Impact of antioxidant therapy on antioxidant capacity in hypertensive patients

Background: Hypertension is consistently related to the development of ischemic heart disease, heart failure, stroke, and chronic kidney disease. Oxidative stress has been associated with mechanisms of hypertension which could be nullified by antioxidants such as Vitamin C and Vitamin E. 

Aim and Objectives: The objectives of the study are as follows: (i) To estimate the impact of antioxidant therapy on antioxidant capacity in hypertensive patients; (ii) to measure serum levels of glutathione, glutathione peroxidase (GPx), glutathione reductase (GR), and superoxide dismutase (SOD) in hypertensive patients before and after giving them antioxidant therapy for 45 days. 

Materials and Methods: Thirty randomly selected hypertensive patients were given Supradyn tablet once a day for 45 days. Ferric reducing ability of plasma (FRAP), SOD, GR, GPx, and reduced Glutathione assays were measured before and after the intervention therapy. 

Results: Total antioxidant capacity as measured by serum FRAP in hypertensive patients before and after the therapy was increased significantly from 578.8 ± 60.85 to 592.1 ± 59.66 (μmol/L), respectively. The levels of SOD, GPx, GR, and Glutathione in hypertensive patients before giving antioxidant therapy were 1.6 ± 0.49 U/ml, 184.6 ± 17.1 μmol/L/min, 8.96 ± 1.15 μmol/L/min, and 8.03 ± 0.96 μmol/g of Hb, respectively. The same after giving them antioxidant therapy were 1.7 ± 0.46 U/ml, 182.4 ± 15.98 μmol/L/min, 8.83 ± 1.11 μmol/L/min, and 7.83 ± 0.94 μmol/g of Hb, respectively. The levels of GPx, GR, and Glutathione were significantly decreased after giving antioxidant therapy for 45 days while SOD level did not change significantly. 

Conclusion: Antioxidant therapies for 45 days led to a significant increase in total antioxidant capacity as shown by plasma FRAP levels and a significant decrease in serum levels of enzymatic antioxidants such as GPx, GR and Glutathione in hypertensive patients. However, serum levels of SOD did not show a significant change.