Oral evening-primrose-seed oil improves atopic eczema

Herbal Medicine in Children and Adults With Atopic Dermatitis: A Systematic Review and Meta-Analysis

Herbal medicine is widely used for dermatological diseases, particularly atopic dermatitis. This study aims to systematically review existing literature on the efficacy of both topical and systemic herbal interventions for atopic dermatitis across various age groups. Conducting a comprehensive search on MEDLINE/PubMed, Scopus, and the Cochrane Central Register of Controlled Trials (Central) until April 12, 2023, only randomized controlled trials (RCTs) were included. The review is reported following the PRISMA guidelines and was conducted in accordance to Cochrane recommendations. Two authors independently extracted details, including demographics, medication, control/placebo groups, outcomes, adverse events, and results, with quality assessment using the Cochrane risk of bias tool 2.0. A meta-analysis, utilizing the random-effects model, was conducted, and publication bias was assessed through funnel plot inspection. The quality of evidence adhered to GRADE working group recommendations. The primary focus was evaluating atopic dermatitis or pruritus severity. The review encompassed 51 RCTs (3763 participants). Of these, 31 RCTs explored 19 distinct herbs and five complex remedies, whereas 20 RCTs (1088 participants) specifically investigated evening primrose oil (EPO). Herbs such as sunflower, licorice, figs, coconut, EPO, indigo naturalis, licorice, mauve, St. John's wort, and a combination of aloe vera and olive oil were found to have evidence of efficacy in the local treatment of atopic dermatitis. A meta-analysis on systemic used EPO, involving 13 RCTs, found no significant difference in atopic dermatitis severity compared with placebo (SMD: 0.14; 95% CI [-0.45; 0.73], 13 RCTs). In conclusion, this review provides a nuanced perspective on herbal substance efficacy for atopic dermatitis. While the EPO meta-analysis failed to show a discernible benefit beyond placebo, individual herbal preparations showed promising results in RCTs included in this review. Nevertheless, larger, methodologically rigorous studies are essential to establish evidence for herbal remedies in atopic dermatitis treatment.

Oral Lipids/Fatty Acids Supplements and Eczema: What Is Known?

The pathogenesis of atopic dermatitis (AD) points to skin barrier dysfunction as a critical piece of the puzzle. Deficiencies in fatty acids and ceramides-key elements of the skin barrier-have been linked to AD. Fatty acids can be separated into omega-3 and omega-6, which can be found in a variety of foods such as fish, nuts, seeds, and even plants. In dogs, supplementation with oral fatty acids has shown promising benefits. This review aims to explore whether humans can similarly benefit from these supplements based on current literature. The results of our search varied by compound type. For borage oil and evening primrose oil, evidence of their effectiveness is mixed, though they may offer some preventative benefits. Fish oil supplements appear to be effective in treating AD, as they reduce clinical scores and symptom severity. Oral ceramides, blackcurrant seed oil, and hempseed oil have yet to be thoroughly studied, but preliminary results are promising. Among the studies, the supplementation doses and duration of treatment varied extensively. The literature did not provide comparative analysis between the supplements, and data on the overall safety and tolerability of these supplements are limited. While some evidence is promising, the reliability of these products, as well as their optimal dosage and frequency, remains uncertain.

The effect of Oenothera biennis (Evening primrose) oil on inflammatory diseases: a systematic review of clinical trials

BACKGROUND

Evening primrose oil (EPO), extracted from the seeds of Oenothera biennis, has gained attention for its therapeutic effects in various inflammatory conditions.

METHOD

We performed a systematic search in multiple databases and defined the inclusion criteria based on the following PICOs: P: Patients with a form of inflammatory condition, I: EPO, C: Placebo or other therapeutic interventions, O: changes in inflammatory markers or patients' symptoms; S: randomized controlled trials. The quality of the RCTs was evaluated using Cochrane's RoB tool.

RESULTS

Several conditions were investigated in the literature. In rheumatoid arthritis, mixed results were observed, with some studies reporting significant improvements in symptoms while others found no significant impact. EPO showed some results in diabetes mellitus, atopic eczema, menopausal hot flashes, and mastalgia. However, it did not demonstrate effectiveness in chronic hand dermatitis, tardive dyskinesia, psoriatic arthritis, cystic fibrosis, hepatitis B, premenstrual syndrome, contact lens-associated dry eyes, acne vulgaris, breast cyst, pre-eclampsia, psoriasis, or primary Sjogren's syndrome. Some results were reported from multiple sclerosis after EPO consumption. Studies in healthy volunteers indicated no significant effect of EPO on epidermal atrophy, nevertheless, positive effects on the skin regarding hydration and barrier function were achieved.

