Tetracarboxy-phthalocyanines: From excited state dynamics to photodynamic inactivation against Bovine herpesvirus type 1.

Herein we present the excited state dynamic of zinc and aluminum tetracarboxy-phthalocyanines (ZnPc and AlPc) and its application in the photodynamic inactivation (PDI) of Bovine herpesvirus type 1 (BoHV-1) in vitro. The excited state dynamic provides valuable data to describe the excited state properties of potential optical limiters and/or photosensitizers (PSs), such as: the excited state cross-sections, fluorescence lifetime and triplet state quantum yield. The excited state characterization was performed using three different Z-scan techniques: Single Pulse, White Light Continuum and Pulse Train. Considering the photodynamic inactivation of BoHV-1, an initial viral suspension containing 105.75TCID50/mL was incubated with the PSs for 1h at 37°C under agitation and protected from light. The samples were placed in microtiter plates and irradiated (180mW/cm2). During irradiation, a sample was taken every 15min and the viability of the virus was evaluated. The results show that both phthalocyanines were efficient against viruses. However, a higher photodynamic efficiency was observed by ZnPc, which can be attributed to its higher triplet and singlet quantum yields. The results presented here are important for animal health (treatment of BoHV-1) and also open up a field of studies to use AlPc and ZnPc as potential agents against a wide range of microorganisms of veterinary interest.

Acetone extract from Streptoverticillium sp., a bacterium isolated from Brazilian Cerrado soil, induces anti-inflammatory activity in mice.

The Streptoverticillium sp. Z1 is an actinomycete isolated from the soil under Cerrado vegetation, the extract of this strain was investigated in nociceptive and inflammatory models. The Streptoverticillium extract (ExS) 50 and 100 mg/kg (s.c.) produced a significant inhibition of acetic acid-induced abdominal writhings thereby demonstrating an anti-nociceptive effect. In the tail flick test the ExS (s.c.) was inactive. This result implited that ExS does not contain opioid-like compounds with central analgesic properties. In the inflammatory models, ExS 100 and 200 mg/kg (s.c.) were able to inhibit the croton oil-induced ear edema and, ExS 200 and 500 mg/kg (s.c.) inhibited the leukocyte migration on the carrageenan-induced peritonitis. The phospholipase A2 enzymatic assay showed that the anti-inflammatory activity of ExS was not due to direct effect on phospholipase A2 activity. These data suggest that Streptoverticillium sp. produces metabolites with anti-inflammatory effect and that these metabolites are unable to directly inhibit phospholipase A2 enzyme.