In vitro anthelmintic action of some indigenous medicinal plants on Ascardia galli worms

Different parts of ten indigenous medicinal plants were screened for their in vitro anthelmintic activity against Ascaridia galli worms of the birds. Preparations from Carica papaya, Sapindus trifoliatus, Butea frondosa and Momordica charantia were more effective than piperazine hexahydrate.     

In vitro antibacterial activity of cefoperazone-sulbactam

This study was conducted to evaluate the antibacterial activity of CPZ-SBT in 1,146 clinical isolates and compared with that of CPZ and other antimicrobial agents. CPZ-SBT has much better antibacterial activity than CPZ against B-lactamase producing organisms. Of the 834 gram negative organisms tested, 165 were CPZ resistant, but 94 (57.0%) of them were still susceptible to CPZ-SBT, CPZ-SBT broadens the antibacterial spectrum of CPZ, it has good activity against Acinetobacter spp and B fragilis. Compared with other antimicrobial agents tested, CPZ-SBT is as active as ceftazidime, amikacin and ciprofloxacin against Enterobacteriaceae, P aeruginosa and Acinetobacter spp, but slightly less active than imipenem. It is as active as imipenem, timentin and metronidazole against B fragilis and other anaerobes. The results show that CPZ-SBT is a new member of the broad spectrum antimicrobial agents. It may become a promising agent for the treatment of severe infections caused by cefoperazone-resistant Gram negative bacilli including P aeruginosa.     

In vitro antimycobacterial activity of 5-chloropyrazinamide

5-Chloropyrazinamide and 5-chloropyrazinoic acid were evaluated for in vitro activity against Mycobacterium tuberculosis, Mycobacterium bovis, and several nontuberculous mycobacteria by a broth dilution method. 5-Chloropyrazinamide was more active than pyrazinamide against all organisms tested. It is likely that this agent has a different mechanism of action than pyrazinamide.     

Synthesis and in vitro anthelmintic activity against Nippostrongylus brasiliensis of new 2-amino-4-hydroxy-delta-valerolactam derivatives

The synthesis of a series of 2-amino-4-hydroxy-delta-valerolactam derivatives is described (compounds 4 to 10). These compounds showed a high anthelmintic in vitro activity against the Nippostrongylus brasiliensis model.     

In vitro activity of dirithromycin against Chlamydia trachomatis

Dirithromycin is a new macrolide antibiotic with an active metabolite, erythromycylamine. We evaluated the in vitro activities of both drugs against 16 isolates of Chlamydia trachomatis and compared them with that of doxycycline. In vitro susceptibility testing was performed with McCoy cell monolayers. The MIC was defined as the lowest concentration of antibiotic without inclusions. The MBC was defined as the lowest concentration of antibiotic yielding no inclusions after passage onto 24-h-old antibiotic-free McCoy cell monolayers. Dirithromycin and erythromycylamine appeared to be equally effective against these 16 strains of C. trachomatis (MIC for 90% of strains tested, 1 mg/ml; MBC for 90% of strains tested, 2 micrograms/ml). Both were less active than doxycycline (MIC for 90% of strains tested, 0.06 micrograms/ml; MBC for 90% of strains tested, 0.12 micrograms/ml). The combination of dirithromycin and erythromycylamine appeared to be additive.     

