Ameliorative effects of half-dose saffron and chamomile combination on Psycho-endocrinological changes in a diabetic murine model.

INTRODUCTION: Diabetes mellitus is a chronic metabolic disorder with an increasing prevalence worldwide. Reduction in blood insulin level alters brain function by inducing oxidative stress with changes in dopamine and norepinephrine neurotransmission, ultimately leading to neuropsychological symptoms. The efficacy of currently available psychotropic drugs is not satisfactory. Therefore, this study was conducted to explore the beneficial effects of a combination of the natural herbs, saffron and chamomile, in treating diabetes and its resultant neuropsychological effects using a rodent model of diabetes mellitus. METHOD: The rats were randomly divided in to eight groups (n = 10), healthy control (HC), diabetic control (DC) and six groups of diabetic rats treated with various concentrations and combinations of saffron and chamomile. Diabetic treatment groups individually received methanolic extract and water decoction of chamomile (30 mg/kg) and saffron (10mg/kg) and their combined half doses (saffron 5mg/kg and chamomile 15mg/kg) for two weeks. Open field test (OFT) and forced swim test (FST) were used to measure the anxiolytic and antidepressant effects of herbs, respectively. Finally, biochemical, and neurochemical estimations were made. RESULTS: The present study suggests the therapeutic effects of herbs especially in co-administrated decoction, against diabetes with improved antioxidant profile and enhanced levels of dopamine and norepinephrine. Anxiolytic and antidepressant effects were evident with improvements in the OFT and FST. Examination of the cortex of the diabetic group revealed cellular damage and tangle formation, which indicates advanced stages of dementia. CONCLUSION: This study shows that the use of a combination of saffron and chamomile improves diabetes control and reduces its related psychiatric effects.

Pyrazinamide Is Active against Mycobacterium tuberculosis Cultures at Neutral pH and Low Temperature.

For the past decades, an acidic pH has been used to render Mycobacterium tuberculosis susceptible to pyrazinamide for in vitro testing. Here, we show that at the standard breakpoint concentration and reduced culture temperatures, pyrazinamide (PZA) is active against tuberculosis (TB) at neutral pH. This finding should help unravel the mechanism of action of PZA and allow drug susceptibility testing (DST) methods to be optimized.

Direct drug susceptibility testing of Mycobacterium tuberculosis for rapid detection of multidrug resistance using the Bactec MGIT 960 system: a multicenter study.

Conventional indirect drug susceptibility testing of Mycobacterium tuberculosis with liquid medium is well established and offers time-saving and reliable results. This multicenter study was carried out to evaluate if drug susceptibility testing (DST) can be successfully carried out directly from processed smear-positive specimens (direct DST) and if this approach could offer substantial time savings. Sputum specimens were digested, decontaminated, and concentrated by the laboratory routine procedure and were inoculated in Bactec MGIT 960 as well as Lowenstein-Jensen (LJ) medium for primary isolation. All the processed specimens which were acid-fast bacterium (AFB) smear positive were used for setting up direct DST for isoniazid (INH) and rifampin (RIF). After the antimicrobial mixture of polymyxin B, amphotericin B, nalidixic acid, trimethoprim, and azlocillin (PANTA) was added, the tubes were entered in the MGIT 960 instrument using the 21-day protocol (Bactec 960 pyrazinamide [PZA] protocol). Results obtained by direct DST were compared with those obtained by indirect DST to establish accuracy and time savings by this approach. Of a total of 360 AFB smear-positive sputum specimens set up for direct DST at four sites in three different countries, 307 (85%) specimens yielded reportable results. Average reporting time for direct DST was 11 days (range, 10 to 12 days). The average time savings by direct DST compared to indirect DST, which included time to isolate a culture and perform DST, was 8 days (range, 6 to 9 days). When results of direct DST were compared with those of indirect DST, there was 95.1% concordance with INH and 96.1% with rifampin. These findings indicate that direct DST with the Bactec MGIT 960 system offers further time savings and is a quick method to reliably detect multidrug resistance (MDR) cases.

In vitro antituberculosis activities of the constituents isolated from Haloxylon salicornicum.

In vitro antituberculosis activities of fractions and pure compounds (1-20) including seven triterpenes, two alkaloids, two cycloheximide derivatives, two coumarins six sterol derivatives and a long chain alcohol, respectively, isolated from Haloxylon salicornicum were determined against Mycobacterium tuberculosis H37Rv. Actively growing cultures were tested by rapid colorimetric method while the stationary phase cultures were tested by drug exposure methods for bactericidal activity. The MIC values were found to be 50 microg/ml for compounds 15, 19 and 20 where as rest of the compounds invariably showed MIC value of 100 microg/ml against the logarithmic phase culture. These were compare to Isoniazid as a control drug. The compounds exhibited no activity against the stationary phase culture of M. tuberculosis H37Rv up to 200 microg/ml. Further studies are required to investigate the in vivo efficacies and activities of the compounds in combination with antimicrobials that are already being used for TB therapy.

Multicenter evaluation of Bactec MGIT 960 system for second-line drug susceptibility testing of Mycobacterium tuberculosis complex.

