Title:Inhibitory Effect of Ascorbic Acid on Glutathione S-transferase from
Human Erythrocytes
Volume: 19
Issue: 3
Author(s): Yunus Emre Erat, Ayşe Rümeysa Erat and Mustafa Erat*
Affiliation:
- Department of Chemistry and Chemical
Processing Technologies, Technical Sciences Vocational College, Atatürk University, Erzurum, Türkiye
- Department of
Nanoscience and Nanoengineering, Graduate School of Natural and Applied Sciences, Atatürk University, Erzurum,
Türkiye
Keywords:
Glutathione S-transferase, ascorbic acid, chemotherapy, purification, inhibition, enzyme kinetics.
Abstract:
Background: Inhibition of certain specific glutathione S-transferase isozymes is associated
with the efficacy of chemotherapy in the treatment of cancer patients.
Objective: We aimed to determine whether ascorbic acid, which can be used as a drug and antioxidant
food supplement, is a glutathione S-transferase isozyme inhibitor.
Methods: For this purpose, glutathione S-transferase was first purified from human erythrocytes and the
in vitro effect of ascorbic acid on enzyme activity was investigated. Then, kinetic studies were performed
to evaluate the inhibition potential of ascorbic acid, which was determined to be an inhibitor of
the enzyme.
Results: The enzyme was purified 1286-fold with a yield of 81% and specific activity of 18.00 U/mg
protein. The effects of ascorbic acid were tested on the in vitro enzyme activity of glutathione Stransferase
and detected to be an inhibitor for the enzyme with 10 mM of IC50 value. Ki constants and
inhibition type were also determined for the enzyme.
Conclusion: This finding indicates that ascorbic acid can be an effective inhibitor of some GST isozymes
increased in cancer cells. Abundant ascorbic acid intake may prevent cancer formation by
strengthening the antioxidant defense system, on the other hand, it may increase the effectiveness of
cancer treatment by inhibiting the chemotherapy-resistant GST enzyme.
