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Biomedical subjects

B Ali

Publications and source records attributed to B Ali.

At least 55 records · Page 3Linked to original sources
PubMed1983

Selective induction of xenobiotic metabolizing esterases/amidases of liver by methaqualone consumption.

The present investigation reports the influence of po and ip methaqualone administration on the hydrolytic metabolism of acetylsalicylic acid, procaine, p-nitrophenylacetate, acetanilid, and butyrylcholine in the liver, kidney, and brain of male rats. Oral administration of methaqualone (60 mg/kg/day) to rats for 20 days caused 41.0, 46.5, and 55.0% stimulation of acetylsalicyclic acid esterase I, acetylsalicyclic acid esterase II, and acetanilid N-deacetylase, respectively, in the liver. Under such conditions, the activities of other esterases remained unaffected. The responses of tissue esterases to ip methaqualone treatment (40 mg/kg/day for 6 days) were similar to those observed after po methaqualone administration. Since a single po dose of methaqualone failed to produce any alteration in the rate of metabolism of acetylsalicylic acid, procaine, p-nitrophenylacetate, acetanilid, and butyrylcholine within 20 hr, it may be interpreted that the stimulation of acetylsalicylic acid and acetanilid metabolism is possibly due to selective enhanced de novo synthesis of the enzymes/isozymes necessary for the hydrolysis of the two drugs. The ability of the kidney and brain to metabolize the esters/amides was not modified by po or ip methaqualone pretreatment suggesting the possibility of noninducible forms of renal and neuronal esterases/amidases.

Amidohydrolases↗
PubMed1982

Stimulation of drug and carcinogen metabolism by prolonged oral tobacco consumption.

Oral administration of tobacco to rats for 21 days caused remarkable stimulation of the metabolism of phenacetin, aniline and benzo[a]pyrene, a carcinogen, by hepatic microsomal mixed function oxidases (MFO). Such treatment for 6 days resulted in a small increase in the activities of phenacetin O-dealkylase and aromatic hydrocarbon hydroxylase (AHH) without affecting aniline hydroxylase activity. Nicotine given orally was found to be a relatively weak inducer of phenacetin O-dealkylase and aniline hydroxylase, and elicited a maximum increase in their activities within 6 days which remained unchanged even after 21 days of continuous administration. However, these two enzyme systems were not affected following only one or two doses of tobacco and nicotine. Both tobacco and nicotine inhibited these biotransformations in vitro.

Animals↗
PubMed1982

Effect of anti-inflammatory thiosemicarbazone indoles on hyaluronidase, acid phosphatase and trypsin.

The present study was designed to evaluate the molecular basis of anti-inflammatory effects of nine 2-aryl-3-[4-(substituted phenyl)-3-thiosemicarbazone] indoles and their interaction with lysosomal and proteolytic enzymes. All compounds exhibited anti-inflammatory activity, which was reflected by 5-67% reduction in carrageenin-induced oedema in rat. Substituted thiosemicarbazone indoles caused concentration-dependent inhibition of hyaluronidase activity in vitro while the activities of acid phosphatase and trypsin were unaltered. Substitution of the aryl group attached to indole moiety resulted in a 2- to 3-fold increase in hyaluronidase inhibition by these compounds. Preincubation of the compounds with hyaluronidase produced time-dependent inactivation of the enzyme. Determination of enzyme inhibition kinetics with 2-aryl-3-[4-(2-methylphenyl)-3-thiosemicarbazone] indole by Lineweaver-Burk and Dixon plots indicated competitive nature of hyaluronidase-compound interaction. These studies failed to demonstrate any definite relationship between anti-inflammatory activity and hyaluronidase inhibition.

Acid Phosphatase↗
PubMed1982

Membrane stabilization and inhibition of lipid peroxidation by anti-inflammatory indoles.

