Protective effect of liposomal formulation of tuftsin (a naturally occurring tetrapeptide) against cyclophosphamide-induced genotoxicity and oxidative stress in mice

Tuftsin, a naturally occurring tetrapeptide with a sequence Thr-Lys-Pro-Arg was evaluated for its in vivo protective effect against cyclophosphamide-induced genotoxicity and oxidative stress in Swiss albino mice. The anticancer drug cyclophosphamide (CP) was administered intra-peritonially to induce mutagenic effect. The drug treatment caused significant increase in chromosomal aberrations, formation of micronucleated polychromatic erythrocytes (MNPCE's), as well as oxidative stress and decrease in lipid peroxidation in liver of the animals. The pretreatment with tuftsin abolished such effects in dose-dependent manner and also increased mitotic index in the experimental animals. Results of the present study validated chemo-preventive properties of tuftsin against CP-induced chromosomal mutations and cellular injury of liver by oxidative stress.

Comparison of the antidiabetic activity of Berberis lyceum root extract and berberine in alloxan-induced diabetic rats

Berberine has been shown to have hypoglycaemic activity in several in vitro and in vivo models, although the mechanism of action is not fully known. Berberis lyceum Royle root produces high concentrations of berberine, and in traditional medicine, the whole extract of this plant is used widely to treat diabetes. The antidiabetic activity of the ethanol root extract of Berberis lyceum was compared with pure berberine in normal and alloxan-diabetic rats using similar doses of each. The concentration of berberine in the extract was determined to be 80% dry weight with only trace amounts of other alkaloids present. The purpose of the study was to investigate the effects of berberine and a whole extract of Berberis lyceum on blood glucose and other parameters associated with diabetes, to compare the effects of the crude extract with those of pure berberine and thus validate its use as a therapeutic agent, and finally to identify any contribution of the other components of the extract to these effects. Oral administration of 50 mg/kg of Berberis extract and berberine to normal and experimental diabetic rats produced a significant (p < 0.05) reduction in blood glucose levels from days 3-7 days of treatment. Significant effects were also observed on the glucose tolerance, glycosylated haemoglobin, serum lipid profiles and body weight of experimental animals. Berberis extract and berberine demonstrated similar effects on all parameters measured, and although the extract was comparable in efficacy to berberine, it did not produce any effects additional to those shown by pure berberine. The results support the use of the extract in traditional medicine, and demonstrate that apart from being a highly cost-effective means of treating with berberine, the total extract does not appear to confer any additional benefits or disadvantages compared with the pure compound.

Syntheses and anthelmintic activity of alkyl 5(6)-(substituted carbamoyl)- and 5(6)-(disubstituted carbamoyl)benzimidazole-2-carbamates and related compounds

A number of alkyl 5(6)-(substituted-carbamoyl)- and 5(6)-(disubstituted-carbamoyl)benzimidazole-2-carbamates and related compounds have been synthesized, and their anthelmintic activity against various intestinal helminths of experimental animals have been evaluated. A large percentage of the compounds synthesized showed noteworthy activity against Ancylostoma ceylanicum and at higher doses against Hymenolepsis nana infections. Compared to the alkyl 5(6)-(substituted-carbamoyl)benzimidazole-2-carbamates, the disubstituted carbamoyl analogues were found to exhibit better anthelmintic activity. The most active compound of the series, namely, methyl 5(6)-[(N-2-pyridylpiperazino)carbamoyl]benzimidazole-2-carbamate (90), has been screened against intestinal helminths in higher animals and as a micro- and macrofilaricidal agent. Compound 90 has been identified as a broad-spectrum anthelmintic agent. Compound 90 has been identified as a broad-spectrum anthelmintic in view of its efficacy against A. ceylanicum (hamsters and dogs), H. nana (rats), Nippostrongylus brasiliensis (rats), Syphacia obvelata (mice), A. tubaeformis (cat), Toxocara spp. (cat), and Litomosoides carinii (cotton rat).