CONCLUSION

Some evidence regarding the potential benefits of EPO in inflammatory disorders were reported however caution is due to the limitations of the current survey. Overall, contemporary literature is highly heterogeneous and fails to provide strong recommendations regarding the efficacy of EPO on inflammatory disorders. Further high-quality studies are necessitated to draw more definite conclusions and establish O. biennis oil effectiveness as an assuring treatment option in alleviating inflammatory conditions.

Therapeutic Benefits of Natural Ingredients for Atopic Dermatitis

Although a variety of regimens are available for the treatment of atopic dermatitis (AD), severe adverse reactions and unpopular costs often limit their usage. In contrast, certain inexpensive, naturally-occurring ingredients are proven effective for AD with fewer side effects. The beneficial effects of these ingredients can be attributed to inhibition of cytokine and chemokine expression, IgE production, inflammatory cell infiltration, histamine release, and/or the enhancement of epidermal permeability barrier function. Since herbal medicines are widely available, inexpensive and generally safe, they could be valuable alternatives for the treatment of AD, particularly for those patients who are not suitable for the utilization of immune modulators. In this review, we summarize the therapeutic benefits of natural ingredients for the treatment of AD and the mechanisms of their actions.

Nutraceuticals for Skin Care: A Comprehensive Review of Human Clinical Studies

The skin is the body’s largest organ, it participates in sensitivity and offers protection against microorganisms, chemicals and ultraviolet (UV) radiation. Consequently, the skin may suffer alterations such as photo-ageing, immune dysfunction and inflammation which may significantly affect human health. Nutraceuticals represent a promising strategy for preventing, delaying, or minimising premature ageing of the skin and also to alleviate certain skin disorders. Among them, bioactive peptides and oligosaccharides, plant polyphenols, carotenoids, vitamins and polyunsaturated fatty acids are the most widely used ingredients. Supplementation with these products has shown evidence of having an effect on the signs of ageing and protection against UV radiation ageing in several human trials. In this review, the most relevant human studies on skin nutraceuticals are evaluated and the statistical resolution, biological relevance of their results, and, the trial protocols are discussed. In conclusion, quality and rigorousness of the trials must be improved to build credible scientific evidence for skin nutraceuticals and to establish a cause-effect relationship between the ingredients the beneficial effects for the skin.

Topical application of THC containing products is not able to cause positive cannabinoid finding in blood or urine

A male driver was checked during a traffic stop. A blood sample was collected 35min later and contained 7.3ng/mL THC, 3.5ng/mL 11-hydroxy-THC and 44.6ng/mL 11-nor-9-carboxy-THC. The subject claimed to have used two commercially produced products topically that contained 1.7ng and 102ng THC per mg, respectively. In an experiment, three volunteers (25, 26 and 34 years) applied both types of salves over a period of 3days every 2-4h. The application was extensive (50-100cm²). Each volunteer applied the products to different parts of the body (neck, arm/leg and trunk, respectively). After the first application blood and urine samples of the participants were taken every 2-4h until 15h after the last application (overall n=10 urine and n=10 blood samples, respectively, for each participant). All of these blood and urine samples were tested negative for THC, 11-hydroxy-THC and 11-nor-9-carboxy-THC by a GC-MS method (LoD (THC)=0.40ng/mL; LoD (11-hydroxy-THC)=0.28ng/mL; LoD (THC-COOH)=1.6ng/mL;. LoD (THC-COOH in urine)=1.2ng/mL). According to our studies and further literature research on in vitro testing of transdermal uptake of THC, the exclusive application of (these two) topically applied products did not produce cannabinoid findings in blood or urine.

Complementary and Alternative Medicine for Atopic Dermatitis: An Evidence-Based Review

BACKGROUND

Complementary and alternative interventions are becoming increasingly utilized as adjuncts to conventional treatment of atopic dermatitis (AD). While the number of studies continues to grow, the vastness of the subject coupled with the relatively poor quality and small size of the studies limit their usefulness to clinicians.

PURPOSE

Our aim was to comprehensively review randomized controlled trials (RCTs) of complementary and alternative therapies for AD.

METHODS

Searches were performed on PubMed, the Cochrane Central Register of Controlled Trials, EMBASE, and the Global Resource for EczemA Trial (GREAT) databases, focusing on RCTs of alternative or complementary AD therapies, with a sample size of ≥10, through March 2015 and limited to the English language. A total of 70 manuscripts met the inclusion criteria and were included in the final analysis.

