Multiple spatially resolved reflection spectroscopy to monitor cutaneous carotenoids during supplementation of fruit and vegetable extracts in vivo.

BACKGROUND: A nutrition rich in fruit and vegetables and a healthy lifestyle become more and more important in the industrial countries to counteract oxidative stress and promote health. For many years, it has been possible to control human cutaneous carotenoids noninvasively by resonance Raman spectroscopic systems and by spatially resolved reflectance spectroscopy. METHODS: Ten volunteers took a commercially available fruit and vegetable extract daily for a time period of 5 weeks. A second group served as control group and did not take any supplements (10 volunteers). To monitor the status of the cutaneous carotenoids noninvasively, an optical sensor based on multiple spatially resolved reflectance spectroscopy was applied once a week. RESULTS: The study could demonstrate that the intake of the supplement significantly increase the cutaneous carotenoid values of the young adults by 50%. The control group without any supplementation showed also significantly increased values, ie, by 10%, which might be due to the fact that their lifestyle was controlled. CONCLUSION: The results illustrate that a biofeedback by measuring the skin carotenoids could improve the lifestyle of young adults and that a regular consumption of fruit and vegetables directly or as a drink can increase the concentration of cutaneous carotenoids significantly.

Alcohol consumption decreases the protection efficiency of the antioxidant network and increases the risk of sunburn in human skin.

In recent years, epidemiological data has demonstrated that alcohol consumption is a risk factor for sunburn, melanoma and nonmelanoma skin cancer. We hypothesized that if the concentration of the antioxidants in the skin has already decreased due to alcohol consumption, then an adequate neutralization of the free radicals induced by ultraviolet light cannot be performed. Based on this hypothesis, we determined the carotenoid concentration in the skin and the minimal erythema dose (MED) of 6 male human volunteers before and after consumption of alcohol or alcohol and orange juice combined. The results showed a significant decrease in the carotenoid concentration in the skin and the MED after alcohol consumption, but no significant decrease after a combined intake of alcohol and orange juice.

Influence of dietary carotenoids on radical scavenging capacity of the skin and skin lipids.

Nutrition rich in carotenoids is well known to prevent cell damage, premature skin aging, and skin cancer. Cutaneous carotenoids can be enriched in the skin by nutrition and topically applied antioxidants have shown an increase in radical protection after VIS/NIR irradiation. In this paper, it was investigated whether orally administered carotenoids increase the radical scavenging activity and the radical protection of the skin using in vivo electron paramagnetic resonance spectroscopy and the skin lipid profile was investigated applying HPTLC on skin lipid extracts. Furthermore, in vivo Raman resonance spectroscopy was used to measure the cutaneous carotenoid concentration. A double blind placebo controlled clinical study was performed with 24 healthy volunteers, who have shown a slow but significant and effective increase in cutaneous carotenoids in the verum group. The enhancement in carotenoids increases the radical scavenging activity of the skin and provides a significant protection against stress induced radical formation. Furthermore, the skin lipids in the verum group increased compared to the placebo group but only significantly for ceramide [NS]. These results indicate that a supplementation with dietary products containing carotenoids in physiological concentrations can protect the skin against reactive oxygen species and could avoid premature skin aging and other radical associated skin diseases.

In vivo investigations on the penetration of various oils and their influence on the skin barrier.

BACKGROUND: The skin represents a potent barrier to the environment, which can be enhanced by the topical application of skin care products, such as oil and oil-based formulations by moisturizing the skin. METHODS: The aim of this study was the investigation of the penetration behaviour of four vegetable oils and of paraffin oil into the stratum corneum by laser scanning microscopy. In addition, the occlusion capacity of these substances was assessed by transepidermal water loss (TEWL) measurements. Petrolatum served as a positive control for skin occlusion. The study was conducted in vivo and included six healthy volunteers. RESULTS: Paraffin oil, as well as the vegetable oils, penetrated only into the first upper layers of the stratum corneum. TEWL measurements indicated that the application of the vegetable oils (except jojoba oil) as well as paraffin oil, led to a similar occlusion of the skin surface. The most effective occlusion was found for petrolatum. CONCLUSION: For the investigated oils, a deeper penetration than into the first upper layers of the stratum corneum could be excluded. The decreased TEWL values indicate that the application of the oils leads to a semi-occlusion of the skin surface as it is intended by the use of oils to retain moisture in skin.