In vitro antineoplastic activity of a novel lanthionine-containing peptide

It has been a long-term goal to discover peptides that can kill tumor cells while sparing normal tissues. Lan-7 is a novel, chemically stable peptide structurally related to somatostatin that contains a lanthionine bridge between the two cysteines in the peptide; TT-232 is a less stable analogue containing a disulfide bridge. The antitumor activity of Lan-7 was examined, relative to that of TT-232 and the clinically used analogue octreotide, against a panel of malignant human tumor cell lines and normal human hematopoietic precursors. Lan-7 was cytotoxic to all four tumor cell lines, with IC50 values ranging over a 2-fold range from 16 to 36 microM. The potency of Lan-7 was comparable to that of TT-232, and both of these agents were two to three times more potent than octreotide. At concentrations that were highly cytotoxic to tumor cells, Lan-7 produced no significant toxicity to normal human hematopoietic precursors. Lan-7 induced apoptosis in human ovarian carcinoma 2008 cells over the same concentration range at which it produced cytotoxicity, but it did so without activating G1, S, or G2 checkpoints, given that it produced no perturbation of cell cycle phase distribution. Cells engineered to overexpress P-glycoprotein were not more resistant to Lan-7 than isogeneic cells not expressing the mdr1 gene. These results make Lan-7 of interest as a potential cancer chemotherapeutic agent.     

In vitro activity of macrolides against intracellular Legionella pneumophila

The antibacterial effects of clarithromycin, azithromycin, and erythromycin were determined against five strains of Legionella pneumophila including L. pneumophila ATCC 33823 and four clinical isolates. Extracellular minimum inhibitory concentrations (MICs) and MBCs were determined by a microdilution method. Clarithromycin was the most active drug (MIC < or = 0.015-0.06), followed by azithromycin (MIC 0.03-0.12) and erythromycin (MIC 0.06-0.25). The antibacterial effect of these macrolides was then determined against L. pneumophila grown intracellularly in MRC-5 human fetal lung fibroblast cells. At two and eight times the extracellular MBC, erythromycin, azithromycin, and clarithromycin were equally effective in inhibiting growth of these five strains of intracellular L. pneumophila.     

In vivo and in vitro antiinflammatory activity of saikosaponins

Buddlejasaponin I and saikosaponin 1 and 2, biologically active compounds from Scrophularia scorodonia and Bupleurum rigidum respectively, exert potent in vivo antiinflammatory effects on mouse ear edema induced by phorbol myristate acetate (PMA). The effects of these compounds on swelling and other inflammatory parameters are described. In screening for in vitro effects of saikosaponins on cellular systems generating cyclooxygenase (COX) and lipoxygenase (LOX) metabolites, we observed that most saikosaponins showed a significant effect. The action is more marked on LOX metabolite LTC4. Our data support the inhibition of arachidonic acid metabolism as one of the biochemical mechanisms that might be the rationale for the putative antiphlogistic activity of these saikosaponins.     

In vitro antimalarial activity of chalcones and their derivatives

A series of chalcones and their derivatives have been synthesized and identified as novel potential antimalarials using both molecular modeling and in vitro testing against the intact parasite. A large number of chalcones and their derivatives were prepared using one-step Claisen-Schmidt condensations of aldehydes with methyl ketones. These condensates were screened in vitro against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum and shown to be active at concentrations in the nanomolar range. The most active chalcone derivative, 1-(2,5-dichlorophenyl)-3-(4-quinolinyl)-2-propen-1-one (7), had an IC50 value of 200 nM against both a chloroquine-resistant strain (W2) and a chloroquine-sensitive strain (D6). The resistance indexes for all compounds were substantially lower than for chloroquine, suggesting that this series will be active against chloroquine-resistant malaria. Structure-activity relationships (SAR) of the chalcones in the context of a homology-based model structure of the malaria trophozoite cysteine protease, the most likely target enzyme, are presented.     

