Chronic khat (Catha edulis) chewing and genotoxicity: The role of antioxidant defense system and oxidative damage of DNA

Background: Khat chewing is culturally endemic in the Southern areas of Saudi Arabia. Many health-related issues such as the incidence of carcinogenicity and comorbidities associated with the chewing of khat have been reported earlier. Objectives: Mainly, the objective of the study was to assess the risk of genotoxicity caused due to oxidative stress that may result from khat chewing among chronic chewers from Jazan Province of Saudi Arabia. Materials and Methods: Hundred and twenty-two adult males were recruited after signing informed consent. Ninety participants were chronic khat chewers (CKCs), while the control group consisted of 32 non-chewers of matched age and gender for the study group. A blood sample was collected from all participants and kept at 4°C until the time of assay. The activity of superoxide dismutase (SOD) and glutathione reductase (GR) were estimated in erythrocyte lysate as well as 8-hydroxydeoxyguanosine (8-OHdG) level in plasma. Results: There is a decreased SOD activity, which might be due to an increase in the endogenous production of reactive oxygen species resulted from the increase in lipid hydroperoxides. Furthermore, the significant elevation in GR activity was observed, reflecting the presence of highly toxic compounds. The 8-OHdG levels were higher in khat chewers group in comparison to the control, but this increase was statistically insignificant. Conclusion: CKCs will be at considerable risk of oxidative stress as a result of a significant reduction in antioxidant enzymes. This would be a good reason for them to quit chewing khat for health benefits.