This study evaluated the antioxidant and anti-inflammatory activities of an extract mixture containing the Boswellia serrata and Urtica dioica methanol leaves extract, codenamed as M-BSUD, using various in vitro mechanistic models. The antioxidant capacity was assessed through ABTS radical decolorizing and Hydroxyl Radical Scavenging Activity (HRSA) assays, while anti-inflammatory efficacy was determined using RAW 264.7 macrophages exposed to LPS to measure cytokine production. For the ABTS assay, quercetin demonstrated superior antioxidant activity with the lowest IC50 value of 64.31 µg/mL, indicating its potent radical scavenging ability. Ascorbic acid and the extract also showed significant antioxidant properties but required higher concentrations to achieve similar effects, with IC50 values of 131.04 µg/mL and 124.87 µg/mL, respectively. Similar trends were observed in the HRSA assay, where quercetin again showed the highest effectiveness with an IC50 of 80.68 µg/mL, followed by ascorbic acid and the extract with IC50 values of 116.96 µg/mL and 143.77 µg/mL, respectively. In the anti-inflammatory tests, a dose-dependent decrease in the production of IL-1β, TNF-α, and IL-6 was observed across all treatment concentrations in RAW 264.7 macrophages. The highest concentration tested (120 µg/mL) resulted in cytokine levels approaching those of the untreated control, underscoring the potential anti-inflammatory benefits of the treatments. These findings highlighted the robust antioxidant and anti-inflammatory properties of the extract mixture, M-BSUD, comparable to the standards showing the most promise as both an antioxidant and anti-inflammatory agent. This suggested its potential utility in therapeutic settings where oxidative stress and inflammation are implicated.