gov website. Share sensitive information only on official, secure websites. An allergy is an immune response, or reaction, to substances allergens that are usually not harmful. In someone with allergies, the immune response is oversensitive. When it recognizes an allergen, the immune system launches a response.

Chemicals such as histamines are released. These chemicals cause allergy symptoms. Antihistamines are medicines that treat allergy symptoms by blocking the effects of histamine. Antihistamines come as pills, chewable tablets, capsules, liquids, nasal sprays, and eye drops.

There are also injectable forms used mainly in health care settings. Treating symptoms can help you or your child to feel better during the day and sleep better at night.

For many people with allergies, symptoms are the worst around 4 a. Taking an antihistamine at bedtime may help you or your child feel better in the morning during allergy season.

Ask your health care provider what type of antihistamine and what exact dosage is right for you or your child. Make sure you understand how much to use and how many times a day to use it.

Be sure to read the label carefully. Or ask your pharmacist if you have questions. Ask your provider if antihistamines are safe for you or your child, what side effects to watch for, and how antihistamines may affect other medicines you or your child take.

Allergic rhinitis - antihistamine; Hives - antihistamine; Allergic conjunctivitis - antihistamine; Urticaria - antihistamine; Dermatitis - antihistamine; Eczema - antihistamine.

Corren J, Baroody FM, Togias A. Allergic and nonallergic rhinitis. In: Burks AW, Holgate ST, O'Hehir RE, et al, eds. In addition to the anti-inflammatory, anti-viral, antineoplastic and immune regulatory pharmacological effects, GA was found to possess anti-allergic activity in our study.

The three main mechanisms of anti-allergic effect of GA are summarized in Fig. Many reports have identified that GA can affect the secretion of cytokines to modulate the immune microenvironment. In contrast, the level of IL-2 was enhanced with The results of above reports are consistent with our study, which identified the modulatory effect of GA on T H cells.

OVA-specific IgE was decreased significantly in a dose-dependent manner after GA treatment in an allergic rhinitis mouse model, which may be induced by inhibiting T H 2 cell differentiation and maturation, and IL-4 production subsequently prevented allergic rhinitis development That GA can suppress the production of T H 2 antibodies IgE and IgG 1 from OVA-specific antibody producing B cells is probably because of the effect of GA on the T H cell differentiation.

GA produced a more significant suppressive effect on IgG 1 , which may subsequently inhibit the IgG 1 -mediated basophil activation Previous studies have found that GA can inhibit histamine synthesis and release in mast cells co-cultured with Swiss 3T3 fibroblasts In our study, passive cutaneous anaphylaxis, which mainly depends on mast cells in vivo , showed that GA significantly reduced vascular permeability in a way similar to sodium cromoglycate.

Similarly, GA can inhibit the release of β-hexosaminidase, a biomarker of degranulation, in RBL-2H3 cells. Based on the combined in vitro and in vivo analysis of GA treatment, we can conclude that GA exerts an anti-allergic effect by influencing T H helper cells, OVA-specific antibody-producing B cells and mast cells or basophils Fig.

After the allergen is captured by dendritic cells through the disrupted epithelium, allergen-activated dendritic cells mature and migrate to regional lymph nodes where they present processed allergen epitopes to cognate T cells.

IL-4, which may be derived from T H 2 cells, mast cells, and basophils, also activates immunoglobulin heavy chain gene CSR for allergen-specific IgE production However, GA inhibits the synthesis and production of OVA-specific IgE and IgG 1 from the antibody producing B cells.

Allergen-specific IgE can bind to FcεRI to stimulate mast cell degranulation 30 and to FcγRIII to activate PAF release from basophils 19 ; these processes recruit and activate T H 2 cells 31 to begin a positive feedback loop. In conclusion, as confirmed by active systemic allergic reaction, passive cutaneous anaphylaxis and RBL-2H3 cell-based immunology assay, GA exerts anti-allergic activity and can be used as a potential anti-allergic nutrient in the future.

TransScript One-Step gDNA Removal and cDNA Synthesis SuperMix AT and TransStart Top Green qPCR SuperMix AQ TransGen Biotech, China. HRP-tagged goat anti mouse IgG 1 ab , HRP-tagged goat anti mouse IgE ab , Anti-TRPC-1 antibody ab , Anti-Orai1 antibody ab and Anti-Stromal interaction molecule 1 antibody ab Abcam, UK.

