FREE RADICAL INDUCED CELL DAMAGE: PROTECTED BY PURIFIED COLEUS AROMATICUS LEAVES PROTEIN

Objective: Many studies have demonstrated the antioxidant properties of extracts of Coleus aromaticus. The purified Coleus aromaticus leaves protein was studied to investigate its in-vitro antioxidant activity, preventing oxidative DNA damage induced by hydrogen peroxide (H₂O₂) and its protective effect on lymphocyte cell viability. Materials and Methods: In-vitro antioxidant capacity by DPPH assay, hydrogen peroxide (H₂O₂) used to damage the calf thymus DNA, the purified Coleus aromaticus leaves protein (CALP) at 25 μg concentration was used to prevent the H₂O₂ induced DNA damage, which was demonstrated on submarine agarose gel electrophoresis. The protective effect of purified CALP on cell viability of human peripheral lymphocytes against damage induced by H₂O₂ was studied by the Trypan dye blue exclusion method. Standard antioxidants like gallic acid, ascorbic acid, and butylated hydroxyanisole were used. Results: The purified CALP protein showed significant antioxidant activity when compared to Gallic acid. At 25 μg concentration of purified CALP provided almost equal protection as given by standard antioxidant Ascorbic acid at 400 μM concentrations against H₂O₂ induced DNA fragmentation in submarine agarose gel electrophoresis. The cell viability study showed that human peripheral lymphocytes treated with the purified CALP (25 µg) had 71 ± 2% viability, BHA (400 μM) had 68 ± 3% viability, and Ascorbic acid (400 µM) had 78 ± 2% viability when compared to untreated lymphocytes (83 ± 4%). Conclusion: The study demonstrated that the purified CALP possesses significant antioxidant activity, protective effect on H₂O₂ induced DNA damage, and lymphocyte cell damage, which showed itself is not toxic.