Nine 2-aryl-3-[4-(substituted phenyl)-3-thiosemicarbazone] indoles were evaluated for their ability to protect the human erythrocyte membrane against hypo-osmotic hemolysis and inhibit lipid peroxidation in rat liver homogenate in vitro. All compounds caused membrane stabilization and inhibition of lipid peroxidation when tested at final concentrations of 5 X 10(-4) and 2.5 X 10(-5) mol/l, respectively. These biochemical effects were not related to the anti-inflammatory property exhibited by the compounds.

Animals↗
PubMed1982

Induction of hepatic UDP-glucuronyltransferase by oral methaqualone consumption.

Repeated oral administration of methaqualone (100 mg/kg/day) to rats for 6 consecutive days evoked approximately two and a half fold increase in p-nitrophenol glucuronidation by hepatic microsomes. Interestingly, the magnitude of UDP-glucuronyltransferase stimulation by methaqualone, when assessed in crude liver homogenate, was comparable to that obtained with isolated microsomes.

Administration, Oral↗
PubMed1980

Differential stimulation of diphenhydramine, pethidine, morphine and aniline metabolism by chronic methaqualone treatment.

In the present study, the effect of chronic oral methaqualone treatment (60 mg/kg/24 h for 25 days) was examined on the metabolism of diphenhydramine, pethidine, morphine and aniline in rat liver microsomes. Such chronic methaqualone treatment caused an enhancement of microsomal drug metabolizing enzymes catalyzed N-demethylations of diphenhydramine, pethidine, morphine and aromatic hydroxylation of aniline. A single oral dose of methaqualone (60 mg/kg) did not result in any significant change in the activities of drug metabolizing enzymes. Methaqualone inhibited drug metabolizing enzymes when used at final concentrations of 1 and 3 mmol/l in vitro. These observations led to suggest that the stimulation of drug metabolism noted in this study is possibly due to the induction of microsomal drug metabolizing enzymes. It was interesting to note that the induction of N-demethylases by repeated methaqualone intake was differential in nature since diphenhydramine and morphine N-demethylases were induced about twofold whereas pethidine N-demethylase was enhanced about fourfold. These results should be of extreme importance in understanding the biochemical mechanism of the specific and differential drug tolerance by continued methaqualone abuse and its possible interaction with other drugs.

Aniline Compounds↗
PubMed1979

Monoamine oxidase inhibition by substituted benzylideneamino guanidines and their CNS activities.

The present study reports the synthesis and characterization of eight new substituted benzylideneamino guanidines. All compounds inhibited the monoamine oxidase (MAO) activity of rat brain mitochondria in vitro. The I50 values were determined and were found to be in the range of 10(-4) to 10(-5) mol/l. Preincubation, dialysis and kinetic studies carried out with isolated brain mitochondria by conventional Dixon plot revealed reversible and noncompetitive type of MAO inhibition. These compounds were also screened for anticonvulsant and antidepressant activities. In the present series of compounds only one compound -- 1-amino-3-(4-chloromethylbenzylidene-amino)guanidine hydroiodide -- was found to afford 20% protection against pentetrazol-induced seizures in mice. 1-Amino-3-(3,4-dichlorobenzylideneamino)guanidine hydroiodide which produced maximum inhibition of MAO activity, also produced reversal of reserpine-induced sedation and miosis into excitation and mydriasis in mice.

Animals↗
PubMed1978

Selective inhibition of xanthine oxidase by substituted pyridopyrimidines.

Six 2-methyl-3-substituted-pyrido-(2,3-d)-pyrimidine 4 (3H)-ones were synthesized and evaluated for their ability to inhibit xanthine oxidase and other purine catabolizing enzymes of rat liver. All compounds inhibited xanthine oxidase selectively when tested at a final concentration of 0.5 mM in vitro. Adenosine deaminase, guanosine deaminase and guanine deaminase were unaffected. The inhibition of xanthine oxidase was found to be competitive in nature.

Aminohydrolases↗