Tos (seca)

Two parallel-design, double-blind, placebo-controlled trials administered 100 mg AGIQ/day for 8 weeks to subjects with Japanese cedar pollinosis (hay fever). Both studies reported significant improvement in ocular allergy symptoms (eye comfort, quality of life scores), with nasal airflow unchanged. The proposed mechanism involves mast cell stabilization and inhibition of IgE-mediated histamine release.

Astragalus membranaceus has been studied for allergic rhinitis in RCTs and was listed by NCCIH among nutritional approaches studied for seasonal allergies. A meta-analysis of 9 clinical trials placed it as a promising herbal treatment with potential for allergic rhinitis. Traditional use in Chinese medicine for wei qi (defensive energy) and respiratory allergy is well documented.

Pilot clinical studies in children and adults with allergic rhinitis show B. clausii significantly modulates nasal cytokine profiles, reducing IL-4 (Th2) and increasing IFN-γ, IL-12, TGF-β, and IL-10 (Th1/Treg). It was also found to reduce eosinophil infiltration and may synergize with antihistamines for nasal symptom relief. Evidence comes from small pilot studies.

Oral beta-glucan has been shown in a double-blind RCT to alleviate ongoing symptoms of rhinitis and rhinoconjunctivitis during the cedar pollen season. Symptom reduction correlated with decreases in allergen-specific and total IgE titers. Superfine dispersed formulations were required for intestinal absorption and effect.

A pediatric double-blind RCT using a Bifidobacteria mixture including B. breve M-16V demonstrated significant improvement in seasonal allergic rhinitis symptoms and quality of life in children allergic to pollen. The mechanism involves restoration of a Th1-polarized immune response and dampening of IgE-driven inflammation. Evidence is primarily from multi-strain studies where B. breve is a component.

An exploratory RCT demonstrated that B. lactis NCC2818 mitigated immune parameters and allergic symptoms during seasonal grass-pollen exposure. The strain reduced markers of Th2 immune activation during the allergy season. Results are preliminary, warranting larger confirmatory trials.

B. longum MM-2 improved rhinoconjunctivitis-specific quality of life in healthy individuals with self-reported seasonal allergies during allergy season. A Bifidobacterium mixture including B. longum BB536 significantly improved nasal allergy symptoms and quality of life in a placebo-controlled RCT in children with allergic rhinitis.

Clinical studies show N. sativa seed (25–250 mg/kg/day) or oil (25 µl–0.5 ml/day) for 15–30 days alleviates symptoms of allergic rhinitis. Antihistaminic, immunomodulatory, and anti-inflammatory mechanisms have been identified in human studies.

A randomized controlled trial tested a Boswellia serrata and bromelain compound in 150 patients with seasonal allergic rhinitis (SAR) complicated by recurrent respiratory infections, finding large clinical benefit. The compound's anti-5-LOX and anti-thromboxane actions provide the mechanistic rationale.

Bromelain, a proteolytic enzyme from pineapple, is considered a principal proposed natural treatment for hay fever (allergic rhinitis) in authoritative integrative medicine references. It reduces nasal tissue edema, decreases mucus secretion, and exerts anti-inflammatory effects through multiple pathways relevant to seasonal allergies. EBSCO Research Starters lists it as one of the principal proposed natural treatments for seasonal allergies.

Multiple randomized controlled trials, including a landmark BMJ 2002 double-blind RCT (n=125), found butterbur extract ZE 339 comparable to cetirizine for seasonal allergic rhinitis. Its active petasines inhibit leukotriene and histamine synthesis. A 2008 postmarketing surveillance study of 580 patients confirmed efficacy and safety. NCCIH acknowledges the clinical research.

Topical intranasal capsaicin is acknowledged by NCCIH as a studied approach for allergic rhinitis. Capsaicin desensitizes TRPV1 receptors on sensory neurons in the nasal mucosa, reducing neurogenic inflammation, sneezing, and rhinorrhea. Multiple clinical studies have evaluated intranasal capsaicin for non-allergic and allergic rhinitis.

Hesperidin exhibits anti-allergic properties by inhibiting mast cell degranulation, reducing histamine release, and suppressing IgE-mediated responses and Th2 cytokines. These mechanisms are directly relevant to seasonal allergic (type I hypersensitivity) reactions. Evidence is primarily preclinical; human clinical trial data for seasonal allergies specifically are limited.

