Evening Primrose (Oenothera biennis) Oil in Management of Female Ailments

Oenothera biennis with the common name of “evening primrose” is containing a valuable fixed oil with commercial name of EPO. Evening primrose oil has two types of omega-6-fatty acid including linoleic acid (60%–80%) and γ-linoleic acid (8%–14%). Essential fatty acids are considered as essential compounds for body health, especially among women. The aim of this study was to evaluate the efficacy of evening primrose oil in the management of women ailments. The document was prepared by investigation in scientific articles of electronic resources (Google Scholar, PubMed, Science Direct, Wiley, Scopus, and Springer) by keywords of evening primrose oil and women. The results of our investigations showed that evening primrose oil has been the subject of several clinical studies, including premenstrual syndrome (PMS), hot flash, mastalgia, fibroadenomas, gestational diabetes, cervical ripening, and dilation. The major clinical studies are focused on mastalgia, followed by PMS. The results of studies confirmed the evening primrose oil's efficacy in women health, but the immediate response should not be expected from it, therefore, it should be regularly used up to 4 or 6 months.

Antioxidant and antiobesity activities of oral treatment with ethanol extract from sprout of evening primrose (Oenothera laciniata) in high fat diet-induced obese mice / 한국영양학회지

PURPOSE: Sprouts of evening primrose (Oenothera laciniata, OL) were reported to have high contents of flavonoids and potent antioxidant activity. This study examined the antioxidant and antiobesity activities of OL sprouts to determine if they could be a natural health-beneficial resource preventing obesity and oxidative stress.METHODS: OL sprouts were extracted with 50% ethanol, evaporated, and lyophilized (OLE). The in vitro antioxidant activity of OLE was examined using four different tests. The antiobesity activity and in vivo antioxidant activity from OLE consumption were examined using high fat diet-induced obese (DIO) C57BL/6 mice.RESULTS: The IC₅₀ for the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD)-like activities of OLE were 26.2 µg/mL and 327.6 µg/mL, respectively. OLE exhibited the ferric reducing antioxidant power (FRAP) activity of 56.7 µg ascorbic acid eq./mL at 100 µg/mL, and an increased glutathione level by 65.1% at 200 µg/mL compared to the control in the hUC-MSC stem cells. In an animal study, oral treatment with 50 mg or 100 mg of OLE/kg body weight for 14 weeks reduced the body weight gain, visceral fat content, fat cell size, blood leptin, and triglyceride levels, as well as the atherogenic index compared to the high fat diet control group (HFC) (p < 0.05). The blood malondialdehyde (MDA) level and the catalase and SOD-1 activities in adipose tissue were reduced significantly by the OLE treatment compared to HFC as well (p < 0.05). In epididymal adipose tissue, the OLE treatment reduced the mRNA expression of leptin, PPAR-γ and FAS significantly (p < 0.05) compared to HFC while it increased adiponectin expression (p < 0.05).CONCLUSION: OLE consumption has potent antioxidant and antiobesity activities via the suppression of oxidative stress and lipogenesis in DIO mice. Therefore, OLE could be a good candidate as a natural resource to develop functional food products that prevent obesity and oxidative stress.

Effect of Evening Primrose Oil on Korean Patients With Mild Atopic Dermatitis: A Randomized, Double-Blinded, Placebo-Controlled Clinical Study

BACKGROUND: Atopic dermatitis (AD) is related to a deficiency of delta-6-desaturase, an enzyme responsible for converting linoleic acid to gamma-linolenic acid (GLA). Evening primrose oil (EPO) as a source of GLA has been of interest in the management of AD. OBJECTIVE: The aim of this randomized, double-blinded, placebo-controlled clinical study is to evaluate the efficacy and safety of EPO in Korean patients with AD. METHODS: Fifty mild AD patients with an Eczema Area Severity Index (EASI) score of 10 or less were enrolled and randomly divided into two groups. The first group received an oval unmarked capsule containing 450 mg of EPO (40 mg of GLA) per capsule, while placebo capsules identical in appearance and containing 450 mg of soybean oil were given to the other group. Treatment continued for a period of four months. EASI scores, transepidermal water loss (TEWL), and skin hydration were evaluated in all the AD patients at the baseline, and in months 1, 2, 3, and 4 of the study. RESULTS: At the end of month 4, the patients of the EPO group showed a significant improvement in the EASI score (p=0.040), whereas the patients of the placebo group did not. There was a significant difference in the EASI score between the EPO and placebo groups (p=0.010). Although not statistically significant, the TEWL and skin hydration also slightly improved in the EPO patients group. CONCLUSION: We suggest that EPO is a safe and effective medicine for Korean patients with mild AD.

