Biomedical subjects

M C Herrera

Publications and source records attributed to M C Herrera.

At least 19 recordsLinked to original sources

PubMed2005

Ultrasound-assisted extraction of phenolic compounds from strawberries prior to liquid chromatographic separation and photodiode array ultraviolet detection.

Ultrasound-assisted extraction was used for the determination of phenolic compounds present in strawberries. The optimization study of the extraction was carried out using spiked samples (100 mg/kg). The sample immersed in an aqueous solution containing hydrochloric acid (0.4 M) was sonicated for 2 min (duty cycle 0.2 s, output amplitude 20% of the nominal amplitude of the converter, applied power 100 W with the probe placed 1cm from the bottom of the water bath and 5 cm from the walls of the precipitate glass). Subsequent separation was carried out by liquid chromatography (LC) with photodiode array UV detection. Calibration curves using the standard addition in green strawberries typically gave linear dynamic ranges of 2-300 mg/l for all analytes; R(2) values exceeded 0.996 in all cases. The method was applied to two types of strawberries to demonstrate the applicability of the proposed method, which is much faster and produces less analyte degradation than methods as solid-liquid, subcritical water and microwave-assisted extraction.

Chromatography, Liquid↗

PubMed2004

Ultrasound-assisted extraction for the analysis of phenolic compounds in strawberries.

A semiautomatic method based on application of ultrasounds has been developed to leach and hydrolyse phenolic compounds, such as naringin, rutin, naringenin, ellagic acid, quercetin and kaempferol, from strawberries. Two grams of lyophilized sample was placed into a sample cell and 5 mL of acetone containing hydrochloric acid was added. The cell was immersed in a water bath and sonicated for 30 s (duty cycle 0.8 s, output amplitude 50% of the nominal amplitude of the converter, applied power 100 W and with the probe placed 2 cm from the top surface of the extraction cell) for three times: each time 5 mL extractant displaced the previous extract. When the extraction was completed, the combined extracts were evaporated for 10 min, diluted to 10 mL with water adjusted to pH 8, and transferred to a cleanup-preconcentration manifold; here the analytes were retained in two in-series minicolumns packed with HR-P sorbent and then eluted with 4 mL methanol, and injected for individual separation-quantitation into a chromatograph-photodiode array detector assembly. Optimisation of the extraction was carried out using samples spiked with 4 mg kg(-1) of each analyte. Calibration curves using the standard addition in red strawberries typically gave linear dynamic ranges of 4-40 mg L(-1) for all analytes, except for ellagic acid (40-400 mg L(-1)). The r(2) values exceeded 0.98 in all cases.

Fragaria↗

PubMed2003

Enzyme inhibition-based biosensors and biosensing systems: questionable analytical devices.

An overview of methods based on enzyme inhibition is presented. Both biosensors and biosensing systems (implemented in continuous and discontinuous approaches) are considered. The aim of the overview is to alert users on the use of these devices which, despite they can involve selective biocatalysts, the inhibition effect is not selective. Tables and examples illustrate this assertion.

Biosensing Techniques↗

PubMed2002

Study of the feasibility of focused microwave-assisted soxhlet extraction of N-methylcarbamates from soil.

A study of the feasibility of a focused microwave-assisted Soxhlet device for the extraction of N-methylcarbamates from soil has been performed. The main factors contributing to the extraction efficiency-namely microwave power, irradiation time and number of cycles--were optimized by means of a two-level full factorial design. The extracts were analysed by HPLC-post-column fluorescence derivatization-detection at excitation wavelength 340 nm and emission wavelength 445 nm. The method has allowed the extraction of carbamate pesticides from contaminated soil with quantitative recoveries, similar to those provided by the US Environmental Protection Agency method 8318, without degradation of the target compounds during the extraction and using less organic solvent, as 75-80% of the extractant was recycled.

Calibration↗

PubMed1999

Parallel conductance determination in cardiac volumetry using dilution manoeuvres: theoretical analysis and practical implications.

