Evaluation of the Interaction Between Menthol and Camphor, Major Compounds of <i>Clinopodium nepeta</i> Essential Oil: Antioxidant, Anti‐inflammatory and Anticancer Activities Against Breast Cancer Cell Lines

Abstract

ABSTRACT This study evaluates the antioxidant, anti‐inflammatory, and anticancer activities of camphor, menthol, and their equimolar combination. In silico toxicity analysis confirmed the absence of toxic effects for both compounds. Antioxidant activity, assessed by 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) assays, revealed a synergistic effect of the equimolar combination with half‐maximal inhibitory concentration (IC 50 ) values of 10.3 µg/mL (DPPH) and 8.9 µg/mL (ABTS), surpassing the efficacy of ascorbic acid (IC 50 = 12.4 µg/mL). Evaluation of anti‐inflammatory activity showed that the combination more effectively inhibited 5‐lipoxygenase (72.5% vs. 48.3% for camphor and 52.9% for menthol) and COX‐1 and COX‐2 cyclooxygenases (78.1% and 79.4% respectively, vs. 60.4% and 62.7% for camphor, 64.2% and 66.3% for menthol). Anticancer activity, tested on MCF‐7, MDA‐MB‐231, and MDA‐MB‐436 breast cancer lines, revealed that the equimolar combination exhibited IC 50 of 27.6, 31.2, and 36.5 µg/mL, respectively, with an IC 50 of 52.3 µg/mL on normal cells, demonstrating remarkable selectivity for cancer cells. These results suggest that the camphor‐menthol combination represents a promising therapeutic approach against pathologies associated with oxidative stress, inflammation, and carcinogenesis.