In vitro activity of the new fluoroquinolone CP-99,219

The in vitro activity of the new fluoroquinolone CP-99,219 [7-(3-azabicyclo[3.1.0]hexyl)naphthyridone] was compared with those of four other quinolones against 541 gram-negative, 283 gram-positive, and 70 anaerobic bacterial isolates. CP-99,219 inhibited 90% of many isolates in the family Enterobacteriaceae at a concentration of < or = 0.25 micrograms/ml (range, < 0.008 to 1 microgram/ml), an activity comparable to those of tosufloxacin and sparfloxacin and two times greater than that of temafloxacin. Ninety percent of the Proteus vulgaris, Providencia rettgeri, Providencia stuartii, and Serratia marcescens isolates were inhibited by 0.5 to 2 micrograms of CP-99,219 per ml. CP-99,219 inhibited 90% of the Pseudomonas aeruginosa and Haemophilus influenzae isolates at 1 and 0.015 micrograms/ml, respectively. The compound inhibited methicillin-susceptible Staphylococcus aureus at 0.06 micrograms/ml, whereas a ciprofloxacin concentration of 1 microgram/ml was required to inhibit these organisms. CP-99,219 inhibited 90% of methicillin-resistant S. aureus isolates at a concentration of < or = 4 micrograms/ml, while ciprofloxacin and temafloxacin had MICs against these isolates of > 16 micrograms/ml. Streptococci were inhibited by < or = 0.25 micrograms/ml, an activity comparable to that of tosufloxacin. CP-99,219 was eight times more active than ciprofloxacin against Streptococcus pneumoniae. Bacteroides species were inhibited by CP-99,219 at a concentration of 2 micrograms/ml, whereas inhibition of these species required 4- and 16-microgram/ml concentrations of tosufloxacin and ciprofloxacin, respectively. The MBCs of CP-99,219 ranged from two to four times the MICs, and inoculum size had a minimal effect on MIC. CP-99,219 was active against P. aeruginosa at pH 5.5, with only a fourfold increase in MIC compared with values obtained at pH 7.5. The addition of up to 9 mM Mg(2+) increased the MIC range from 0.03 to 0.06 microgram/ml to 0.12 to 0.5 microgram/ml. In view of its excellent in vitro activity against both gram-positive and gram-negative bacteria, CP-99,219 merits further study to determine it's clinical pharmacologic properties and potential for therapeutic use.     

In vitro activity of biapenem against beta-lactamase producing Enterobacteriaceae

The activity of biapenem was compared with that of imipenem and cefotaxime against 108 strains of beta-lactamase producing Enterobacteriaceae. Biapenem and imipenem were very active, inhibiting 90% of the strains at a concentration of 0.5 microgram/ml. Both carbapenems were very active against plasmidic beta-lactamase producers, with MIC90s below 1 microgram/ml. However, the MIC90 of biapenem for cephalosporinase producers was 1 microgram/ml. Against strains producing extended-spectrum beta-lactamases, biapenem exhibited better activity against TEM-type producers (MIC90 0.25 microgram/ml) than against SHV-type producers (MIC90 0.5 microgram/ml). Overall, the in vitro antibacterial activity of biapenem is similar to that of imipenem.     

In vitro influence of phenylalanine on acetylcholinesterase activity and DNA

Acetylcholinesterase (AChE) is a significant component of the membrane contributing to the permeability changes during synaptic transmission and conduction. Phenylketonuria is a group of metabolic disorders in which phenylalanine (Phe) is highly elevated in blood (up to 0.1 M) resulting in mental retardation etc. AChE activity was measured spectrophotometrically after incubation with various Phe concentrations. Phe interaction with DNA was evaluated with an established HPLC method. Phe was found to inhibit AChE almost 40%, at a concentration of 5 mM, whereas a 62.5% DNA peak exclusion (molecular interaction) was observed when Phe was incubated with DNA at a concentration of 3 mM. In addition the ratio of DNA: Phe determined the potency of the observed molecular effect.     

In vitro cytostatic activity of 1,2,4-triazolo- and 1,2,3,4-tetrazolo pyridazines

