Plavsky Vitaly
Chief of Laboratory B. I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus 68 Nezavisimosti Ave., Minsk, 220072 Republic of Belarus

Abstract:

We have studied the possibility of using drugs on the basis of Hypericum perforatum and Eucalyptus viminalis Labill extracts as photosensitizers for antimicrobial photodynamic therapy. It is well known that these drugs are traditionally used as medicines, having antimicrobial, antiviral and anti-inflammatory action. Studies have shown that drugs on the basis of eucalyptus («Eucalyptus Tincture», «Galenophyllipt», «Сhloroрhyllipt») and St. John's wort («Diahyperonum», «St. John's wort tincture») except for the well-known ability to provide the dark (in the absence of light), antimicrobial and antiseptic action may cause photosensitizer action and act as agents for antimicrobial photodynamic therapy (APDT). Photosensitizer effect of alcohol tinctures of eucalyptus is determined by the presence in it of chlorophyll a and chlorophyll b and is characterized by high efficiency of singlet oxygen formation (gD = 0.23). Copper analogues of chlorophyll and Cu+2–pheophytin, prevailing in the galenophyllipt and chloroрhyllipt, are characterized by low photochemical activity: gD = 0.014 and gD = 0.02 respectively. Photodynamic action of St. John's wort preparations (alcohol form) is characterized gD = 0.17 and is due to chlorophyll and hypericin components, which contribution to the sensitization effect is determined by the wavelength of incident radiation. The most promising method for the implementation of APDT is the use of eucalyptus and diahyperonum as photosensitizers tincture, while therapeutic devices based on semiconductor lasers and LEDs as sources of radiation.