Antibacterial activity of extracts of Stevia rebaudiana Bertoni against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa

"Plants have been an important source of secondary metabolites known for their diverse biological activities; some have been shown to inhibit the development of certain pathogenic microorganisms. Herein, the antimicrobial activity of the carbon tetrachloride, hexane, ethanol, and aqueous extracts of leaves of Stevia rebaudiana Bertoni against Staphylococcus aureus (strain 921), Staphylococcus epidermidis (strains 965, 982, and 735), and Pseudomonas aeruginosa (strains RO3 and RO4) was presented. The antibacterial activity was evaluated using the disk diffusion method, and the minimal inhibitory concentration (MIC) was determined. The results show that, even at the lowest evaluated concentration (1.06 mg/mL), the hexane extract had an inhibitory effect for all the studied microorganisms. The aqueous extract exhibited high inhibition values (84.4%), on S. epidermidis (strain 965). These results indicate that compounds contained in non-polar extracts of S. rebaudiana could be potential candidates as conventional pharmaceutical drugs against bacteria, resistant to conventional antibiotics"

Characterization of Polyphenolic Compounds from Bacopa procumbens and Their Effects on Wound-Healing Process

Wounds represent a medical problem that contributes importantly to patient morbidity and to healthcare costs in several pathologies. In Hidalgo, Mexico, the Bacopa procumbens plant has been traditionally used for wound-healing care for several generations; in vitro and in vivo experiments were designed to evaluate the effects of bioactive compounds obtained from a B. procumbens aqueous fraction and to determine the key pathways involved in wound regeneration. Bioactive compounds were characterized by HPLC/QTOF-MS, and proliferation, migration, adhesion, and differentiation studies were conducted on NIH/3T3 fibroblasts. Polyphenolic compounds from Bacopa procumbens (PB) regulated proliferation and cell adhesion; enhanced migration, reducing the artificial scratch area; and modulated cell differentiation. PB compounds were included in a hydrogel for topical administration in a rat excision wound model. Histological, histochemical, and mechanical analyses showed that PB treatment accelerates wound closure in at least 48 h and reduces inflammation, increasing cell proliferation and deposition and organization of collagen at earlier times. These changes resulted in the formation of a scar with better tensile properties. Immunohistochemistry and RT-PCR molecular analyses demonstrated that treatment induces (i) overexpression of transforming growth factor beta (TGF-β) and (ii) the phosphorylation of Smad2/3 and ERK1/2, suggesting the central role of some PB compounds to enhance wound healing, modulating TGF-β activation