Development of a Complete Atrioventricular Block Associated with Intake of Evening Primrose Oil / 대한내과학회지

A complete atrioventricular block is seen in patients due to a variety of causes, including drugs. The resolution of a drug-induced atrioventricular block is often accomplished by drug discontinuation. We report a case of a complete atrioventricular block in a 31-year-old woman following a month of treatment with evening primrose oils. After excluding all other likely causes of conduction disorders, an adverse effect of the evening primrose oils seemed to be the most likely diagnosis. After discontinuation of the oils, no associated symptoms or conduction disturbances were observed for 4 months after discharge. We stress the reconsideration of taking medicines and functional foods continuously as most patients are not aware of the hazards they pose.

A Study on the Statistical Method for the Target Component of a Glucose-lowering Functional Material in Extracts of Evening Primerose Seeds

BACKGROUND: The use of the extracts from evening primrose seeds as a health functional food has been gradually increased. Therefore, the monitoring and screening process has been considerably required for its quality control. OBJECTIVE: This study aimed to estimate the measurement uncertainty associated with determination of penta-o-galloyl β-D-glucose (PGG) in extracts from evening primrose seeds by high-performance liquid chromatography. METHODS: The sources of measurement uncertainty was expressed in accordance with mathematical/statistical theories of GUM & EURACHEM Guide. The expanded uncertainty was calculated by using the relative standard uncertainty between analytical result and sources of uncertainty in measurement (sample weight, final volume, extraction volume, standard solution, matrix and instrument etc). RESULTS: In the results of 95% confidence interval, the uncertainty in measurement was 10,253.34 ± 1,844.50 µg/kg (k = 2.0). CONCLUSION: In this study, it showed that the value of uncertainty in measurement for determination of PGG in extracts from evening primrose seeds by HPLC has about 18.0% influence on PGG contents of the analytical results. The results would be very useful for the monitoring and screening of evening primrose seeds marketed in Korea for its quality control as dietary supplement.

Comparative analysis of anti-Helicobacter pylori activities of FEMY-R7 composed of Laminaria japonica and Oenothera biennis extracts in mice and humans / 한국실험동물학회지

Helicobacter pylori-eliminating effects of FEMY-R7, composed of Laminaria japonica and Oenothera biennis extracts, were investigated in mice and humans. Male C57BL/6 mice were infected with the bacteria by intragastric inoculation (1x10(9) CFU/mouse) 3 times at 2-day intervals, and simultaneously, orally treated twice a day with total 20, 64 or 200 mg/kg/day FEMY-R7 for 2 weeks. In Campylobcter-like organism (CLO)-detection tests on gastric mucosa and feces, FEMY-R7 reduced the urease-positive reactivity in a dose-dependent manner; i.e., the positivity ratios were decreased to 70, 20, and 10% for gastric mocosa and to 80, 50, and 20% for feces. In a clinical sudy, human subjects, confirmed to be infected with Helicobacter pylori, were orally administered twice a day with capsules containing total 100, 320 or 1,000 mg/man/day FEMY-R7 (matching doses for 20, 64 or 200 mg/kg/day, respectively, in mice from a body surface area-based dose translation) for 8 weeks. FEMY-R7 decreased the positivity ratios in feces to 70, 40, and 30%, respectively. In bacterial culture, H. pylori was identified from the CLO-positive stools of mice and humans. The bacterial identification ratios exhibited a good correlation between the matching doses in mice and humans. It is suggested that FEMY-R7 could be a promising functional food without tolerance as an adjunct to reduce the dosage of antibiotics for the treatment of recurrent H. pylori infection.

Erratum: In vitro and in vivo anti-Helicobacter pylori activities of FEMY-R7 composed of fucoidan and evening primrose extract / 한국실험동물학회지

As the request of the authors, Acknowledgments section has been changed.

