Allergenicity and cross-reactivity of Russian olive pollen (Eleagnus angustifolia)

The effects of Elaeagnus angustifolia L. whole fruit on the sex hormone profile in menopausal women: A double-blind, randomized, placebo-controlled study

ETHNOPHARMACOLOGICAL RELEVANCE

Menopause is a product of interrupted ovarian activity and decrease in its estradiol production. Herbal medicines as an alternative to hormone therapy are increasingly used by menopausal women. Elaeagnus angustifolia L. (Senjed in Persian) is a well-known herbal remedy with various therapeutic effects according to Iranian traditional medicine which is recommended to relieve the menopausal side effects. The aim of present study was to evaluate the effects of oral intake of whole fruit powder of E. angustifolia on the sex hormones profile in menopausal women.

MATERIALS AND METHODS

In present double-blind randomized placebo-controlled trial, 58 eligible women who were referred to Kamali Women Hospital (Karaj, Iran, 2017) were randomly assigned into herbal medicine (15 g E. angustifolia) and placebo (7.5 g cornstarch +7.5 g isomalt) groups. Initially and after 10 weeks of the treatment, serum levels of estradiol, progesterone, testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) hormones were measured.

RESULTS

According to between-group analyses, the changes in the studied parameters were not significant between herbal medicine and placebo groups, except for joint pain that improved significantly in herbal medicine group. However, by within-group analysis the levels of FSH and FSH to testosterone showed a significant increase, whereas the level of progesterone decreased significantly after 10 weeks of E. angustifolia consumption.

CONCLUSIONS

The improvement of the sex hormone profile was not in a full accordance with Iranian folklore after E. angustifolia consumption in the present menopausal participants. However, considering a strong belief on the beneficial effects of E. angustifolia in Iranian folklore, a long-term studies of larger group participants are needed to evaluate the efficacy.

Russian olive (Elaeagnus angustifolia) as a herbal healer

Introduction:Elaeagnus spp. is one in the family of riparian trees growing near the rivers or water corridors. In this family, Elaeagnus angustifolia (Russian olive) is famous because of its medical applications.

Methods: A comprehensive review was performed to extract the related data from published literature.

Results: Traditionally, it has been used as an analgesic, antipyretic and diuretic herbal medicine. A large number of compounds have been derived from Russian olive and made this plant a source of flavonoids, alkaloids, minerals and vitamins. Although the purpose of most studies is to use this plant for preparation of herbal medicines and as an ingredient for drug formulation, there is no available drug dosage form commercially.

Conclusion: This review aimed to provide the most important documentary information on the active components of Elaeagnus spp. and their relation to the pharmacological properties and compare them with reported medicinal effects.

Russian olive (Elaeagnus angustifolia L.): From a variety of traditional medicinal applications to its novel roles as active antioxidant, anti-inflammatory, anti-mutagenic and analgesic agent

Elaeagnus angustifolia L., which is commonly known as oleaster or Russian olive, is a deciduous plant from Elaeagnacea family. This plant can tolerate and survive a wide variety of environmental conditions. Different parts of E. angustifolia plant, especially the fruits and flowers, have been used traditionally in treating a variety of common illnesses such as nausea, cough, asthma, fever, jaundice, and diarrhea. The use of fruit powder and extract of E. angustifolia L. have shown to be effective in alleviating pain in patients with rheumatoid arthritis and also in reducing the healing time of wounds in injured person. In addition, some recent reports have indicated the anti-oxidant, anti-inflammatory, antimicrobial, anticancer and some other properties of oleaster plant. The other important property of this plant would be its role in bio-monitoring the environment for some toxic elements and also its action as a bio-fertilizer agent in distressed lands. It seems that with more advanced studies on E. angustifolia L. and its bioactive components, this plant might be potentially effective and can be used as a natural alternative resource in pharmaceutical industries for treating chronic and serious problems, Fig. 1.

A comprehensive review on phytochemical and pharmacological aspects of Elaeagnus angustifolia L

Objective

Elaeagnus angustifolia L., commonly known as oleaster or Russian olive, is used worldwide as a traditional natural remedy or nutritional agent for the management of a wide range of illnesses. The aim of the present study is to comprehensively review the ethnopharmacological uses, biological activities and phytochemistry of E. angustifolia.