Left ventricular volume calibration based on the conductance catheter depends on the correct determination of the parallel conductance (Gp). Baan's saline manoeuvre procedure leads to Gp by finding the end-systolic (Ges) and end-diastolic (Ged) conductances, for each beat of the dilution curve rising limb. After plotting such values in an xy-system, their linear regression is back-projected to intersect the identity line, so yielding an estimated Gp. The objective is to theoretically analyse all possible lines, Ges = aGed + b (Baan's line) and, based on experimental results, to establish their limitations. This was attained by calculating the regression lines using, first Ged = f1(Ges) and thereafter, Ges = f2(Ged), which led to two values, Gp2 and Gp1, for the parallel conductance. The morphology of the saline curve was also modified to assess its effect on the extrapolation. Multiple dilutions were recorded in eight experimental dogs injecting different concentrations. Each curve was classified according to the maximum change (VAR) reached by the total average conductance. Over 138 manoeuvres, 276 regressions were processed yielding correlations higher than 0.65. Of this total, 92.4% gave positive parallel conductances. The rest produced negative values and, thus, were neglected. If the two (Ged, Ges) statistical relationships were ideal, they should yield Gp = Gp1 = Gp2; however, there were differences which, when Gp1 was studied against Gp2, led to: Gp1 = 0.97 Gp2 + 0.055, with r = 0.9476, and n = 85. The remaining 53 were discarded because either some Gp values were negative, or the correlation of Ges which Ged (or vice versa) was < 0.85, and/or VAR < 15%; the two latter conditions were found necessary for reliable calibration. Baan's line high correlation is not a unique condition to ensure the accuracy and precision of Gp determination because the slope a depends on VAR and, thus, different intersections with the identity line may be obtained. Its recommended that manoeuvres be used with at least eight data points, with VAR > 15% and, finally, with (Ges, Ged) correlation better than 0.85. Theoretical analysis of Baan's line offers a reference frame, which contains only a limited number of practical possibilities.

Animals↗

PubMed1999

Parallel conductance estimation by hypertonic dilution method with conductance catheter: effects of the bolus concentration and temperature.

The conductance catheter has gained momentum since its introduction in cardiovascular dynamics back in 1980. However, measuring errors are still blurring its clinical acceptance. The main objective here was to study the effects of the injected saline concentration and temperature on the evaluation of the parallel conductance, Gp, and thus, on the correction volume Vp. That conductance, Gp, and its associated volume, Vp, were computed using 167 saline dilution curves obtained with boluses at different concentrations and temperatures, injected in seven anesthetized closed-chest dogs. The excursion of the total conductance relative to the steady-state value during a saline maneuver showed good correlation with the injected concentration at both studied temperatures. The reference parallel volume (one reference per dog) was defined as the average value obtained with three successive maneuvers, at 6-M concentration and at body temperature; therefore, the method acted as its own reference. The variation of Vp relative to the reference value was clearly dependent on the injected concentration and on its temperature; dispersion was greater at 22 degrees C than at 40 degrees C. The variability would recognize also other causes, such as uncertainty of the extrapolation procedure and the thoracic redistribution of electrical field lines. As conclusion, it is recommended to characterize each maneuver by its concentration and temperature. Body temperature and 6-M concentration appear as the most recommendable combination for the injectate in most animals. Finally, these results intend to characterize the Vp estimation procedure in order to minimize errors. The variability of Vp, in different experimental conditions, demonstrated that both concentration and temperature are additional parameters that may modify the Gp estimate.

Animals↗

PubMed1998

Rat liver transport and biotransformation of a cytostatic complex of bis-cholylglycinate and platinum (II).

BACKGROUND/AIMS: Bile acids have previously been used as shuttles for directing organic drugs to the liver. The aim of this study was to investigate liver transport and biotransformation of a new cytostatic bioinorganic complex (Bamet-H2), that was obtained by binding platinum(II) to two cholylglycinate moieties. METHODS: Using rat hepatocytes in primary culture, the kinetics of cholylglycinate, cisplatin and Bamet-H2 uptake were studied. Sodium-dependency of Bamet-H2 uptake was investigated by replacement of 116 mM NaCl by 116 mM choline chloride. Liver biotransformation was investigated by HPLC analysis of bile samples collected from anesthetized rats following intravenous Bamet-H2 administration. Using isolated rat liver preparations, which were perfused with erythrocyte- and albumin-free Krebs-Henseleit solutions for 40 min, measurement of cholylglycinate, cisplatin and Bamet-H2 uptake and bile output was carried out. Interaction between Bamet-H2 and cholylglycinate for liver transport was studied by co-administration of 1 microM Bamet-H2 plus 500 microM cholylglycinate and 1 microM [14C]-cholylglycinate plus 500 microM Bamet-H2. RESULTS: Both cholylglycinate and Bamet-H2 uptake by rat hepatocytes followed saturation kinetics. Comparison between the two compounds indicated that the Vmax (22.2 versus 8.5 nmol.5 min(-1).mg protein(-1)), and Kt (365 versus 171 microM) were higher for Bamet-H2 uptake. The efficiency of Bamet-H2 uptake (Vmax/Kt) was significantly reduced (-35%) in the absence of sodium. Cisplatin uptake by rat hepatocytes was approximately 10-fold lower than that for Bamet-H2 at any dose used. Moreover, this was not saturable up to 400 microM cisplatin. Bamet-H2 was not biotransformed during its intrahepatic residence in anesthetized rats. Bamet-H2 uptake and secretion into bile by isolated rat livers exceeded cisplatin but were less than cholylglycinate. Differences between Bamet-H2 and cholylglycinate were more marked for bile output than for liver uptake. Thus, higher drug liver content was found after perfusion with Bamet-H2 than with cholylglycinate or cisplatin. Co-administration of Bamet-H2 and cholylglycinate revealed the existence of partial cross-inhibition in both liver uptake and bile output. Bamet-H2 induced a more profound alteration on cholylglycinate uptake and bile secretion than cholylglycinate on both process for Bamet-H2. CONCLUSION: These results suggest that in the transfer of Bamet-H2 from the sinusoids to the canaliculi both bile acid and non-bile acid transport systems are involved.