RESULTS

There is at least some level I evidence to support the use of acupuncture and acupressure, stress-reducing techniques such as hypnosis, massage, and biofeedback, balneotherapy, herbal preparations (with many important caveats), certain botanical oils, oral evening primrose oil, vitamin D supplementation, and topical vitamin B₁₂. Many other therapies either have sufficient data to suggest that they are ineffective, or simply do not have enough evidence to formulate a verdict.

CONCLUSIONS

Careful review of the literature reveals several promising therapies in this domain; such findings may help direct further research that is necessary to bolster clinical recommendations for alternative or complementary treatments of AD.

Triacylglycerol structure of plant and fungal oils containing ψ-linolenic acid

The triacylglycerol stereospecific structure was determined for the major plant oils containing ψ-linolenic acid (GLA): evening primrose oil (EPO), black currant oil (BCO), borage oil (BO), andMucor javanicus fungal oil (MJO). It was found that GLA, although not α-linolenic acid, resisted pancreatic lipase hydrolysis. Therefore, the 2-position analysis was determined using phospholipase C-generated 1,2-diacylglycerol and phospholipase A2-generated lysophosphatidylcholine. GLA was found to be concentrated in the 3-position of EPO and BCO, the 2-position of BO, and the 2- and 3-positions of MJO. In BCO, octadecatetraenoic acid (n-3), also a †-6 fatty acid, was distributed similarly to GLA, but α-linolenic acid was found predominantly in the 1-position. Linoleic acid was nearly evenly distributed in all positions of EPO and BCO but was concentrated in the 1-position of BO and the 2-position of MJO. Both palmitic and stearic acids were found predominantly in the 1-position of all of the oils. The results demonstrate similarities and differences in the positional distribution of fatty acids in GLA-containing oils.

Electrical conductance: a controversial parameter in the evaluation of emollients in atopic dermatitis

BACKGROUND/AIMS

Essential fatty acids are important in maintaining skin function and their deficiency is associated with scali-ness and increased transepidermal water loss (TEWL). This can be one of the pathogenic processes implicated in atopic dermatitis (AD). Several studies have assessed the value of essential fatty acid-enriched diets in AD but the benefits of topical γ-lino-lenic acid (GLA) therapy have been less well evaluated. The aims of this study were: a) to compare the effects of GLA-con-taining emollients and classical emollients, regarding clinical benefits, cutaneous hydration (by a conductance method) and TEWL; b) to assess the clinical relevance of these two biomet-rical methods (conductance and TEWL).

METHODS

Twenty-three AD children were randomised into four groups, to compare three emollients containing GLA in different concentrations and one classical emollient. They were evaluated in eight visits for 12 weeks, using a clinical score and measurements of TEWL with the Tewameter™ and of cutaneous hydration with the Nova™.

RESULTS

Kruskal-Wallis statistical analysis showed significant differences in cutaneous hydration (P<0.05) between each of the three treatment groups and the control group. TEWL and clinical scores did not show statistically significant differences. During the study no children from the GLA groups developed eczematous lesions versus two children from the non-GLA group.

CONCLUSIONS

Discrepancies between conductance and TEWL measurements may represent false positive results of the former method due to electrical phenomena related to polarity of the GLA molecule or of other elements in the formulations. However, some differences in clinical evolution between the GLA and non-GLA groups require further studies to assess the possible additional benefits of topical emollients containing GLA.

The codon-optimized Δ(6)-desaturase gene of Pythium sp. as an empowering tool for engineering n3/n6 polyunsaturated fatty acid biosynthesis

Background

The ∆⁶-desaturase gene, encoding a key enzyme in the biosynthesis of polyunsaturated fatty acids, has potential in pharmaceutical and nutraceutical applications.

Results

The ∆⁶-desaturase gene has been isolated from a selected strain of Oomycetes, Pythium sp. BCC53698. The cloned gene (PyDes6) contained an open reading frame (ORF) of 1401 bp encoding 466 amino acid residues. The deduced amino acid sequence shared a high similarity to those of other ∆⁶-desaturases that contained the signature features of a membrane-bound ∆⁶-desaturase, including a cytochrome b₅ and three histidine-rich motifs and membrane-spanning regions. Heterologous expression in Saccharomyces cerevisiae showed that monoene, diene and triene fatty acids having ∆⁹-double bond were substrates for PyDes6. No distinct preference between the n-3 and n-6 polyunsaturated fatty acyl substrates was found. The ∆⁶-desaturated products were markedly increased by codon optimization of PyDes6.

