Superoxide Dismutase 1 Inhibits Alpha-Melanocyte Stimulating Hormone and Ultraviolet B-Induced Melanogenesis in Murine Skin

BACKGROUND: Over the last decade, the incidence of ultraviolet B (UVB)-related skin problems has increased. Oxidative stress caused by UVB induces the secretion of melanocyte growth and activating factors from keratinocytes, which results in the formation of cutaneous hyperpigmentation. Therefore, increasing the antioxidant abilities of skin cells is thought to be a beneficial strategy for the development of sunscreen agents. Superoxide dismutase 1 (SOD1) is an antioxidant enzyme that is known to exhibit antioxidant properties. OBJECTIVE: The purpose of this study was to investigate the effect of SOD1 on alpha-melanocyte stimulating hormone (alpha-MSH) and UVB-induced melanogenesis in B16F10 melanoma cells and HRM-2 melanin-possessing hairless mice. METHODS: The inhibitory effect of SOD1 on tyrosinase activity was evaluated in a cell-free system. Additional experiments were performed using B16F10 melanoma cells to demonstrate the effects of SOD1 in vitro, and HRM-2 melanin-possessing hairless mice were used to evaluate the antimelanogenic effects of SOD1 in vivo. RESULTS: We found that SOD1 inhibited melanin production in a dose-dependent manner without causing cytotoxicity in B16F10 melanoma cells. SOD1 did not inhibit tyrosinase activity under cell-free conditions. The results indicate that SOD1 may reduce pigmentation by an indirect, nonenzymatic mechanism. We also found that SOD1 decreased UVB-induced melanogenesis in HRM-2 melanin-possessing hairless mice, as visualized through hematoxylin and eosin staining and Fontana-Masson staining. CONCLUSION: Our results indicate that SOD1 has an inhibitory effect on alpha-MSH and UVB-induced melanogenesis, indicating that SOD1 may be a promising sunscreen agent.

Advances in percutaneous nephrostomy

Management of urologic patients is being gradually but dramatically altered with new advances in technical innovation and refinements of interventional uroradiology. The broadening of indications for percutaneous nephrostomy became possible only after it was learned that it is a safe and effective means of establishing access to the renal collecting system. Percutaneous stone extraction (Nephrolithotomy) and Endopyelotomy are now well established procedures. These techniques have clear advantages over the surgical treatment for the same conditions and will increase the quality of patient care and reduce health care cost.