Animals↗

PubMed1997

Bile secretion by the rat liver during synchronized regeneration.

Simultaneous coexistence of differentiated, proliferating and redifferentiated hepatocytes occurs during normal liver regeneration (LR). The aim of the present work was to study the time course of the capacity of the liver to form bile during synchronized LR. Following two-thirds partial hepatectomy (PH) in rats, i.v. administration of the ribonucleotide reductase reversible inhibitor hydroxyurea (HU) was used to transiently block liver cells at G1/S boundary. Experiments were performed at 0 and 4 hours, and 1, 3 or 7 days after releasing HU-induced inhibition. Bile acid pool size was determined by collecting bile samples over 24 hours. Initial (first hour) bile flow and bile acid output were increased early on during synchronized LR as compared with the values found in non-hepatectomized control animals. These values were thereafter (1 day) reduced, but increased again at 3 days after halting HU infusion. The time course of bile acid depletion and changes in bile flow were very similar in control and synchronized LR, except that in the latter a more important early reduction in bile flow and bile acid output was found. Shortly after PH, part of the bile acid pool was lost, but this was quickly restored, soon (1 day) reaching a net bile acid pool size very similar to that found in control rats. The highest pool size relative to liver weight was found on day 1, when bile acid output and bile flow reached their lowest values. Additional experiments were performed using in situ perfused regenerating rat livers in which stepwise infusion of taurocholate (TC) was carried out. PH alone modified neither the bile acid-independent (BAIF) nor the bile acid-dependent fraction of bile flow (BADF). However, in normal LR, the BAIF decreased on day 1 and recovered at 7 days, while in synchronized LR it remained depressed up to 7 days. The BADF was only reduced during the early phase of normal LR and did not change significantly in synchronized LR. The maximal secretion rate (SRmax) for TC, as expressed per gram of remaining liver tissue, was not affected immediately after PH, but a marked reduction was observed on day 1 in both normal and synchronized LR. Afterwards, SRmax was quickly restored in both synchronized LR and, although in a slower way, normal LR. These results suggest that synchronization of LR involves changes in the time required to the recovery of specific liver functions such as bile formation.

Animals↗

PubMed1997

Effect of bile acids on hepatobiliary transport of cisplatin by perfused rat liver.

The liver and kidney collaborate in the excretion of the cytostatic drug, cis-diamminedichloroplatinum(II) (cisplatin) from the body. Enhancement of this process is envisaged as a way of reducing cisplatin toxicity, thus allowing increases in the doses administered. In this sense, using different compounds, several attempts have been made to enhance cisplatin biliary excretion. In this study, the ability of endogenous compounds belonging to the bile acid family to improve cisplatin excretion by the isolated perfused rat liver was investigated. A highly choleretic bile acid (ursodexoycholic acid) and two others bile acids with marked micelle-forming properties (glycocholic acid and chenodeoxycholic acid) were chosen for study. When these drugs were given at concentrations (1 microM) that did not affect the viability of liver preparations, a correlation between the biliary excretion of platinum and bile acid output was found. This was not due to the incorporation of cisplatin into mixed micelles because no correlation between the biliary output of lecithin or cholesterol and platinum was observed. Moreover, a wash-out effect of bile acids was probably not the cause of bile acid-induced platinum output into bile because no correlation between this and bile flow was found. An enhancement in cisplatin transport processes by the hepatocyte or by direct binding of cisplatin to bile acid monomers or aggregates cannot be ruled out. In spite of the biliary induction of cisplatin output, the net excretion of platinum was reduced under bile acid administration. This was related to lower platinum contents in the liver tissue, probably due to an inhibition of the ability of the hepatocyte to take up and/or retain cisplatin while subject to bile acid infusion. In summary, our results indicate that bile acids reduce the net excretion of cisplatin by the liver even though they induce an enhancement in the transport of this compound from the hepatocyte into bile.

