Investigating Neuroprotective Effect of Eugenol Against Traumatic Brain Injury in Rat

Abstract

Purpose and Background- Traumatic brain injury (TBI) occurs on the transmission of the external force to the head which can lead to cognitive disabilities either short term or long term. TBI is the leading cause of mortality and morbidity in the world. Eugenol as an investigating chemical is having anti-inflammatory, anti-oxidant, and anti-excitotoxicity activity. These characteristics of eugenol can improve the condition of patients suffering from traumatic brain injury. We aim to investigate whether eugenol can improve the neuro-behavioral and biochemical parameters in the weight drop method induced traumatic brain injury in rats. Methods- Wistar rats of either sex, weighing of 350-400g were used in this study. The animals were divided into five groups: Sham control group, TBI group, and Eugenol group(25 mg/kg, 50 mg/kg, and 100 mg/kg). Treatment group animals were given eugenol for 6 days before the induction of trauma. On day 6, weight drop method was performed on each group except the sham control group where the only preparative procedure was performed. On day 7, animals of the treatment group were given eugenol while sham control and TBI group vehicle. Finally, behavioral studies (Rotarod, rearing, actophotometer, beam walking test, and Y-Maze) were performed in each group, and after that animals were sacrificed. The brain was taken out for the estimation of brain water content, blood-brain barrier permeability, and lipid peroxidation Results- In this study, we found out that eugenol improves the neurobehavioral activity of rats after induction of traumatic brain injury by the weight-drop method. Motor activity, motor coordination, and spatial & learning memory of eugenol treated rats were improved. Specifically, 100 mg/kg treatment group animals were showing significant improvement in neuro-behavioral parameters. Evaluation of Blood-brain barrier (BBB) integrity was done using Evans blue dye test and evaluation of edema formation in the brain was done by brain water content test. We found that eugenol at the dose of 100 mg/kg was able to significantly reduced BBB disruption, brain edema formation, and lipid peroxidation Conclusion- In conclusion, in the present study pharmacological evaluation of eugenol at the animal dose before the weight drop method or post-trauma improvement was seen in case of Histopathological, neurochemical and behavioural parameters. Out of the three-dose of the eugenol which is 25, 50, and 100 mg/kg, in this research work we observed that in every parameter 100mg/kg dose was showing the positive response and a significant improvement