Seasonal influences on stratum corneum ceramide 1 fatty acids and the influence of topical essential fatty acids

Abstract

Synopsis Ceramide 1 is the main repository of stratum corneum linoleic acid, and changes in the levels of ceramide 1 linoleate are associated with cutaneous abnormalities: essential fatty acid deficiency, atopic dermatitis and acne. We have previously reported seasonal variation in stratum corneum lipids where lipids, particularly ceramides, are very much reduced in winter which probably influences the appearance of skin xerosis in this season. However, investigations into the seasonal variation in ceramide 1 fatty acid levels and the effects of topical essential fatty acids on the composition of these lipid species have not been conducted in healthy subjects. We determined the composition of stratum corneum ceramide 1 esterified fatty acids in leg skin from Caucasian women in winter and summer and also investigated the effects of topical triglycerides rich in linoleic acid on stratum corneum ceramide 1 fatty acid levels in winter. A dramatic seasonal variation was observed. Whereas decreased levels of linoleic acid and some saturated fatty acids (C-15 and C-24) were observed in the winter months, increased levels of oleic acid were found. Nevertheless, it was possible to normalize the levels of stratum corneum ceramide 1 linoleate following topical application of formulations containing linoleic acid-rich triglycerides for 4 weeks. The reduction in ceramide 1 linoleate may lead to impaired stratum corneum function and increased susceptibility to skin xerosis in winter. However, by using formulations containing linoleic acid esters it is possible to correct these changes and possibly improve barrier resilience.

Analysis of Epidermal Lipids of the Healthy Human Skin: Factors Affecting the Design of a Control Population

“…5 ml of a staining mixture containing acetic acid/H 2 SO 4 /H 3 PO 4 /H 2 O 5:1:1:95 Table 1. Controllable variables found in the literature playing a role in the outcome of human skin lipid profiles [10] Person linked Age [4], sex [11], phototype [12], interindividual variation [13] Environmental factors Seasonal variation [14], UV irradiation [15] Methodology Sampling body site [16], sampling skin depth [17], sample contamination [18] Extraction procedure [19], extraction efficiency [20], expression of results [8] Solvents for lipid separation [21], analytical technique for lipid determination [22] (v/v/v/v) and 0.5% CuSO 4 , after which the lipids were charred by heating the plates at 160°C for 10 min.…”

Investigation of the Molecular Structure of the Human Stratum Corneum Ceramides [NP] and [EOS] by Mass Spectrometry

“…A first step towards analyzing the variation of chain lengths in different parts of the CER molecules was the use of gas chromatography-mass spectrometry (GC-MS) after hydrolysis of the CER [9,13,19,20] . This method is very time consuming and does not allow for identification of isobaric subspecies due to the hydrolysis step.…”

Essential Fatty Acids and Atopic Dermatitis

“…In vitro studies have shown that glucosylation of CER EOS occurs before omega oxidation of the N-acylated fatty acid and presumably esterification with linoleic acid (Uchida and Holleran 2008). Whether this sequence of events was operating in the studies of Conti et al (1996) is unknown. However, the hydrolyzed EFAs from the oils may also be acting as PPAR agonists to induce epidermal differentiation, as discussed earlier.…”

“…In normal, healthy adults, topical borage and sunflower seed oils have been shown to be beneficial in winter when the levels of CER EOS linoleate are reduced (Conti et al 1996). After treatment, the levels of CER EOS linoleate were normalized.…”