PROBLEM: There is considerable controversy concerning the root cause and mechanisms of early embryo loss. It has been suggested that most pregnancy losses occur due to morphogenetic anomalies of the embryo. It has also been suggested that the maternal specific immune system rejects the embryo. METHODS: Existing data on the cell and molecular biology of early embryo loss in murine experimental models is reviewed. RESULTS: Using the CBA(female) x DBA/2(male) model of early embryo loss, it has been established that maternal inflammatory cells infiltrate the decidua basalis of all implantation sites within 48 hr after implantation. For most embryos, the relatively low numbers of macrophages (Mphi) and natural killer-like (NK-like) cells of maternal origin remain relatively constant after day 8, whereas 20-30% of the embryos show a significant increase in inflammatory cells in the maternal decidua, corresponding to the incidence of early embryo resorption visible at day 12. Evidence will be reviewed to suggest that decidual NK-like cells are not cytolytic but may be producing the Mphi-activating cytokine interferon gamma (IFN-gamma), which activates decidual Mphi and other cells. Furthermore, embryo loss is ameliorated by in vivo treatment with anti-IFNgamma or anti-NK antisera, indicating that NK-like cells and/or IFNgamma are required for embryo loss, but not for embryo survival. In resorbing embryos, the inflammatory Mphi show evidence of having been primed during early pregnancy, in that in vitro incubation with lipopolysaccharide induced the production of tumor necrosis factor alpha and nitric oxide. CONCLUSION: These findings support the concept that early embryo loss is a nonspecific event mediated by the triggering of cytotoxin production by primed decidual macrophages.     

In vitro antimalarial activity of a new organometallic analog, ferrocene-chloroquine

OBJECTIVES: Diagnostic peritoneal lavage (DPL) had been widely used in evaluating patients with suspected intraperitoneal injuries due to its high sensitivity. If the positive criteria are strictly followed, however, the incidence of nontherapeutic laparotomies will be unacceptably high. This realization has become more important recently with the popularization of nonoperative treatment for blunt solid organ injuries. For these patients, the early diagnosis of an associated hollow organ perforation is mandatory. METHODS: Three hundred and twenty patients undergoing DPL over an 18-month period were retrospectively reviewed to evaluate the usefulness of "cell count ratio" in diagnosing hollow organ perforation. The cell count ratio was defined as the ratio between white blood cell count and red blood cell count in the lavage fluid divided by the ratio of the same parameters in the peripheral blood. RESULTS: Two hundred twelve patients were diagnosed as having a positive DPL according to the classic criteria. Forty-four patients (21%) had a cell count ratio of greater than or equal to 1. The diagnosis at laparotomy was small bowel perforation in 31 patients, colon perforation in eight patients, diaphragmatic hernia in one patient, pancreatic transection in two patients, and liver laceration in two patients. None of the patients with a cell count ratio of less than I sustained hollow organ perforation. The average interval from injury to DPL was 5 hours, with the shortest being 1.5 hours. CONCLUSION: A cell count ratio of greater than or equal to 1 predicted hollow organ perforation with a specificity of 97% and a sensitivity of 100%. The selective use of the cell count ratio has improved the probability of early diagnosis of bowel perforation without increasing the cost of care. Nonoperative management can be applied more confidently to those patients sustaining a blunt solid viscus injury of the abdomen if the cell count ratio is low. We conclude that the cell count ratio of DPL effluent is a very sensitive and specific indicator of hollow organ perforation. In the treatment of blunt abdominal injuries, if the cell count ratio is positive, nonoperative treatment should be abandoned and a laparotomy undertaken.     

In vitro antioxidant activity of Vietnamese ginseng saponin and its components

To elucidate the antioxidant action of Vietnamese ginseng saponin against free radial-mediated cellular damage, we examined the effect of Vietnamese ginseng saponin on lipid peroxidation in the mouse brain, liver, and liver microsomes by using two in vitro free radical generating systems (iron ferrous+ascorbic acid and iron ferrous+hydrogen peroxide). Free radical-mediated lipid peroxidation was determined by measuring the endogenous and stimulated accumulation of thiobarbituric acid reactive substance (TBA-RS). Vietnamese ginseng saponin (0.05-0.5 mg/ml), as well as vitamin E, significantly inhibited the formation of TBA-RS in tissue homogenates. Panax ginseng saponin, at the same concentration range as Vietnamese ginseng saponin, also had inhibitory action on free radical-mediated lipid peroxidation. However, majonoside-R2, ginsenoside-Rg1 and ginsenoside-Rb1, the main saponin components of Vietnamese ginseng saponin fraction, had no effect on lipid peroxidation. These results suggest that Vietnamese ginseng exerts a protective action against free radical-induced tissue injury and that this effect is attributable to minor components rather than the main saponin components tested.     

