Evaluation of the Anticancer Properties of Cedrus atlantica Essential Oil on Skin and Colorectal Cancer Cell ^†

Skin and colorectal cancers are among the most pressing global health concerns, highlighting the urgent need for the development of novel therapeutic strategies. Plant-derived natural products, including essential oils, represent a promising reservoir of bioactive molecules with potential anticancer properties [1]. The purpose of this study was to investigate the cytotoxic activity of Cedrus atlantica essential oil (CAEO) against three human cell lines: non-cancerous keratinocytes (HaCaT), malignant melanoma cells (A375), and colorectal adenocarcinoma cells (HT-29). The effects of water-dispersed CAEO (0.5% and 1%) and CAEO formulations (100 μg/mL and 200 μg/mL) with PEG-400 (CAEO-PEG) and Tween 20 (CAEO-Tw) on cell viability were evaluated using the Alamar Blue assay. The chemical composition of CAEO was analyzed through gas chromatography-mass spectrometry (GC-MS). The results showed that CAEO significantly reduced the viability of both A375 and HT-29 cancer cells by more than 50%, regardless of the formulation used. In contrast, the HaCaT cell line maintained over 85% viability, indicating no toxicity in non-cancerous cells. The most abundant components responsible for CAEO’s cytotoxic activity were identified as β-Himachalene (39.23%), 1H-benzocycloheptene,2,4a,5,6,7,8,9,9a-octahydro-3,5,5-trimethyl-9-methylene-,(4aS-cis) (16.76%), cis-(-)-2,4a,5,6,9a-Hexahydro-3,5,5,9-tetramethyl-(1H)-benzocycloheptene (12.92%), δ-Cadinene (2.54%) and several other minor components. These findings highlight the potential of CAEO as a selective anticancer agent, warranting further investigation to confirm its therapeutic value and to elucidate the underlying mechanism of action.