Liver function tests in patients of pulmonary tuberculosis using four different drug regimens

BACKGROUND

Chemotherapy is the basic approach to clinical tuberculosis control. Antituberculous therapy causes derangement of hepatic functions revealed by disturbed liver function tests. The incidence of side effects may vary depending upon a number of factors. The primary purpose of this study was to determine the relative and absolute hepatotoxicity of different antituberculous drug regimens in Pakistani population where majority of the tuberculous patients belong to poor socioeconomic status.

METHODS

One hundred patients between 30 to 70 years of age with newly diagnosed pulmonary tuberculosis were selected and divided into four groups on the basis of different drug regimens. Blood and urine tests of these patients were made. Liver function tests were performed before therapy and then after one, two, three, six and nine months of treatment.

RESULTS & CONCLUSIONS

Antituberculous therapy causes derangement of hepatic function to a variable extent in patients of four different antituberculous drug regimens under study. Drug combination of Streptomycin, Isoniazid and Myambutol seem to be best tolerated of all the four regimens. Monitoring of the liver function in patients on antituberculous therapy indicated that liver dysfunction most frequently occurs during first three months of therapy. There is a tendency for enzyme values to return to normal inspite of continuous treatment. The mechanism underlying this adaptation to injury to the liver is unknown. Biochemical tests in the patients presenting with jaundice yielded the pattern of acute hepatocellular necrosis with high transaminases and moderately elevated Alkaline Phosphatase. None of the patients had hepatitis associated antigen in their serum.

New norditerpenoid alkaloids from Aconitum falconeri

The roots of Aconitum falconeri have yielded two new norditerpenoid alkaloids, faleoconitine (1) and 3'-methoxyacoforestinine (2) along with the known compounds, karakoline, 3-hydroxy-2-methyl-4H-pyran-4-one, and 3,4-dimethoxymethylbenzoate, which have been isolated for the first time from this plant. The previously reported pseudaconitine (3) was also isolated. Compounds 1 and 3 were found to be moderate inhibitors of the enzyme acetylcholinesterase.

Syntheses and antifilarial profile of 7-chloro-4-(substituted amino) quinolines: a new class of antifilarial agents

The syntheses of 7-chloro-4-(substituted amino) quinolines (2-22) and their antifilarial activities are delineated. Some of the screened compounds have shown promising filarial response and sterilization effect on female Acanthocheilonema viteae in rodents.

Quinolones: novel probes in antifilarial chemotheraphy

Quinolones have been discovered in our laboratory as a new class of antifilarial agents. This has led to the design, synthesis, and antifilarial evaluation of a number of N-substituted quinol-4(1H)-one-3-carboxamide derivatives 4-6. The macrofilaricidal activity of the target compounds was initially evaluated in vivo against Acanthoeilonema viteae by oral administration of 200 mg/kg x 5 days. Among all the synthesized compounds, 13 displayed activity, with the most potent compound (4a) exhibiting 100% macrofilaricidal and 90% microfilaricidal activities. Compound 4e elicited significant macrofilaricidal (80%) response while compound 5c showed 100% sterilization of female worms. Finally, the two most potent macrofilaricidal compounds, namely 4a and 4e, have been screened for their potency against DNA topoisomerase II, and it has been observed that both have the capability to interfere with this enzyme at 10 micromol/mL concentration. The structure-activity relationship (SAR) associated with position-3 and aryl ring substituents is discussed.

Potent 1,3-disubstituted-9H-pyrido[3,4-b]indoles as new lead compounds in antifilarial chemotherapy

