Design, synthesis, and evaluation of substituted 2-acylamide-1,3-benzo[d]zole analogues as agents against MDR- and XDR-MTB

N-(5-Chlorobenzo[d]oxazol-2-yl)-4-methyl-1,2,3-thiadiazole-5-carboxamideox-amide has been identified as a potent inhibitor of Mtb H37Rv, with a minimum inhibitory concentration (MIC) of 0.42 μM. In this study, a series of substituted 2-acylamide-1,3-zole analogues were designed and synthesized, and their anti-Mtb activities were analyzed. In total, 17 compounds were found to be potent anti-Mtb agents, especially against the MDR- and XDR-MTB strains, with MIC values < 10 μM. These analogues can inhibit both drug-sensitive and drug-resistant Mtb. Four representative compounds were selected for further profiling, and the results indicate that compound 18 is acceptably safe and has favorable pharmacokinetic (PK) properties. In addition, this compound displays potent activity against Gram-positive bacteria, with MIC values in the range of 1.48-11.86 μM. The data obtained herein suggest that promising anti-Mtb candidates may be developed via structural modification, and that further research is needed to explore other compounds.

Rapid and highly sensitive quantification of the anti-tuberculosis agents isoniazid, ethambutol, pyrazinamide, rifampicin and rifabutin in human plasma by UPLC-MS/MS

With the increased cases of multidrug- or rifampicin-resistant tuberculosis and co-infection with HIV globally, it is difficult to achieve ideal clinical responses because of poor drug absorption and drug-drug interactions. Herein, a bioanalytical UPLC-MS/MS method was developed and validated to quantify five anti-TB agents in human plasma samples for detecting blood drug concentrations to improve therapeutic effects. To overcome the matrix effects, stable isotope labeled analogue of each analyte was used for internal standardization. A simple single-step protein precipitation by acetonitrile was employed for the sample preparation, then the analytes including rifampicin, rifabutin, pyrazinamid, ethambutol, isoniazid and their isotope labeled internal standards (ILISs) were implemented on an HILIC silica column with a gradient mode. The linear range for each analyte was covering the peak drug concentration (C_max) in the 20 times diluted plasma samples. The coefficient of variation of intra- and inter-day precision was less than 17.0 %, and the accuracy ranged between 91.5 and 110.0 %. The extraction recoveries of all agents were ≥90.2 %, and the matrix effects with internal standard-normalization for all agents were 97.1-110.0 %. The optimal blood sampling time was designed basing on the results of stability validation. This UPLC-MS/MS method with a run time of 3.5 min was successfully applied to routine therapeutic monitoring of the five anti-TB agents in patient plasma.

Monoammonium glycyrrhizinate protects rifampicin- and isoniazid-induced hepatotoxicity via regulating the expression of transporter Mrp2, Ntcp, and Oatp1a4 in liver

CONTEXT

Drug-induced liver injury (DILI) is associated with altering expression of hepatobiliary membrane transporters. Monoammonium glycyrrhizin (MAG) is commonly used for hepatic protection and may have a correlation with the inhibition effect of multidrug resistance-associated protein 2 (Mrp2).

OBJECTIVE

This study evaluates the dynamic protective effect of MAG on rifampicin (RIF)- and isoniazid (INH)-induced hepatotoxicity in rats.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into four groups of 15 rats. Liver injury was induced by co-treatment with RIF (60 mg/kg) and INH (60 mg/kg) by gavage administration; MAG was orally pretreated at the doses of 45 or 90 mg/kg 3 h before RIF and INH. Rats in each group were sacrificed at 7, 14, and 21 d time points after drug administration.

RESULTS

Liver function, histopathological analysis, and oxidative stress factors were significantly altered in each group. The expression of Mrp2 was significantly increased 230, 760, and 990% at 7, 14, and 21 time points, respectively, in RIF- and INH-treated rats. Compared with the RIF and INH groups, Mrp2 was reduced and Ntcp was significantly elevated by 180, 140, and 160% in the MAG high-dose group at the three time points, respectively. The immunoreaction intensity of Oatp1a4 was increased 170, 190, and 370% in the MAG low-dose group and 160, 290, and 420% in the MAG high-dose group at the three time points, respectively, compared with the RIF and INH groups.

DISCUSSION AND CONCLUSION

These results indicated that MAG has a protective effects against RIF- and INH-induced hepatotoxicity. The underlying mechanism may have correlation with its effect on regulating the expression of hepatobiliary membrane transporters.