Argentine plant extracts active against polymerase and ribonuclease H activities of HIV-1 reverse transcriptase

Lipophilic and hydrophilic extracts of four Argentine plants (Gamochaeta simplicaulis Cabr. 1, Achyrocline flaccida Wein. D. C. 2, Eupatorium buniifolium H. et A. 3, and Phyllanthus sellowianus Muell. Arg. 4) were examined in vitro for their ability to inhibit the polymerase and ribonuclease H (RNase H) activities of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) (wild and Y181C mutant types). The active extracts were also examined as inhibitors of viral replication in HLT4LacZ-1IIIB cell cultures, evaluating their cytotoxicity in parallel. Infusions 2I and 4I, among the crude extracts, showed the highest activity. These extracts were refractioned into four fractions; 2I4 and 4I4 were active as inhibitors of DNA-polymerase (wild and Y181C types) and RNase H activities. These fractions were potent as inhibitors of viral replication and were not cytotoxic. Refractionation of 2I4 yielded five new fractions, two of which, 2I4-4 and 2I4-5, showed notable activity. Refractionation of 4I4 yielded for new fractions; of these, 4I4-3 and 4I4-4 were active. The marked biological activity found in the infusion of A. flaccida and P. sellowianus makes them sufficiently attractive to be considered in the combined chemotherapy of the disease

Thermal analysis of lipoic acid and evaluation of the compatibility with excipients

Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compatibility of lipoic acid with some currently employed cosmetic excipients. In the first phase of the study DSC was used as a tool to detect any interaction. Based on the DSC results alone, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 °C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy.Fil: Moyano, María A.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Broussalis, Adriana M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacognosia; ArgentinaFil: Segall, Adriana Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

Argentine plant extracts active against polymerase and ribonuclease H activities of HIV-1 reverse transcriptase

Lipophilic and hydrophilic extracts of four Argentine plants (Gamochaeta simplicaulis Cabr. 1, Achyrocline flaccida Wein. D. C. 2, Eupatorium buniifolium H. et A. 3, and Phyllanthus sellowianus Muell. Arg. 4) were examined in vitro for their ability to inhibit the polymerase and ribonuclease H (RNase H) activities of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) (wild and Y181C mutant types). The active extracts were also examined as inhibitors of viral replication in HLT4LacZ-1IIIB cell cultures, evaluating their cytotoxicity in parallel. Infusions 2I and 4I, among the crude extracts, showed the highest activity. These extracts were refractioned into four fractions; 2I4 and 4I4 were active as inhibitors of DNA-polymerase (wild and Y181C types) and RNase H activities. These fractions were potent as inhibitors of viral replication and were not cytotoxic. Refractionation of 2I4 yielded five new fractions, two of which, 2I4-4 and 2I4-5, showed notable activity. Refractionation of 4I4 yielded for new fractions; of these, 4I4-3 and 4I4-4 were active. The marked biological activity found in the infusion of A. flaccida and P. sellowianus makes them sufficiently attractive to be considered in the combined chemotherapy of the disease