Efficacy of Biodegradable Lipid Glyceryl Monostearate Lipomer of Dosyclycline Against Brucella Abortus
| dc.contributor.advisor | Bannalikar, A. S. | |
| dc.contributor.author | Mhase, P. P. | |
| dc.date.accessioned | 2017-06-13T10:17:57Z | |
| dc.date.available | 2017-06-13T10:17:57Z | |
| dc.date.issued | 2012 | |
| dc.description.abstract | The efficacy of doxycycline hydrochloride (DH), doxycycline hydrochloride lipomer (DH LNP), rifampicin (RIF), rifampicin entrapped in polymer Gantrez 119 (NP RIF) and the combinations of these drug formulations against B. abortus was evaluated in vitro in U937 human macrophage cell line and in vivo in mice. All the drug formulations were subjected to cytotoxicity assays, uptake studies and estimation of minimum inhibitory concentration (MIC) before taking up efficacy studies. The assessment of cytotoxicity by MTT assay and trypan blue dye exclusion technique revealed that the maximum non-toxic concentration of DH was 5 μg/ml whereas that of DH LNP was 2 μg/ml. The maximum non-toxic concentration of RIF was 10 μg/mL while that of NP RIF 5 μg/mL. The maximum non-toxic concentration of combinations DH + RIF and DH LNP + NP RIF DH + RIF was 20 μg/mL Both the methods i.e. MTT assay and trypan blue dye exclusion technique yielded similar results and were found equally suitable. The minimum inhibitory concentration (MIC) of the drug formulations against B. abortus was estimated by resazurin microtitre assay (REMA) and broth microdilution method (BMM). The MIC of DH, DH LNP, RIF, NP RIF and DH + RIF was 0.5 μg/ml while that of combination DH LNP + NP RIF was 0.25 μg/ml. The results of MIC produced by both the methods, REMA and BMM were concordant with each other. The studies on uptake of the nanoparticulate drugs by the macrophages by fluorescence microscopy revealed that at higher doses the formulations were taken up rapidly while the uptake was poor at lower concentrations. All the formulations attained optimum intracellular concentration at 1 μg/ml between 30 to 60 min. Evaluation of in vitro efficacy DH and DH LNP against B. abortus in macrophages revealed that the reduction in log10 cfu/ml values achieved in DH treated cells was slightly greater that that of DH LNP treated cells. The DH LNP thus did not prove adequately effective in reducing the intracellular B. abortus. The RIF and NP RIF both caused significant reduction in the intracellular B. abortus counts at all the concentrations tested. Comparison of log10 reduction values by unpaired ‘t’ test revealed that the reduction in intracellular B. abortus counts achieved by NP RIF was significantly greater than that of RIF at all the doses ranging from 0.250 – 4 μg / ml. The results thus revealed a definite superiority of NP RIF over RIF in clearance of intracellular B. abortus. The combinations of DH + RIF and DH LNP + NP RIF were found effective against B. abortus and caused significant reduction in intracellular counts as compared to untreated control. The comparison of results of DH + RIF and DH LNP + NP RIF unpaired ‘t’ test revealed that the log10 reductions achieved in the cells treated DH LNP + NP RIF were significantly higher than those of DH + RIF treated cells at all the concentrations tested. Overall comparison of the values of log10 reductions achieved in response to treatment with different drug formulations revealed that the greatest log10 reduction in intracellular B. abortus counts was evident in cells treated with NP RIF followed by those treated with DH LNP + NP RIF. The drug formulations next in order in terms of efficacy were plain RIF and combination of DH + RIF. The evaluation of in vivo efficacy of DH and DH LNP in mice revealed that the reduction in splenic B. abortus counts achieved with both the treatments was almost equal. The DH LNP treatment thus did not prove superior to DH. The RIF and NP RIF both caused reduction in mean log10 cfu per spleen values as compared to untreated control mice. The comparison of log10 reduction between RIF and NP RIF treated mice revealed that the reduction achieved in NP RIF treated mice was significantly greater (over two fold) than that of RIF treated mice. Evaluation of in vivo efficacy of combination RIF + NP RIF revealed that there was a complete clearance of B. abortus from spleens of infected mice. Comparison of log10 reductions achieved in spleens of mice treated RIF and RIF + NP RIF revealed that the reduction in RIF + NP RIF treated mice was significantly higher (4.5294+ 0.001) causing complete clearance of B. abortus from spleens. The combination RIF + NP RIF thus could be of potential value in therapeutic management of brucellosis in animals and human. The future research should focus on evaluation of RIF + NP RIF combination in clinical cases of brucellosis in animals. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810019835 | |
| dc.keywords | Efficacy of Biodegradable Lipid Glyceryl Monostearate Lipomer of Dosyclycline Against Brucella Abortus | en_US |
| dc.language.iso | en | en_US |
| dc.pages | 187 | en_US |
| dc.publisher | MAFSU, Nagpur | en_US |
| dc.sub | Veterinary Microbiology | en_US |
| dc.subject | null | en_US |
| dc.theme | Efficacy of Biodegradable Lipid Glyceryl Monostearate Lipomer of Dosyclycline Against Brucella Abortus | en_US |
| dc.these.type | Ph.D | en_US |
| dc.title | Efficacy of Biodegradable Lipid Glyceryl Monostearate Lipomer of Dosyclycline Against Brucella Abortus | en_US |
| dc.type | Thesis | en_US |