All other chemicals and solvents used in this study were of analytical grade. Beijing, China. The study was conducted in the specific pathogen free SPF animal laboratory of College of Food Science and Nutritional Engineering, China Agricultural University Beijing, China. Feed and water were supplied ad libitum.

The commercial SPF rodent maintenance feed produced by Ke Ao Xie Li feed Co. Beijing, China met the Chinese Standard GB Animal experiments in our research were carried out in accordance with the Guide for the Animal Experimental Welfare and Ethical in the Food Science and Nutritional Engineering College of China Agricultural University and were approved by the Animal Experimental Welfare and Ethical Inspection Committee in China Agricultural University.

All efforts were made during the animal experiments to minimize suffering. The experimental treatment design is shown in Fig. We first determined the anti-allergic effect of GA based upon the clinical allergic symptom score system and rectal temperature.

Cytokines were quantified using a commercial mouse ELISA kit eBioscience, Inc. All tested mice received an intradermal injection of 0. The experimental treatment design is summarized in Fig. After challenge, Evans blue extravasation in the right ears was recorded by a Canon EOS camera to qualitatively analysis the vascular permeability.

The release of β-hexosaminidase was calculated as follows Equation 1. Cells were seeded into a well black opaque cell culture plate. Total RNA was prepared using Trizol reagent and cDNA was transcribed using the TransScript One-Step gDNA Removal and cDNA Synthesis SuperMix.

RT-PCR was performed using the TransStart Top Green qPCR SuperMix for STIM1, Orai1, TRPC1, IP3R and β-actin. PCR for RBL-2H3 was performed with primers as follows:. The cell samples were homogenized in a lysis buffer with protease inhibitors.

The protein concentration of the supernatant was determined using a BCA Protein Assay Kit. The signal was visualized by enhanced chemiluminescence and exposure to an X-ray film Sage creation Mnin Chemi II, China. Statistical significance was determined by one-way analysis of variance ANOVA using GraphPad Prism 5.

Jackson, K. Trends in allergic conditions among children: United States, — Nchs Data Brief , 1—8 Google Scholar. Nitin, J. et al. Prevalence, severity and risk factors of allergic disorders among people in south India. Health Sci. Muraro, A. EAACI Food Allergy and Anaphylaxis Guidelines: diagnosis and management of food allergy.

Allergy 69 , — Article CAS PubMed Google Scholar. Mathias, C. IgE-mediated systemic anaphylaxis and impaired tolerance to food antigens in mice with enhanced IL-4 receptor signaling. J Allergy Clin. Article Google Scholar.

Dupont, C. Food Allergy: Recent Advances in Pathophysiology and Diagnosis. Masilamani, M. Soybean isoflavones regulate dendritic cell function and suppress allergic sensitization to peanut.

Tokura, T. Inhibitory effect of polyphenol-enriched apple extracts on mast cell degranulation in vitro targeting the binding between IgE and FcepsilonRI. Article CAS Google Scholar. Kamei, R. A flavanone derivative from the Asian medicinal herb Perilla frutescens potently suppresses IgE-mediated immediate hypersensitivity reactions.

Article PubMed Google Scholar. Kinney, S. Curcumin Ingestion Inhibits Mastocytosis and Suppresses Intestinal Anaphylaxis in a Murine Model of Food Allergy.

Plos One 10 , e Article PubMed PubMed Central Google Scholar. Magrone, T. Influence of polyphenols on allergic immune reactions: mechanisms of action. Akiyama, H. Dietary unripe apple polyphenol inhibits the development of food allergies in murine models. Febs Lett. Gumpricht, E. Licorice Compounds Glycyrrhizin and 18β-Glycyrrhetinic Acid Are Potent Modulators of Bile Acid-induced Cytotoxicity in Rat Hepatocytes.

Isbrucker, R. Risk and safety assessment on the consumption of Licorice root Glycyrrhiza, sp. Tokiwa, T. Oriental medicinal herb, Periploca sepium, extract inhibits growth and IL-6 production of human synovial fibroblast-like cells.

Raphael, T. Effect of naturally occurring triterpenoids glycyrrhizic acid, ursolic acid, oleanolic acid and nomilin on the immune system. Phytomedicine 10 , — Ram, A. Glycyrrhizin alleviates experimental allergic asthma in mice. Menegazzi, M. Glycyrrhizin attenuates the development of carrageenan-induced lung injury in mice.

Marrack, P. Towards an understanding of the adjuvant action of aluminium. Article CAS PubMed PubMed Central Google Scholar. Jönsson, F. Back to Health A to Z. Antihistamines are medicines often used to relieve symptoms of allergies, such as hay fever , hives , conjunctivitis and reactions to insect bites or stings.

