A Review of the Clinical Efficacy of Evening Primrose

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.

Comparison of the effect of vaginal misoprostol and evening primrose oil capsule with misoprostol alone on the consequences of abortion in women with intrauterine fetal death: a randomized clinical trial

BACKGROUND

Misoprostol is the choice drug for inducing an abortion with intrauterine fetal death, but it has several side effects that increase with accumulating the dose received. Induction abortion with cheap and non-invasive methods with minimal complications is essential. This study aimed to compare the effect vaginal misoprostol plus vaginal evening primrose oil capsule with vaginal misoprostol alone on the consequences of abortion in pregnant women with intrauterine fetal death at 12-20 weeks of pregnancy.

METHODS

This study is a randomized, triple-blind clinical trial with two parallel groups at a ratio of 1:1. We randomized 82 women with indications of termination of pregnancy due to intrauterine fetal death into two groups. The experimental group (n = 42) received 200 mcg of misoprostol tablet with 1000 mg evening primrose oil capsule intravaginal. The control group (n = 40) received 200 mcg of misoprostol tablet with 1000 mg evening primrose oil placebo capsule intravaginal. Both groups received the drugs every 4 h for up to five doses. The primary outcome was the mean induction-to-fetal expulsion interval. Secondary outcomes were the mean dose of misoprostol, the highest pain intensity in the induction-to-fetal expulsion interval, the frequency of participants requiring blood transfusion, curettage, and the frequency of side effects of misoprostol or evening primrose oil. Pain intensity was measured through the Visual Analog Scale.

RESULTS

The mean age of the experimental group was 32.30 ± 6.19 years, and the control group was 30.27 ± 7.68 years. The mean gestational age of the experimental group was 15.29 ± 2.26 weeks, and the control group was 15.10 ± 1.89 weeks. The mean induction-to-fetal expulsion interval in the experimental group (3.12 ± 2.17 h) was significantly lower than that in the control group (8.40 ± 4.1 h) (p < 0.001). The mean dose of misoprostol received in the experimental group (271.42 ± 115.39 mcg) was significantly lower than that in the control group (520 ± 201.53 mcg) (p < 0.001). Also, the mean pain intensity in the experimental group (5.02 ± 0.60) was significantly lower than that in the control group (8.65 ± 1.001) (p < 0.001). The two groups were not significantly different in the frequency of blood transfusion requirements, analgesia and drug side effects. The need for curettage in the experimental group (4.8%) was significantly lower than that in the control group (47.5%) (p < 0.001).

CONCLUSIONS

Vaginal administration of evening primrose oil with misoprostol reduced duration of time of fetal expulsion, pain intensity, mean dose of misoprostol received, and the need for curettage in participants. Therefore, we suggest this method for induced abortion in women with intrauterine fetal death.

TRIAL REGISTRATION

IRCT20181207041873N3. Dated 16/2/2021 prospectively registered https://en.irct.ir/user/trial/53681/view .

Enhanced mechanical performance and wettability of PHBV fiber blends with evening primrose oil for skin patches improving hydration and comfort

The growing problem of skin diseases due to allergies causing atopic dermatitis, which is characterized by itching, burning, and redness, constantly motivates researchers to look for solutions to soothe these effects by moisturizing skin properly.

Effect of evening primrose oil on postoperative pain after appendectomy: A double-blind, randomized, clinical trial

Background and objective

Despite advances in surgical techniques and pharmacology, postoperative pain remains a common problem after appendectomy, and its management continues to be suboptimal. The aim of this study was to evaluate the effect of evening primrose oil on the reduction of postoperative pain after appendectomy.

Materials and methods

In a double-blind, randomized, clinical trial, a total of 80 adults patients with acute appendicitis who were undergoing appendectomy at the Shahid Beheshti Emdad Hospital in Sabzevar, were included. Patients were randomly allocated into two equally sized groups (n = 40). In postoperative period and after recovering from the anesthesia, each of the intervention and control groups received one evening primrose (1000 mg) or placebo capsules every 30 min for 3 times, respectively. All patients in both groups were asked to rate the intensity of their pain on a 0-10 point Visual Analogue Scale (VAS) and also McGill pain questionnaire, before and 1 h after the last administration of the drug, postoperatively.