Conclusion

The codon-optimized ∆⁶-desaturase gene generated in this study is a promising tool for further reconstitution of the fatty acid profile, in a host system of choice, for the production of economically important fatty acids, particularly the n-3 and n-6 polyunsaturated fatty acids.

Electronic supplementary material

The online version of this article (doi:10.1186/s12896-015-0200-6) contains supplementary material, which is available to authorized users.

Oral administration of whole dihomo-γ-linolenic acid-producing Saccharomyces cerevisiae suppresses cutaneous inflammatory responses induced by croton oil application in mice

Polyunsaturated fatty acids have been attracting considerable interest because of their many biological activities and important roles in human health and nutrition. Dihomo-γ-linolenic acid (DGLA; C20: 3n-6) is known to have an anti-inflammatory activity, but its range of effects was not well studied because of its limited natural sources. Taking advantage of genetic tractability and increasing wealth of accessible data of Saccharomyces cerevisiae, we have previously constructed a DGLA-producing yeast strain by introducing two types of desaturase and one elongase genes to convert endogenous oleic acid (C18:1n-9) to DGLA. In this study, we investigated the efficacy of oral intake of heat-killed whole DGLA-producing yeast cells in the absence of lipid purification on cutaneous inflammation. Topical application of croton oil to mouse ears induces ear swelling in parallel with the increased production of chemokines and accumulation of infiltrating cells into the skin sites. These inflammatory reactions were significantly suppressed in a dose-dependent manner by oral intake of the DGLA-producing yeast cells for only 7 days. This suppression was not observed by the intake of the γ-linolenic acid-producing (C18:3n-6, an immediate precursor of DGLA) yeast, indicating DGLA itself suppressed the inflammation. Further analysis demonstrated that DGLA exerted an anti-inflammatory effect via prostaglandin E1 formation because naproxen, a cyclooxygenase inhibitor, attenuated the suppression. Since 25-fold of purified DGLA compared with that provided as a form of yeast was not effective, oral administration of the whole DGLA-producing yeast is considered to be a simple but efficient method to suppress inflammatory responses.

Oral evening primrose oil and borage oil for eczema

BACKGROUND

Eczema is a chronic inflammatory skin condition, which usually develops in early childhood. Many children outgrow this disorder as they reach secondary school age, and although It may improve with age, there is no cure. Constant itch makes life uncomfortable for those with this condition, no matter what age they are, so it may have a significant effect on a person's quality of life. Its prevalence seems to be increasing as populations move from rural locations to cities. Some people, who do not see an adequate improvement or fear side-effects of conventional medical products, try complementary alternatives to conventional treatment. This is a review of evening primrose oil (EPO) and borage oil (BO) taken orally (by mouth); these have been thought to be beneficial because of their gamma-linolenic acid content.

OBJECTIVES

To assess the effects of oral evening primrose oil or borage oil for treating the symptoms of atopic eczema.

SEARCH METHODS

We searched the following databases up to August 2012: Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 1946), EMBASE (from 1974), AMED (from 1985), and LILACS (from 1982). We also searched online trials registers and checked the bibliographies of included studies for further references to relevant trials. We corresponded with trial investigators and pharmaceutical companies to try to identify unpublished and ongoing trials. We performed a separate search for adverse effects of evening primrose oil and borage oil in November 2011.

SELECTION CRITERIA

All randomised controlled, parallel, or cross-over trials investigating oral intake of evening primrose oil or borage oil for eczema.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied eligibility criteria, assessed risk of bias, and extracted data. We pooled dichotomous outcomes using risk ratios (RR), and continuous outcomes using the mean difference (MD). Where possible, we pooled study results using random-effects meta-analysis and tested statistical heterogeneity using both the Chi(²) test and the I(²) statistic test. We presented results using forest plots with 95% confidence intervals (CI).

MAIN RESULTS

A total of 27 studies (1596 participants) met the inclusion criteria: 19 studies assessed evening primrose oil, and 8 studies assessed borage oil. For EPO, a meta-analysis of results from 7 studies showed that EPO failed to significantly increase improvement in global eczema symptoms as reported by participants on a visual analogue scale of 0 to 100 (MD -2.22, 95% CI -10.48 to 6.04, 176 participants, 7 trials) and a visual analogue scale of 0 to 100 for medical doctors (MD -3.26, 95% CI -6.96 to 0.45, 289 participants, 8 trials) compared to the placebo group.Treatment with BO also failed to significantly improve global eczema symptoms compared to placebo treatment as reported by both participants and medical doctors, although we could not conduct a meta-analysis as studies reported results in different ways. With regard to the risk of bias, the majority of studies were of low risk of bias; we judged 67% of the included studies as having low risk of bias for random sequence generation; 44%, for allocation concealment; 59%, for blinding; and 37%, for other biases.