They're also sometimes used to prevent motion sickness , to treat feeling sick nausea or being sick vomiting , and as a short-term treatment for insomnia.

Most antihistamines can be bought from pharmacies and shops, but some are only available on prescription. They also come in several different forms — including tablets, capsules, liquids, syrups, creams, lotions, gels, eyedrops and nasal sprays.

There's not much evidence to suggest any particular antihistamine is better than any other at relieving allergy symptoms. Some people find certain types work well for them and others do not.

You may need to try several types to find one that works for you. Non-drowsy antihistamines are generally the best option, as they're less likely to make you feel sleepy. But types that make you feel sleepy may be better if your symptoms stop you sleeping.

Ask a pharmacist for advice if you're unsure which medicine to try as not all antihistamines are suitable for everyone. Take your medicine as advised by the pharmacist or doctor, or as described in the leaflet that comes with it.

The advice varies depending on the exact medicine you're taking. If you're not sure how to take your medicine, ask a pharmacist. Check the leaflet that comes with your medicine for a full list of possible side effects and advice about when to get medical help. If you think your medicine has caused an unwanted side effect, you can report it through the Yellow Card Scheme.

Speak to a pharmacist or GP before taking antihistamines if you're already taking other medicines.

Fexofenadine is the main active ingredient in Allegra. It helps relieve runny nose, sneezing, itchy and watery eyes, and itching of the nose or throat due to hay fever or other upper respiratory allergies. Allegra can also be used to treat hives and skin rash.

It comes in a tablet, a tablet that dissolves in your mouth, a gel-coated capsule, and a liquid. If you have allergies, you have a range of choices for OTC medications.

These include brand-name antihistamines such as:. And if you take other medications to treat allergy symptoms, make sure that the active ingredients are not the same or in the same drug class as the active ingredient in the antihistamine you want to take.

To help prevent this, always check with your doctor or pharmacist. If you need help finding an Allergist and Immunologist, then check out our FindCare tool here. Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available.

Zyrtec and Claritin are similar over-the-counter allergy medicines. Your choice may come down to a subtle difference. Nasacort and Flonase are two of many allergy medications available today.

While they both treat allergy symptoms, they contain different active…. The sneezing, itchy eyes, congestion, and sinus pressure that come with seasonal allergies — all of these symptoms can become nearly unbearable. Learn about histamine and how it contributes to conditions like allergies and eczema.

Sulfa allergies are an uncommon reaction to some medications. Hair coloring products contain many ingredients that can irritate the skin and cause allergic reactions. Hair dye brand names can be deceiving, since…. Skeeter syndrome is another name for a mosquito bite allergy.

Nearly everyone is sensitive to mosquito bites, but the reaction can be serious for…. Are you feeling dizzy? One symptom of allergies can be dizziness. An airborne allergy could be the cause of your dizziness. A Quiz for Teens Are You a Workaholic?

How Well Do You Sleep? Health Conditions Discover Plan Connect. Popular Over-the-Counter Oral Antihistamine Brands. Medically reviewed by Zara Risoldi Cochrane, Pharm.

First-generation brands Second- and third-generation brands Takeaway. How we vet brands and products Healthline only shows you brands and products that we stand behind. Our team thoroughly researches and evaluates the recommendations we make on our site.

To establish that the product manufacturers addressed safety and efficacy standards, we: Evaluate ingredients and composition: Do they have the potential to cause harm? ex Baker Skornick. and A. Poulsen from Zingiberaceae family significantly inhibited systemic allergic reaction and histamine release Kim et al.

et al. villosa extract has shown several actions that were beneficial in alleviating the symptoms in immediate hypersensitivity reaction. The activity of W. villosa in inhibiting histamine release was moderate since there was not so much of significant difference when a higher dose of its extract was used.

Apart from its anti-allergic rhinitis effect, the ethyl acetate extract of W. Other mechanisms suggested that the ethyl acetate extract of W. villosa regulated fibrogenic cytokines, especially TGF-β Lee et al. Hydroalcoholic extract of Cinnamomum verum J.

There were induction of rubbing reflex and sneezing in AR control mice as compared to normal mice upon histamine challenge. These elevation in histamine release may results in increased mucus secretion, vascular permeability, edema and contraction of smooth muscle.

The treatment with C. verum extracts significantly reduced these histamine-induced symptoms. CZ-TAPP has showed a strong inhibition in IgE serum and histamine release as compared with AR control mice while showing reduction of symptoms as well such as sneezing and rubbing Aswar et al.

