Comparable down-regulation of TYR, TYRP1 and TYRP2 genes and inhibition of melanogenesis by tyrostat, tocotrienol-rich fraction and tocopherol in human skin melanocytes improves skin pigmentation.

BACKGROUND AND OBJECTIVE: Antioxidant has been recognized to inhibit UV-induced melanogenesis. This study aimed to elucidate the molecular mechanism of tyrostat, tocopherol and tocotrienol-rich fraction in inhibiting melanogenesis in human skin melanocytes. MATERIALS AND METHODS: Primary culture of melanocytes was exposed to repeated doses of 0.6 J/cm2 UVA for 6 days and treated with tyrostat, tocotrienol-rich fraction or tocopherol alone or in combination. RESULTS: UVA irradiation increased melanin content and tyrosinase activity and up-regulated TYR, TYRP1 and TYRP2 genes. Treatment with tyrostat, tocotrienol-rich fraction or tocopherol decreased melanin content and down-regulated TYR, TYRP1 and TYRP2 genes with decreased tyrosinase activity. Combined treatment exerted better effects as compared to treatment with single compound in decreasing the melanin content and down-regulating TYR, TYRP1 and TYRP2 genes. These findings indicated that tyrostat, tocotrienol-rich fraction and tocopherol inhibit melanogenesis by modulating the expression of genes involved in the regulation of melanin synthesis and inhibiting tyrosinase activity. CONCLUSIONS: Tyrostat, tocopherol and tocotrienol-rich fraction possessed anti-melanogenic properties and might be useful in improving skin pigmentation caused by UVA exposure.

Visualization of dual coronary artery fistulae drainage to the right ventricle by transthoracic echocardiography.

Coronary artery fistula is a rare abnormality of coronary circulation. It is mostly congenital but acquired forms can also occur. Fistulae are usually asymptomatic and can sometimes be visualized during cardiac imaging such as transthoracic echocardiogram, cardiac magnetic resonance imaging, coronary computed tomography angiography and coronary angiography.