Key findings

Modern scientific investigations suggest that the plant possesses a broad spectrum of pharmacological and therapeutic effects, including antimicrobial, insecticidal, antioxidant, anti-arthritic, wound healing, cardioprotective, hypolipidemic, antinociceptive, anti-inflammatory, antimutagenic, antitumour and gastroprotective activity. Various phytochemical constituents, including β-carboline alkaloids, polysaccharides, esters, flavone glycosides, phenols, phenolic acids, ketones, phenyl ethers, pyrimidines, steroids and terpenes, as well as nutritional components such as essential and non-essential amino acids and nutraceuticals like vitamins and fatty acids, have been identified in E. angustifolia.

Summary

Considering its wide variety of pharmacological activity as well as its huge diversity of active phytochemicals, E. angustifolia could be proposed as a good candidate for discovering new drugs. Further clinical and experimental studies are necessary to reveal the beneficial therapeutic, safety and pharmaceutical properties of E. angustifolia and its phytochemicals as a complementary and alternative medicine for the management of various disorders.

Analysis of olive allergens

Olive pollen is one of the most important causes of seasonal respiratory allergy in Mediterranean countries, where this tree is intensely cultivated. Besides this, some cases of contact dermatitis and food allergy to the olive fruit and olive oil have been also described. Several scientific studies dealing with olive allergens has been reported, being the information available about them constantly increasing. Up to date, twelve allergens have been identified in olive pollen while just one allergen has been identified in olive fruit. This review article describes considerations about allergen extraction and production, also describing the different methodologies employed in the physicochemical and immunological characterization of olive allergens. Finally, a revision of the most relevant studies in the analysis of both olive pollen and olive fruit allergens is carried out.

Molecular diagnosis in allergy

Development and progress made in the field of recombinant allergens have allowed for the development of a new concept in allergy diagnosis, molecular diagnosis (MD), which makes it possible to identify potential disease-eliciting molecules. Microarray-based testing performed with a small amount of serum sample enables clinicians to determine specific-IgE antibodies against multiple recombinants or purified natural allergen components. Performance characteristics of allergens so far tested are comparable with current diagnostic tests, but have to be confirmed in larger studies. The use of allergen components and the successful interpretation of test results in the clinic require some degree of knowledge about the basis of allergen components and their clinical implications. Allergen components can be classified by protein families based on their function and structure. This review provides a brief overview of basic information on allergen components, recombinants or purified, currently available or soon to become commercially available in ImmunoCAP or ISAC systems, including names, protein family and function. Special consideration is given to primary or species-specific sensitization and possible cross-reactivity, because one of the most important clinical utility of MD is its ability to reveal whether the sensitization is genuine in nature (primary, species-specific) or if it is due to cross-reactivity to proteins with similar protein structures, which may help to evaluate the risk of reaction on exposure to different allergen sources. MD can be a support tool for choosing the right treatment for the right patient with the right timing. Such information will eventually give clinicians the possibility to individualize the actions taken, including an advice on targeted allergen exposure reduction, selection of suitable allergens for specific immunotherapy, or the need to perform food challenges. Nevertheless, all in vitro tests should be evaluated together with the clinical history, because allergen sensitization does not necessarily imply clinical responsiveness.

A clinically relevant major cross-reactive allergen from mesquite tree pollen

BACKGROUND

Prosopis juliflora (mesquite) is one of the major sources of pollinosis in tropical and semi-arid countries of the world. The present study was undertaken to purify and characterize a major cross-reactive allergen from this tree species.

MATERIALS AND METHODS

Mesquite pollen extract was purified using reverse-phase chromatography. Allergen characterization was done by electrophoresis, enzyme-linked immunosorbent assay (ELISA) and Western blotting. Clinical relevance of the purified protein was analyzed by in vivo (skin tests) and in vitro experiments such as ELISA, histamine release, peripheral blood mononuclear cells (PBMC) proliferation and cytokine assays. Cross-reactivity of purified protein with allergenic tree species and lima bean (food) was assessed by inhibition assays.

RESULTS

A 66-kDa protein was purified from mesquite pollen extract using octadecyl silica resin. Purified protein recognized 90% of mesquite-sensitized patients in skin test and ELISA. It induced significant histamine release in allergic patients' blood and interleukin-4 secretion in the PBMC culture supernatants. Inhibition assays suggested close allergenic relationship of this protein with Ailanthus excelsa, Cassia siamea, Salvadora persica pollen and Phaseolus lunatus (lima bean - an edible legume).

CONCLUSIONS

A 66-kDa major cross-reactive allergen was isolated from mesquite pollen using single-step purification procedure. The protein seems relevant for clinical applications in allergic disorders.

