Rats were treated with Dextramycin 0.05-1.0 mg/g.

Antibacterial activity was screened against two Gram positive (Staphylococcus aureus MTCC 96, Streptococcus pyogenes MTCC 442) and two Gram negative (Escherichia coli MTCC 443, Pseudomonas aeruginosa MTCC 441) bacteria by using gentamycin, ampicillin, chloramphenicol, ciprofloxacin, norfloxacin as a standard antibacterial agents. Serial dilutions were prepared in primary and secondary screening. The control tube containing no antibiotic was immediately subcultured (before inoculation) by spreading a loopful evenly over a quarter of plate of medium suitable for the growth of the test organism and put for incubation at 37 C overnight. The tubes were then incubated overnight. The MIC of the control organismwas read to check the accuracy of the drug concentrations. The lowest concentration inhibiting growth of the organism was recorded as the MIC. All the tubes not showing visible growth (in the same manner as control tube described above) was subcultured and incubated overnight at 37 C. The amount of growth from the control tube before incubation (which represents the original inoculum) was compared. Subcultures might show: similar number of colonies indicating bacteriostatic; a reduced number of colonies indicating a partial or slow bactericidal activity and no growth if the whole inoculum has been killed. The test must include a second set of the same dilutions inoculated with an organism of known sensitivity. Each synthesized drug was diluted obtaining 2000 mg/mL concentration, as a stock solution. In primary screening 500, 250 and 125 mg/mL concentrations of the synthesized drugs were taken. The active synthesized drugs found in this primary screening were further tested in a second set of dilution against all microorganisms. The drugs found active in primary screening were similarly diluted to obtain 100, 50, 25, 12.5, 6.250, 3.125 and 1.5625 mg/mL concentrations. The highest dilution showing at least 99% inhibition is taken as MIC.