In vitro evolution of horse heart myoglobin to increase peroxidase activity

Random mutagenesis and screening for enzymatic activity has been used to engineer horse heart myoglobin to enhance its intrinsic peroxidase activity. A chemically synthesized gene encoding horse heart myoglobin was subjected to successive cycles of PCR random mutagenesis. The mutated myoglobin gene was expressed in Escherichia coli LE392, and the variants were screened for peroxidase activity with a plate assay. Four cycles of mutagenesis and screening produced a series of single, double, triple, and quadruple variants with enhanced peroxidase activity. Steady-state kinetics analysis demonstrated that the quadruple variant T39I/K45D/F46L/I107F exhibits peroxidase activity significantly greater than that of the wild-type protein with k1 (for H2O2 oxidation of metmyoglobin) of 1. 34 x 10(4) M-1 s-1 ( approximately 25-fold that of wild-type myoglobin) and k3 [for reducing the substrate (2, 2'-azino-di-(3-ethyl)benzthiazoline-6-sulfonic acid] of 1.4 x 10(6) M-1 s-1 (1.6-fold that of wild-type myoglobin). Thermal stability of these variants as measured with circular dichroism spectroscopy demonstrated that the Tm of the quadruple variant is decreased only slightly compared with wild-type (74.1 degreesC vs. 76.5 degreesC). The rate constants for binding of dioxygen exhibited by the quadruple variant are identical to the those observed for wild-type myoglobin (kon, 22.2 x 10(-6) M-1 s-1 vs. 22.3 x 10(-6) M-1 s-1; koff, 24.3 s-1 vs. 24.2 s-1; KO2, 0.91 x 10(-6) M-1 vs. 0.92 x 10(-6) M-1). The affinity of the quadruple variant for CO is increased slightly (kon, 0.90 x 10(-6) M-1s-1 vs. 0.51 x 10(-6) M-1s-1; koff, 5.08 s-1 vs. 3.51 s-1; KCO, 1.77 x 10(-7) M-1 vs. 1.45 x 10(-7) M-1). All four substitutions are in the heme pocket and within 5 A of the heme group.     

In vitro activity of guinea pig transfer factor released into plasma

Plasma fractions and plasma dialysate from 2,4-dinitrochlorobenzene- and tuberculin-sensitive guinea pigs that had been treated with either antilymphocytic serum or normal control serum were analyzed for their ability to transfer lymphocyte transformation, passive cutaneous anaphylaxis, and macrophage migration inhibition, as well as delayed hypersensitivity in vivo. Antilymphocytic serum caused rapid release of material, which has characteristics of transfer factor, into the plasma. It was dialyzable, migrated electrophoretically with the alpha globulins and albumin, possessed a 280/260 (nm) optical density ratio of 0.7, and caused in vitro lymphocyte transformation in the presence of the specific antigen. Passive cutaneous anaphylaxis antibodies were also present in the plasma of sensitive animals, but they were isolated in electrophoretic or dialysis fractions separate from those containing transfer activity.     

In vitro antimicrobial activity of a new antiseptic central venous catheter

A central venous catheter coated with a new antiseptic combination, silver chloride (AgCl) and benzalkonium chloride (BKC) in a polymer matrix, was developed. The antimicrobial efficacy and the ability to prevent surface colonization, after elution in both serum and saline, were evaluated and compared to catheters coated with silver sulfadiazine/chlorhexidine. The results of in vitro assays demonstrated that the AgCl-BKC coated catheters had a broad spectrum of activity against bacteria and C. albicans and prolonged antimicrobial activity for extraction periods of up to 30 days. These data suggest that AgCl-BKC coated catheters may provide another solution for reduction of catheter-related infections.