Isolation of a Quinone-rich Fraction from Ardisia crispa Roots and its Attenuating Effects on Murine Skin Tumorigenesis

Ardisia crispa (Family: Myrsinaceae) is an evergreen, fruiting shrub that has been traditionally used asfolklore medicine. Despite a scarcity of research publications, we have succeeded in showing suppressive effectson murine skin papillomagenesis. In extension, the present research was aimed at determining the effect ofa quinone-rich fraction (QRF) isolated from the same root hexane extract on both initiation and promotionstages of carcinogenesis, at the selected dose of 30 mg/kg. Mice (groups I-IV) were initiated with a single doseof 7,12-dimethylbenz(α)anthracene (DMBA, 100 μg/100 μl) followed by repeated promotion of croton oil (1%)twice weekly for 20 weeks. In addition, group I (anti-initiation) received QRF 7 days before and after DMBA;group II (anti-promotion) received QRF 30 minutes before each croton oil application; group III (anti-initiation/promotion) was treated with QRF as a combination of group I and II. A further two groups served as vehiclecontrol (group V) and treated control (group VI). As carcinogen control, group IV showed the highest tumorvolume (8.79±5.44) and tumor burden (3.60±1.17). Comparatively, group III revealed only 20% of tumorincidence, tumor burden (3.00±1.00) and tumor volume (2.40±1.12), which were significantly different fromgroup IV. Group II also showed significant reduction of tumor volume (3.11), tumor burden (3.00) and tumorincidence (11.11%), along with prominent increase of latency period of tumor formation (week 12). Group I,nonetheless, demonstrated marked increment of tumor incidence by 40% with prompted latency period of tumorformation (week 7). No tumor formation was observed in groups V and VI. This study provided clear evidenceof inhibitory effects of QRF during promotion period which was in agreement with our previous findings. Themechanism(s) underlying such effects have yet to be elucidated.