Animals↗

PubMed1997

Synthesis and characterization of a new bile acid and platinum(II) complex with cytostatic activity.

With a view to using bile acids as shuttles for delivering platinum-related cytostatic drugs to the liver, a cholylglycine(CG)-derivative of platinum(II) has been synthesized. The complex, named Bamet-H2, was characterized by elemental analysis, FT-IR, NMR, FAB-MS, and UV spectroscopy. The results indicate the following composition: C52H84N2O12ClNa Pt(II). Conductivity data suggest that the complex behaves as a sodium salt (1:1) of a complex of Pt(II) bound to one cl-, one bidentate CG moiety, and another monodentate CG moiety, i.e., Na[Pt(CG-O,N)(CG-O)Cl]. The compound is highly soluble (up to 10 mM) in water, ethanol, methanol, DMF, and DMSO. Bamet-H2 was stable in solution (either water or 150 mM NaCl solution), as measured by HPLC, up to 24 h. At this time, more than 90% of the platinum present in water or saline solutions was found to be Bamet-H2. Cytostatic activity against L1210 murine leukemia cells was found. This characteristic was stronger against rat hepatocytes in primary culture. Isolated in situ rat livers were perfused for 40 min with a recirculating medium containing 1 microM Bamet-H2, CG, or cisplatin. Uptake and excretion into bile were much greater for Bamet-H2 than for cisplatin, but less than for CG. Liver content was higher for Bamet-H2 than for cisplatin or CG. The results point to the potential usefulness of Bamet-H2 in the antitumoral therapy of neoplasias derived from liver parenchymal cells.

Animals↗

PubMed1995

Role of amidation in bile acid effect on DNA synthesis by regenerating mouse liver.

Effect of bile acids on DNA synthesis by the regenerating liver was investigated in mice in vivo after partial hepatectomy (PH). Radioactivity incorporation into DNA after [14C]thymidine intraperitoneal administration peaked at 48 h after PH. At this time a significant taurocholate-induced dose-dependent reduction in DNA synthesis without changes in total liver radioactivity content was found (half-maximal effect at approximately 0.1 mumol/g body wt). Effect of taurocholate (0.5 mumol/g body wt) was mimicked by chocolate, ursodeoxycholate, deoxycholate, dehydrocholate, tauroursodeoxycholate, taurochenodeoxycholate, and taurodeoxycholate. In contrast, chenodeoxycholate, glycocholate, glycochenodeoxycholate, glycoursodeoxycholate, glycodeoxycholate, 5 beta-cholestane, bromosulfophthalein, and free taurine lacked this effect. No relationship between hydrophobic-hydrophilic balance and inhibitory effect was observed. Analysis by high-performance liquid chromatography indicated that inhibition of thymidine incorporation into DNA was not accompanied by an accumulation of phosphorylated DNA precursors in the liver but rather by a parallel increase in nucleotide catabolism. Bile acid-induced modifications in DNA synthesis were observed in vivo even in the absence of changes in toxicity tests, which suggests that the inhibitory effect shared by most unconjugated and tauroconjugated bile acids but not by glycoconjugated bile acids should be accounted for by mechanisms other than nonselective liver cell injury.

Animals↗

PubMed1993

Volume profiles obtained by a conductimetric method.

