Active substances of plants in the treatment of allergic rhinitis: a systematic review and network meta-analysis

Growing rates of patients with allergic rhinitis (AR) worldwide call for novel approaches to treatment, and active substances of plants present a promising therapeutic option.This study aims to evaluate the effects of 24 plant-derived active substances including Benifuuki Green Tea, Broccoli Sprout Extract, Chamomile Liquid Extract, Cinnamon Bark Extract, Fermented Red Ginseng , Flos Magnoliae Volatile Oil, Ginger Extract, Glycyrrhiza glabra Extract, Grapeseed Extract, Hop Water Extract, Immature Sword Bean Pod , Nepeta bracteata Benth , Ma-al-Shaeer , Nigella sativa Oil, Perilla frutescens Extract, Phlai , Pycnogenol , Shallot Extract, Spirulina , Stinging Nettle Root Extract, Ten-Cha , Tomato Extract, Zataria multiflora Extract, and Petasites hybridus leaf extract ( Ze 339), on the symptoms and laboratory indicators of patients with allergic rhinitis . A systematic search of PubMed, Embase, Cochrane Library, and Web of Science was conducted to identify randomized controlled trials (RCTs) investigating the effects of these 24 plant-based interventions on symptoms and laboratory indicators in patients with allergic rhinitis. The methodological quality of included studies was assessed using the Cochrane Risk of Bias Tool, and data were analyzed using Stata 15.4. Twenty-seven RCTs encompassing 1,681 participants, published up to March 2025, were included. Network meta-analysis revealed that Tomato Extract significantly improved Total Nasal Symptom Scores (TNSS) (SUCRA = 78.0%), Glycyrrhiza glabra Extract effectively reduced Sino-Nasal Outcome Test-22 (SNOT-22) scores (SUCRA = 92.6%), Spirulina reduced Visual Analog Scale (VAS) scores and improved quality of life (SUCRA = 100%), Fermented Red Ginseng reduced serum immunoglobulin E (IgE) levels (SUCRA = 99.7%), Flos Magnoliae Volatile Oil decreased serum eosinophil (EOS) counts (SUCRA = 80.6%), and Phlai significantly reduced Interleukin-5 (IL-5) levels (SUCRA = 100%). Based on the network ranking, Tomato Extract, Glycyrrhiza glabra Extract, Spirulina , Fermented Red Ginseng , Flos Magnoliae Volatile Oil, and Phlai demonstrate more favorable efficacy profiles compared to other plant-derived interventions in improving symptoms and quality of life in patients with allergic rhinitis. The protocol was registered on PROSPERO (registration number: CRD420251052539).