Substituted 9H-pyrido[3,4-b]indoles (beta-carbolines) identified in our laboratory as potential pharmacophore for designing macrofilaricidal agents, have been explored further for identifying the pharmacophore responsible for high order of adulticidal activity. This has led to syntheses and macrofilaricidal evaluations of a number of 1-aryl-9H-pyrido[3,4-b]indole-3-carboxylate derivatives (3-7). The macrofilarical activity was initially evaluated in vivo against Acanthoeilonema viteae. Amongst all the synthesized compounds, only twelve compounds namely 3a, 3c, 3d, 3f, 4c, 4d, 4f, 5a, 6f, 6h, 6i and 7h have exhibited either > 90% micro- or macrofilaricidal activity or sterilization of female worms. These compounds have also been screened against Litomosoides carinii and of these only 3f and 5a have also been found to be active. Finally these two compounds have been evaluated against Brugia malayi. The structure activity relationship (SAR) associated with position-1 and 3 substituents in beta-carbolines have been discussed. It has been observed that the presence of carbomethoxy at position-3 and an aryl substituent at position- in beta-carbolines effectively enhance antifilarial activity particularly against A. viteae. Amongst the various compounds screened, methyl 1-(4-methylphenyl)-9H-pyrido[3,4-b]indole-3-carboxylate (4c) has shown highest adulticidal activity and methyl 1-(4-chlorophenyl)-1,2,3,4-tetrahydro-9H-pyrido[3,4-b]indole-3-carboxyla te (3a) has shown highest microfilaricidal action against A. viteae at 50 mg/ kg x 5 days (i.p.). Another derivative of this compound namely 1-(4-chlorophenyl)-3-hydroxymethyl-9H-pyrido[3,4-b]indole (5a) exhibited highest activity against L. carinii at 30 mg/kg x 5 days (i.p.) and against B. malayi at 50 mg/kg x 5 days (i.p.) or at 200 mg/kg x 5 days (p.o.).

Potent 1,3-disubstituted-9H-pyrido[3,4-b]indoles as new lead compounds in antifilarial chemotherapy

Substituted 9H-pyrido[3,4-b]indoles (beta-carbolines), identified in our laboratory as potential pharmacophores for designing macrofilaricidal agents, have been explored further for identifying the pharmacophore responsible for the high order of adulticidal activity. This has led to syntheses and macrofilaricidal evaluations of a number of 1-aryl-9H-pyrido[3,4-b]indole-3-carboxylate derivatives (3-7). The macrofilaricidal activity was initially evaluated in vivo against Acanthoeilonema viteae. Among all the synthesized compounds, only 12 compounds, namely 3a, 3c, 3d, 3f, 4c, 4d, 4f, 5a, 6f, 6h, 6i, and 7h, have exhibited either >90% micro- or macrofilaricidal activity or sterlization of female worms. These compounds have also been screened against Litomosoides carinii, and of these only 3f and 5a have also been found to be active. Finally these two compounds have been evaluated against Brugia malayi. The structure-activity relationship (SAR) associated with position 1 and 3 substituents in beta-carbolines has been discussed. It has been observed that the presence of a carbomethoxy at position 3 and an aryl substituent at position 1 in beta-carbolines effectively enhances antifilarial activity particularly against A. viteae. Among the various compounds screened, methyl 1-(4-methylphenyl)-9H-pyrido[3,4-b]indole-3-carboxylate (4c) has shown the highest adulticidal activity and methyl 1-(4-chlorophenyl)-1,2,3,4-tetrahydro-9H-pyrido[3, 4-b]indole-3-carboxylate (3a) has shown the highest microfilaricidal action against A. viteae at 50 mg/kg x 5 days (ip). Another derivative of this compound, namely 1-(4-chlorophenyl)-3-(hydroxymethyl)-9H-pyrido[3,4-b]indole (5a), exhibited the highest activity against L. carinii at 30 mg/kg x 5 days (ip) and against B. malayiat 50 mg/kg x 5 days (ip) or at 200 mg/kg x 5 days (po).

Functional glycosylation sites of the rat luteinizing hormone receptor required for ligand binding

