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A practical hindrance in using many therapeutic agents is their limited solubility in aqueous matrixes. This is usually overcome by incorporating the active compounds in a matrix, with the aid of a non-ionic surfactant. Three water-insoluble natural polyphenols with inherent biological activity, quercetin (CAS 117-39-5), caffeic acid and caffeic acid phenylethyl ester, were solubilized in water, with the aid of Tween 80 (an esterified and polyethoxylated derivative of sorbitan), Solutol HS15 (a polyethoxylated derivative of 12-hydroxy-stearic acid), Cremophor RH40 (a ricinoleic acid derivative) or Cremophor EL and the effect of the solubilized polyphenols on histamine release was studied in vitro (mast cells) and in vivo in the rat. In vivo Cremophor EL alone increased, and Tween 80 decreased histamine plasma levels. All four groups injected with solubilized quercetin exhibited a decrease in their plasma histamine levels. Caffeic acid solubilized in Cremophor RH40 decreased histamine levels, too. In vitro Tween 80 increased histamine release in a dose-dependent mode. Quercetin in vitro inhibited histamine release in all solubilizers used. It is concluded that the ability of the studied polyphenols to release histamine is not only depending on the condition of the storage vesicles in the mast cells, but also on the surfactant used to solubilize them.

Ethanolic extract of propolis (EEP), known to possess marked antibacterial activity, was incubated with 8 different common antibiotics in culture medium containing a fixed amount of a standard strain of Staphylococcus aureus. The antibiotic compounds used were: penicillin G, doxycycline, streptomycin, cloxacillin, chloramphenicol, cefradine, ampicillin and polymyxin B. They were used in varying levels, ranging between 0.000005-125.0 micrograms/ml or units, resp. Firstly, their minimal inhibitory concentrations were established in the absence of EEP, than EEP was added in concentrations up to 600 micrograms/ml. EEP had a marked synergistic effect on the antibacterial activity of streptomycin and cloxacillin, and a moderate synergistic effect on the others, except ampicillin.

An increase of total cell number was shown in the cell culture in vitro under the influence of ethanol extract of propolis (EEP). Addition of EEP to the nutrient medium of the cells caused a strong activation of mitoses. Besides, distinctly intensified metabolism of these cells expressed by a strong activation of NADH2-reductase was also observed.

The presence of 19 elements has been shown in the ethanol extracts of propolis (EEP). Three fractions have been obtained by filtration through a structural gel that did not show an initial antibacterial activity when investigated separately. Fractions 2 and 3 joined together have regained this activity. EEP solutions maintain their anitbacterial activity in acidic or neutral pH. Insensitivity of EEP solutions on temperautre of 75 degrees C for 30 min has been found.

Under experimental conditions parenteral administration of ethanol extract of propolis (EEP) solutions to rabbits induced no synthesis of antibodies as investigated by means of ring precipitation, double diffusion gel precipitation and complement fixation test.

In the experiment on rats the ethanol extract of propolis (EEP) injections caused an activation of all experimental enzymes. The greatest effect EEP exerted was on NADPH2 tetrazolium reductase and glucose-6-phosphatase.

Artificially induced bone tissue losses after the application of ethanol extract of propolis (EEP) showed an accelerated rate of ossification. The osteogenetic process was just about half as long as in the control group.

Solutions of the ethanol extract of propolis (EEP) have shown a lethal effect on Trichomonas vaginalis in vitro. Similar lethal action was exhibited by EEP after a 24-h contact with Toxoplasma gondii.

Dressing of artificially formed losses of the cartilaginous tissue with the preparation containing ethanol extract of propolis (EEP) caused acceleration of regenerating processes in the lesioned cartilage. EEP inserted into the joint is well tolerated.

A study consisting of an examination of the acute toxicity of ethanol extract of propolis (EEP) in mice, its effect on spontaneous movement in mice and rats, its analgesic properties and its influence on body temperature in mice was conducted. Also examined was the activity of EEP on animals under the influence of narcotics and spontaneous movement under the influence of amphetamine, its effects on blood pressure and respiration in rats. The results of these examinations indicate that EEP injected i.p. has a weak general effect on the experimental animals.

Mice were given i.v. injections of water solutions of ethanol extract of propolis (EEP) over a varying period of time. Some of the animals were sacrificed immediately following the last injection and some within 2--4 weeks after the last injections. Internal organ samples were taken and underwent a microscopic examination. Insignificant pathological changes in the liver were observed. These changes were transient and regressed within 2--4 weeks after the application of EEP.

The use of ethanol extract of propolis (EEP) on injured dental pulp results in the stimulation of regenerative processes. A reduction of disorders of the circulatory system is observed, inflammatory and degenerative processes are also reduced.

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. Culturing Staphylococcus resistant to EEP in an environment devoid of this compound caused a remission to sensitivity of the strain investigated.