IMPLICATIONS FOR PRACTICE

Oral borage oil and evening primrose oil lack effect on eczema; improvement was similar to respective placebos used in trials. Oral BO and EPO are not effective treatments for eczema.In these studies, along with the placebos, EPO and BO have the same, fairly common, mild, transient adverse effects, which are mainly gastrointestinal.The short-term studies included here do not examine possible adverse effects of long-term use of EPO or BO. A case report warned that if EPO is taken for a prolonged period of time (more than one year), there is a potential risk of inflammation, thrombosis, and immunosuppression; another study found that EPO may increase bleeding for people on Coumadin® (warfarin) medication.

IMPLICATIONS FOR RESEARCH

Noting that the confidence intervals between active and placebo treatment are narrow, to exclude the possibility of any clinically useful difference, we concluded that further studies on EPO or BO for eczema would be hard to justify.This review does not provide information about long-term use of these products.

Impact of polyunsaturated fatty acid consumption prior to ischemic stroke

OBJECTIVE

The Japanese have higher levels of n-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in their diets. These facts may contribute to the lower rates of atherosclerosis in Japanese. The purposes of this study were to assess the PUFA levels in patients with subtypes of acute ischemic stroke and to assess the relationship between severity and PUFA levels.

MATERIAL AND METHODS

We studied 75 patients with lacunar infarction (LI; n = 25), atherothrombotic infarction (AT; n = 32), and cardiogenic embolism (CE; n = 18). The patients underwent blood examinations in a fasting state next morning of hospitalization, including examination of low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), triglyceride (TG), blood glucose, hemoglobin A1c (HbA1c), uric acid, and fatty acid fractions of EPA, DHA, dihomo-γ-linolenic acid (DGLA), and arachidonic acid (AA). We used the modified Rankin Scale (mRS) to assess clinical severity at discharge.

RESULTS

There was no significant difference in the EPA/AA and DHA/AA ratio among the three stroke subgroups, although the DGLA/AA ratio was significantly higher in patients with LI than in patients with CE. Considering the confounding factors, the mRS was negatively correlated with EPA/AA and positively correlated with age, DHA/AA, and blood glucose.

CONCLUSIONS

High EPA/AA ratio was associated with good outcome in ischemic stroke. Our paper suggests that prestroke dietary habits affect the severity in patients with ischemic stroke.

Nutrition and nutritional supplementation: Impact on skin health and beauty

Skin acts as a natural barrier between internal and external environments thus plays an important role in vital biological functions such as protection against mechanical/chemical damages, micro-organisms, ultraviolet damage. Nutrition has a critical impact on strengthening skin's capabilities to fight against these multiple aggressions.Nutritional deficiencies are often associated with skin health disorders, while diets can either positively or negatively influence skin condition. More recently, the concept of nutritional supplementation has emerged as a new strategy in the daily practice of dermatology as well as a complementary approach to topical cosmetics in the field of beauty. Focusing on human clinical data, this paper proposes to illustrate the link between skin health and nutrition and to exemplify the beneficial actions of nutritional supplementation in skin health and beauty.

Oral supplementation with dihomo-gamma-linolenic acid-enriched oil altered serum fatty acids in healthy men

Dihomo-gamma-linolenic acid (DGLA)-enriched oil (50 or 150 mg as free DGLA) was administered to healthy men for 4 weeks. The DGLA content in serum phospholipids dose-dependently increased and returned to the initial level after a 4-week washout. No side effects or changes in platelet aggregation were observed. These results indicate that oral supplementation with DGLA oil can safely increase serum DGLA content.