The Effect of Evening Primrose Oil for the Prevention of Xerotic Cheilitis in Acne Patients Being Treated with Isotretinoin: A Pilot Study

BACKGROUND: The most common adverse effects of oral isotretinoin are cheilitis, skin dryness, dry eyes, and conjunctivitis, whereas evening primrose oil (EPO) is known to improve skin moisture and transepidermal water loss (TEWL) in healthy adults and atopic patients. OBJECTIVE: To evaluate the clinical efficacy and safety of EPO in preventing xerotic cheilitis in acne patients being treated with oral isotretinoin. METHODS: Forty Korean volunteers of Fitzpatrick skin types III and IV, having moderate acne, were enrolled and randomized to receive either isotretinoin with or without EPO for 8 weeks. The efficacy of treatment was evaluated on the basis of global acne grading system scores, number of inflammatory and noninflammatory lesions, TEWL, corneometry, physician's global assessment, and patient satisfaction. RESULTS: The results after 8 weeks of treatment showed that the TEWL of the lip increased significantly during isotretinoin treatment, whereas the TEWL of the hand dorsum showed no significant change. The increase of the TEWL of the lip was more definite in the control group than in the experimental group. The number of acne lesions decreased significantly in both groups, and there were no differences between them. CONCLUSION: Our study suggests that the addition of EPO improved xerotic cheilitis in acne patients being treated with oral isotretinoin. However, besides TEWL and corneometry assessments, additional studies are required for a complete understanding of the role of EPO in xerotic cheilitis in acne patients being treated with oral isotretinoin.

In vitro and in vivo anti-Helicobacter pylori activities of FEMY-R7 composed of fucoidan and evening primrose extract / 한국실험동물학회지

Effects of FEMY-R7, composed of fucoidan and evening primrose extract, on the bacterial growth and intragastric infection of Helicobacter pylori as well as gastric secretion were investigated in comparison with a proton-pump inhibitor pantoprazole. For in vitro anti-bacterial activity test, H. pylori (1x10(8) CFU/mL) was incubated with a serially-diluted FEMY-R7 for 3 days. As a result, FEMY-R7 fully inhibited the bacterial growth at 100 microg/mL, which was determined to be a minimal inhibitory concentration. In addition, 6-hour incubation with H. pylori, FEMY-R7 inhibited urease activity in a concentration-dependent manner, showing a median inhibitory concentration of 1,500 microg/mL. In vivo elimination study, male C57BL/6 mice were infected with the bacteria by intragastric inoculation (5x10(9) CFU/mouse) 3 times at 2-day intervals, and simultaneously, orally treated twice a day with 10, 30 or 100 mg/kg FEMY-R7 for 7 days. In Campylobcter-like organism-detection test and bacterial identification, FEMY-R7 exerted a high bacteria-eliminating capacity at 30-100 mg/kg, comparably to 30 mg/kg pantoprazole. In contrast to a strong antacid activity of pantoprazole in a pylorus-ligation study, FEMY-R7 did not significantly affect gastric pH, free HCl, and total acidity, although it significantly decreased fluid volume at a low dose (10 mg/kg). The results indicate that FEMY-R7 eliminate H. pylori from gastric mucosa by directly killing the bacteria and preventing their adhesion and invasion, rather than by inhibiting gastric secretion or mucosal damage.

Anti-Helicobacter pylori activities of FEMY-R7 composed of fucoidan and evening primrose extract in mice and humans / 한국실험동물학회지

Helicobacter pylori-eliminating effects of FEMY-R7, composed of fucoidan and evening primrose extract, were investigated in mice and humans. Male C57BL/6 mice were infected with the bacteria by intragastric inoculation (1x10(9) CFU/mouse) 3 times at 2-day intervals, and simultaneously, orally treated twice a day with 10 or 100 mg/kg FEMY-R7 for 2 weeks. In Campylobcter-like organism-detection test, FEMY-R7 markedly reduced the urease-positive reactivity. In a clinical sudy, human subjects, confirmed to be infected with Helicobacter pylori, were orally administered twice a day with a capsule containing 150 mg FEMY-R7 for 8 weeks. FEMY-R7 significantly decreased both the Delta over baseline-value in urea breath test and the serum pepsinogens I and II levels. The results indicate that FEMY-R7 not only eliminates H. pylori from gastric mucosa of animals and humans, but also improves gastric function.

