Flower extract of Nyctanthes arbor-tristis modulates glutathione level in hydrogen peroxide treated lymphocytes

BACKGROUND: Nyctanthes arbor-tristis Linn (Oleaceae) is a well-known traditional medicinal plant used throughout the India as an herbal remedy for treating various infectious and non-infectious diseases. OBJECTIVE: To evaluate the antioxidative activity of hydro-alcoholic extract of flower in the lymphocytes exposed to oxidative stress induced by H(2)O(2) . MATERIALS AND METHODS: Isolated lymphocytes were treated in vitro with extract or extract+H(2)O(2,) and the level of reduced glutathione (GSH) as well as the activity of glutathione-S-transferase (GST) and lactate dehydrogenase (LDH) were measured. RESULTS: Treatment of lymphocyte with flower extract (50, 100, and 200 μg/ ml) significantly increased the level of GSH and decreased the activity of GST. The LDH activity measured in the cell-free medium decreased significantly. Pre-treatment of lymphocyte with flower extract protects the lymphocyte from the H(2)O(2) induced oxidative stress by significantly increasing the levels of GSH as compared to the cells treated only with H(2)O(2). Pre-treatment also reduced the activity of LDH significantly as compared to the cells treated only with H(2)O(2). The LDH activity in cell-free medium is associated with membrane damage, the decreased levels of LDH activity reflects the reduced level of membrane damage due to H(2)O(2). CONCLUSION: The present findings suggest the protective role of the hydro-alcoholic extracts of the flower of Nyctanthes arbor-tristis against membrane damage induced by H(2)O(2). The results also suggest that the extract might be rich in phytochemicals with antioxidant/radical scavenging potentials, which might find application in antioxidant therapy.