Influence of enhancers on the absorption and on the pharmacokinetics of cefodizime using in-vitro and in-vivo models

Antibiotic Followed by a Potential Probiotic Increases Brown Adipose Tissue, Reduces Biometric Measurements, and Changes Intestinal Microbiota Phyla in Obesity

The development of adjuvant therapies for obesity treatment is justified by the high prevalence of this disease worldwide, and the relationship between obesity and intestinal microbiota is a promising target for obesity treatment. Therefore, this study aimed at investigating the adjuvant treatment of obesity through the use of potential probiotics and antibiotics, either separately or sequentially. In the first phase of the experiment, animals had diet-induced obesity with consumption of a high saturated fat diet and a fructose solution. After this period, there was a reduction in caloric supply, that is the conventional treatment of obesity, and the animals were divided into 5 experimental groups: control group (G1), obese group (G2), potential probiotic group (G3), antibiotic group (G4), and antibiotic followed by potential probiotic group (G5). The adjuvant treatments lasted 4 weeks and were administered daily, via gavage: Animals in G1 and G2 received distilled water, the G3 obtained Lactobacillus gasseri LG-G12, and the G4 received ceftriaxone. The G5 received ceftriaxone for 2 weeks, followed by the offer of Lactobacillus gasseri LG-G12 for another 2 weeks. Parameters related to obesity, such as biometric measurements, food consumption, biochemical tests, histological assessments, short-chain fatty acids concentration, and composition of the intestinal microbiota, were analyzed. The treatment with caloric restriction and sequential supply of antibiotics and potential probiotics was able to reduce biometric measures, increase brown adipose tissue, and alter the intestinal microbiota phyla, standing out as a promising treatment for obesity.

Enhanced antibacterial effect of ceftriaxone sodium-loaded chitosan nanoparticles against intracellular Salmonella typhimurium

The aim of the present study was to utilize chitosan (CS) nanoparticles for the intracellular delivery of the poorly cell-penetrating antibiotic, ceftriaxone sodium (CTX). In vitro characterization of (CTX-CS) nanoparticles was conducted leading to an optimized formula that was assessed for its biocompatibility to blood (hemolysis test) and cells (MTT assay). Progressively, confocal laser scanning microscopy (CLSM), cellular uptake (microfluorimetry), and antibacterial activity of the nanoparticles were investigated in two cell lines: Caco-2 and macrophages J774.2 pre-infected with Salmonella typhimurium. Results showed that the optimized formula had size 210 nm, positive zeta potential (+30 mV) and appreciable entrapment efficiency for CTX (45%) and included a biphasic release pattern. The nanoparticles were biocompatible and were internalized by cells as verified by CLSM whereas microfluorimetry indicated substantial cellular uptake. Moreover, the CTX-chitosan nanoparticles showed a significant reduction in the count of intracellular S. typhimurium in Caco-2 and macrophages J774.2. This reduction was significantly higher than that obtained in case of placebo nanoparticles, CTX, and CTX-chitosan solutions and might be attributed to enhanced endocytic uptake of the nanoaprticles and antibacterial effect of the chitosan polymer. In conclusion, the results provide evidence for the potential use of chitosan nanoparticles to enhance the intracellular delivery and antibacterial effect of CTX in enterocytes and macrophages.

Thalidomide, dexamethasone and lovastatin with autologous stem cell transplantation as a salvage immunomodulatory therapy in patients with relapsed and refractory multiple myeloma