Subchronic (13-week) oral toxicity study of dihomo-gamma-linolenic acid (DGLA) oil in rats

Dihomo-gamma-linolenic acid (DGLA) is one of the essential fatty acids, and has anti-inflammatory and anti-allergic effects. To assess the toxicity of a novel DGLA oil produced by the fungus Mortierella alpina, we examined it in the Ames test and in acute and subchronic oral toxicity tests in rats. In the Ames test, no mutagenicity was found up to 5000 microg/plate. The acute toxicity test revealed no toxicity related to DGLA oil at 10 g/kg. In the subchronic toxicity test, DGLA oil (500, 1000, and 2000 mg/kg) was orally administered. Water and soybean oil (2000 mg/kg) were used for the no-oil control and soybean oil control groups, respectively. There was no death in either sex. Because of administration of large amounts of oil, food consumption was low in the soybean oil control and the three test groups, which appeared to mildly decrease urinary excretion of Na, K, and Cl, as well as total serum protein, albumin, and blood urea nitrogen levels. There were no toxicological changes in body weight, food consumption, ophthalmological examination, urinalysis, hematological examination, blood biochemical examination, necropsy, organ weight, or histopathological examination. These findings show that the no-observed-adverse-effect level of the DGLA oil was 2000 mg/kg.

Linoleic acid metabolite levels and transepidermal water loss in children with atopic dermatitis

BACKGROUND

It has been suggested that atopic dermatitis (AD) is associated with impaired delta-6 desaturase activity and the subsequent altered composition of n-6 essential fatty acids (EFAs).

OBJECTIVE

To investigate whether n-6 EFA deficiency accounts for AD by affecting transepidermal water loss or the immune response.

METHODS

Serum levels of n-6 EFAs were measured using gas chromatography-mass spectrometry in a well-defined group of 35 children with AD (IgE level >150 U/mL); 35 age-matched children with allergic rhinitis, asthma, or both (IgE level >150 U/mL); and 31 nonatopic controls (IgE level <100 U/mL). Skin barrier function was evaluated by measuring transepidermal water loss and severity of AD by computing the Scoring Atopic Dermatitis (SCORAD) index.

RESULTS

Atopic children had higher levels of linoleic acid (LA) and lower levels of its metabolites. Furthermore, gamma-linolenic acid to LA and dihommo-gamma-linolenic acid to LA ratios were significantly reduced in atopic patients. Transepidermal water loss and the SCORAD index were negatively correlated with serum levels of LA metabolites. There was no correlation between the SCORAD index and IgE level (P = .51) or between n-6 EFA concentrations and IgE level (P > .10).

CONCLUSIONS

Deficits in n-6 EFAs were correlated with the severity of AD by affecting skin barrier function and cutaneous inflammation. The link between impaired n-6 EFA metabolism and IgE level could not be defined.

Oral administration of dihomo-gamma-linolenic acid prevents development of atopic dermatitis in NC/Nga mice

Disorders of the metabolism of essential fatty acids (EFAs) are related to atopic dermatitis (AD). Concentrations of dihomo-gamma-linolenic acid (DGLA), an EFA, in the serum of AD patients are lower than those in healthy volunteers. Recently we developed a fermented DGLA oil, and examined whether oral administration of DGLA prevents development of dermatitis in NC/Nga mice, which spontaneously develop human AD-like skin lesions. NC/Nga mice were fed a diet either containing or not containing DGLA for 8 weeks under in air-uncontrolled conventional circumstances. Clinical skin severity scores were significantly lower in mice fed DGLA than in mice not fed it. Scratching behavior and plasma total IgE levels were also reduced in the DGLA group, in association with histological improvement. DGLA suppressed clinical severity of skin lesions dose-dependently, with an increase in DGLA contents in phospholipids of skin, spleen, and plasma. Discontinuation of DGLA administration resulted in the onset of dermatitis and a decrease in DGLA contents in skin, spleen, and plasma. These findings indicate that oral administration of DGLA effectively prevents the development of AD in NC/Nga mice, and that DGLA in phospholipids is a compound of key importance in the development and prevention of dermatitis.

Distribution and metabolism of dihomo-gamma-linolenic acid (DGLA, 20:3n-6) by oral supplementation in rats

We compared the dietary effects of dihomo-gamma-linolenic acid (DGLA) contained in the DGLA oil produced by a fungus with gamma-linolenic acid (GLA) on the fatty acid composition. Wistar rats were fed with three kinds of oil for two weeks as follows: (i) control group: corn oil; (ii) GLA group: borage oil; (iii) DGLA group: DGLA oil/safflower oil = 55:45. The DGLA concentrations in the liver, serum, and brain of the DGLA group were higher than those of the GLA oil group. We also examined the dose effect of DGLA. The DGLA levels in the liver, serum, and brain significantly increased with increasing dosage of DGLA in the diet. DGLA administration significantly increased the ratio of PGE1/PGE2 in the rat plasma. The mechanism for GLA administration to improve atopic eczema is thought to involve an increase in the concentration of DGLA metabolized from GLA, so these results suggest that the dietary effect of DGLA would be more dominant than GLA.

