Artemisia herba-alba (AHA) is a medicinal plant known for its preventive capacities against chronic diseases. Inflammation is a naturally occurring cellular response to noxious stimuli, and both acute and chronic inflammation are involved in human disorders. Preventing and limiting the negative impact of inflammation by using phytocompounds has attracted a lot of attention. Here, we show that AHA extracts are potent anti-inflammatory products at low doses in white blood cells, treated with phorbol myristate acetate (PMA), a pro-inflammatory trigger. Regardless of the mode of extraction, i.e. maceration or microwave, all extracts reduced on dose-dependent manner reactive oxygen species (ROS) production induced by the pro-inflammatory compound PMA in white blood cells and leukemic Jurkat cell line. The induction of the anti-inflammatory effect was evaluated by the measurement of glutathione metabolism (glutathione reductase, transferase, and peroxidase), and protein-free thiols in Jurkat cells. Jurkat cells incubated with low to high concentrated AHA extracts, ranged from 10 to 100 g/mL, induced a fast cell response measured at one and six hours. Interestingly, extracts from the microwave showed a stronger induction, 5 to 10 fold changes at early time points, and maintained over 72 h. On the other hand, AHA extracts showed a moderate anti-proliferative effect in the leukemic Jurkat line. We concluded that AHA extracts enhance directly anti-inflammatory cell response, earlier via ROS induction. Later, however, vigorously maintained, independently from ROS, suggesting the intervention of the cellular metabolism in enhancing these effects. Considering the preventive and anti-inflammatory potential of AHA, regular consumption is advisable, and phytotherapeutic applications are encouraged to treat local inflammations.