OVA sensitization and challenge in an in vivo model led to an increase in histamine and OVA-specific IgE titers in sera, increased IL-4 release in nasal lavage and infiltration of inflammatory cells in the epithelium and sub epithelium of the nasal mucosa Bahekar et al.

Oral administration of Ostericum grosseserratum Maxim. methanol extract at doses of 0. Based on this study, O. grosseserratum has shown a strong activity in AR-induced model.

Another plant that has exhibited histamine suppression effect was Artemisia abrotanum L. The use of nasal spray preparation has shown a rapid onset of action and relief of nasal symptoms such as congestion, rhinorrhea, and sneezing within a few minutes of application Remberg et al.

The overall tolerability in all of the twelve patients dealing with a mild to moderate locally appearing stinging sensation was good although it was reported to happen immediately after applying the nasal spray preparation Remberg et al.

The histamine action was proved by the reduction of early AR symptoms deemed to be strongly related to the early phase cycle of AR pathophysiology. The flavonoids were likely the important compounds in this species that inhibited the effects mediated by histamine Bergendorff and Sterner, This study might have shown a good response on its effect in alleviating the symptoms after its application.

However, there was no evidence of histamine inhibition that was clearly explained or well conducted in this particular study.

has been reported to inhibit histamine release from peritoneal mast cells of actively sensitized rats Inoue et al.

The identify the compounds contained in the peppermint extract which leads to such a remarkable result was determined. There were six flavonoid glycosides isolated from the extract and luteolin O -rutinoside 5 was the one that showed a potent inhibitory effect on histamine release from rat peritoneal mast cells.

Another study has also been conducted to thoroughly study the structure of this compound and it was found that the catechol structure in the Bring and the C2—C3 double bond in the C ring were essential for the inhibition of the histamine release Amellal et al.

Cytokines particularly cysteinyl-leukotrienes were released by mast cells activated by IgE-mediated mechanism in AR Pawankar and Ra, In the early phase of IgE-mediated allergic reaction, some types of cytokines such as IL-4 and IL will be released by activated T lymphocytes and will interact with B lymphocytes to induce the synthesis of allergen-specific IgE Pawankar et al.

Besides histamine, cytokines is also one of the major vasoactive mediators. Eosinophils synthesize and release cytokines such as IL-3, IL-5 and GM-CSF that play crucial roles in the late phase and on-going allergic inflammation Yang et al.

The nasal mucosal tissues of AR has illustrated an elevation in the levels of pro-inflammatory cytokines such as the IL-1, thymic stromal lymphopoietin TSLP , and TNF-α Kim H.

Being a specific inducer of IgE, IL 4 modulates a variety of inflammatory mediators release from immune cells, resulting in increased vascular permeability, increased mucus secretion in the nasal mucosa and inflammatory cells infiltration Chai et al.

Therefore, cytokine IL-4 is an important key component in alleviating AR symptoms through a downstream of its level in AR patients. The methanol extract of A. Besides, it also downregulated NF-κB signaling pathways that consequently reduced proinflammatory mediators. Previous study has reported that increasing the IFN-γ level and reducing the IL-4 level in the blood could alleviate the pathological lesion of AR in rats Li et al.

These findings indicated that the mechanism of shikonin attenuated AR may also involved reducing the level of IL-4 and increasing the level of IFN-γ in the body Wang et al. Apart from interleukins, several other types of cytokines that might be involved in the cascades of allergic reaction in AR are interferon-gamma IFN-ƴ and retinoid-related orphan receptor gamma t RORc.

An in vivo study investigated the possible chemical mediators or key components involved in the pathophysiology of AR such as Th1 related cytokines as well as Th17 related cytokines Yang et al. Besides, P. nigrum also showed a significant effect on Th17 related cytokines such as IL-5, IL, and RORc.

The lowest dose of P. nigrum was given to the subject. This shows that P. nigrum may provide a promising strategy for immunotherapy in airway diseases such as AR as it exhibits several different mechanisms that act against the cascades in AR model to alleviate the symptoms present through a subsequent series of a pathway in the pathophysiology of AR.

A syrup formulation of Zataria multiflora Boiss. was prepared and investigated in a randomized clinical trial conducted in 43 individuals with a history of seasonal AR. multiflora hydroalcoholic extract was diluted to achieve the final concentration of thymol and carvacrol of The study investigated the effect of this formulation on the expression of Treg related cytokines IL, IL-4 as well as other types of cytokines and TH17 cells.

