Citrus jabara is a cultivar of citrus native to Kitayama village in Wakayama prefecture, Japan.Jabara has gained much attention in recent years for its effect on alleviating seasonal allergy symptoms . Jabara has been found to be particularly rich in the dietary flavonoid narirutin (naringenin-7-O-β-D-rutinoside) commonly found in citrus that is reported to possess anti-allergic property. The anti-allergic property of narirutin has been shown in both in vitro and in vivo studies using a mouse model of atopic dermatitis and airway inflammation.

Citrus jabara

Millions of people who react to airborne allergens such as pollens suffer from symptoms including rhinitis, atopic dermatitis, and asthma, which could reduce the patients’ quality of life. These allergic symptoms are induced by the activation of inflammatory cells such as mast cells.Mast cells express Fc epsilon receptor (FcεRI), which can bind to immunoglobulin E (IgE). Stimulation of IgE-sensitized mast cells with a specifific antigen results in a cascade of events leading to the secretion and production of proinflflammatory molecules such as histamine, lipid mediators and cytokines. These secreted molecules play critical roles in the inflflammatory reactions in patients with allergic diseases. 

Allergic symptoms can impair the patients’ quality of life by causing chronic fatigue, cognitive impairment, and many other symptoms associated with the condition. While there are many anti-allergy medications on the market, more effffective and safer drugs are still being sought.Use of natural products for the prevention and treatment of allergic diseases is an attractive and advantageous option in that they have fewer side effects.

In the process of Immunotherapy research, Seisho Azuma ect made a research on  Anti-inflammatory effects of flavonoids in Citrus jabara fruit peels, whose result was pulished in the journal of Trends in Immunotherapy.For the alleviation of allergic symptom, anti-inflammatory effects are also important. In this study, characteristics of flavonoids in C. jabara fruit peels, and the anti-inflammatory effects of these purified flavonoids were investigated. Our results revealed that C. jabara is a unique Citrus that almost all of flavonoids in fruit peels was narirutin. 

References:

[1]https://pubmed.ncbi.nlm.nih.gov/32252468/

[2]https://systems.enpress-publisher.com/index.php/ti/article/view/844

[3]Minatoguchi, S.; Ohno, Y.; Funaguchi, N.; Baila, B.; Nagashima, K.; Fujiwara, H. Effffect of “Jabara” juice on symptoms and QOL in patients cedar pollionsis. Clin. Immunol. Allergol. 2008, 50, 360–364. 

[4]Kubo, M.; Matsuda, H.; Tomohiro, N.; Harima, S. History and therapeutic evaluation of Citrus hassaku HORT. Tanaka. Yakushigaku Zasshi 2004, 39, 363–364.