Berberine antibacterial activity

In another study, the structure-activity relationships of berberine and its derivatives were examined for their antibacterial activity. Among the 13-alkyl-substituted and the 13-unsubstituted protoberberinium salts, an increase in antibacterial activity was observed with the 13-ethyl-9-ethoxyl, the 13-ethyl, and the 13-methyl derivatives against S. aureus by eight-, four-,... 

The antibacterial activity of berberine. Fig. 4, a naturally occurring isoquinoline alkaloid isolated from a number of plants including Coptis chinensis,... 

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.

Recently, it has been demonstrated that medicinal plants contain MDR pump inhibitors that actually enhance the activity of their own natural antimicrobial compounds. Plant amphipathic cations, such as berberine, have been shown to be good MDR substrates. Recent research has shown that in addition to berberine, Berberis species produce 5 -methoxyhydnocarpin-D, Fig. 10, an MDR inhibitor that enhances the action of this compound. In addition, isoflavones isolated Ifom Lupinus argenteus were found to enhance the antibacterial activity of a-linolenic acid, also found in the same plant [99]. 

Figure 10. The structure of 5 -methoxyhydnocarpin-D, an MDR inhibitor isolated from Berberis species that enhances the antibacterial activity of berberine.

A new method of bioactivity-directed fractionation, based on multidrug resistant pump (MDR) inhibition in Staphylococcus aureus, was reported for medicinal plants. This work resulted in the isolation, from berberine-containing Berberis species, two compounds that are themselves devoid of antibacterial activity, but that form potent synergistic couples with a sub-inhibitory concentration of berberine. The bacterial MDR pump inhibitors were identified as the flavonolignan 2 and the porphyrin 3 [98]. The isoflavones not only enhanced the antibacterial activity of the natural product, berberine. Fig. 4, but also the activity of synthetic... 

Whereas most alkaloids appear to be specifically directed towards animals, others show a broader activity spectrum. For example, alkaloids with marked antibacterial activities include ajmaline, berberine, boldine, cinchonidine, cinchonine, harmaline, harmine, lobeline, narcotine, norharman, quinidine, quinine, sanguinarine, strychnine and yohimbine (see reviews [5, 73, 96]. Only the benzophenanthridine alkaloid... 

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... 

Iwasa K, Kamigauchi M, Ueki M, Taniguchi M (1996) Antibacterial activity and structure-activity relationships of berberine analogs. Eur J Med Chem 31(6) 469 78... 

Berberine (79, 103) occurs in the bark of a Rutaceae tree, Phellodendron amurense. Bark, 2-4 mm thick, can be ripped from the wood of an old tree. Cuttings of the bark are used as a crude drug in Chinese medicine as a bitter stomachic. Berberine is a quaternary base with a yellow color. The bark of R amurense is also yellow because of the presence of over 1% berberine. The alkaloid exhibits antibacterial activity. 

Berberine is used widely throughout the world, but not to any great extent in the United States. It is an abundant alkaloid and is easily extracted from a number of plant sources. It is particularly useful in the treatment of bacillary dysentery, for it has good antibacterial activity and is poorly absorbed from the gastrointestinal tract when administered orally. 

Phellodendron amurense Rupr. P amurense Rupr. f. molle (Nakai) Y. C. Chu P chinensis Schneid Huang Bai (Cork tree) (bark) Berberine, palmatine, candicine, phellodendrine, obacunone.33 Antibacterial, stimulate the phagocitic activity of leukocytes, against dysentery. 

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,... 

Berberine is reported to have pharmacological properties resembling those of hydras-tine. Its many activities include stimulating secretion of the bile in humans, sedative effect on cats and mice upon intraperitoneal administration, lowering the blood pressure of laboratory animals, anti arrhythmic effects and strong antibacterial effects (as mentioned... 

Chinese corktree bark contains similar constituents, but with higher berberine content (4—8%). Aqueous extracts of Amur corktree bark have strong antioxidant as well as strong and broad antibacterial and antifungal activities (berberine is one of the active components) the alkaloids (esp. berberine, phellodendrine, and palmatine) also have hypotensive action in animals other activities include hypoglycemic, hypocholesterolemic, and blood platelet protective effects (jilin wang). 

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