Reproductive and cytogenetic toxicity of metronidazole in male mice

Metronidazole promotes oxidative stress and DNA fragmentation-mediated myocardial injury in albino mice

The purpose of the present study was to investigate the cardiotoxic effects of Metronidazole (Mtz) in albino mice. The mice were divided into four experimental groups: Gp.I (control group): saline, Gp.II:125 mg/kg b.w Mtz, Gp.III:250 mg/kg b.w, Gp.IV:500 mg/kg b.w Mtz. Heart weight ratio, markers of cardiac injury, markers of oxidative stress, histopathological examinations, DNA fragmentation and spectral analysis were used to determine cardiotoxicity. Administration of 125-500 mg/kg Mtz caused an increase in heart weight and a decrease in body weight. Administration of 500 mg/kg Mtz increased heart weight by 35.5% and decreased body weight by 21.9% compared with control. Mtz-treated mice showed a significant increase in cardiac injury biomarkers and serious alterations in cardiac oxidative stress markers. Histopathological changes of cardiac tissues observed in mice treated with Mtz include myocardial hypertrophy, fibrosis, myocarditis, separation of the muscle fibers, congestion-narrowing in vessels, necrosis, myocardium-vacuolation, myocytolysis, myocyte degeneration, nuclear aggregation, cytoplasmic fragmentation and prevalent nuclei. Mtz treatment already resulted in a significant decrease in the percentage of head DNA and an increase in the percentage of tail DNA. The most striking tail formation among the Mtz-treated groups was observed in the group receiving 500 mg/kg Mtz. In the presence of Mtz, there was a hypochromic shift in the absorption spectrum of DNA, and the potential DNA-Mtz interaction was found to occur in the intercalation mode. These results show that Mtz used against anaerobic bacteria and protozoa in gastrointestinal infections can cause severe cardiotoxic findings in albino mice and cause fragmentation in DNA.

Emergency contraceptive use of Metronidazole among University female students in Dodoma region of Tanzania: a descriptive cross-sectional study

BACKGROUND

Metronidazole is known for its therapeutic effect as antibacterial and anti-parasitic. However, its toxicity on the reproductive system remains unclear. Metronidazole use in rodents is associates with toxic effects on the reproductive system, including hormonal alterations, reduced number of fertile cells and reduced sites for implantation, size of the placental disc area, constituent elements of the labyrinth, and spongiotrophoblast layers. Its use at a therapeutic dose among humans has been associated with an increased risk of spontaneous abortion. The effects on the reproductive system in humans may result in misconceptions about contraceptive effects hence sexually active individuals like students who, for any reason, fail to access safe contraceptive services use any possible methods to protect them from conception. This study aims to investigate the unofficial (un-prescribed) use of Metronidazole as an emergency contraceptive and some of its associated factors.

METHODS

This quantitative cross-sectional study involved 470 participants where stratified random sampling technique was used to obtain the sample from three educational institutions in the Dodoma Municipal, Dodoma region. Collected data were analyzed using SPSS version 25, descriptive statistical analysis was done to determine frequencies, percentages, and association, p < 0.05 was used to determine statistical significance. Further analysis using Multivariate binary logistic regression was done to determine the nature of the association between the study variables.

RESULTS

The finding shows that 169(62.4%) use Metronidazole as an emergency contraceptive. Notably, 345(73.4%) stated that they had ever heard someone use Metronidazole for contraception, especially their peers. Furthermore, an increase in the year of study was significantly associated with reduced use of Metronidazole as an emergency contraceptive (B = [-0.45], p = [0.02]). Furthermore, an increase in age, studying in non-medical college/university, the experience of using contraceptive methods, and hearing someone ever used Metronidazole was found to be positively associated with its use as an emergency contraceptive, although not statistically significant.

CONCLUSION

Metronidazole was found to be used as an emergency contraceptive in high doses, different factors associated with its use, and reasons influencing its use. Further research may be done to explore the toxicological effect of high doses of Metronidazole as a contraception and compare the efficiency of Metronidazole over other emergency contraceptives.

Thiazolidin-4-one-based derivatives - Efficient tools for designing antiprotozoal agents. A review of the last decade

Thiazolidin-4-one derivatives have a wide range of therapeutic implementations and clinical significance for medicinal chemistry. This heterocyclic ring has been reported to possess a variety of biological activities, including antiprotozoal activities that have inspired scientists to integrate this scaffold with different pharmacophoric fragments to design novel and effective antiprotozoal compounds. There are reviews describing thiazolidin-4-ones small molecules as good candidates with a single type of antiprotozoal activity, but none of these show collected news associated with the antiprotozoal activity of thiazolidin-4-ones and their SAR analysis from the last decade. In this review we are focusing on the antitoxoplasmic, anti-trypanosomal, antimalarial, antileishmanial, and antiamoebic activity of these derivatives, we attempt to summarize and analyze the recent developments with regard to the antiprotozoal potential of 4-TZD covering the structure-activity relationship and main molecular targets. The importance of various structural modifications at C2, N3, and C5 of the thiazolidine-4-one core has also been discussed in this review. We hope that all information concluded in this review can be useful for other researchers in constructing new effective antiprotozoal agents.

