Structure-activity relationship in the ability of flavonols to inhibit chemiluminescence.

Fourteen flavonoids were evaluated for their ability to inhibit chemiluminescence, either of neutrophils that had been briefly exposed to both luminol and phorbol-myristate acetate or to an enzymatic system with H2O2, luminol and horseradish peroxidase. Using chemiluminescence as the quantitative parameter, it can be concluded that the hydroxyl group in position 3 of the flavonols is vital for their inhibitory effect, and that two hydroxyl groups on the phenyl ring are optimal for such an effect. It was also noted that the C2-C3 double bond is essential for the flavonols' anti-oxidative effect.

Biological properties and clinical application of propolis. III. Investigation of the sensitivity of Staphylococci isolated from pathological cases to ethanol extract of propolis (EEP). Attempts on inducing resistance in laboratory Staphylococcus strain to EEP.

Staphylococci isolated from pathological material exhibited a reduced sensitivity to ethanol extract of propolis (EEP) in 90% of cases. No cross-resistance of the staphylococci to EEP and to any commonly used antibiotics was found. The induction of resistance to EEP in laboratory strain of Staphylococcus aureus (Oxford 209 P) can be achieved already after serial passages on nutrient media containing EEP.