Interaction of Flavones from the Roots of Scutellaria baicalensis with the Benzodiazepine Site

Abstract

A radioreceptor binding assay was used to guide the isolation of four chemical constituents in the organic solvent extracts of Scutellaria baicalensis Georgi capable of binding to the benzodiazepine site (BZD-S) of the GABA_A receptor: wogonin (K_i =2.03 ± 0.24µM), baicalin (K_i =77.10 ± 4.79µM), baicalein (K_i =5.69 ± 0.95µM), and scutellarein (K_i =12.00 ± 1.27µM). All four compounds contain the flavonoid phenylbenzopyrone nucleus. Based on BZD-S binding, the order of affinity among these four compounds was wogonin > baicalein > scutellarein > baicalin.

References

• 1 Huang K C. In: The Pharmacology of Chinese Herbs. CRC press 1993: pp. 290-291
• 2 Ai J, Dekermendijian K, Wang X, Nielsen M, Witt M R. Drug Develop Res 1997 41: 99-106
• 3 Liao J F, Wang H H, Chen M C, Chen C C, Chen C F. Planta Med 1998 64: 571-572
• 4 Tomimori T, Miyaichi Y, Imoto Y, Kizu H. Shoyakugaku Zasshi 1984 38: 249-252
• 5 Miyaichi Y, Imoto Y, Saida H, Tomimori T. Shoyakugaku Zasshi 1998 42: 216-219
• 6 Zhang Y Y, Guo Y Z, Onda M, Hashimoto K, Ikeya Y, Okada M, Maruno M. Phytochem 1994 35: 511-514
• 7 Tomimori T, Miyaichi Y, Kizu H. Yakugaku Zasshi 1982 102: 388-391
• 8 Miyaichi Y, Imoto Y, Tomimori T, Namba T. Chem Pharm Bull 1988 36: 2371-2376
• 9 Vogel H G, Vogel W H. In Drug Discovery and Evaluation: Pharmacology Assay . New York; Springer 1997: pp 218-219
• 10 Squires R F, Braestrup C. Nature 1977 266: 732-734
• 11 Cheng Y, Prusff W H. Biochem Pharm 1973 22: 3099-3108