Results

In patients who received evening primrose, both VAS and McGill pain intensity scores significantly decreased after intervention, when compared prior to initiation of the intervention (p < 0.0001). While in the control group, changes of pain intensity scores were not significantly different before and after the intervention (p > 0.05).

Conclusion

It seems that oral evening primrose can be used as a simple and safe potential adjunctive treatment for postoperative pain control after appendectomy.

The effect of evening primrose oil on fatigue and quality of life in patients with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic progressive and inflammatory disease of the central nervous system that is characterized by demyelination in the central nervous system. In regard to the prevalence of diseases and enormous costs imposed on society and the health system, finding a way to stop the progression of the disease using drugs with fewer side effects seems a serious sanitation issue to the health of the international community. This study aimed to evaluate the effect of evening primrose oil (EPO) on fatigue and quality of life in patients with MS.

MATERIALS AND METHODS

In this double-blind randomized clinical trial, 52 patients with MS were chosen and categorized into 2 groups which received 2 doses of EPO and placebo. In addition, the quality of life and fatigue scale in these patients were investigated before the treatment and again 3 months after therapy. The findings were then compared between the 2 groups.

RESULT

EPO consumption significantly increased cognitive function, vitality, and overall life satisfaction and also reduced pain and fatigue compared to placebo (P<0.05).

CONCLUSION

Our findings indicated that EPO consumption had no impact on the quality of life in general; however, it had a significant effect on several important aspects of life quality such as the increase of cognitive function, vitality, and overall life satisfaction. It also reduced the pain and fatigue in comparison to the placebo consumption. Herbal medicines are brittle and have fewer side effects than chemical drugs. With use of this plant, reduced fatigue and improved quality of life were observed in MS patients. But the drug did not prevent the progression of the disease.

Localization of a defensive volatile 4-hydroxy-4-methylpentan-2-one in the capitate glandular trichomes of Oenothera glazioviana

Glandular trichomes of plants produce a wide variety of secondary metabolites which are considered as major defensive chemicals. The capitate glandular trichomes of Oenothera glazioviana (Onagraceae) were collected with laser microdissection and analyzed by gas chromatography-mass spectrometry. The volatile compound 4-hydroxy-4-methylpentan-2-one (1) was identified. We found that compound 1 displays antimicrobial, insecticidal, and phytotoxic activities. These results suggest that compound 1 might function as a defensive compound in the capitate glandular trichomes of O. glazioviana against pathogens, insect herbivores, and presumably competitive plants as well.

Mixed seeds juice with high antioxidant capacity and digestive enzyme activity and its application

To investigate the synergistic and combined effects of a seed-vegetable combination, oilseed crops (safflower seed, evening primrose seed, and sesame seed) and cereals (whole buckwheat grain) were extracted with carrot using a low-speed juice extractor. Nutrient composition showed that the mixed seeds juice provided a well-balanced diet to supplement nutrient deficiency. Four assays of antioxidant activities showed that all seed juices exhibited higher activities than carrot juice. Similarly, mixed seeds juice displayed the highest α-amylase and protease activities, implicating the formulation in the improvement of the relatively low digestibility of seed. These results indicated that juice extraction significantly (p<0.001) influenced the nutrient contents, antioxidant activities, and digestion enzyme activities of seed juice. The synergistic and combined interactions of seeds and vegetables may be beneficial in enhancing biological functions and result in a well-balanced diet.

Clinical effectiveness of vitamin E and vitamin B6 for improving pain severity in cyclic mastalgia

Background:

Recent attempts have been focused on employing chemical and natural supplemental agents for treatment of cyclic mastalgia. Among various agents, the potential effects of vitamins remain questionable. In the present study, we examined the efficacy of two types of these vitamin supplements (vitamin E and vitamin B6) in improving pain severity in cyclic mastalgia.

