In vitro interference of Hyptis martiusii Benth. & chlorpromazine against an aminoglycoside - resistant Escherichia coli.

The antibacterial and synergistic activity of the ethanol extract from Hyptis martiusii Benth. was assayed by microdillution. The growth of two isolates of Escherichia coli tested was inhibited by the extract. The minimum inhibitory and minimum bactericidal concentrations (MIC and MBC) values ranged from 512 and >1024 μg/ml for the E. coli 27 and 1024 and > 1024 μg/ml for the E. coli ATCC8539, respectively. A synergism between this extract and all aminoglycosides assayed was demonstrated. In the same form synergism between chlorpromazine and kanamycin, amikacin and tobramycin was observed, indicating the involvement of an effl ux system. Extracts from H. martiusii could be used as a source of plant derived natural products with modifying antibiotic activity and these products may interact and affect multidrug resistance systems (MDR) as efflux pumps.

Interaction of chlorpromazine with low molecular mass ion-transporting ATPase modulator proteins from rat brain cytosol.

Two low molecular mass proteins (13 kDa which inhibits Na+,K(+)-ATPase and 12 kDa which modulates Ca2+, Mg(2+)- and Ca(2+)-ATPases), purified from rat brain cytosol form complexes with chlorpromazine (CPZ) on incubation. The conformational characteristics of the proteins and their complex have been studied by comparing the fluorescence and CD spectra. The tryptophan fluorescence data show that the inhibitor-CPZ complex does not quench the fluorescence of NA+,K(+)-ATPase significantly. CD spectra indicate that the structure of the inhibitor is changed on formation of the complex. The inhibitor-CPZ complex significantly changes the conformation of Na+,K(+)-ATPase. The regulator protein-CPZ complex does not have any appreciable effect on Ca2+, Mg(2+)- and Ca(2+)-ATPase activities. The Trp-fluorescence of Ca2+,Mg(2+)- and Ca(2+)-ATPase are not significantly affected in presence of the complex. CD spectra indicate that the structure of the regulator is abruptly affected on formation of the complex. The conformations of Ca2+,Mg(2+)- and Ca(2+)-ATPases are found to be altered in presence of the complex.

Interaction of chlorpromazine with hemoglobin.

Binding of chlorpromazine (CPZ), a widely used antidepressant tranquilizer, with hemoglobin has been studied by equilibrium dialysis method. r/Cf versus r plot was typically concave downwards revealing the positive cooperative nature of binding. Binding parameters, namely the affinity constant (K) and the degree of cooperativity (nH) were determined from the Hill plot. Oxygen was found to be released gradually from hemoglobin with gradual addition of CPZ, the extent of oxygen release depending on the stoichiometric ratio of CPZ: hemoglobin (D/P).

A dehydrogenase system to demonstrate oxidation of amphetamine and related compounds by rat brain homogenate.

Amphetamine, ephedrine, mescaline and chlorpromazine act as substrate for dehydrogenase system of rat brain homogenate. This system appears quite different from the usual deaminating process of these compounds, which required NADP and oxygen. The present system proceeds more rapidly in anaerobic condition.