One problem faced by intracardiac conductance volumetry is the non-uniform distribution of the injected current. Salo, in 1989, proposed a method to correct this undesirable effect. The objective here is to test Salo's method in known volumes of simple geometry by obtaining volume profiles. A plastic rod with 15 metallic rings simulated the conductance catheter. Five sections were used for the resistance measurements employing the upper electrode as fixed current source and the lowest one as the shifting source. This is part of Salo's procedure. The source-to-section distance was measured from the moving source to the section (linear definition) or using the equivalent distance concept (Salo's). Thereafter, each sectional resistance set of values was plotted as a function of the inverse of the source-to-section distance (either definition) elevated to an empirical exponent k to obtain the corrected sectional resistance by extrapolation back to zero of the regression line, i.e., a value produced by a source theoretically placed at infinity. In addition, a mathematical analysis was attempted, searching for an optimum k based on minimum volume error. The best volume profiles for two cylinders and a frustum were obtained with k = 2 using the linear definition of distance (errors of -3.49%, -1.25% and -3.65%, respectively). Moreover, the frustum angle was determined within 0.4 degrees (2.7%) of the real value. The theoretical analysis led to an inverse logarithmic relationship between the exponent k and the source-to-section distance.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Volume↗

PubMed1993

Bile acid-induced modifications in DNA synthesis by the regenerating perfused rat liver.

Liver cell proliferation is a complex process that can be affected by a large number of factors such as bile acids, which have been reported to be associated to the pathogenesis of liver cancer. In this work, bile acid-induced modifications in DNA synthesis by regenerating perfused rat liver were investigated. Two-thirds hepatectomy was carried out 24 hr before perfusion of liver with recirculating, erythrocyte-free Krebs-Henseleit solution. The viability of the preparations was maintained under all experimental conditions, as indicated by bile flow, oxygen uptake, perfusion pressure, perfusion flow and release of lactate dehydrogenase and potassium into the perfusate. Livers received (min 10 to min 60) bile acid infusion at a rate of 25 nmol/min/gm liver (i.e., maximal secretion rate/2) in regenerating livers as calculated for taurocholate in separate experiments). Trace amounts of [methyl-14C]thymidine were added to the perfusate at min 30. At the end of the experiments (min 60) the livers were washed, removed, weighed and homogenized to determine radioactivity in whole tissue, in DNA and in non-DNA-related fractions. Taurocholate and, to a lesser extent, taurodeoxycholate and dehydrocholate (but not ursodeoxycholate) were found to reduce 14C incorporation into DNA. This was not due to changes in the content of 14C in whole, regenerating liver tissue. Taurocholate, taurodeoxycholate, dehydrocholate and ursodeoxycholate had no effect on thymidine uptake; moreover, the proportion of 14C found in bile was negligible. However, bile acid-induced modification in the fate of intracellular thymidine was observed. In regenerating livers receiving no bile acid, the 14C carried by thymidine metabolites accounted for about 60% of 14C in whole liver tissue. Taurocholate markedly increased this proportion to about 80%. Reverse-phase high-pressure liquid chromatography revealed that most of this 14C (about 80%) was recovered at the elution time, corresponding to thymidine catabolites rather than to DNA precursors. These results suggest that bile acids induce enhancement of thymidine catabolism that reduces its incorporation into DNA; inhibition in the process of DNA synthesis itself, leading to a subsequent increase in the metabolism of DNA precursors; or both. Moreover, from the diversity in this property for bile acid species it might be inferred that changes in the composition and size of the bile acid pool during liver carcinogenesis or regeneration play a role in the modulation of the proliferative process.

Animals↗

PubMed1992

Further evaluation of the interrelationship between the hepatocellular transport of bile acids and endocytosed proteins.

Experiments on the relationship between the hepatocellular transport of endogenous or exogenously loaded bile acids (sodium taurocholate, TC, 0.5 mumol/min/100 g body wt) and horseradish peroxidase (HRP) or immunoglobulin A (IgA) (0.5 mg/100 g body wt) were carried out on anaesthetized Wistar rats. The time course of HRP excretion into bile (acceleration in the secretory peak), but not the total amount of HRP output, was affected by TC infusion. Administration of HRP was found to have no stimulatory effect on either spontaneous or TC-induced bile flow, bile acid, lecithin or cholesterol output. Spontaneous bile acid output was increased (25 and 67%, respectively) in rats that were treated for 12-h fasting or by oral administration of TC (45 mg/100 g body wt, every 12 h, for 2 days). These manoeuvres did not change the inability of HRP and IgA to increase bile acid output. Exogenous TC load had no stimulatory effect on the hepatocellular transport of endogenous bile acid pool, that was labelled by a combination of fasting and oral administration of 14C-glycocholic acid 12 h before the experiments. Therefore, exogenous bile acid load-induced stimulation of transcytosis had no effect on endogenous bile acid output. Moreover, bile secretion of both endogenous and exogenously loaded bile acids is unaffected by the administration of proteins, irrespective of whether they are endocytosed by a receptor or nonreceptor mediated process.

Animals↗

PubMed1986

Multichannel tetrapolar admittance meter (MY) for intracardiac volume measurements in animals.

