Scavenging effect of berbamine on active oxygen radicals in phorbol ester-stimulated human polymorphonuclear leukocytes

Activity of Berberis aetnensis root extracts on Candida strains

The antifungal activity of methanolic extract and alkaloidal fraction of Berberis aetnensis against Candida species was investigated. The crude extract was active against Candida species, this activity being higher than that of the alkaloidal fraction and berberine.

Cytotoxic constituents from the whole plant of Corydalis pallida

Here we report the cytotoxic activity of three known compounds isolated for the first time from Corydalis pallida (Papaveraceae). An isoquinoline alkaloid, berberine, exhibited cytototoxic activity against two human cancer cell lines, HT-1080 (human fibrosarcoma) and SNU-638 (human stomach adenocarcinoma), with IC50 values of 3.2 and 3.4 microg/mL, respectively. N-trans-feruloyltyramine and N-trans-feruloylmethoxytyramine were also isolated from this plant but were inactive.

Study on the anti-inflammatory action of Berberis vulgaris root extract, alkaloid fractions and pure alkaloids

Extracts obtained from the roots of Berberidaceae species have been used in Eastern and Bulgarian folk medicine in rheumatic and other chronic inflammatory disorders. The investigations of the chemical composition and immunological properties show that their activity is mainly due to the alkaloid constituents. In the present study the anti-inflammatory properties of total ethanol extract (TEE), three alkaloid fractions, a major alkaloid berberine and oxyacanthine isolated from Berberis vulgaris roots were compared. All these were applied in acute inflammation (carrageenan- and zymosan-induced paw oedema), as the TEE showed the highest reducing effect. Their ability to alter in vivo and in vitro complement activity was determined. Also, the TEE was most effective in a chronic inflammatory model of adjuvant arthritis. The protoberberine fractions Bv2, Bv3 and berberine suppressed a delayed type hypersensitivity (DTH) reaction. Fraction Bv1 and berberine diminished antibody response against SRBC in vivo. The in vitro treatment of splenocytes with berberine showed that the anti-SRBC antibody synthesis was influenced in a different manner depending on the time course of its application. Oxyacanthine was less effective than berberine in the tests used.

Structure-antioxidative activity relationships in benzylisoquinoline alkaloids

The antioxidative properties of the aporphines boldine, glaucine and apomorphine, and of the benzyltetrahydroisoquinolines (+/-)-coclaurine and (+/-)-norarmepavine were compared in the brain homogenate autoxidation model. The IC50 values found lay in the 16-20 microM range for the aporphines and were 131.7 microM, and 79.3 microM for coclaurine and norarmepavine, respectively. These results indicate that the antioxidative capacity (AC) of these compounds is related to the presence of the biphenyl system rather than phenol groups. The non-phenolic glaucine inhibited the 2,2'-azobis-(2-amidinopropane)(AAP)-induced inactivation of lysozyme with an IC50 value of 12 microM, while the corresponding values for the phenolic coclaurine and norarmepavine were 10 and 20 microM, respectively. N-Methylation of glaucine to its quaternary ammonium reduced its protective effect by two-thirds. This result suggests that a benzylic hydrogen neighbouring a nitrogen lone electron pair may be the key to the protective effect of non-phenolic aporphines.

Effect of bisbenzylisoquinoline alkaloids from Mahonia aquifolium on the isolated rat aorta

1. The extract from roots of Mahonia aquifolium as well as berbamine and oxyacanthine relaxed K(+)-precontracted rat aortal rings with IC50 values of about 20 mumol/l. 2. Relaxation was not inhibited by denudation of the endothelium or by premedication of the aortas with indomethacin, methylene blue or propranolol. 3. Berbamine and oxyacanthine inhibited contractions induced by noradrenaline, phenylephrine and serotonin in a non-competitive manner. Further, they competitively blocked calcium-induced contraction in Ca(2+)-free depolarizing PSS. 4. The blockade of calcium entry appears to be the main mechanism of the dilatory effect of the drugs tested, but their interaction with alpha-adrenoceptors could not be excluded.

Iron-reducing and free-radical-scavenging properties of apomorphine and some related benzylisoquinolines

The scavenging and iron-reducing properties of a series of benzylisoquinolines of natural and synthetic origin have been studied. Bulbocapnine, boldine, glaucine, and stepholidine acted as scavengers of hydroxyl radical in the deoxyribose degradation by Fe(3+)-EDTA + H2O2. On the contrary, laudanosoline, apomorphine, protopapaverine, anonaine, and tetrahydroberberine increased deoxyribose degradation by a mechanism related to generation of superoxide anion. Only apomorphine had a stimulating effect in the system using citrate instead of ethylenediaminetetraacetic acid (EDTA) as well as in the absence of chelator. Apomorphine also stimulated DNA damage by Cu2+. The iron-ion reducing ability of apomorphine and laudanosoline was confirmed using cytochrome c. Both compounds scavenged peroxyl radicals in an aqueous medium, while in Fe(3+)-induced microsomal lipid peroxidation apomorphine acted as an inhibitor and laudanosoline stimulated the process. It is suggested that in microsomes the chain-breaking antioxidant properties of apomorphine overcome its possible influence on redox cycling of iron, or prooxidant properties.

Antioxidant action of benzylisoquinoline alkaloids

The antioxidant action of a series of benzylisoquinoline alkaloids has been investigated. Laudanosoline, protopapaverine, anonaine, apomorphine, glaucine, boldine, bulbocapnine, tetrahydroberberine and stepholidine produced a dose-dependent inhibition of microsomal lipid peroxidation induced by Fe2+/ascorbate, CCl4/NADPH or by Fe3+ ADP/NADPH. Apomorphine exerted the highest inhibitory effects in the three systems of induction used, with a potency higher than propyl gallate. Laudanosoline was particularly effective in the first system, while bulbocapnine and anonaine were more potent when CCl4/NADPH or Fe3(+)-ADP/NADPH were used as inducers. Laudanosoline, protopapaverine, apomorphine, tetrahydroberberine and stepholidine were also potent inhibitors of nitroblue tetrazolium (NBT) reduction. The presence of a free hydroxyl group or preferably of a catechol group is a feature relevant for inhibition of lipid peroxidation and NBT reduction, nevertheless the antioxidant activity of benzylisoquinoline alkaloids cannot be only ascribed to the formation of phenoxy radicals and other free radical species may be formed during aporphine and tetrahydroprotoberberine oxidation. The influence of this series of compounds on the time course of lipid peroxidation suggests that some of them, like apomorphine and boldine act as chain-breaking antioxidants.

Inhibition of nonenzymic lipid peroxidation by benzylisoquinoline alkaloids

A group of benzylisoquinoline alkaloids, including five simple benzylisoquinolines, three phtalideisoquinolines, six aporphines, three protoberberines, and two benzophenanthridines, have been studied as inhibitors of lipid peroxidation stimulated by Fe2+/cysteine in rat liver microsomal fractions. Protopapaverine, apomorphine, laudanosoline, tetrahydroberberine, isoboldine, bulbocapnine, boldine, anonaine, glaucine, and stepholidine showed antiperoxidative effects, and structure-activity relationships were established. In simple benzylisoquinolines, the presence of phenolic hydroxyls or similar reactive groups is necessary for inhibition of peroxidation, while in aporphines and protoberberines nonhydroxylated compounds can exert antiperoxidative effects. The phtalideisoquinolines and benzophenanthridines tested were inactive.