EXPLORING THE EFFICACY OF GALLIC ACID IN INDUCING APOPTOSIS AND MODULATING ROS IN MYELOID AND LYMPHOID LEUKEMIA CELL LINES

Abstract

Leukemia is the fifth most prevalent cancer worldwide. Despite significant progress in treatment through new drugs, side effects remain a major challenge. Plant derivatives are important sources for cancer treatment. Gallic acid (GA), a natural polyphenol widely distributed in plants, fruits, and foods, has demonstrated antioxidant, anti-inflammatory, and antitumor properties. Recent studies suggest that gallic acid can induce apoptosis in various cancer cell types, indicating its potential as a therapeutic agent. In this study, we evaluated the capacity of gallic acid to induce apoptosis and the production of intracellular reactive oxygen species (eROS) in several leukemia cell lines, including THP-1, K562, KG-1, HEL, MOLT-4, Daudi, and Jurkat. Cells were treated with concentrations of gallic acid ranging from 75 to 150 μM for periods of 24 to 48 hours. Apoptosis analysis was performed using flow cytometry, while ROS production was measured using 25 μM 2’,7’-dichlorofluorescein diacetate (DCFDA) by flow cytometry. The cell lines were treated with concentrations of 1 μM and 75 μM, and the evaluation periods were 30 min, 1 h, 3 h, and 6 h. The results indicate that gallic acid has a variable effect on the induction of apoptosis in different leukemia cell lines: THP-1, K562, KG-1, and Jurkat: These cell lines showed apoptosis percentages of 14.5% at 75 μM and up to 24% at 150 μM, maintaining these levels for both 24 and 48 hours of treatment. Hel: Apoptosis ranged from 14% to 26% at 24 hours and up to 40% at 48 hours. Molt-4: Apoptosis ranged from 28% to 65% at 24 hours and up to 77% at 48 hours. Daudi: Apoptosis ranged from 7% to 12% at 24 hours and from 18% to 29% at 48 hours. Jurkat: Apoptosis ranged from 7% to 17% at both 24 and 48 hours. To determine if apoptosis induced by gallic acid was related to abnormal intracellular ROS levels, we performed preliminary analyses of ROS generation. These analyses showed that both the Hel and Molt-4 cell lines experienced a reduction in ROS at the concentration of 75 μM at 3 and 6 hours of treatment. However, at 1 μM, there was a slight increase in ROS generation compared to the control at 1, 3, and 6 hours. Gallic acid demonstrates a variable but generally effective ability to induce apoptosis in different leukemia cell lines. Myeloid leukemia cell lines (THP-1, K562, KG-1, Hel) tend to be more responsive to gallic acid-induced apoptosis compared to lymphoid lines (Daudi, Jurkat), with Molt-4 being an exception among lymphoid lines showing high sensitivity. These findings suggest that gallic acid could be a more potent therapeutic agent for myeloid leukemias, and its efficacy in lymphoid leukemias may depend on specific cellular contexts. Regarding ROS generation, preliminary results indicate that the compound acts as a scavenger at the analyzed concentration and times. Further studies are needed to elucidate the mechanisms underlying these differential responses and to explore the potential of gallic acid in combination therapies for treating various subtypes of leukemia.