Disruption of mitochondrial membrane potential by ferulenol and restoration by propolis extract: antiapoptotic role of propolis.

This paper reports an investigation of the ability of propolis extract (a resinous substance collected by honeybees from various plant sources) to restore the collapse of mitochondrial membrane potential induced by ferulenol, a sesquiterpene prenylated coumarin derivative isolated from the plant Ferula vesceritensis . We show that ferulenol was able to induce the permeability transition pore (PTP) opening. This effect is caused by the interaction of the compound with the mitochondrial respiratory chain, more particularly by the fall of membrane potential and the inhibition of complex II. We have previously demonstrated that this inhibition results from a limitation of electron transfers involved in the respiratory chain and initiated by the reduction of ubiquinone. We hypothesized that the protective effect of propolis could be due to a direct action on mitochondrial functions. So we have investigated in vitro the mitochondrial effects of Algerian propolis using rat liver mitochondria, by analysing their effects on membrane potential, mitochondrial respiration and mitochondrial swelling. We show that propolis extract was able to restore the fall of mitochondrial membrane potential. Taken together these data reveal that propolis extract may be an interesting inhibitor of PTP and provide an additional mechanism by which the natural product propolis extract may restore the mitochondrial membrane potential and to prevent apoptotic process.

Cardioprotective effects and mechanism of action of polyphenols extracted from propolis against doxorubicin toxicity.

Propolis is one of the major hive products of bees and is rich in flavonoids, which are known for antioxidant activities. It is well known that the chemical properties of phenolic acids or flavonoids, in terms of the availability of the phenolic hydrogens as hydrogen donating radical scavengers, predict their antioxidant properties. In this study, the flavonoids scavenging activity of propolis has been exploited to obtain protection against the peroxidative damage in rat heart mitochondria which was induced by the administration of an acute dose of doxorubicin (20 mg kg(-1), i.p). The peroxidative lesions were evaluated biochemically and biophysically, 24 H after DXR administration. Abnormal biochemical changes in heart mitochondria from DXR treated rats including a marked increase in both malondialdehyde (MDA) and anion superoxide production; decrease both of respiratory chain ratio (RCR= V3/V4) and P/O. Pretreatment of rats with propolis extract, given per os (100 mg/kg/day) during four days prior to DXR injection, substantially reduced the peroxidative damage in the heart mitochondria: we showed significant reducing both of mitochondrial MDA formation and production of superoxide anion, restoration of RCR and P/O and reducing of rate and the amplitude of mitochondrial swelling. The data demonstrate that antioxidants from natural sources may be useful in the protection of cardiotoxicity in patients who receive doxorubicin and as reported for its claimed beneficial effect on human health by biomedical literature.

Polyphenolic fraction of Algerian propolis protects rat kidney against acute oxidative stress induced by doxorubicin.

We evaluated the effects of propolis extract on renal oxidative stress induced by doxorubicin throughout an analytical and pharmacological study of the eastern Algerian propolis using thin layer chromatography, ultra-violet-high-performance liquid chromatography) and gas chromatography-mass spectrometry. The pharmacological study was carried out in vivo on Wistar rat pre-treated with propolis extract 100 mg/kg/day for seven days. Doxorubicin at 10 mg/kg of body weight was administered intravenously on Day 7. Serum creatinine concentration, scavenging effect of flavonoids, lipid peroxidation and glutathione concentration were measured. Chemical analysis allowed identification and quantification of the phenolic compounds including pinostrombin chalcone (38.91%), galangin (18.95%), naringenin (14.27%), tectochrysin (25.09%), methoxychrysin (1.14%) and a prenylated coumarin compound suberosin (1.65%). The total flavonoid concentration in the propolis extract was 370 mg (quercetin equivalents QE) /g dry weight (QE/g DWPE). Propolis extract restored the renal functions and reduced the toxic effect of doxorubicin. These data show a protective effect of Algerian propolis extract against doxorubicin-induced oxidative stress.