Chlorogenic acid and iridoid derivatives from L. japonica flower buds have been shown to have allergy-preventive effects in published pharmacological research. Polysaccharides demonstrate anti-allergic and immune-regulatory activities. TCM uses honeysuckle for wind-heat presentations overlapping with seasonal allergy symptoms.

The clinical evidence base for seasonal allergies overlaps directly with the allergic rhinitis trial (Badar et al., 2005), which enrolled hay fever patients. T. cordifolia extract significantly reduced hallmark seasonal allergy symptoms including sneezing, nasal discharge, and itching versus placebo over 8 weeks. It is recognized by EBSCO Research Starters as showing anti-allergic benefits specifically for hay fever.

Animal studies confirm that I. racemosa petroleum ether extract demonstrates significant mast cell-stabilizing and antihistamine activity, relevant to the IgE-mediated type I hypersensitivity reactions underpinning seasonal allergic responses. These preclinical data support biological plausibility of anti-seasonal-allergy effects.

A randomized, prospective, double-blind trial of 187 preschool children with allergic asthma and/or rhinitis evaluated 12 months of L. casei fermented milk (10⁸ cfu/mL). While no statistically significant difference was found for asthmatic episodes, rhinitis-related outcomes were explored. Mechanistically, L. casei modulates IgE production and Th1/Th2 balance relevant to seasonal allergies.

L. gasseri SBT2055 has been studied for immune modulation relevant to allergic conditions. In vitro, it interacts with intestinal dendritic cells to produce TGF-β and IL-10, cytokines that support regulatory T cell function and suppress IgE-mediated responses. A multi-strain probiotic including L. gasseri KS-13 improved rhinoconjunctivitis-specific quality of life in a double-blind RCT in seasonal allergy sufferers.

L. paracasei LP-33 has been specifically studied in randomized, placebo-controlled trials during pollen seasons for hay fever. Active treatment groups reported fewer sneezing episodes, less nasal congestion, and improved quality of life compared to placebo. The immunomodulatory mechanism involves rebalancing Th1/Th2 cytokine ratios and reducing allergic IgE responses.

L. rhamnosus GG has been evaluated in multiple clinical trials for seasonal allergic rhinitis, with mixed but overall suggestive evidence. As add-on to immunotherapy in children (n=100), LGG enhanced immune responses versus immunotherapy alone. LGG combined with L. gasseri in fermented milk alleviated nasal blockage symptom scores in adults with Japanese cedar pollinosis.

Licorice root's antihistaminic properties and Th2 immunomodulation are directly relevant to seasonal allergic rhinitis. A 2025 clinical study of nasal irrigation with licorice extract demonstrated significant improvement in sneezing, itchiness, and rhinorrhea scores compared to saline in allergic rhinitis patients. Animal models confirm Th2 cytokine and IgE suppression.

Luteolin is a flavone that acts as a potent mast cell stabilizer and histamine release inhibitor, with anti-allergic mechanisms similar to quercetin. In vitro and animal studies demonstrate inhibition of IgE-mediated degranulation and Th2 cytokine production. It is included in evidence reviews of natural anti-allergic agents for allergic rhinitis.

Stinging nettle (Urtica dioica) has traditional European use for hay fever and a 2017 randomized double-blind placebo-controlled trial (n=74) showed significant improvement in allergic rhinitis symptom scores and reduction in nasal eosinophils. In vitro research shows nettle extract inhibits key enzymes in the allergic cascade. NCCIH acknowledges it among studied nutritional approaches for allergic rhinitis.

Quercetin, the dominant flavonoid in onion, is the most extensively studied natural anti-allergic compound for hay fever and seasonal rhinitis. It inhibits mast cell degranulation, reduces histamine release, and improves clinical symptoms in allergic rhinitis patients. A 2025 systematic review concluded that quercetin reduces oxidative stress markers and improves clinical outcomes in allergic rhinitis.

A 21-day randomized, double-blind, placebo-controlled trial (Takano et al., Exp Biol Med, 2004; PubMed 14988517) found rosmarinic-acid-enriched Perilla frutescens extract significantly improved itchy nose, watery eyes, itchy eyes, and total symptom response rates in seasonal allergic rhinoconjunctivitis, and reduced nasal neutrophil and eosinophil counts. Perilla has also been used traditionally in Asian medicine for respiratory allergies.

