Antifungal Activity of Mahonia aquifolium Extract and its Major Protoberberine Alkaloids

Human mycoses, which may be life-threatening in immuno-compromised patients, are not always successfully treated due to ineffectiveness or toxicity of the available drugs (Feresin et al., 2001). The most important antifungal drugs include camphotericin B, with a polyene structure, and the more recently discovered azole derivatives (Goldstein et al., 2000; Lee et al., 2001). 

In addition, the emergence of fungal strains resistent to existing antifungal therapeutics is becoming a further problem. Thus, there are still continuing efforts to develop new, more effective and safe antifungal agents. 

Medicinal plants may represent a valuable, untapped source of novel antifungal drugs, especially protoberberine alkaloids, which are readily extractable from Chinese and Korean medicinal plants, and have been shown to possess diverse biochemical and pharmacological actions while being nontoxic to man even at high dosages. Their antifungal activity has been demonstrated against some Candida species (Park et al., 1999; Sarma et al., 1999). 

Previously, we have reported the isolation of four protoberberine, six bisbenzylisoquinoline alkaloids and some polysaccharide components from the stem bark of M. aquifolium (Kost’álová et al., 1987; 2001). The main alkaloid constituents of M. aquifolium are berberine and jatrorrhizine with minor amounts of palmatine and columbamine. Although berberine is generally considered the physiologically dominant alkaloid (Iwasa et al., 1998), other components of the Mahonia extract may also be important.