Cannabis Sativa and 'Karole' Induced Oxidative Stress and Altered Brain Serotonin in Adult Wistar Rats

Abstract

Background: Cannabis sativa (marijuana) has been used recreationally and medicinally for several years; and there has been a steady increase in the consumption of cannabis among young people. 'Karole' is a therapeutical drug for the treatment of pain. Cannabis and analgesics have been reported to influence the central nervous system.
Objectives: The study is to determine the effects of Cannabis sativa and 'Karole' on oxidative properties and brain serotonin in Wistar rats.
Methods: Twenty four adult male rats ( 135.29 ± 7.26g), were randomly assigned into three treatment groups (n=6) and a control group (n=6). The treatments were administered orally and daily with marijuana extract (25mg/kg body weight), 'karole' (100 mg/kg body weight), and 10% ethanol for two weeks and five weeks. The rats in the control group received saline. The rats were allowed to feed ad libitum on rat chow. Three rats from each group were sacrificed at the end of second and fifth weeks of the experiment. Brain and liver homogenates were used to assay for activities of superoxide dismutase (SOD), catalase, levels of malondialdehyde (MDA) and reduced glutathione (GSH). The brain serotonin concentration was also determined.
Results: There was a significant decrease (p<0.01) in the liver GSH level in marijuana, marijuana+karole and ethanol groups of 2weeks administration, but an increase in marijuana and ethanol group after 5weeks of administration. Superoxide dismutase and catalase activities decreased significantly in the liver of rats in marijuana, marijuana+karole, ethanol groups of 2weeks administration and marijuana group of 5weeks administration. There was a significant increase of liver MDA in marijuana, marijuana+karole groups and there was no significant difference in ethanol group of 2weeks administration and all the groups of 5weeks administration. Brain SOD and catalase activities were significantly reduced in all the three groups of 2weeks administration and marijuana+karole group of 5weeks administration. There was a significant increase in brain MDA level in marijuana and marijuana+karole groups of 2weeks administration. Brain serotonin level reduced in all the groups of 2weeks administration, for 5weeks administration, only marijuana+karole group increased, but was not significant.
Conclusion: Cannabis sativa and 'karole' induced oxidative damage in the liver and brain of adult Wistar rats. The administration of Canabis sativa and 'Karole' for 5weeks impaired brain serotonin level and resulted in inflammatory changes in the brain and liver tissues of adult Wistar rats.

Key words: Cannabis sativa, 'Karole', serotonin, oxidative stress, rat