Materials and Methods:

In a randomized double-blinded clinical trial, 80 patients suffering from cyclic mastalgia were randomly assigned to receive 200 IU of vitamin E daily or 40 mg/day of vitamin B6 for 2 months. Written informed consent was obtained from all participants. Severity of breast pain was detected by the Cardiff breast pain score during one menstrual cycle before and two menstrual cycles after the intervention. Data were analyzed using t-test, Chi-squared test, analysis of variance (ANOVA), and regression with SPSS version 19 and P < 0.05 was considered significant.

Results:

There was no significant difference in the mean of severity of cyclic mastalgia during one menstrual cycle before the intervention between the vitamin E and B6 groups (9.1 ± 2.1 and 8.4 ± 3.1, respectively), but the difference was significant during the first cycle (5.1 ± 1.6 and 5.2 ± 2.5, respectively) and the second menstrual cycle (2.3 ± 1.0 and 2.6 ± 2.0, respectively) in the two groups after the intervention. The trend of changes in pain severity score showed significant downward trend of pain severity score within the study period in both the treatment groups (P < 0.001), while these trends were similar in both groups when examined by the repeated-measure ANOVA test. By multivariable linear regression analysis adjusted for baseline variables, we found that both the treatment regimens resulted in similar reduction in breast pain severity (P = 0.067).

Conclusions:

Both regimens containing vitamin E and vitamin B6 are similar in reducing breast pain severity in cyclic mastalgia.

A molecular docking study of phytochemical estrogen mimics from dietary herbal supplements

PURPOSE

The purpose of this study is to use a molecular docking approach to identify potential estrogen mimics or anti-estrogens in phytochemicals found in popular dietary herbal supplements.

METHODS

In this study, 568 phytochemicals found in 17 of the most popular herbal supplements sold in the United States were built and docked with two isoforms of the estrogen receptor, ERα and ERβ (a total of 27 different protein crystal structures).

RESULTS

The docking results revealed six strongly docking compounds in Echinacea, three from milk thistle (Silybum marianum), three from Gingko biloba, one from Sambucus nigra, none from maca (Lepidium meyenii), five from chaste tree (Vitex agnus-castus), two from fenugreek (Trigonella foenum-graecum), and two from Rhodiola rosea. Notably, of the most popular herbal supplements for women, there were numerous compounds that docked strongly with the estrogen receptor: Licorice (Glycyrrhiza glabra) had a total of 26 compounds strongly docking to the estrogen receptor, 15 with wild yam (Dioscorea villosa), 11 from black cohosh (Actaea racemosa), eight from muira puama (Ptychopetalum olacoides or P. uncinatum), eight from red clover (Trifolium pratense), three from damiana (Turnera aphrodisiaca or T. diffusa), and three from dong quai (Angelica sinensis). Of possible concern were the compounds from men's herbal supplements that exhibited strong docking to the estrogen receptor: Gingko biloba had three compounds, gotu kola (Centella asiatica) had two, muira puama (Ptychopetalum olacoides or P. uncinatum) had eight, and Tribulus terrestris had six compounds.

CONCLUSIONS

This molecular docking study has revealed that almost all popular herbal supplements contain phytochemical components that may bind to the human estrogen receptor and exhibit selective estrogen receptor modulation. As such, these herbal supplements may cause unwanted side effects related to estrogenic activity.

An integrated web medicinal materials DNA database: MMDBD (Medicinal Materials DNA Barcode Database)

BACKGROUND

Thousands of plants and animals possess pharmacological properties and there is an increased interest in using these materials for therapy and health maintenance. Efficacies of the application is critically dependent on the use of genuine materials. For time to time, life-threatening poisoning is found because toxic adulterant or substitute is administered. DNA barcoding provides a definitive means of authentication and for conducting molecular systematics studies. Owing to the reduced cost in DNA authentication, the volume of the DNA barcodes produced for medicinal materials is on the rise and necessitates the development of an integrated DNA database.