IL-7 is a cytokine which produces TH17 cell that plays a major role in fighting extracellular pathogens Kleinewietfeld and Hafler, This pro-inflammatory cytokine can upregulate T cell-triggered inflammation and hematopoiesis by stimulating stromal cells to secret other cytokines and growth factors Wong et al.

IL may play a great role in reducing AR symptoms Ariaee et al. The clinical study that has been carried out against Z. multiflora has shown a moderate activity in reducing IL against patient with AR. Apart from its anti-allergic rhinitis effect, the erial parts of Z.

multiflora has an anti-amnesic effect and might improve memory deficit through anticholinesterase activity. Multiple-dose injection of Z. multiflora extract could dose-dependently inhibit acetylcholinesterase AchE in the brain hippocampus of scopolamine-induced amnesia rats Sheibani et al.

Tussilagone 6 , a sesquiterpene compound isolated from the dried flower buds of Tussilago farfara L. has been identified as the major bioactive component of the plant Jin et al. IL-6 is a type of cytokine that is also an important key component in the pathophysiology of AR.

The aggravation of the inflammatory symptoms may be induced by the mast cells. This is caused by the recruitment of various inflammatory cells to the nasal mucosa by cytokines including IL-6 and TNF-α Bernstein et al.

Another study has also shown a significant decrease in LPS-stimulated production of IL-1β, and IL-6 mRNA through the inhibition of MAPK and NF-ƙB pathways Choi et al. The phosphorylation of MAPKs may upregulate the gene expression of multiple inflammatory cytokines by transcription factor activation Passante and Frankish, The inhibition of the MAPK pathway in the mast cells has been identified to be one of the mechanisms to alleviate AR symptoms in this study Jin et al.

Petasol butenoate complex, Ze, a herbal extract from Petasites hybridus L. and Schreb. leaves is known to be effective in treating AR.

The use of this medicinal plant has led to decreased local production of IL-8 and LTB4 measured in nasal lining fluid and a faster recovery from nasal obstruction in allergic patients in a placebo-controlled double blind randomized clinical trial Dumitru et al. Petasin 7 is a racemic mixture consisting of the isoforms of isopetasin 7a and neopetasin 7b.

They have been found to be the active components of the extract of this medicinal plant in an in vitro study on human nasal epithelial cells Steiert et al. Thus, Ze and its constituents, isopetasin and neopetasin are potential candidates for the development of agents for the treatment of immune deviations associated with continuous cytokine-induced inflammation.

Eosinophils and mass cells are the key inflammatory cells in allergic inflammation. Eosinophil infiltration has been considered as the major attribute of AR mucosal inflammation as it is Minai-Fleminger and Levi-Schaffer, ; Wang et al.

In fact eosinophils infiltration is the best marker of allergic inflammation that results in severe inflammation and causes the most severe symptoms Ciprandi et al. Production of eosinophil is induced by Th2 cells in the early phase but it might be released during the latent recruitment phase through the release of cytokines and activation of endothelial cells Baraniuk, Eosinophils produce several important cytokines such as IL-5 that act to promote eosinophil survival and activation Tomaki et al.

The eosinophil may as well degranulates and participate in the response to nasal challenge with allergen apart from triggering nasal provocation evidenced by the recovery of major basic protein in nasal lavage fluids Naclerio et al.

An overall state of allergic conditions may be determined by the increase in eosinophils in the blood. Eosinophils level was increased in toluene 2,4-diisocyanate TDI -induced allergic mice model showing that this is one of the most important key components in understanding AR.

Results from this study have shown that the treatment with an oral dose of Acanthus ilicifolius L. Symptoms wise, A. It may be well explained with the significant suppression of related key components that play important roles in this disease such as eosinophil.

There is an association between the levels of eosinophil and Th Both components have been investigated in an in vivo study of Piper nigrum L. Treatment with ethanol extract of P. The study emphasized the important key components of eosinophil which are very crucial in most allergic reactions including AR.

Thus, suppression of eosinophil may result in the alleviation of AR symptoms. In another in vivo study, eosinophil suppression was found to be significant when treated with a standardized extract of Rosa multiflora Thunb. Bui et al. multiflora were used in this study. multiflorae extracts compared with the OVA-induced model.

Hence, the standardized R. multiflorae extracts at the stated doses might have nearly the same efficacy as the present conventional drug, dexamethasone Bui et al.