Open trial of supplements of omega 3 and 6 fatty acids, vitamins and minerals in atopic dermatitis

OBJECTIVE

To investigate whether dietary supplementation with polyunsaturated fatty acids (PUFA) of the omega 3 series (n-3 PUFA: 18:3, n-3; 20:5, n-3; and 22:6, n-3), the omega 6 series (n-6 PUFA: 18:3, n-6), vitamins and minerals have a clinical effect on atopic dermatitis.

METHODS

A total of 19 patients aged 17-43 years with moderate to severe atopic dermatitis participated in an open trial of high oral doses of n-3 and n-6 PUFA in dry form (powder) or omega 3,6,9 fatty acid capsules, vitamin E tablets (d-alpha-tocopherol), zinc solution or tablets, and multivitamin capsules daily for 16 weeks.

RESULTS

The mean SCORAD improved in 14 of 17 patients by more than 50% after 8 weeks and 16 weeks of treatment (p<0.01 and p<0.001, respectively).

CONCLUSION

The open nature of this trial and the small number of subjects are major limitations of this study. The possible role of dietary omega 3 and 6 fatty acids in the treatment of atopic dermatitis should be tested more extensively in a double-blind trial using high doses of antioxidants combined with PUFA.

The clinical benefit of moisturizers

Moisturizing creams marketed to consumers often contain trendy ingredients and are accompanied by exciting names and attractive claims. Moisturizers are also an important part of the dermatologist's armamentarium to treat dry skin conditions and maintain healthy skin. The products can be regarded as cosmetics, but may also be regulated as medicinal products if they are marketed against dry skin diseases, such as atopic dermatitis and ichthyosis. When moisturizers are used on the so-called dry skin, many distinct disorders that manifest themselves with the generally recognized symptoms of dryness are treated. Dryness is not a single entity, but is characterized by differences in chemistry and morphology in the epidermis depending on the internal and external stressors of the skin. Patients and the society expect dermatologists and pharmacists to be able to recommend treatment for various dry skin conditions upon evidence-based medicine.

LEARNING OBJECTIVE

Upon completing this paper, the reader should be aware of different types of moisturizers and their major constituents. Furthermore, s/he will know more about the relief of dryness symptoms and the functional changes of the skin induced by moisturizers.

EFA supplementation in children with inattention, hyperactivity, and other disruptive behaviors

This pilot study evaluated the effects of supplementation with PUFA on blood FA composition and behavior in children with Attention-Deficit/Hyperactivity Disorder (AD/HD)-like symptoms also reporting thirst and skin problems. Fifty children were randomized to treatment groups receiving either a PUFA supplement providing a daily dose of 480 mg DHA, 80 mg EPA, 40 mg arachidonic acid (AA), 96 mg GLA, and 24 mg alpha-tocopheryl acetate, or an olive oil placebo for 4 mon of double-blind parallel treatment. Supplementation with the PUFA led to a substantial increase in the proportions of EPA, DHA, and alpha-tocopherol in the plasma phospholipids and red blood cell (RBC) total lipids, but an increase was noted in the plasma phospholipid proportions of 18:3n-3 with olive oil as well. Significant improvements in multiple outcomes (as rated by parents) were noted in both groups, but a clear benefit from PUFA supplementation for all behaviors characteristic of AD/HD was not observed. For most outcomes, improvement of the PUFA group was consistently nominally better than that of the olive oil group; but the treatment difference was significant, by secondary intent-to-treat analysis, on only 2 out of 16 outcome measures: conduct problems rated by parents (-42.7 vs. -9.9%, n = 47, P = 0.05), and attention symptoms rated by teachers (-14.8 vs. +3.4%, n = 47, P = 0.03). PUFA supplementation led to a greater number of participants showing improvement in oppositional defiant behavior from a clinical to a nonclinical range compared with olive oil supplementation (8 out of 12 vs. 3 out of 11, n = 33, P = 0.02). Also, significant correlations were observed when comparing the magnitude of change between increasing proportions of EPA in the RBC and decreasing disruptive behavior as assessed by the Abbreviated Symptom Questionnaire (ASQ) for parents (r = -0.38, n = 31, P < 0.05), and for EPA and DHA in the RBC and the teachers' Disruptive Behavior Disorders (DBD) Rating Scale for Attention (r = -0.49, n = 24, P < 0.05). Interestingly, significant correlations were observed between the magnitude of increase in alpha-tocopherol concentrations in the RBC and a decrease in scores for all four subscales of the teachers' DBD (Hyperactivity, r = -0.45; Attention, r= -0.60; Conduct, r = -0.41; Oppositional/Defiant Disorder, r = -0.54; n = 24, P < 0.05) as well as the ASQ for teachers (r = -0.51, n = 24, P < 0.05). Thus, the results of this pilot study suggest the need for further research with both n-3 FA and vitamin E in children with behavioral disorders.