Picroliv (the standardized iridoid glycoside fraction of P. kurroa) has demonstrated anti-allergic and anti-anaphylactic activity in animal models, inhibiting passive cutaneous anaphylaxis. Traditional Ayurvedic use for 'allergy' is well-documented. The NDNR notes clinical use for hayfever based on immunomodulatory properties.

Pine bark extract (Pycnogenol) has demonstrated benefits for seasonal allergic symptoms in clinical studies by reducing pro-inflammatory cytokines and leukotriene synthesis. A published RCT showed pre-seasonal supplementation reduced symptom severity and antihistamine use. Anti-inflammatory and anti-leukotriene mechanisms are documented.

Pycnogenol, the patented extract of French maritime pine bark, was tested in two RCTs for seasonal allergic rhinitis and found to significantly reduce nasal and ocular symptoms when started 5+ weeks before pollen season. NCCIH names Pycnogenol (pine bark) among studied approaches for allergic rhinitis.

Animal studies show bromelain reduces allergic sensitization, inhibits CD11c+ dendritic cells and antigen-presenting cells, and attenuates inflammatory airway responses. These findings suggest immune-modulating effects relevant to allergic disease. Human clinical data are limited but mechanistic evidence is well established.

Quercetin is a flavonoid that stabilizes mast cells and inhibits histamine, leukotriene, and pro-inflammatory cytokine release. A 2022 placebo-controlled RCT in adults with hay fever showed symptom improvements at 200 mg/day for 4 weeks. NCCIH acknowledges quercetin among studied approaches for allergic rhinitis.

A 21-day randomized double-blind placebo-controlled trial (Takano et al., Exp Biol Med, 2004; Osakabe et al., Biofactors, 2005) found rosmarinic acid significantly improved itchy nose, watery eyes, itchy eyes, and total symptom response rates in seasonal allergic rhinoconjunctivitis, and reduced nasal neutrophil and eosinophil counts. It inhibits PMNL infiltration via NF-κB suppression and ROS scavenging.

Rutin, as a quercetin glycoside, shares quercetin's mast cell-stabilizing and histamine-suppressing mechanisms. Dietary rutin has been noted to inhibit mast cell histamine release in studies of related flavonoids. The anti-allergic flavonoid evidence predominantly belongs to quercetin, of which rutin is the glycoside form.

SD has been studied in OVA-induced allergic rhinitis mouse models with results showing reduced IgE, histamine, and allergic cytokines, providing preclinical scientific support for its traditional use in seasonal allergic conditions. Network pharmacology studies also confirm multi-target antiallergic mechanisms including inhibition of mast cell degranulation. No human trials exist.

A double-blind placebo-controlled RCT (Cingi et al., Eur Arch Otorhinolaryngol, 2008; PubMed 18343939) found spirulina significantly improved nasal discharge, sneezing, nasal congestion, and itching versus placebo in allergic rhinitis patients. NCCIH lists spirulina among studied nutritional approaches for allergic rhinitis.

Lipoxins and resolvins have been measured in human nasal secretions and are reduced in seasonal allergic rhinitis patients. SPMs suppress mast cell and eosinophil activation relevant to seasonal allergen responses. Omega-3 supplementation has been shown to upregulate nasal SPM levels in human subjects.

Sulforaphane-rich broccoli sprout extract attenuated nasal allergic responses to airborne challenge in a human clinical study. Via Nrf2 activation, SFN reduces oxidant-mediated mast cell degranulation and histamine-driven nasal inflammation. Clinical trial reviews confirm a supportive role in allergic rhinitis.

A. annua pollen is a major aeroallergen in northern China, and sublingual immunotherapy (SLIT) using A. annua allergen extracts has been tested in multiple Phase III RCTs with significant reductions in nasal symptom scores. This represents one of the more robustly clinically-tested applications of the plant.

A randomized double-blind placebo-controlled trial (PubMed 15619563; n=75) found Tinospora cordifolia extract produced highly significant relief from sneezing, nasal discharge, nasal obstruction, and pruritus in allergic rhinitis patients compared to placebo over 8 weeks. It is also an established Ayurvedic immunomodulator (guduchi/giloy) traditionally used for respiratory allergies.

