Chemopreventive effects of wild carrot oil against 7,12-dimethyl benz(a)anthracene-induced squamous cell carcinoma in mice.

BACKGROUND

Daucus carota L. ssp. carota (Apiacea) is widely distributed throughout the world and has many uses in traditional medicine.

OBJECTIVE

The present study investigates the chemopreventive effects of oil extract of D. carota umbels on 7,12-dimethyl benz(a)anthracene (DMBA)-induced skin cancer in mice.

METHODS

D. carota oil extract (DCOE) was prepared by extracting the dried umbels with 50:50 acetone:methanol. Skin papilloma were initiated by DMBA and promoted by 12-O-tetradecanoyl phorobol-13-acetate (TPA). The extract was administered to animals via gavage (0.02 mL of 100% oil), intraperitoneal (0.3 mL of 2% oil), and topical (0.2 mL of 5, 50, and 100% oil) routes for 20 weeks. Tumor appearance, incidence, yield, and volume were compared with those of a non-treated control group.

RESULTS

Topical 100% treatment delayed tumor appearance, and inhibited tumor incidence and yield by 40 and 89%, respectively. Topical 50% treatment inhibited tumor incidence and yield by 30 and 83%, respectively, whereas the 5% treatment inhibited tumor yield by 36%. Tumor volume was decreased by 99, 91, and 70% following topical treatments with 100, 50, and 5% oil, respectively. Intraperitoneal treatment inhibited tumor yield by 43%, and decreased tumor volume by 85%, whereas gavage treatment showed minimal effects on both. Intraperitoneal and topical treatment decreased infiltration and hyperplasia with an increase in the level of hyperkeratosis.

CONCLUSIONS

These findings demonstrate that DCOE has remarkable antitumor activity against DMBA-induced skin cancer compared with non-treated animals paving the ground for further investigations.