Anti-tumor and antioxidant effects of Daucus carota water extract. (c2009)

Abstract

Daucus carota (Linnaeus) ssp. carota, also known as wild carrot, is listed by the council of Europe as a natural source of food flavoring. It is confined to temperate regions of Europe, Asia and South Africa. The plant is known in the Lebanese folklore for its protective effects against gastric ulcer and diabetes without affecting other body functions. The present study is considered to be the first research on the effectiveness of Daucus carota water extract in inhibiting the promotion phase of carcinogenesis in mouse skin. The anti-tumor promoting effects of Daucus carota water extract on skin carcinogenesis was established through the DMBA (7, 12-dimethyl benze-{a)anthracene)- initiation TPA (12- 0- tetradecanoalyl phorbol-13- acetate) promotion mouse skin carcinogenesis model. The extract was either applied topically to mouse skin at concentrations of 50, 250, 500 mg/kg, or injected intraperitoneally or given by gavage (force feeding) at 100% twice per week for 17 weeks, 20 minutes prior to each promotion treatment with TP A. At week 15, the anti-tumor effect was only observed with the intraperitoneal mode of treatment, where the % inhibitions of papilloma incidence, yield and volume were 28 %, 23% and 86.4% respectively. Gavage treatment failed to inhibit tumor incidence, yield and volume. Topical application using a cream appeared to be an inappropriate mode of delivery to study the effect of the extract since the control failed to show significant papilloma formation. The Daucus carota water extract was also studied for its antioxidant activity and phenolic compound content. The extract exhibited a relatively high free radical scavenging activity (65.4%) and antioxidant power (508 ).lmol FeS04), but a low phenolic compound content (10.8 mg gallic acid/g extract). In conclusion, our results indicate that Daucus carota water extract has a suppressive activity against tumor promotion in mouse skin which we suspect to be related to the antioxidant properties of the extract.