Resveratrol, a phytoalexin present in grapes, has been reported to inhibit multistage mouse skin carcinogenesis. Recent studies showed that topically applied resveratrol significantly inhibited cyclooxygenase-2 (COX-2) expression and activation of nuclear factor-kappaB (NF-kappaB) induced by tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in mouse epidermis. The aim of the present study was to further explore the effect of resveratrol on TPA-induced signaling pathways in mouse epidermis and to compare with its dimethylether, pterostilbene. Resveratrol and pterostilbene significantly reduced activator protein 1 (AP-1) and NF-kappaB activation. In the case of AP-1, the binding of c-Jun subunit was particularly affected, while only slight effect on c-Fos binding to TPA-responsive element (AP-1 binding consensus sequence) (TRE) site was observed. Both stilbenes inhibited the activation of NF-kappaB by blocking the translocation of p65 to the nucleus and increasing the retention of IkappaBa in the cytosol. The latter might be related to decreased activity of IkappaB kinase and/or proteasome 20S. Reduced activation of transcription factors decreased the expression and activity of COX-2 and inducible nitric oxide synthase (iNOS). In most assays, pterostilbene was either equally or significantly more potent than resveratrol. Pterostilbene might show higher biological activity due to its possible better bioavailability, since substitution of hydroxy with methoxy group increases lipophilicity.
Department of Pharmaceutical Biochemistry, Poznan University of Medical Sciences, Poznan, Poland.
Researchers from The University of Texas Health Science Center at San Antonio have made a fascinating discovery about the synergistic effects of certain fruit and vegetable compounds on preventing skin cancer. Resveratrol, a powerful antioxidant found in grape skins, grape seed extract, D-glucarate, a cellular detoxifier, calcium and ellagic acid all seem to work in harmony together to protect against skin cancer. (more…)
It goes against most things we hear, but Dr. Leonard Coldwell says the sun can actually help prevent skin cancer. He also describes how he thinks sunscreen is a cause of skin cancer.
Even in the summer, it’s quite possible to lack sufficient vitamin D because sunscreen, which blocks our ability to produce the “sunshine vitamin,” is so widely used. And it’s difficult to consume adequate vitamin D from food.
Your skin is the largest organ in your body. (more…)
Since the 1980s, physicians and cancer groups have regularly warned the public against the potential health dangers of direct sunlight on skin. As a result, many people have stayed out of the sunlight completely, covered their limbs even in warm weather or slathered themselves with UV protection products, all in the interest of lowering their risk of melanomas.
However, more recent findings indicate that this kind of nearly vampiric avoidance of the sun may not benefit your cancer odds after all. (more…)
Question: I’ve read your advice on increasing vitamin D levels by getting plenty of sunshine, but my concern is that I’ve had skin cancer in the past and my doctor warned me that going out in the sun without sunscreen will make it return. Is there anything I can do to prevent that from happening? (more…)
Researchers at the Environmental Working Group, a Washington-based nonprofit, released their annual report claiming nearly half of the 500 most popular sunscreen products may actually increase the speed at which malignant cells develop and spread skin cancer because they contain vitamin A and its derivatives, retinol and retinyl palmitate. (more…)