The relative symptomatic effect might be explained by observing the epithelial swelling of OVA-induced subject as eosinophils-derived mediators induced epithelial damage leading to nasal mucosal swelling Skoner, Dexamethasone might have a better effect on alleviating the symptoms by ameliorating the epithelial swelling.

However, a clinical trial on its effect on human subjects is needed to investigate its effects on the human subject. Yet, this medicinal plant may have a promising future as an alternative treatment for AR. There was a statistically significant reduction in mean nasal smear eosinophil count observed in a patient administered with Urtidin F.

C tablet containing mg of Urtica dioica L. This study was conducted in a randomized double-blind study clinical trial to identify the significant effects of the tablet formulation among AR patients.

However, similar effects were demonstrated between the placebo group compared with the treated group based on the Sino-Nasal Outcome Test 22 SNOT of stinging nettle controlling the symptoms of AR.

Therefore, the outcomes of this study showed a weak association between the effect of eosinophil suppression with its symptomatic relief outcomes. Mangiferin 8 isolated from Mangifera indica L. The result showed a similar significant difference in eosinophil level in the animal models treated with 2.

The number of eosinophils, goblet cells, and mast cells infiltrating the nasal mucosa were estimated quantitatively in the histologic sections. Mangiferin 8 may have the potential to be a better alternative to alleviate AR symptoms than conventional medicines with less side effects.

However, the safety and efficacy of this compound may need further research. The medicinal plants discussed in this review might have potential to be developed as alternatives to treat symptoms of AR. However, further studies should be carried out to determine their safety level for human use specifically in treating AR.

Safety is the most important aspect in developing medicinal or health products. Thus, toxicity studies of the medicinal plants and their bioactive metabolites should be performed and reviewed to identify their potential acute or chronic toxicity that might be encountered upon using them as therapeutic agents for treating allergic diseases such as AR.

Some toxicity studies have been conducted for some of these potential medicinal plants. Presl have been conducted by Shah et al. Thirty-five mice were randomly divided into six C.

verum -treatment groups and a control and the mice were observed for signs of toxicity and mortality after 24 h.

verum extract for three weeks. Mortality in the C. It was observed that only one male mouse developed inflammation of hind limb which was cleared up during the next few weeks. The condition of the viscera and vital organs weight in the treated animals were normal and comparable to the control except for a decrease in the weight of the liver.

There was a decrease in hemoglobin contents base on hematological studies. The fixed oil of Nigella sativa L. was evaluated for its acute toxicity in mice.

Oral dose administration of the oil in the mice showed a LD 50 value of It was observed that oral and intraperitoneal administration of the oil at all doses resulted in behavioral perturbations with immediate agitation, temporary writhing, followed by a quiet attitude period and sedation.

Diarrhea was generally observed and the animals died 12 h after oil administration. for 12 weeks. The compound believed to cause toxicity in Petasites hybridus L.

is pyrrolizidine alkaloids Dreger et al. The secondary metabolite in the plants known with its hepatotoxic, cardiotoxic, pneumotoxic and nephrotoxic properties provides a defense mechanism against herbivores.

Acute toxicity study of P. Hemorrhagic necrosis, hepatomegaly, and ascites were found to be the signs of acute toxicity. Moreover, hepatic veins obstruction that results in venous-occlusive disease while in chronic poisoning, liver failure due to necrosis, fibrosis, and cirrhosis were some of the effects observed in subacute toxicity testing Aydın et al.

The acute toxicity test of aqueous and hexane extracts of Urtica dioica L. Acute toxicity effects of aqueous and ethanolic extracts of erial parts of Zataria multiflora Boiss extracts in mice were conducted.

The animals were injected intraperitoneally with various doses of the extracts and the mortality was determined at 48 h after treatment. Based on the LD 50 values, the ethanolic extract 3. The maximum non-fatal doses for the aqueous and ethanol extracts were 2.

The most common potential target in treating AR is the suppression of histamine release as histamine is one of the most important key components in an early phase of AR pathophysiology and gives immediate symptoms within few minutes of allergen exposure.

Current conventional treatment administers antihistamine drugs as first-line therapy. However, other mechanistic effects such as suppression of IgE, inhibition of cytokines production and suppression of eosinophil production have also been used as targets in efforts to search for bioactive principles from medicinal plants with strong anti-allergic rhinitis activity.

Various in vivo, in vitro and clinical studies on medicinal plants and their bioactive metabolites have been carried out to evaluate their anti-allergic and anti-inflammatory properties particularly in treating AR by using various immune cells, AR-induced models or AR patients.