The treatment of patients with multiple myeloma usually includes many drugs including thalidomide, lenalidomide and bortezomib. Lovastatin and other inhibitors of HMG-CoA reductase demonstrated to exhibit antineoplasmatic and proapoptotic properties in numerous in vitro studies involving myeloma cell lines. We treated 91 patients with relapsed or refractory multiple myeloma with thalidomide, dexamethasone and lovastatin (TDL group, 49 patients) or thalidomide and dexamethasone (TD group, 42 patients). A clinical response defined of at least 50% reduction of monoclonal band has been observed in 32% of TD patients and 44% of TDL patients. Prolongation of overall survival and progression-free survival in the TDL group as compared with the TD group has been documented. The TDL regimen was safe and well tolerated. The incidence of side effects was comparable in both groups. Plasma cells have been cultured in vitro with thalidomide and lovastatin to assess the impact of both drugs on the apoptosis rate of plasma cells. In vitro experiments revealed that the combination of thalidomide and lovastatin induced higher apoptosis rate than apoptosis induced by each drug alone. Our results suggest that the addition of lovastatin to the TD regimen may improve the response rate in patients with relapsed or refractory myeloma.

Lovastatin and thalidomide have a combined effect on the rate of multiple myeloma cell apoptosis in short term cell cultures

OBJECTIVE

Multiple myeloma is characterized by an accumulation of plasma cells in bone marrow. Despite many therapeutic regimens introduced recently, the prognosis for patients suffering from treatment-resistant or relapsing multiple myeloma is still very poor. Thus, there is an urgent medical need for novel innovative drugs. Thalidomide is successfully used in resistant or relapsing myeloma patients, being reported to induce apoptosis or G1 growth arrest of myeloma cells and to regulate microvessel density and cytokine secretion. Lovastatin, largely used for the treatment of hypercholesterolemia, is another promising drug in multiple myeloma. High doses of lovastatin have been shown to have antiproliferative effect by inhibition of malignant cell proliferation and inducing programmed cell death.

METHODS

In this study, we tried to assess whether thalidomide and lovastatin had a combined effect on apoptosis of myeloma cells. We analyzed apoptosis induced by mixture of these two drugs in short-term cell culture of myeloma plasmocytes. To assess apoptosis, we used Annexin V and propidium iodide binding. We also examined the regulation of BCL-2 and BAX protein expression in the population of CD138+ plasmocytes. The cells were analyzed with the use of flow cytometry technique. The experiments were done before and after 72 h of cell culture.

RESULTS

We detected a higher rate of apoptosis induced by lovastatin and thalidomide mixture in comparison to apoptosis induced by lovastatin or thalidomide alone. In most patients, the BCL-2/BAX ratio was lower in cell cultures supplemented with mixture of lovastatin and thalidomide in comparison with cell cultures supplemented with lovastatin or thalidomide alone.

CONCLUSION

Based on our research we conclude that the mixture of lovastatin and thalidomide may increase the rate of multiple myeloma cells apoptosis in comparison to the single drug and the precise mechanism of this effect should be approved by further research.

Influence of absorption enhancers on the pharmacokinetic properties of non-oral beta-lactam-cefpirom using the rabbit (Chinchilla) in vivo model

The oral application is the application of the first choice for drug administration. A lot of drugs exhibit relatively low bioavailability. This may be caused by binding of the drug in the gastro-intestinal tract, by poor penetration of the intestinal mucose or by highly hydrophilic properties. Therefore, problem drugs were only used for i.v. administration (intravenously) or for i.m. administration (intramuscularly). In the present study, cefpirom was investigated as a model substance. Cefpirom (Cp) is a semi-synthetic amino-2-thiazolyl-methoxyimino cephalosporin. It exhibits highly hydrophilic properties (P(ow)=0.02+/-0.01) and a very low bioavailability (AUC=524+/-403 microg min/ml). It was only applied i.v. or i.m. In this work, the influence of absorption enhancers (aggregation and ion-pair formation) on the bioavailability and on the hydrophilic properties of Cp was investigated. The bioavailability of cefpirom was improved through the combination with absorption enhancers (hexadecyldimethylbenzylammonium chloride, BAC; hexylsalicylic acid, HSA). The absolute bioavailability of the Cp combination with absorption enhancers was 21 times larger for BAC and 15 times larger for HSA than in the case when Cp was used alone.