Oral essential fatty acid supplementation in atopic dermatitis-a meta-analysis of placebo-controlled trials

BACKGROUND

Essential fatty acids are components of cell membranes and precursors of immunomodulating factors that may play a role in the inflammatory and immunological pathogenesis of atopic dermatitis. Trials of supplementation with essential fatty acids (EFA) to alleviate atopic dermatitis (AD) have given inconsistent results.

OBJECTIVES

To summarize and quantify the results of placebo-controlled trials with EFA for AD.

DESIGN

Publications of clinical trials were searched in a systematic way and the study characteristics assessed independently by three assessors. Trials were selected for inclusion in the meta-analysis when they had included a placebo group and when the outcome measure included the severity of AD. The pooled effect sizes of improvement of the overall severity of AD were calculated by random effects meta-analysis. The dependence of the results on study characteristics was studied using meta-regression analysis.

RESULTS

We identified 34 publications of controlled trials in AD up to April 2002. Nineteen trials of gamma-linolenic acid (GLA) and five trials of fish oil matched our inclusion criterion of placebo-controlled trial. The effect size of GLA supplementation on the improvement of the overall severity of AD could be calculated from 11 of these trials. The pooled effect size was 0.15 [95% confidence limits (CL) - 0.02, 0.32]. The effect size of fish oil supplementation, calculated from three trials was - 0.01 (95% CL - 0.37, 0.30). For component subscales such as itch, scaling and lichenification, EFA supplementation showed no benefit. The study characteristics showed no detectable influence on the overall result.

CONCLUSIONS

Supplementation with EFA has no clinically relevant effect on the severity of AD.

Role of topical emollients and moisturizers in the treatment of dry skin barrier disorders

Emollients and moisturizing creams are used to break the dry skin cycle and to maintain the smoothness of the skin. The term 'moisturizer' is often used synonymously with emollient, but moisturizers often contain humectants in order to hydrate the stratum corneum. Dryness is frequently linked to an impaired barrier function observed, for example, in atopic skin, psoriasis, ichthyosis, and contact dermatitis. Dryness and skin barrier disorders are not a single entity, but are characterized by differences in chemistry and morphology in the epidermis. Large differences also exist between moisturizing creams. Moisturizers have multiple functions apart from moistening the skin. Similar to other actives, the efficacy is likely to depend on the dosage, where compliance is a great challenge faced in the management of skin diseases. Strong odor from ingredients and greasy compositions may be disagreeable to the patients. Furthermore, low pH and sensory reactions, from lactic acid and urea for example, may reduce patient acceptance. Once applied to the skin, the ingredients can stay on the surface, be absorbed into the skin, be metabolized, or disappear from the surface by evaporation, sloughing off, or by contact with other materials. In addition to substances considered as actives, e.g. fats and humectants, moisturizers contain substances conventionally considered as excipients (e.g. emulsifiers, antioxidants, preservatives). Recent findings indicate that actives and excipients may have more pronounced effects in the skin than previously considered. Some formulations may deteriorate the skin condition, whereas others improve the clinical appearance and skin barrier function. For example, emulsifiers may weaken the barrier. On the other hand, petrolatum has an immediate barrier-repairing effect in delipidized stratum corneum. Moreover, one ceramide-dominant lipid mixture improved atopic dermatitis and decreased transepidermal water loss (TEWL) in an open-label study in children. In double-blind studies moisturizers with urea have been shown to reduce TEWL in atopic and ichthyotic patients. Urea also makes normal and atopic skin less susceptible against irritation to sodium laurilsulfate. Treatments improving the barrier function may reduce the likelihood of further aggravation of the disease. In order to have optimum effect it is conceivable that moisturizers should be tailored with respect to the epidermal abnormality. New biochemical approaches and non-invasive instruments will increase our understanding of skin barrier disorders and facilitate optimum treatments. The chemistry and function of dry skin and moisturizers is a challenging subject for the practicing dermatologist, as well as for the chemist developing these agents in the pharmaceutical/cosmetic industry.