Allergy-Preventive Effects of the Flowers of Impatiens textori

Abstract

Whole plant of Impatiens textori MIQ. (Balsaminaceae) is an annual herbaceous plant that grows naturally along waterfronts in the mountains in almost every region of Japan. It has been used for detoxication and treatment of carbuncles and contusions in Chinese medicine. 1) However, there has been no report on the antiallergic effects of the flowers of I. textori. In a previous study, we demonstrated the antianaphylactic, antipruritic, and antiplatelet activating factor (PAF) activities of a 35% EtOH extract (IT) of the flowers of I. textori, and isolated apigenin (1), apigenin 7-glucoside (2), luteolin (3), luteolin 7-glucoside (4), quercetin (5), kaempferol (6), and kaempferol 3-glucoside (7). 2,3)In a continuing search for allergy-preventive substances from natural sources, using our previously developed in vivo assay method to estimate complicated allergy, 4) we found that IT exhibited allergy-preventive activity. This in vivo assay method monitors the decrease in blood flow in the tail vein of mice subjected to hen egg-white lysozyme (HEL) sensitization alone without the HEL challenge as a guide.4) The blood flow in HEL-sensitized mice (control group) gradually and significantly decreased to about 70% of that in normal mice on day 9. Thus, the induction phase of allergy caused by xenobiotics can be dynamically and easily measured using blood flow monitoring. This blood flow decrease is considered to be due to the contraction of peripheral blood vessels and increase in blood viscosity, because no relationship with blood pressure was observed. Although anti-HEL immunoglobulin E (IgE) antibody significantly increased after HEL sensitization, there was no significant increase in the number of leukocytes. Thus the decrease in blood flow reflects the promoter process of an allergic reaction. The blood flow decrease is regulated by various factors such as nitric oxide (NO), thromboxane (TX) A 2 , prostacyclin (PGI 2 ), and endothelin (ET)-1, together with granulocytic elastase (GE), cyclooxygenase (COX)-1 and -2, inducible nitric oxide synthase (iNOS), and constitutive nitric oxide synthase (cNOS). 4) Additionally, the blood flow decrease occurs via both pathways of the iNOS-independent and -dependent response.5) Therefore this monitoring system should be useful for searching for preventive substances against complicated allergy involving NO, TXA 2 , PGI 2 , ET-1, GE, COX-1, and COX-2. 4,5) This paper describes the evaluation of the allergy-preventive effects of a 35% EtOH extract (IT) of the flowers of I. textori and compounds (1-7) previously isolated from IT. MATERIALS AND METHODS MaterialsThe 35% EtOH extract (IT) of the flowers of I. textori was used for our present and previous studies. 2,3)Apigenin (1), apigenin 7-glucoside (2), luteolin (3), luteolin 7-glucoside (4), quercetin (5), kaempferol (6), and kaempferol 3-glucoside (7) were isolated from IT as previously reported.2) HEL and complete Freund's adjuvant (CFA) were purchased from Sigma Chemical (St. Louis, MO, U.S.A.), Difco (Detroit, Michigan, U.S.A.)...

Interaction betweenPlectranthus barbatusherbal tea components and human serum albumin and lysozyme: Binding and activity studies

“…It is long known that some flavonoids may act as lysozyme inhibitors [20]. Previous works also reported that plant extracts mainly composed of apigenin, luteolin and luteolin glucosides decreased allergy symptoms caused by egg-white lysozyme sensitization in rats [8]. The same anti-allergic effect was observed for Perilla frutescens water extract, and by its major component, rosmarinic acid [16].…”

Effect of methionine on production of naphthoquinones inImpatiens balsaminaroot cultures and detection of some secondary metabolites

“…This compound has been isolated from the flowers of Impatiens textori Miq. and exhibited anti-allergic property in mice (Iwaoka et al, 2010). Normally, the flavonoids found in I. balsamina are kaempferol, quercetin and myriticin.…”

Phytochemical and Pharmacological Significance of Genus: Impatiens

“…The activity used in vivo assay methods for monitoring the blood flow decrease in the tail vein microcirculation of mice subjected to sensitization with hen egg white lysozyme. The principal compounds in Impatiens textori: apigenin and luteolin 7-glucoside showed significant allergy preventive effect (Iwaoka E et al, 2010).…”