Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna

We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida) that grow in the Argentine Puna (3800 m above sea level) and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL), mainly flavones and flavonols (0.1-0.8 mg/mL). The extracts showed hydrogen donating ability (DPPH and ABTS) and reactive oxygen species scavenging activity (O2●-, OH-, H2O2). The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2) was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 µg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 µM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.

Formulation and conservation of a pharmaceutical form with leaf extracts from Acacia aroma Gill. ex Hook et Arn

Leaf fluid extracts of Acacia aroma GILL. ex Hook et Arn showed antibacterial activity against antibiotic multiresistant bacteria isolated from clinical samples, antioxidant and ant-inflammatory activities. Toxicological studies carried out on Artemia salina and Allium cepa attested none toxicity potential. The aim of this work was to elaborate a formulation of topical antibacterial hydrogel with Carbopol acrylic acid polymer containing an A. aroma fluid extract in order to compare with a hydrogel containing commercial antibiotic. The optimal extract concentration in this formulation was determined according to the values of minimal inhibitory concentration and minimal bactericidal concentration for Staphylococcus aureus, methicillin-resistant (F7) and Pseudomonas aeruginosa (F352). Physical, chemical, rheological and microbiological stability was observed at least during one year. The hydrogel containing Acacia leaves fluid extract shows remarkable antibacterial effect with a broadspectrum efficacy against Gram positive and Gram negative bacteria at low concentration.