Dose-Dependent Effects of Evening Primrose Oil in Children and Adolescents with Atopic Dermatitis

BACKGROUND: Previous clinical trials with evening primrose oil in atopic dermatitis (AD) treatment have shown different results. In addition, the optimal dose and duration of treatment with evening primrose oil have not yet been determined. OBJECTIVE: The aim of this study is to investigate the dose-response treatment effects of evening primrose oil on clinical symptoms of AD and serum concentrations of polyunsaturated fatty acids. METHODS: Forty AD patients were enrolled for the study and randomly divided into 2 groups: those who received evening primrose oil 160 mg daily for 8 weeks and those who received 320 mg of evening primrose oil twice daily for 8 weeks. We evaluated the Eczema Area Severity Index (EASI) scores of all AD patients at weeks 0, 2, 4 and 8. In addition, we measured the levels of serum fatty acids, including C16 : 0 (palmitic), C18 : 2n (linoleic), C18 : 3n (linolenic) and C20 : 4 (arachidonic acid) using gas chromatography. RESULTS: The serum fatty acid levels C18 : 3n and C20 : 4 were higher in the 320 mg group than in the 160 mg group, with statistical significance. After evening primrose oil treatment, EASI scores were reduced in the 2 groups. The improvement in EASI scores was greater in the 320 mg group than in the 160 mg group. There were no side effects seen in either group during the study in the 2 groups. CONCLUSION: The results of this study suggest that the 320 mg and 160 mg groups may be equally effective in treating AD patients and show dose-dependent effects on serum fatty acid levels and EASI scores.

Dose-Dependent Effects of Evening Primrose Oil in Children and Adolescents with Atopic Dermatitis

BACKGROUND: Previous clinical trials with evening primrose oil in atopic dermatitis (AD) treatment have shown different results. In addition, the optimal dose and duration of treatment with evening primrose oil have not yet been determined. OBJECTIVE: The aim of this study is to investigate the dose-response treatment effects of evening primrose oil on clinical symptoms of AD and serum concentrations of polyunsaturated fatty acids. METHODS: Forty AD patients were enrolled for the study and randomly divided into 2 groups: those who received evening primrose oil 160 mg daily for 8 weeks and those who received 320 mg of evening primrose oil twice daily for 8 weeks. We evaluated the Eczema Area Severity Index (EASI) scores of all AD patients at weeks 0, 2, 4 and 8. In addition, we measured the levels of serum fatty acids, including C16 : 0 (palmitic), C18 : 2n (linoleic), C18 : 3n (linolenic) and C20 : 4 (arachidonic acid) using gas chromatography. RESULTS: The serum fatty acid levels C18 : 3n and C20 : 4 were higher in the 320 mg group than in the 160 mg group, with statistical significance. After evening primrose oil treatment, EASI scores were reduced in the 2 groups. The improvement in EASI scores was greater in the 320 mg group than in the 160 mg group. There were no side effects seen in either group during the study in the 2 groups. CONCLUSION: The results of this study suggest that the 320 mg and 160 mg groups may be equally effective in treating AD patients and show dose-dependent effects on serum fatty acid levels and EASI scores.

Separation of gamma linolenic acid from evening primrose oil with urea inclusion--orthogonal experiment of optimizing technological parameters and observation of urea inclusion compound I / 中国中药杂志

<p><b>OBJECTIVE</b>The influence on the urea inclusion compound under different conditions (allocated proportion, time of inclusion, temperature of inclusion) were studied through the orthogonal test, and theoretical reference of urea inclusion process for further optimization wound be offered.</p><p><b>METHOD</b>The orthogonal experiment was adopted, and microscope was used to observe the shape, aperture size of the urea inclusion compound under different technological parameters, the GC was employed to inspect the purity of GLA.</p><p><b>RESULT</b>The results indicated that the ratio of fatty acids and urea, inclusion of temperature, time of inclusion had great effect on urea inclusion compound. The three factors and its interactions significantly affected the purity of GLA. The results also showed that the best process was that the ratio of fatty acids and urea was 1 : 3, temperature of inclusion was--15 degrees C, time of inclusion was 24 h.</p><p><b>CONCLUSION</b>Under the best condition, the purity of GLA reach up to 95.575 9%; and it is feasible to observe the shape and the amount of the urea inclusion compound to reflect and guide the urea inclusion technology.</p>

Effects of the Mixture of Vitamin C, Vitamin E, Pycnogenol and Evening Primrose Oil on the UV-Induced Pigmentation and Wrinkle Reductions in Human Skin

