Protective effect of silk lutein on ultraviolet B-irradiated human keratinocytes

Carotenoids are efficient antioxidants that are of great importance for human health. Lutein and zeaxanthin are carotinoids present in high concentrations in the human retina which are involved in the photoprotection of the human eye. Lutein may also protect the skin from ultraviolet (UV)-induced damage. The present study investigated the protective effect of lutein extracted from yellow silk cocoons of Bombyx mori on human keratinocytes against UVB irradiation. A human keratinocyte cell line and primary human keratinocytes were used to investigate the UVB protection effects of silk lutein and plant lutein. Silk lutein showed no cytotoxicity to keratinocytes. Treatment with silk lutein prior to UVB irradiation enhanced cell viability and cell proliferation, and reduced cell apoptosis. The protective effects of silk lutein may be superior to those of plant lutein. Silk lutein may have a benefit for protection of keratinocytes against UVB-irradiation.

Reduced interleukin-17 expression of Burkholderia pseudomallei-infected peripheral blood mononuclear cells of diabetic patients.

Burkholderia pseudomallei is the causative agent of melioidosis. One of the main risk factors for B. pseudomallei infection in endemic areas is diabetes mellitus. The present study investigated IL-17 mRNA and protein expression by peripheral blood mononuclear cells in response to B. pseudomallei infection in 10 diabetic patients in comparison to 10 healthy blood donors. The IL-17 expression in diabetic patients was significantly lower (p < 0.05) than in the controls. However, IL-23 mRNA expression of the 2 groups was comparable. The present findings suggest that melioidosis affects T cell IL-17 production and that patients with diabetes mellitus have a defective IL-17 production in response to this type of infection.