With an 8-electrode catheter, this instrument measures simultaneously five intraventricular sections of admittance and, also, total admittance, the latter obtained as the sum of five component sections. It injects through the two outermost electrodes of the catheter a constant current (828 microA rms) of high frequency (14 kHz). Actually, the instrument measures the mathematical inverse of the resistive component (conductance) of the impedance seen by the voltage sensing electrodes. The sensitivity per channel was adjusted to 25 V/mho, resulting in an overall sensitivity of 5.28 V/mho for the total intraventricular admittance. Nonlinearity in any single channel was less than or equal to 3.4% while, for the total admittance, it was less than or equal to 1.5%. The difference between any two individual channels when the same calibration resistor was connected, relative to the expected value, was less than or equal to 4.8%. The equipment demonstrated good performance in animal experiments and showed the possibility of detecting localized dysfunctions. Human applications still remain to be done.

Animals↗

PubMedDate not supplied

A comparison of the performance of male and female CBD distributors in Peru.

This report presents the results of an operations research project to increase male involvement in family planning in Peru. Two community-based distribution (CBD) programs, PROFAMILIA of Lima and CENPROF of Trujillo, Peru, recruited male contraceptive distributors and compared their performance to that of female distributors recruited at the same time. Both programs found it harder to recruit men than women as distributors. Program supervisors, who were women, were less comfortable with men than with other women, even though there were no differences in distributor compliance with program norms. Male distributors were more likely to serve male clients and sell male methods (condoms), while female distributors were more likely to serve female clients and sell female methods (pills). Men sold as much or more total couple-years of protection than did women, and they recruited as many or more new acceptors. Gender was found to exert an impact on method mix independent of other distributor characteristics, such as age, education, marital status, and number of living children. The study suggests that family planning programs can influence method mix and client characteristics by recruiting men as CBD distributors.

Contraceptive Devices, Male↗

PubMedDate not supplied

[Lactation and weaning patterns in Mexico. 1986 National Health Survey].

In the process of nutrition, breastfeeding is fundamentally important, due to the nutritional and immunological value of the mother's milk. Within its beneficial effects, it is found that it improves weight and size in children. Another stage in the child's feeding that should be considered during the first year of life is the weaning that complements, at certain age of the breastfeeder, the nutrition given by breastmilk. The decrease or abandonment of breastfeeding is alarming in the developing countries, where this natural product is more available, economical and nutritious. There is evidence that within the health institutions, artificial feeding is encouraged. The National Health Survey collected basic information on sociodemographic variables risk factors, demand and use of health services. It also included questions on breastfeeding and weaning for the population under one year of age. It was found that 19.9 percent was never breastfed. Another important fact is that 42.4 percent of children received breastmilk for just three months or less. This view suggests that breastfeeding in our country is changing, due to various factors, among which we can mention the differences in life styles, education and economical development among states. The results of this study show interesting data that oblige us to consider more detailed and specific analyses in the future.

Breast Feeding↗

PubMedDate not supplied

In vitro cytostatic activity and DNA-interaction of the new liver organotropic complex chloro-bis-cholylglycinate-platinum (II).

BACKGROUND: The liver organotropic properties of the new bioinorganic complex of platinum (II) and glycocholic acid, Bamet-H2 have been reported previously. The aim of this work was to investigate the in vitro cytostatic activity of this compound. MATERIALS AND METHODS: The inhibition of cell growth and DNA synthesis by mouse leukemia L-1210 (mL), mouse hepatoma Hepa 1-6 (mH), rat hepatoma McA-RH7777 (rH) and human colon adenocarcinoma LS-174T (hCC) cells were measured. The effects on the electrophoretic mobility of the pUC18 plasmid, the DNA denaturation temperature and ethidium bromide (EthBr) binding to DNA were studied. RESULTS: A significant antiproliferative effect for Bamet-H2 was found (mH approximately hCC > mL approximately rH). DNA synthesis was also markedly inhibited (mH approximately hCC approximately mL approximately rH). Bamet-H2-induced a change in the electrophoretic mobility of pUC18 and the increase in DNA denaturation temperature suggested the existence of DNA-Bamet-H2 interactions. Scatchard plots obtained from EthBr displacement assays revealed that Bamet-H2 induces a reduction in both the number of DNA sites available and their ability to bind EthBr. CONCLUSION: Bamet H2 is able to interact with DNA, inhibit DNA synthesis, and hence reduce cell proliferation.

Adenocarcinoma↗