Effect of antibacterial steroid alkaloids from three Lorestan medicinal plants on gram-negative/positive bacteria

Abstract

Background: Alkaloids are a group of nitrogen- containing natural compounds derived from a variety of sources including bacteria, fungi, marine organisms and plants. Materials and methods: Fruits, stem or leaves were collected from the Zagros highlands around Azna or Khoramabad city, dried and powdered before being extracted in a soxhalet apparatus. The extract was filtered and concentrated under reduced pressure. After a series of extraction process, the materials were filtered the solvent was evaporated in order to reconstitute the extract in sterile normal saline. Antibacterial assays were performed using six standard (from ATCC) gram positive and gram-negative bacteria. Minimum Inhibitory (MIC) and Bactericidal Concentration (MBC) were examined by broth microdilution technique (1). The bacteria were cultured in Muller Hinton broth or agar (Merk, Germany) and growth (turbidity) or lack of growth was recorded. The experiments were repeated three times and means of values were reported. The results were compared with control antibiotics. Results: Alkaloid steroid extracted from sacchrarum officinarum showed significant activity against Entrococci fecalis and B. cerus (MIC = 40 and MBC = 600 µg/ml). Olenanthe fistulosa had moderate activity against E coli, E. fecalis, B. cerus and s. epidermidis (MIC and MBC = 600µg/ml). Physalis alkekengi was active only on a few bacteria including B. cerus and E. coli. No were effective against Staph aureous and P. aeroginosa. Conclusion: It is feasible to study in vitro effects of steroid alkaloid extracts from some of the plants on animal trial.