Curcumin exhibits immunomodulatory actions relevant to allergic diseases, including modulation of mast cells, eosinophils, Th1/Th2 balance, and IgE responses. Preclinical studies show efficacy in models of allergic rhinitis, asthma, and food allergy. A Phase 2 RCT in moderate-to-severe asthmatics is registered. Human clinical evidence for seasonal allergic rhinitis specifically is limited.

The landmark Shivpuri crossover double-blind trial (J Allergy, 1969) specifically studied both asthma and allergic rhinitis — a condition closely tied to seasonal allergies — finding significant improvement with Tylophora versus placebo. The study population included patients with positive skin tests to common allergens such as pollens, directly relevant to seasonal allergy.

Vitamin C (ascorbic acid) is listed by EBSCO Research Starters as an other proposed natural treatment for seasonal allergies. It has antihistamine properties, supports DAO (diamine oxidase) enzyme activity, and reduces histamine plasma levels. Human studies show that intravenous and high-dose oral vitamin C can reduce allergy symptoms.

The fruit of X. strumarium is one of the most established TCM herbs for allergic rhinitis, with multiple preclinical studies documenting anti-allergic and anti-histamine mechanisms. Its caffeoylquinic acids suppress Th2-driven IgE responses and mast cell activation in rodent models. No human RCTs have been completed, so evidence remains at the animal/mechanistic level.

Chrysanthemum's flavonoid luteolin has antihistamine properties that may reduce allergy symptoms, and the herb is used in TCM for wind-related conditions including seasonal allergies and skin reactions. This is primarily a traditional indication with supporting in vitro mechanistic evidence, but no clinical RCT data in allergic rhinitis patients.

Eucalyptus is traditionally used to manage the nasal congestion and airway symptoms of seasonal allergies via inhalation of steam or topical chest/nasal application. Its well-documented decongestant and anti-inflammatory activity on airway tissue supports this use. No RCTs in seasonal allergic rhinitis patients using eucalyptus as a primary intervention have been published.

Goldenrod has a traditional use in Western herbalism for allergic rhinitis and seasonal allergies, with its anticatarrhal and anti-inflammatory actions considered relevant. Goldenrod itself is not a significant airborne allergen (its pollen is insect-borne). Traditional herbal practice combines it with nettles and eyebright for allergy symptoms. No clinical trials have assessed goldenrod for seasonal allergies.

Goldenseal is traditionally used for allergic rhinitis and seasonal allergies, particularly as part of combination preparations for upper respiratory symptoms. Its mucous membrane-drying and anti-inflammatory properties are the traditional rationale. No clinical trials have confirmed efficacy.

Hydrangea is traditionally listed for hay fever (allergic rhinitis) by RxList and WebMD. The proposed basis is antihistamine activity attributed to the plant's phytochemistry in traditional Western and Chinese herbalism. No human trials have tested hydrangea for seasonal allergies, and evidence remains entirely traditional.

Plantago contains flavonoids (baicalein, scutellarein) with documented antiallergic properties in vitro, inhibiting mast cell degranulation. P. lanceolata is used in European herbal medicine for mild respiratory allergy symptoms. Traditional use for hay fever and allergic rhinitis is documented, though no specific clinical RCTs exist for seasonal allergy as a primary indication.

Hay fever is among the documented traditional applications of Plantago major in ethnobotanical records. Anti-allergic activity for plantamajoside has been demonstrated in vitro (inhibition of histamine release from mast cells). Traditional use for hay fever and rhinitis is recorded in European and Asian folk medicine. No human allergy RCT exists.

Schizonepeta is used in TCM for allergic conditions including seasonal allergic symptoms, attributed to its wind-expelling and anti-allergic properties. In vitro studies demonstrate inhibition of mast cell degranulation and pro-inflammatory cytokines relevant to allergic cascades. Human clinical evidence for seasonal allergy specifically is absent.

S. baicalensis has documented anti-allergic effects: wogonin suppresses IgE and IL-5 (key mediators in seasonal allergic rhinitis); baicalin inhibits histamine release; and skullcap regulates Th1/Th2 balance. TCM prescribes Huang Qin for 'hay fever' and allergic conditions. Animal data support anti-allergic efficacy; human trials are absent.