In this study, the effects of a mixture consisting of vitamin E, vitamin C, pycnogenol and evening primrose oil (mixture LGNC-5) on ultraviolet light (UV) induced pigmentation and wrinkle reductions of normal healthy volunteers were studied. In a double-blind placebo-controlled study, each of 54 subjects took daily either 4 capsules of the mixture LGNC-5 (Group ABC; 282.5 mg/capsule) or placebo (Group Ganada). We irradiated 2.5 MED UV on the upper arms and measured the whitening effect by colorimeter-based L value. The level of wrinkle reduction was determined by image analysis using skin replica around the crow' feet, and the level of serum vitamin E was determined at baseline and 12 weeks. After 12-week oral administration, the treated group showed a significant reduction in skin pigmentation and wrinkles compared with the placebo group (p = 0.011 and p = 0.000005 , respectively). Also, the level of serum vitamin E was significantly increased in the treated group after 12-week oral adminstration of the mixture compared with that in the placebo group (p = 0.0001). In conclusion, 12-week oral administration of LGNC-5 as a dietary supplement could be effective to reduce both UV induced pigmentation and skin wrinkle without side effects.

Prepared evening primrose oil microspheres by spray drying / 中国中药杂志

<p><b>OBJECTIVE</b>To explore the best technique parameters on preparing evening primrose oil microspheres by spray drying technique.</p><p><b>METHOD</b>GC and internal standard method were used to determine the content of gamma-linolenic acid methyl esters, the technological parameters were investigated by orthogonal experimental design with the yield and entrapment rate as indexes.</p><p><b>RESULT</b>The charging rate as 3 mL x min(-1), atomizing pressure as 100 kPa and the temperature of inlet as 105 degrees C were the best technique parameters.</p><p><b>CONCLUSION</b>Evening primrose oil microspheres accorded with the expecting demand. The main influencing factor is the charging rate. Spray drying is reasonable and practical for preparing evening primrose oil microspheres.</p>

Danazol versus oil of evening primrose in the treatment of mastalgia

To evaluate the efficacy of Danazol and Oil of Evening Primrose [OEP] in the treatment of Mastalgia, and to note their undesirable effects during the course of treatment. An open, non-randomized, comparative study, carried out from Nov 2004 to Nov 2005. Department of General Surgery, Surgical Unit-Ill [Ward 26], Jinnah Postgraduate Medical Centre, Karachi. A total of 100 female patients with moderate to severe breast pain who visited the Out-patient Surgical Department of Jinnah Postgraduate Medical Centre, Karachi. After clinical evaluation, investigations and informed consent, all patients were assigned to two groups alternatively. Mastalgia in all the patients was gauged before and during the treatment according to the Cardiff Breast pain Score [CBS]. Patients with discrete lumps, nipple discharge, lactation, pregnancy and breast abscess were excluded from the study. Group-I [n = 50] patients were given Danazol 100mg b. i. d per oral and Group-II [n = 50] Efamol [Oil of evening primrose] 500mg b. i. d per oral for three months periods. All patients were seen at 4 and 12 weeks, their level of mastalgia assessed and information sought about adverse effects of the drug. Out of the 100 patients, 70% belong to the age group 15-25 years, 20% to 26-35 years and 10% beyond 35 years of age. The overall response with Danazol was 76% in contrast to 68% response in the patients treated with OEP The patients who were treated with Danazol showed 32% distressing but reversible side effects as compared to 12% in OEP which were not distressing and also reversible. Danazol offers good pain control in mastalgia but with distressing side effects, where as Oil of Evening Primrose [OEP] also showed good pain control but without mtich distressing side effects

Study on the encapsulation technique of high purity gamma-linolenic acid, part 1--saponification reaction and saponification value / 中国中药杂志

<p><b>OBJECTIVE</b>To measure the saponification value and fatty acid formation of evening primrose oil, to study the effects of pH value on production yield and fatty acid formation during the saponification reaction, and to provide rationales for the selection of raw material, the enhancement of production yield of saponification, and the encapsulation of gamma-linolenic acid with urea.</p><p><b>METHOD</b>To measure fatty acid's formation with gas chromatographic method and to measure the saponification value.</p><p><b>RESULT</b>The content of gamma-linolenic acid is 7%-10% in evening primrose oil. The content of gamma-linolenic acid is inversely correlated with that of unsaturated fatty acid. The saponification value, the amount of KOH for saponification of evening primrose oil, and the pH value for subsequent isolations of oils are determined. From the measurement of fatty acids of evening primrose oil in two different cultivation locations, the content of gamma-linolenic acid is determined to be 7%-10%, unsaturated oils account for 90%.</p><p><b>CONCLUSION</b>The saponification value of evening primrose oil is between 180-200, pH value of isolated oil is 1.5-2.0 after saponification reaction. Fatty acids mainly include palmitic acid, stearic acid, oleic acid, linolic acid and gamma-linolenic acid.</p>

