon Doom CHIAHEMEN, Samuel Oluwatosin OGUNDELE, Victor Monjolaoluwa BAMIDELE, Yusuf Taiwo ADETUTU, Toba Samuel BAMGBOSE, Oluwabunmi OGUNDARE, Farida Olamide ZUBAIR, Rukayat Titilayo OGUNBODE, Oluwatoyin Elizabeth OLOWO, and Dolapo Ikeade ADEOLA.

Disclosure Statement

No potential conflict of interest was reported by the author(s).