Antibacterial properties of Persicaria minor (Huds.) ethanolic and aqueous-ethanolic leaf extracts.

Persicaria minor known as small water-pepper is used traditionally for the treatment of dandruffs and stomach indigestion. Therefore, this study was designed to evaluate the antibacterial activity of plant leaf material. 30% aqueous-ethanol and 100% aqueous were used for solvent extraction. Both extracts were evaluated for total protein and polysaccharide contents and results were compared. The extracts were then tested against four strains of bacteria; Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 11229, Staphylococcus aureus ATCC 6538and Pseudomonas aeruginosa ATCC 1544,at different concentrations using disc-diffusion and microplate dilution assays with penicillin being used as a positive control standard. Both extracts showed antibacterial activity against S. aureus, E. faecalis, and E. coli, respectively with aqueous-ethanolic extract being more potent. However, none of the extracts were active against P. aeruginosa. Results from this study truly illustrated high potential of P. minor leaves to be used topically as antibacterial agent for controlling of tested colony.

Inhibition of [[125]I] ET-1 binding to ETA receptors by salicylic acid dimers

Endothelin-1 [ET-1], a potent vasoconstrictor peptide, exerts its physiological effects by binding and activating specific G protein-coupled receptors, named ETA and ATB. A unique property of ET-1 is its ability to bind almost irreversibly to its receptors. Aspirin and salicylic acid [SA] are allosteric inhibitors of ET-1 binding to ETA receptors. Dihalogenated derivatives of SA have been identified as more potent allosteric inhibitors than aspirin. In this study, dihalosalicylic acid dimers were synthesized and tested as inhibitors of [[125]I] ET-1 binding to ETA receptors in rat embryonic cardiomyocyte [H9c2 cell] membranes in aim to development of new potential allosteric inhibitors of ET-1. Some dihalosalicylic acid dimers synthesized in this study showed promising activity as inhibitor of [[125]I] ET-1 binding to ETA receptors in comparing with the dihalosalicylic acid reported in literature. The bromo substituted compound b showed more remarkable activity than other halogen substituted dimers, it causes about 40% inhibition at 100 microM and causes 100% inhibition at 500 microM. We conclude that dihalosalicylic acid dimers can mediate good inhibition activity in comparison to sole dihalosalicylic acid molecule

Allosteric inhibition of [[125]I] ET-1 binding to ETA receptors by salicylic acid dimers

Endothelin-1 [ET-1], a potent vasoconstrictor peptide, exerts its physiological effects by binding and activating specific G protein-coupled receptors, named ETA and ETB. An unique property of ET-1 is its ability to bind almost irreversibly to its receptors. Aspirin and salicylic acid [SA] are allosteric inhibitors of ET-1 binding to ETA receptors. Dihalogenated derivatives of SA have been identified as more potent allosteric inhibitors than aspirin. In this study, dihalosalicylic acid dimers were synthesized and tested as inhibitors of [[125]I] ET-1 binding to ETA receptors in rat embryonic cardiomyocyte [H9c2 cell] membranes in aim to development of new potential allosteric inhibitors of ET-1. Some dihalo- salicylic acid dimers synthesized in this study showed promising activity as inhibitor of [[125]I] ET-1 binding to ETA receptors in comparing with the dihalosalicylic acid reported in literature, the bromo substituted compound B showed very interesting activity than other halogen substituted dimers, it causes about 40% inhibition at 100 microM and causes 100% inhibition at 500 microM. we conclude that dihalosalicylic acid dimers can mediate good inhibition activity in comparison to sole dihalosalicylic acid molecule