Effect of Dietary Oil Containing gamma-Linolenic Acid on the Plasma Lipid Levels and Thrombotic Activity in Rats

This study was carried out to determine the effect of dietary gamma-linolenic acid on decreasing the plasma lipid levels and the thrombotic activity in rats. Sprague-Dawley male rats (B.W 120 g) were fed a experimental diet containing 5% lard (46.05% saturated fatty acids) , corn oil (51.36% linoleic acid) , evening primrose oil (EPO,72.80% linoleic acid and 9.16% gamma-linolenic acid) or borage oil (BO,40.29% linoleic acid and 24.25% gamma-liolenic acid) for 30 days. Although there were no significant differences in the food intake among the groups, the body weight gain of the BO group was significantly lower than that of the other groups. The bleeding time of the BO group was significantly longer than that of the other groups. There were significantly differences in the whole blood clotting time among the groups except for the EPO and corn oil groups, where the whole blood clotting time of the BO group was the highest among the groups, and that of the lard group was the lowest. The plasma triacyglyceride (TAG) , total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) concentrations were the lowest in the BO group, but highest in the lard group, and there were significant differences among the groups. The plasma HDL-C concentrations were in the following order: BO, EPO, corn oil and lard groups and there were significant differences among the groups. The excretions of fecal neutial steroids and acidic steroids of the BO group were the highest among the groups, and there were significant differences compared to the other groups. The results suggest that dietary EPO and BO containing gamma-linolenic acid has an antithrombotic activity, and inhibits the increasing of plasma TAG, TC and LDL-C concentrations compared to lard, which contains saturated fatty acids, or corn oil, which contains linoleic acid.

Estudio fitoquímico comparativo de Oenothera rosea y Oenothera multicaulis (Yawar chonq`a) / I study comparative phytochemical of rosy Oenothera and Oenothera multicaulis (Yawar Chonq'a)

El estudio de los componentes fenólicos de la oenothera rosea y multicaulis pretende aportar a las investigaciones realizadas respecto a estas especies, que validen científicamente sus propiedades farmacológicas. El fin de esta investigación implica el estudio de los componentes fenólicos a través del tratamiento del extracto hidroalcohólico con acetato de etilo. Las pruebas fitoquímicas desarrolladas permiten determinar que los componentes mayoritarios presentes en ambas especies son los flavonoides. El monitoreo de la cromatografía de columna se ha realizado con la cormatografía de capa fina utilizando como eluyente AcOEt; HCO2H; AcOH; H2O, revelado con FeCl3 al 1 por ciento, se observan manchas en la cromatoplaca de color verde para Oenothera multicaulis y azul para Oenothera rosea. El método espectroscópico ultravioleta visible con reactivos de desplazamiento para elucidar la estructura del flavonoide aislado por cromatografía (fracción 12) reporta para Oenothera rosea la presencia de un flavonoide glicosídico denominado Quercetrina, mientras que Oenothera multicaulis no reporta resultados cuantitativos por espectroscopía. Finalmente los resultados determinan que los compuestos fenólicos en lo que respecta a flavonoides no son parecidos en ambas especies.

The Suppressive Effect of Evening Primrose Oil on Murine Contact Sensitivity

BACKGROUND: Evening primrose oil(EPO) is a rich source of cis-linoleic acid and gammalinolenic acid(GLA) and has been used as a therapeutic agent in various skin diseases such as atopic dermatitis. OBJECTIVE: The purpose of this study was to evaluate the suppressive effect of EPO on murine contact sensitivity. METHODS: BALB/c mice were divided into 3 groups, positive control, experimental and negative control groups: the positive control group represents a group of mice which were sensitized and challenged with DNFB, the experimental group represents EPO-pretreated positive control group and the negative control group represents a group of mice which were challenged only. The changes of ear thickness were measured, and H & E staining and immunohistochemical staining for ICAM-1 expression of ear skin were performed to evaluate the histological changes of each group. RESULTS: The Pretreatment of mice with EPO resulted in suppression of contact sensitivity by more than 82%. On H & E staining, only a mild inflammatory reaction was observed in the dermis. Also ICAM-1 expression of keratinocytes, the intensity of the staining was significantly decreased in the experimental group compared with positive group. CONCLUSIONS: Our study indicates that EPO was able to suppress the induction of contact sensitivity.