Anti-tumor Activity of Phyllanthus niruri in Mice

Epithelial carcinogenesis is a multistep process in which an accumulation of genetic events within a single cell line leads to a progressively dysplastic cellular appearance, deregulated cell growth, and finally carcinoma. Cancer chemoprevention, as first defined by Sporn in 1976, uses of natural, synthetic, or biologic chemical agents to reverse, suppress, or prevent carcinogenic progression (Sporn, 1976). Skin cancer accounts for approximately 40% of all new cancer diagnosed (Jemal et al., 2003). Most skin cancers (80%) result from basal cell carcinomas (BCC); another 16% are squamous cell carcinomas (SCC), and 4% are melanomas (Einspahr et al., 2002). Associated risk factors for skin cancer include childhood and chronic sun exposure, individual susceptibility with red or blond hair and fair skinned phenotype, older age, polycyclic aromatic hydrocarbon, immunocompromised status, or xeroderma pigmentosum. Agents effective in inhibiting skin carcinogenesis are identified in a two-stage skin carcinogenesis protocol utilizing DMBA and TPA, which are applied topically to the back skin of SENCAR or CD-1 mice (McCormick and Moon, 1986; Warren and Slaga, 1993). Skin