The contribution of N-linked glycosylation to the ligand binding activity of the rat luteinizing hormone receptor (LHR) was studied in wild-type and mutant LHR expressed in mammalian (COS1) cells and overexpressed in insect (Sf9) cells. The binding affinities of the holoreceptor and its truncated splice variant (form B) lacking the transmembrane domain were equivalent in both cell lines. Tunicamycin-treated transfected Sf9 cells expressed a carbohydrate-free LH receptor that lacked hormone binding activity. Functional carbohydrate chains essential for binding activity were localized to glycosylation sites at Asn-173 and Asn-152. Glycosidase treatment of the double mutant N173Q/N152Q revealed the presence of at least one additional carbohydrate chain at Asn-269, Asn-277, or Asn-291 that does not contribute to hormone binding. Asn-77 was not glycosylated, but its mutation to Gln reduced hormone binding. LHR expressed in insect cells contained only high mannose carbohydrate chains, and those located at Asn-173 and Asn-152 were sufficient for high-affinity hormone binding. Enzymatic cleavage of glycosyl chains indicated that only the proximal N-acetylglucosamine residue, which is common to high mannose and complex carbohydrate forms, is necessary for acquisition of the high affinity conformation of the receptor. The carbohydrate chains of the LHR appear to be involved in intramolecular folding of the nascent receptor rather than in its interaction with the hormone.

Activity of alpha-anilinobenzyl cyanides and 2-methoxycarbonylamino-1-phenylimidazoles, a new class of antifilarial agents

The activity of alpha-anilinobenzyl cyanides (2a-f), 5-aryl-4,5-dihydro-2-methoxycarbonylamino-1-phenylimidazoles (5a-d) and 2-methoxycarbonylamino-1-phenyl-1,3-diazaspiro[4:5]dec-2-ene (5f) have been tested for their micro- and macrofilaricidal activity against Litomosoides carinii and Acanthocheilonema viteae in rodents. In this test alpha-anilinobenzyl cyanides (2a-b), 5-(4-methoxyphenyl)-4,5-dihydro-2-methoxy-carbonylamino-1-phenylim idazole (5b) and 2-methoxycarbonylamino-1-phenyl-1,3-diazaspiro[4:5]dec-2-ene (5f) were found to possess marked filaricidal activity at doses ranging from 3-100 mg/kg given parenterally or orally for 5 days.

Cytotoxic and genotoxic effects of calcium silicates on human lymphocytes in vitro

Calcium silicate has been considered as a possible replacement for asbestos due to its heat and fire resistance. We describe the cytotoxic and genotoxic potential of calcium silicate using peripheral human blood lymphocytes. Calcium silicates at concentrations of 10 and 100 micrograms/ml significantly increased the frequencies of chromosomal aberrations (CAs) and sister-chromatid exchanges (SCEs). The increases in CAs and SCEs were dose-dependent, though not linearly. A significant decrease in the proliferation rate index was observed with increased dose of calcium silicates. The induction of chromatid-type aberrations indicates that the clastogenic activity of calcium silicate is S-phase-dependent.

Effect of anticalmodulin drugs on testosterone synthesis in hCG stimulated mouse Leydig cells

The effect of three anticalmodulin drugs, prepared in this laboratory and a commercially available drug Mastoparan, was tested on the secretion (or synthesis) of testosterone in hCG stimulated Leydig cells. The results of the use of drugs RN-IV A, RN-IV B and RN-IV C indicated that hCG (10 ng/ml), DbcAMP (0.1 mM) and cholera toxin (2 micrograms/ml)-stimulated testosterone production was inhibited in Leydig cells in a dose dependent manner. In hCG stimulated cells, the ID50 for drug RN-IV A was 2 microM, for drug RN-IV B was 25 microM and for drug RN-IV C was 130 microM. Based on ID50 the most effective drug was RN-IV A. Maximum inhibition of testosterone production was obtained at a concentration of 20 microM for drug RN-IV A, 150 microM for drug RN-IV B and 200 microM for drug RN-IV C. Further extensive experiments with drug RN-IV B showed that (a) at 100 microM concentration the drug does not impair the binding of receptor with 125I hCG, (b) the cAMP accumulation was prevented in a dose dependent manner reaching a minimal of 1.1 pM at 50 microM, compared with 3.5 pM in hCG (10 ng/ml) stimulated cells. The drug RN-IV B at a concentration of 100 microM, which failed to prevent conversion of exogenous pregnenolone or progesterone to testosterone, otherwise caused complete inhibition of testosterone production in hCG stimulated cells. Mastoparan also inhibited testosterone production in hCG stimulated cells in a dose dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)