Evaluation of the interaction between Menthol and Camphor, Major Compounds of Clinopodium nepeta Essential Oil: Antioxidant, Anti-inflammatory and Anticancer Activities against Breast Cancer Cell Lines.

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 IC50 values of 10.3 µg/mL (DPPH) and 8.9 µg/mL (ABTS), surpassing the efficacy of ascorbic acid (IC50 = 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 IC50s of 27.6 µg/mL, 31.2 µg/mL, and 36.5 µg/mL respectively, with an IC50 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.