Cross-reactivity of pollen allergens: impact on allergen immunotherapy

OBJECTIVE

To provide guidelines for the rational formulation of allergen immunotherapy extracts based on knowledge of pollen allergen and epitope cross-reactivity.

DATA SOURCES

A PubMed search was performed for articles published from 1966 to 2007 using the keywords pollen, allergen, and cross-reactivity. Older literature was found through cross-referencing of older articles and older reviews on pollen cross-reactivity.

STUDY SELECTION

Articles that dealt with crude pollen extracts and characterized allergens that addressed cross-reactivity were selected for inclusion in this review.

RESULTS

In addition to unique allergens, several families of botanic proteins have similarities that allow them to act as pan-allergens. Although frequently these are minor allergens, in some circumstances they may also be major allergens. Recent studies have investigated nonspecific lipid transfer proteins, calcium-binding proteins, pathogenesis-related protein families, and profilins. Calcium-binding proteins and nonspecific lipid transfer proteins are responsible for pollen-fruit interactions and pollen cross-reactivity. Clarification of pollen allergen enzymatic activity helps explain the ubiquitous nature of these proteins.

CONCLUSION

Characterization of specific pollen allergens and their protein families has provided insight into cross-reactivity. Clarification of these relationships allows for consolidation or substitution in formulation of inhalant extracts.

Hypersensitivity to black locust (Robinia pseudoacacia) pollen: "allergy mirages"

BACKGROUND

The allergenicity of the ornamental tree Robinia pseudoacacia, or black locust, is unknown.

OBJECTIVE

To evaluate the prevalence of sensitization to R. pseudoacacia pollen, its possible allergenic cross-reactivity with other common pollens, and the potential implication of pollen panallergens (profilin, polcalcin, and 1,3-beta-glucanase) as a cause of sensitization to R. pseudoacacia pollen.

METHODS

Skin prick testing with R. pseudoacacia pollen was performed in 149 patients with pollinosis. Nasal challenge with R. pseudoacacia pollen was performed in 10 patients. The prevalence of sensitization to the recombinant forms of profilin (rChe a 2), polcalcin (rChe a 3), and the N-terminal of the 1,3-beta-glucanase (rNtD of Ole e 9) was investigated. Immunoblotting, enzyme-linked immunosorbent assay, and competitive inhibition assays were performed with R. pseudoacacia pollen and recombinant pollen allergens.

RESULTS

Sixty-four patients (43%) had positive skin prick test reactions to R. pseudoacacia pollen. Nasal challenge results were positive in 5 sensitized patients and negative in 4 controls and 1 sensitized patient. The allergenic profile of R. pseudoacacia pollen comprises at least the panallergen profilin, a calcium-binding protein, and a 1,3-beta-glucanase. The prevalence of sensitization to rChe a 2, rChe a 3, and rNtD of Ole e 9 was 60%, 33%, and 87%, respectively, among patients sensitized to R. pseudoacacia pollen. Binding of IgE to R. pseudoacacia extract was completely inhibited by Robinia, Chenopodium, Olea, Cupressus, and Lolium extracts.

CONCLUSIONS

The high prevalence of R. pseudoacacia pollen sensitization in patients with pollinosis is likely to be due to cross-sensitization to panallergens (profilin, polcalcin, and 1,3-beta-glucanase) from other common pollens. This phenomenon may lead to a diagnosis of "allergy mirages."

Cross-reactivity of pollen allergens: recommendations for immunotherapy vaccines

PURPOSE OF REVIEW

This review will summarize recent research on pollen allergen and epitope cross-reactivity. Knowledge of these relationships aids in the rational formulation of allergen immunotherapy vaccines.

RECENT FINDINGS

There has been further clarification of panallergens and their roles as both major and minor allergens. Recent studies have targeted non-specific lipid transfer proteins and calcium-binding proteins (polcalcins), as well as pathogenesis-related protein families and profilins. Polcalcins and non-specific lipid transfer proteins are responsible for pollen-fruit interactions as well as pollen cross-reactivity, in some cases, but not all, accounting for major allergenicity. Delineation of the enzymatic activity of certain allergens explains the ubiquitous nature of these pollen proteins.

SUMMARY

Characterization of specific pollen allergens and their protein families has provided insight into the grounds for cross-reactivity. Continuing clarification of these relationships will allow the substitution and consolidation of inhalant extracts as described in the conclusion.