ACUTE ORAL TOXICITY STUDY IN RATS WITH METHANOLIC LEAF EXTRACT OF LAURUS NOBILIS L. ON HISTOPATHOLOGICAL CHANGES

To determine the effect of methanolic leaf extract of Laurus nobilis L on histopathological changes in acute oral toxicity in Wister albino rats. As described by Akunna et al the acute oral toxicity study of methanolic and chloroform leaf extract of Laurus nobilis L was conducted using the Organization for Economic Cooperation and Development (OECD) (2000) Guidance Document on Humane End points that should reduce the overall suffering of animals used in this type of toxicity test. The test used was the limit dose test of the up and down procedure. Briefly, animals were divided into 2 groups, 5 animals were weighed and individually identified in each group. Group A treated with methanolic extract and group B were treated with chloroform extract. Group A: The first animal was given the test dose 5 mg per kg body weight of methanolic leaf extract of Laurus nobilis L (MELN). The second animal was given the test dose 50 mg per kg body weight of chloroform leaf extract of Laurus nobilis L (MELN). The third and fourth animals were concurrently dosed and the fourth and fifth animals sequentially dosed 300 and 2000 mg per kg body weight and fifth animal were kept as control. Similarly Group B were treated with chloroform extract in the similar fashion of dosing. The results were evaluated as follows (S = Survival, X = death). The animals were observed individually at least once during the first 30 minutes after dosing, periodically during the first 24 hours (with special attention given during the first 4 hours), and daily thereafter for a total period of 14 days. All observations were systematically recorded with individual records maintained for each animal. There were no deaths of mice dosed at 2000 mg/kg body weight of the plants extract both within the short and long outcome of the limit dose test of Up and Down method. Effect of methanolic and chloroform leaf extract of Laurus nobilis L (MELN and CELN) on histopathological changes in acute oral toxicity in rat’s transverse section of Brain, Kidney and Liver showed normal histology upon administration of 2000 mg/kg of Leaf Extract. It was found to be normal epithelium and intact interstitium in rat’s transverse section of Brain, Kidney and Liver. The LD50 was calculated to be greater than 3000 mg/kg body weight orally