There was remarkable amount of experimental data that have been generated and they can be further developed as potential source of new anti-allergic rhinitis agents.

However, most studies on the medicinal plants including clinical trials were carried out using the crude extracts of the plants as the extracts were not standardized or chemically characterized and the active chemical markers were mostly not identified.

The bioactive metabolites contributing to the anti-allergic rhinitis effect have not been well determined. For future studies sufficient preclinical testing should be generated using standardized extracts, which include bioavailability, pharmacokinetic and toxicological studies, before they can be subjected to clinical studies.

Based on in vitro and in vivo studies several bioactive metabolites of the plant extracts including shikonin 1 , okicamelliaside 2 , warifteine 3 , methylwarifteine 4 , luteolin O -rutinoside 5 , tussilagone 6 , petasin 7 , and mangiferin 8 Figure 2 have been identified as potential candidates for development into anti-allergic rhinitis agents.

These bioactive compounds have to be further subjected to systematic and operationally thorough controlled randomized trials to prove its safety and efficacy for human use in treating AR. FIGURE 2. Chemical structures of compounds with strong anti-allergic rhinitis effects.

NAR gathered the literature and drafted the manuscript. KH and IJ participated in the design and concept of the manuscript. All authors were involved in editing and KH gave the approval of the final version to be submitted for publication.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Akdis, M. Immune responses in healthy and allergic individuals are characterized by a fine balance between allergen-specific T Regulatory 1 and T Helper 2 cells.

PubMed Abstract CrossRef Full Text Google Scholar. Amellal, M. Inhibition of mast cell histamine release by flavonoids and biflavonoids. Planta Med. Ariaee, N.

Oral administration of Zataria multiflora extract decreases IL expression in perennial allergic rhinitis. PubMed Abstract Google Scholar. Asher, M. Worldwide time trends in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and eczema in childhood: isaac phases one and three repeat multicountry cross-sectional surveys.

The Lancet , — CrossRef Full Text Google Scholar. Aswar, U. Aydın, A. The medical plant butterbur Petasites : analytical and physiological re view. Ayoub, M. Bahekar, P. Validation of Guinea pig model of allergic rhinitis by oral and topical drugs. Bai, X. Foods 65, Bakhshaee, M. Efficacy of supportive therapy of allergic rhinitis by stinging nettle Urtica dioica root extract: a randomized, double-blind, placebo- controlled, clinical trial.

Iran J. Google Scholar. Baraniuk, J. Pathogenesis of allergic rhinitis. Allergy Clin. Barbosafilho, J. Alkaloids of the menispermaceae. Alkaloids: Chem. Barnes, P. Pathophysiology of allergic inflammation.

Immunological Rev. Bergendorff, O. Spasmolytic flavonols fromArtemisia abrotanum. Bernstein, D. Evaluation of the clinical efficacy and safety of grapeseed extract in the treatment of fall seasonal allergic rhinitis: a pilot study.

Allergy Asthma Immunol. Bharadwaj, A. Dendritic cells in allergic airway inflammationThis article is one of a selection of papers published in the Special Issue on Recent Advances in Asthma Research. Bielory, L. Allergic conjunctivitis and the impact of allergic rhinitis.

Allergy Asthma Rep. Bousquet, J. Allergic rhinitis and its impact on asthma aria update in collaboration with the world health organization, GA 2 len and AllerGen. Allergy 63 Suppl 86 , 8— Bui, T. Cell Immunol. Phytomedicine 55, — Preventive effect of Bupleurum chinense on nasal inflammation via suppressing T helper type 2, eosinophil and mast cell activation.

The protective role of Piper nigrum fruit extract in an ovalbumin-induced allergic rhinitis by targeting of NFκBp65 and STAT3 signalings. Busse, W.

Mechanisms of persistent airway inflammation in asthma. A role for T cells and T-cell products. We first determined the anti-allergic effect of GA based upon the clinical allergic symptom score system and rectal temperature. Cytokines were quantified using a commercial mouse ELISA kit eBioscience, Inc.

All tested mice received an intradermal injection of 0. The experimental treatment design is summarized in Fig. After challenge, Evans blue extravasation in the right ears was recorded by a Canon EOS camera to qualitatively analysis the vascular permeability.

The release of β-hexosaminidase was calculated as follows Equation 1. Cells were seeded into a well black opaque cell culture plate. Total RNA was prepared using Trizol reagent and cDNA was transcribed using the TransScript One-Step gDNA Removal and cDNA Synthesis SuperMix.

