The Combined Effects of Eleutherine bulbosa Ethanol Extract and Tamoxifen On Cox-2 Levels in a BaLB/c Mouse Breast Cancer Model

OBJECTIVE: Chronic inflammation and oxidative stress play important roles in breast cancer progression. Cyclooxygenase-2 (COX-2) is a major proinflammatory enzyme that is often overexpressed in tumor cells. Eleutherine bulbosa (Dayak onion) is a traditional Indonesian medicinal plant with antioxidant and anti-inflammatory properties. This study aimed to evaluate the effect of a combination of ethanol extract of E. bulbosa and tamoxifen on COX-2 levels in a 7,12-dimethylbenz[a]anthracene (DMBA)-induced BALB/c mouse model. METHODS: A total of thirty-six 8-10-week-old female BALB/c mice were randomly divided into six groups: a negative control, a positive control (DMBA alone), and four treatment groups that received E. bulbosa extract (180 mg/kg BW), tamoxifen (10 mg/kg BW), or their combination for 14 days. COX-2 levels were measured using an enzyme-linked immunosorbent assay (ELISA). Statistical analysis included the Shapiro-Wilk test (normality), Levene's test (homogeneity), Brown-Forsythe test, and Games-Howell post hoc test. RESULT: All treatment groups showed a decrease in COX-2 levels compared to the positive control. The combination group (tamoxifen + E. bulbosa) exhibited the lowest COX-2 levels (3.86 ng/mL), close to the value observed in the negative control group (3.07 ng/mL), indicating a synergistic effect between the two agents. CONCLUSION: The combination of tamoxifen and E. bulbosa ethanol extract significantly reduced COX-2 levels in DMBA-induced breast cancer models. These results suggest the potential of this combination as an effective adjuvant therapy. Further studies are needed to confirm the underlying molecular mechanisms and to evaluate its toxicity profile.