DESCRIPTION

We have developed an integrated DNA barcode multimedia information platform- Medicinal Materials DNA Barcode Database (MMDBD) for data retrieval and similarity search. MMDBD contains over 1000 species of medicinal materials listed in the Chinese Pharmacopoeia and American Herbal Pharmacopoeia. MMDBD also contains useful information of the medicinal material, including resources, adulterant information, medical parts, photographs, primers used for obtaining the barcodes and key references. MMDBD can be accessed at http://www.cuhk.edu.hk/icm/mmdbd.htm.

CONCLUSIONS

This work provides a centralized medicinal materials DNA barcode database and bioinformatics tools for data storage, analysis and exchange for promoting the identification of medicinal materials. MMDBD has the largest collection of DNA barcodes of medicinal materials and is a useful resource for researchers in conservation, systematic study, forensic and herbal industry.

Saponified evening primrose oil reduces melanogenesis in B16 melanoma cells and reduces UV-induced skin pigmentation in humans

This study was conducted to determine whether saponified evening primrose oil (sap-EPO) has the potential for use as a whitening agent and to investigate its underlying mechanisms of action. In B16 melanoma cells, sap-EPO dose-dependently inhibited isobutylmethylxanthine-induced melanogenesis with no cytotoxicity. This decrease in melanin production was correlated with reduced enzyme activity and decreased mRNA and protein levels of tyrosinase. The mRNA levels of tyrosinase-related proteins 1 and 2 decreased in response to treatment with sap-EPO, indicating that it regulated tyrosinase at the transcriptional level. Expression of microphthalmia-associated transcription factor was also decreased by sap-EPO as evidenced by decreased mRNA and protein levels. Additionally, topical application of sap-EPO resulted in efficient whitening of UVB-induced hyperpigmentation of human skin. Taken together, these results suggest that sap-EPO has the potential for use as a cosmetic whitening agent.

Complementary and alternative medicine: herbs, phytochemicals and vitamins and their immunologic effects

Complementary and alternative medicines (CAMs) are used in more than 80% of the world's population and are becoming an increasing component of the US health care system, with more than 70% of the population using CAM at least once and annual spending reaching as much as $34 billion. Since the inception of the National Center for Complementary and Alternative Medicine, there has been an enormous increase in the number of basic science and therapy-based clinical trials exploring CAM. The subspecialty of allergy and immunology represents a particularly fertile area with a large number of CAM therapies that have been shown to affect the immune system. Recent work has uncovered potential biochemical mechanisms involved in the immunomodulatory pathway of many supplemental vitamins (A, D, and E) that appear to affect the differentiation of CD4(+) cell T(H)1 and T(H)2 subsets. Other research has shown that herbs such as resveratrol, quercetin, and magnolol may affect transcription factors such as nuclear factor-kappaB and the signal transducer and activator of transcription/Janus kinase pathways with resultant changes in cytokines and inflammatory mediators. Clinically, there have been hundreds of trials looking at the effect of CAM on asthma, allergic rhinitis, and atopic dermatitis. This article reviews the history of CAM and its use among patients, paying special attention to new research focusing on herbals, phytochemicals, and vitamins and their potential interaction with the immune system.

Molecular marker systems for Oenothera genetics

The genus Oenothera has an outstanding scientific tradition. It has been a model for studying aspects of chromosome evolution and speciation, including the impact of plastid nuclear co-evolution. A large collection of strains analyzed during a century of experimental work and unique genetic possibilities allow the exchange of genetically definable plastids, individual or multiple chromosomes, and/or entire haploid genomes (Renner complexes) between species. However, molecular genetic approaches for the genus are largely lacking. In this study, we describe the development of efficient PCR-based marker systems for both the nuclear genome and the plastome. They allow distinguishing individual chromosomes, Renner complexes, plastomes, and subplastomes. We demonstrate their application by monitoring interspecific exchanges of genomes, chromosome pairs, and/or plastids during crossing programs, e.g., to produce plastome-genome incompatible hybrids. Using an appropriate partial permanent translocation heterozygous hybrid, linkage group 7 of the molecular map could be assigned to chromosome 9.8 of the classical Oenothera map. Finally, we provide the first direct molecular evidence that homologous recombination and free segregation of chromosomes in permanent translocation heterozygous strains is suppressed.