RT-PCR was performed using the TransStart Top Green qPCR SuperMix for STIM1, Orai1, TRPC1, IP3R and β-actin. PCR for RBL-2H3 was performed with primers as follows:. The cell samples were homogenized in a lysis buffer with protease inhibitors. The protein concentration of the supernatant was determined using a BCA Protein Assay Kit.

The signal was visualized by enhanced chemiluminescence and exposure to an X-ray film Sage creation Mnin Chemi II, China. Statistical significance was determined by one-way analysis of variance ANOVA using GraphPad Prism 5. Jackson, K.

Trends in allergic conditions among children: United States, — Nchs Data Brief , 1—8 Google Scholar. Nitin, J. et al. Prevalence, severity and risk factors of allergic disorders among people in south India. Health Sci. Muraro, A. EAACI Food Allergy and Anaphylaxis Guidelines: diagnosis and management of food allergy.

Allergy 69 , — Article CAS PubMed Google Scholar. Mathias, C. IgE-mediated systemic anaphylaxis and impaired tolerance to food antigens in mice with enhanced IL-4 receptor signaling. J Allergy Clin. Article Google Scholar. Dupont, C. Food Allergy: Recent Advances in Pathophysiology and Diagnosis.

Masilamani, M. Soybean isoflavones regulate dendritic cell function and suppress allergic sensitization to peanut. Tokura, T. Inhibitory effect of polyphenol-enriched apple extracts on mast cell degranulation in vitro targeting the binding between IgE and FcepsilonRI.

Article CAS Google Scholar. Kamei, R. A flavanone derivative from the Asian medicinal herb Perilla frutescens potently suppresses IgE-mediated immediate hypersensitivity reactions. Article PubMed Google Scholar.

Kinney, S. Curcumin Ingestion Inhibits Mastocytosis and Suppresses Intestinal Anaphylaxis in a Murine Model of Food Allergy. Plos One 10 , e Article PubMed PubMed Central Google Scholar. Magrone, T. Influence of polyphenols on allergic immune reactions: mechanisms of action.

Akiyama, H. Dietary unripe apple polyphenol inhibits the development of food allergies in murine models. Febs Lett. Gumpricht, E. Licorice Compounds Glycyrrhizin and 18β-Glycyrrhetinic Acid Are Potent Modulators of Bile Acid-induced Cytotoxicity in Rat Hepatocytes.

Isbrucker, R. Risk and safety assessment on the consumption of Licorice root Glycyrrhiza, sp. Tokiwa, T. Oriental medicinal herb, Periploca sepium, extract inhibits growth and IL-6 production of human synovial fibroblast-like cells.

Raphael, T. Effect of naturally occurring triterpenoids glycyrrhizic acid, ursolic acid, oleanolic acid and nomilin on the immune system.

Phytomedicine 10 , — Ram, A. Glycyrrhizin alleviates experimental allergic asthma in mice. Menegazzi, M. Glycyrrhizin attenuates the development of carrageenan-induced lung injury in mice. Marrack, P. Towards an understanding of the adjuvant action of aluminium.

Article CAS PubMed PubMed Central Google Scholar. Jönsson, F. Human FcγRIIA induces anaphylactic and allergic reactions. Blood , — Vig, M. Calcium signaling in immune cells. Effect of naturally occurring triterpenoids ursolic acid and glycyrrhizic acid on the cell-mediated immune responses of metastatic tumor-bearing animals.

Li, X. Antioxidant status and immune activity of glycyrrhizin in allergic rhinitis mice. Article ADS CAS PubMed PubMed Central Google Scholar. Myburgh, E. Wu, Q. Respirology 21 , — Tsujimura, Y.

Basophils Play a Pivotal Role in Immunoglobulin-G-Mediated but Not Immunoglobulin-E-Mediated Systemic Anaphylaxis. Immunity 28 , — Lee, Y. Effect of glycyrrhizic acid on histamine synthesis and release. Sun, N. Food Res. Article ADS CAS Google Scholar. Nishida, K. FcεRI-mediated mast cell degranulation requires calcium-independent microtubule-dependent translocation of granules to the plasma membrane.

Cell Biol. Galli, S. IgE and mast cells in allergic disease. Gilfillan, A. The tyrosine kinase network regulating mast cell activation.

Anne, M. Histamine and prostaglandin E2, up-regulate the production of T H 2-attracting chemokines CCL17 and CCL22 and down-regulate IFN-γ-induced CXCL10 production by immature human dendritic cells.