Planta Med 2007; 73(11): 1156-1162
DOI: 10.1055/s-2007-981587
Pharmacology
Original Paper
© Georg Thieme Verlag KG Stuttgart · New York

Potent Suppressive Effects of 3-O-Methylquercetin 5,7,3′,4′-O-Tetraacetate on Ovalbumin-Induced Airway Hyperresponsiveness

Jiunn-Song Jiang1 , Hui-Chi Chien2 , Chien-Ming Chen3 , Chun-Nan Lin4 , Wun-Chang Ko2
  • 1Department of Internal Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
  • 2Graduate Institute of Pharmacology, College of Medicine, Taipei Medical University, Taipei, Taiwan
  • 3Department of Medical Technology, College of Medicine, Taipei Medical University, Taipei, Taiwan
  • 4School of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan
Further Information

Publication History

Received: May 5, 2007 Revised: July 13, 2007

Accepted: July 19, 2007

Publication Date:
07 September 2007 (online)

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Abstract

We investigated the suppressive effects of 3-O-methylquercetin 5,7,3′,4′-O-tetraacetate (QMTA), a more-potent phosphodiesterase (PDE)3/4 inhibitor than quercetin 3-O-methyl ether (3-MQ), which has been reported to have the potential for treating asthma, against ovalbumin (OVA)-induced airway hyperresponsiveness (AHR). The IC50 value of QMTA for PDE3 was significantly less than that for PDE4. According to the Lineweaver-Burk analysis, QMTA (1 - 10 μM) competitively inhibited PDE3 and PDE4 activities. The Ki values were 0.9 ± 0.3 (n = 5) and 3.9 ± 0.5 (n = 5) µM, respectively, which significantly differed from each other, suggesting that QMTA has higher affinity for PDE3 than for PDE4. QMTA (3 - 10 μM) concentration-dependently relaxed the baseline level, and significantly inhibited cumulative OVA (10 - 100 μg/mL)-induced contractions in isolated sensitized guinea pig trachealis suggesting that QMTA has bronchodilator and inhibiting effects on mast cell degranulation. After the secondary challenge, the AHR was measured in unrestrained OVA-sensitized mice, with nebulized methacholine (MCh, 6.25 - 50 mg/mL), by barometric plethysmography using a whole-body plethysmograph. In the present results, QMTA (3 - 10 μmol/kg, i. p.) dose-dependently attenuated the enhanced pause (Penh) value induced by MCh (25 - 50 mg/mL). QMTA (3 - 10 μmol/kg, i. p.) also significantly inhibited total inflammatory cells, macrophages, neutrophils, lymphocytes, and eosinophils in BALF after determination of Penh values. It also significantly suppressed the release of interleukin (IL)-2, IL-4, IL-5, IFN-γ, and TNF-α, with the exception that 3 μmol/kg QMTA did not suppress the releases of IL-5. QMTA even at 1 μmol/kg significantly inhibited eosinophils, IL-2, and TNF-α. In conclusion, our results strongly suggest that QMTA has greater potential than 3-MQ for the treatment of asthma.

Abbreviations

AHR:airway hyperresponsiveness

BALF:bronchoalveolar lavage fluid

CBA:cytometric bead array

IFN-γ:interferon-γ

IL:interleukin

OVA:ovalbumin

PDE:phosphodiesterase

Penh:enhanced pause

QMTA:3-O-methylquercetin 5,7,3′,4′-O-tetraacetate

TNF-α:tumor necrosis factor-α

References

Prof. Dr. Wun-Chang Ko

Graduate Institute of Pharmacology

College of Medicine

Taipei Medical University

250 Wu-Hsing St.

Taipei 110

Taiwan

R.O.C.

Fax: +886-2-2377-7639

Email: wc_ko@tmu.edu.tw