Antibacterial flavone

Sato, M. et al., Flavones with antibacterial activity against carcinogenic bacteria, J. Ethnopharma-col, 54, 171, 1996. 

Callicarpa macrophylla L. Zi Zhu Cao (leaf, root) Tannins, flavone, resin.33 Hemostatic, constricting the blood vessels, antibacterial, treat tubercular bleeding. 

Dracocephalum integrifolium L. Quao Ye Ging Lan (aerial plant) Essential oil, flavone glucoside.33 Antitussive, antiasthmatic, antiphlogistic, antibacterial. 

Lysionotus pauciflorus D. Don Shi Diao Lan (aerial part) Organic acids, flavones, nevadersin33 Antibacterial, antitussive, lower blood pressure. 

Xanthium chinense Mill. X. japonicum Widder X. mongolicum Kitag. X. sibiricum Patr. ex Widd. X. strumarium L. Cang Er (Cocklebur) (fruit) Xanthinin, xanthumin, xanthanol, isoxanthanol, strumaroside, tetrahydroxy flavone, caffeic acid, dicaffeoxylquinic acid.33-48 Antibacterial, antitussive, respiratory stimulating effect, lower blood pressure and blood sugar levels. 

Scutellaria baicalensis Georgi S. macrantha Fisch. China Baicalein, baicalin, wogonin, beta-sitosterol, wognoside, 7-methoxy-baicalein, 7-methoxynorwogonin, skullcap flavones.33 Antibacterial, antiviral, antipyretic, antiinflammatory, antitumor. 

Since ancient times, the roots of Scutellaria baicalensis have been used to treat allergic and inflammatory diseases in China and Japan. We reported the isolation from these roots of three new compounds, i.e., 2 S), 2, 5,6, 7-tetetahydroxy flavanone[25], 2 R), 3(i )-2, 3,5,6, 7-pentahydroxyflavanone and 2, 5,5, 7-tetrahydroxy-6, 8-dimethoxy-flavone, as antibacterial or anti-lipid peroxidation substances [26, 27], as well as six flavonoids, i.e., baicalein, bailcalin, oroxylin A, wogonin, skullcapflavone II, etc. Furthermore, we found that baicalein and baicalin "Fig. (47)" suppressed the development of secondary lesions in adjuvant-induced arthritis in rats "Fig. (48)". 

Figure 5. The structures of the flavones chrysosplenol-D and chrysoplenetin, isolated from Artemisia annua that enhance the antibacterial activity of berberine by inhibiting the MDR pump.

Bioassay-guided fractionation of an extract of Artemisia annua was conducted in order to assess the possible presence in the plant material of inhibitors of bacterial multidrug resistance pumps [218]. Fractions were tested for Staphylococcus aureus growth inhibition in the presence of a subinhibitory dose of weak antibacterial alkaloid berberine. Active fractions yielded the flavones chrysoplenol D and chrysoplenetin,... 

Garcinia kola Heckel (roots) GB-flavones ((I-3,II-8)-Jlavanone-flavone Garcinianin atropisomers (166) GBi (176) GB2 (177) kolaflavanone (178) manniflavanone (179) garciniflavanone (180). GBi showed antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Iwu et al., 1990b Terashima et al., 1995[195], 1999[196] Han et al.,2005[74]. 

Quercetin, a flavone which has numerous pharmacological effects, including antioxidant [101], antiinflammatory [102], antithrombotic [103], antitumoural [104, 105], and antibacterial [106, 107] ones, has also been tried in the prevention of ulcers induced by some experimental models... 

A recent study carried out by Beil et al. (1995) [142] shows that flavone, flavanone and quercetin inhibited H. pylori growth in a concentration-dependent manner. The most potent compound was flavone, with an antibacterial activity similar to that reported by colloidal bismuth subcitrate. 

There are several other examples in which berberine is combined with other substances to potentiate its antibacterial activity. Flavones, chrysosplenol-D, and chrysoplenetm from Artemisia annua L. (Asteraceae), which possess very weak antibacterial action by themselves, produce potent combinations with berberine resulting in very effective inhibition of Staphylococcus aureus growth. The combination of amphotericin B and berberine can reduce by approximately 75 % the amphotericin B dose in the treatment of candidiasis in mice, implying that berberine indeed has synergy with amphotericin B against C. albicans [104]. Another example is methicillin-resistant Staphylococcus aureus (MRSA) bacteria, which are responsible for substantial morbidity and mortality in hospitals. According to Yu et al., berberine is able to restore the effectiveness of / -lactam antibiotics... 

An ethanol extract of the leaves showed cytotoxicity to mammalian cells in vitro and weak in vitro antibacterial activity against Gram-positive and Gram-negative organisms. Numerous sesquiterpene lactones (e.g., eupatilin, eupafolin, eupatorin acetate, and eupaformosanin) and flavones (especially eupatorin) isolated from Eupatorium species have shown cytotoxic and/or antineoplastic activities. ... 

---