Dietary curcumin post-treatment enhances the disappearance of B(a)P-derived DNA adducts in mouse liver and lungs.

To study the post-treatment effects of dietary curcumin on the levels of benzo(a)pyrene [B(a)P]-induced DNA adducts, mice were administered oil or B(a)P and randomized into 7 subgroups after 24 h. One of the subgroups from both the oil and B(a)P groups was killed at 24 h while the remaining 6 subgroups were shifted to powdered control or 0.05% curcumin diet and killed after 24, 72 and 120 h (experiment 1), and 7, 14, and 28 days (experiment 2).

The role of inflammation in skin cancer.

Cancer is an environmental disease and skin cancer (melanoma and non-melanoma) is the most common of all cancers. Epidemiological and experimental evidence suggest "chronic inflammation" to be one of the hallmarks in solar ultraviolet radiation and several other environmental agent-mediated skin cancers. The identification of transcription factors, mainly nuclear factor-kappa B (NF-κB), signal transducer and activator of transcription 3 (STAT3), hypoxia-inducible factor-1 alpha (HIF-1α) and their gene products i.

Polymeric black tea polyphenols modulate the localization and activity of 12-O-tetradecanoylphorbol-13-acetate-mediated kinases in mouse skin: mechanisms of their anti-tumor-promoting action.

Polymeric black tea polyphenols (PBPs) have been shown to possess anti-tumor-promoting effects in two-stage skin carcinogenesis. However, their mechanisms of action are not fully elucidated. In this study, mechanisms of PBP-mediated antipromoting effects were investigated in a mouse model employing the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA).

Antitumor-promoting effects of polyphenolic extracts from seedless and seeded Indian grapes.

Grapes, the widely consumed fruits, are rich in polyphenols. The biological and chemopreventive activities of grape seed polyphenols have been demonstrated, while similar information regarding crude polyphenolic extracts from whole grapes and their components (pulp plus skin, seeds), particularly the seedless varieties, is lacking. Cancer chemoprevention can be achieved by inhibition of either initiation or promotion/progression stages of carcinogenesis.

Curcumin decreases 12-O-tetradecanoylphorbol-13-acetate-induced protein kinase C translocation to modulate downstream targets in mouse skin.

Curcumin has been shown to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumour promotion and some of the TPA-responsive markers in mouse skin. However, its mechanism of action is not fully elucidated. The present study focuses on understanding the role of protein kinase C (PKC), the major cellular receptor of TPA, in mediating TPA-induced biological responses in mouse skin and subsequently, elucidating the effects of curcumin on PKC and its downstream target molecules.

Scavenging effect of Indian grape polyphenols on 2,2'-diphenyl-1-picrylhydrazyl(DPPH) radical by electron spin resonance spectrometry.

Antioxidant potency of Indian grape cultivars varying in their skin color, seed and polyphenol content (Bangalore blue, Pandhari sahebi, Sharad seedless and Thompson seedless) and their components (whole grapes, pulp with skin and seeds) was examined as 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity using electron spin resonance spectrometry. The total polyphenols in Indian grapes ranged between 3-51%. Extracted polyphenols caused a concentration dependent and significant loss in DPPH radical signal, similar to known antioxidants-Vitamin C, catechin and procyanidin B3 used as references.

Expression of enhancing factor/phospholipase A2 in skin results in abnormal epidermis and increased sensitivity to chemical carcinogenesis.

Enhancing factor (EF), a growth factor modulator, is the mouse homologue of human secretory group II phospholipase A(2). EF exhibits growth-promoting activity in vitro, in the presence of epidermal growth factor, and also brings about phenotypic transformation of normal cells. In order to ascertain the role of EF in vivo, a human keratin-14 promoter was used to drive the expression of EF ectopically to squamous epithelial cells.