The Bactec MGIT 960 system for testing susceptibility to second-line drugs was evaluated with 117 clinical strains in a multicenter study. The four drugs studied were levofloxacin, amikacin, capreomycin, and ethionamide. The critical concentration established for levofloxacin and amikacin was 1.5 microg/ml, that established for capreomycin was 3.0 microg/ml, and that established for ethionamide was 5.0 microg/ml. The overall level of agreement between the agar proportion method and the MGIT 960 system was 96.4%, and the levels of agreement for the individuals drugs were 99.1% for levofloxacin, 100% for amikacin, 97.4% for capreomycin, and 88.9% for ethionamide. The rate of reproducibility of the drug susceptibility testing results between the participating laboratories was 99.5%.

Isoniazid induces its own resistance in nonreplicating Mycobacterium tuberculosis.

Isoniazid (INH) resistance is most frequent among drug-resistant Mycobacterium tuberculosis clinical isolates. This study was conducted to investigate whether INH could induce its own resistance. During INH susceptibility testing in BACTEC 12B and MGIT 960 media, weekly subcultures were made from the drug-containing media into fresh medium without drug and susceptibility testing was performed. Rifampin (RIF) was used as a control drug. M. tuberculosis H37Rv and three clinical isolates were tested in this study. INH-resistant subcultures were analyzed for catalase activity, INH susceptibility, and mutations associated with INH resistance. With inoculum size (10(4) bacilli) smaller than a size that contains spontaneously INH-resistant mutants, INH was found to induce resistance to itself in INH-tolerant persisters but not to other drugs. The minimum time required for induction of INH resistance was 5 to 6 days. In contrast, RIF did not induce RIF resistance. Eight subcultures with INH-induced resistance were analyzed, and two had a MIC of 0.4 microg/ml INH and six had MICs of over 2 microg/ml INH. Four of the eight subcultures with INH-induced resistance had lost catalase activity, with three having katG mutations. Despite being a powerful frontline tuberculosis drug, INH has the potential drawback of inducing its own stable genetic resistance in INH-tolerant persisters. This finding helps to explain the higher frequency and prevalence of INH-resistant isolates than isolates with resistance to other drugs in patients.

Multicenter laboratory validation of the BACTEC MGIT 960 technique for testing susceptibilities of Mycobacterium tuberculosis to classical second-line drugs and newer antimicrobials.

The BACTEC MGIT 960 system, a fully automated, nonradiometric, noninvasive system for detection and drug susceptibility testing of mycobacteria, was evaluated for the ability to test susceptibilities to second-line drugs. In this study, which was carried out in three phases (phase I, mostly susceptible strains; phase II, mostly resistant strains; phase III, final testing of the optimal drug concentrations found in phases I and II), we established the critical concentrations for seven drugs to be tested in the BACTEC MGIT 960 system compared to the BACTEC 460TB system. The critical concentrations for the seven drugs used in the MGIT 960 system are as follows: amikacin, 1.0 microg/ml; capreomycin, 2.5 microg/ml; ethionamide, 5.0 microg/ml; protionamide, 2.5 microg/ml; ofloxacin, 2.0 microg/ml; rifabutin, 0.5 microg/ml; linezolid, 1.0 microg/ml. Our results demonstrate that the BACTEC MGIT 960 system is an accurate method for rapid testing of the susceptibilities of Mycobacterium tuberculosis to second-line drugs.

Identification of a Mycobacterium tuberculosis strain with stable, low-level resistance to isoniazid.

We have identified a potential quality control strain of Mycobacterium tuberculosis to monitor isoniazid susceptibility testing. This strain (strain A) has a stable phenotypic low-level resistance to isoniazid, has a mutation of C (-15) --> T in the inhA promoter region, and gave consistent susceptibility test results in 141 laboratories.

New simple and rapid test for culture confirmation of Mycobacterium tuberculosis complex: a multicenter study.

Mycobacterial antigen MPB64 has been identified as a Mycobacterium tuberculoisis complex-specific secretory protein since 1984. Recently, a simple culture confirmation test for M. tuberculosis complex has been developed by using lateral flow immunochromatographic assay (ICA) to detect MPB64 with anti-MPB64 monoclonal antibody. The current multicenter study evaluated the performance of an ICA slide test for MPB64 antigen in the clinical setting. Primary positive cultures from clinical specimens, as well as stock cultures, were tested. Approximately 100 microl of positive liquid culture medium or suspension made from colonies on solid medium was placed into the test well of the plastic slide devise, and the test was read after 15 min. No processing or instrumentation was required. A total of 304 mycobacterial isolates consisting of M. tuberculosis complex (171 isolates) and mycobacteria other than M. tuberculosis (MOTT) complex (133 isolates) belonging to 18 different species were tested. Growth in liquid media (Mycobacteria Growth Indicator Tube [MGIT] and Radiometric 12B), as well as in solid (Löwenstein-Jensen and Middlebrook 7H10 agar) media, was evaluated. Results were compared with those obtained with nucleic acid-based and/or high-pressure liquid chromatography identification. All MOTT were found to be negative on the ICA slide with no cross-reaction. All M. tuberculosis and M. africanum cultures were found to be positive, whereas the results of M. bovis and M. bovis BCG cultures were variable since some of the BCG strains are known to lack MPB64 antigen production. The results did not change with prolonged storage of cultures. This low-tech rapid test with high sensitivity and specificity could provide an alternative to currently available identification methods, particularly for recently introduced nonradiometric liquid culture systems such as MGIT.