Exploration of Maternal and Fetal Toxicity Risks for Metronidazole-Related Teratogenicity and Hepatotoxicity through an Assessment in Albino Rats

Metronidazole is the primary antimicrobial drug for treating acute and chronic vaginal pathogens during pregnancy; however, there has been insufficient research on placental disorders, early pregnancy loss, and preterm birth. Here, the potential activity of metronidazole on pregnancy outcomes was investigated. 130 mg/kg body weight of metronidazole was orally given individually to pregnant rats on gestation days 0-7, 7-14, and 0-20. Pregnancy outcome evaluations were carried out on gestation day 20. It was demonstrated that metronidazole could induce maternal and fetal hepatotoxicity. There is a significant increase in the activities of maternal hepatic enzymes (ALT, AST, and ALP), total cholesterol, and triglycerides compared with the control. These biochemical findings were evidenced by maternal and fetal liver histopathological alterations. Furthermore, metronidazole caused a significant decrease in the number of implantation sites and fetal viability, whereas it caused an increase in fetal lethality and the number of fetal resorptions. In addition, a significant decrease in fetal weight, placental weight, and placental diameter was estimated. Macroscopical examination revealed placental discoloration and hypotrophy in the labyrinth zone and the degeneration of the basal zone. The fetal defects are related to exencephaly, visceral hernias, and tail defects. These findings suggest that the administration of metroniazole during gestation interferes with embryonic implantation and fetal organogenesis and enhances placental pathology. We can also conclude that metronidazole has potential maternal and fetal risks and is unsafe during pregnancy. Additionally, it should be strictly advised and prescribed, and further consideration should be given to the associated health risks.

Comparative pharmacokinetics of metronidazole in healthy and Trichomonas gallinae infected pigeons (Columba livia, var. domestica)

1. This study investigated the pharmacokinetics of metronidazole after intravenous (i.v.) and oral administration to healthy and experimentally Trichomonas gallinae-infected pigeons, and determined the in vitro antiprotozoal activity of metronidazole against T. gallinae.2. Twelve pigeons which were experimentally infected to T. gallinae and twelve healthy pigeons received metronidazole at the dose of 25 mg/kg by oral or i.v. administration. Serial blood sampling was used for pharmacokinetic analysis. The metronidazole minimum lethal concentration (MLC) and the concentration killing 50% of the trophozoites (LC₅₀) in the culture media were determined.3. In vitro data showed that the 24 h LC₅₀ and MLC of metronidazole were 0.31 and 25 µg/ml, respectively. In vivo results showed no statistical differences between pharmacokinetics in infected and non-infected pigeons for both routes of administration. The area under the curve was statistically higher after the i.v. administration in both infected and healthy pigeons. The mean oral bioavailability was similar in the infected (83.8%) and the healthy (81.5%) birds.4. In conclusion, the pharmacokinetics of metronidazole in pigeons was not affected by experimentally-induced trichomoniasis. Despite in vitro susceptibility testing, which showed probable resistance of the isolated T. gallinae to metronidazole, five-day oral treatment of infected pigeons with 25 mg/kg metronidazole twice a day resulted in total eradication of trophozoites recovered in crop lavage of infected birds.

Speculative analysis on the electronic structure, IR assignments and molecular docking of N-{4-[(4-amino-3-phenyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)sulfonyl]phenyl}acetamide, an anti-amoebic agent

An exhaustive quantum mechanical calculations on a pharmaceutically critical molecule N-{4-[(4-amino-3-phenyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)sulfonyl]phenyl}acetamide have been investigated through the B3LYP/6-31G∗∗ Density Functional and HF/6-31G∗∗ Wave Function techniques. Physicochemical parameters along with the advanced electronic structure parameters like; MEP (molecular electrostatic potentials) and highest occupied & lowest unoccupied molecular orbitals (HOMO-LUMO) analysis have additionally been scanned over both methods. The computed HOMO-LUMO energy demonstrates that charge exchange takes place inside the molecule. The estimated small HOMO-LUMO energy gap, through both methods, indicates that the molecule is chemically reactive. Further, the IR vibrational spectra of the molecule have been assigned in the region 400-4000 cm⁻¹ through the DFT technique. The anticipated vibrational assignments have been compared with the experimental values accounted for in the literature. To comprehend the mode of binding, docking investigations of the molecule alongwith the co-crystallized metronidazole (MNZ) molecule were accomplished with O-acetyl-serine-sulfhydrylase (OASS) enzyme using GLIDE-SP and GLIDE-XP modules. Docking simulations and reported biological activities (IC50) demonstrate that the title molecule may act as a lead molecule for constraining the progression of Entamoeba histolytica illness.

Thiamine deficiency and oxidative stress induced by prolonged metronidazole therapy can explain its side effects of neurotoxicity and infertility in experimental animals: Effect of grapefruit co-therapy

We aimed to explore the possible neurotoxicity and infertility mechanisms of prolonged metronidazole (MTZ) use and the effects of antioxidant grapefruit (GP) co-therapy on MTZ-induced complications. Sixty male albino Wistar rats were divided into four groups (n = 15 each). Group I (control group) received 1% dimethyl sulfoxide (27 ml/ kg/day), group II (MTZ group) received MTZ (400 mg/kg/day), group III (MTZ + GP) received MTZ (400 mg/kg/ day) plus GP juice (27 ml/kg/ day) and group IV (GP group) received GP juice (27 ml/kg) for 60 days. Semen analyses were performed. Free testosterone, gonadotrophin (follicle-stimulating hormone (FSH) and luteinizing hormone) and thiamine levels were measured. Samples of cerebellar, testicular and epididymal tissues were used for both colorimetric assays of oxidative stress markers and histopathological examinations. Significant decreases in the sperm count, percent total sperm motility, serum thiamine levels, free testosterone levels and FSH levels were observed in the MTZ and MTZ + GP groups (p < 0.05 for all parameters). Significantly higher oxidative stress levels (p < 0.05) were observed in the cerebellar and testicular tissue homogenates of these groups than in those of the control group, and associated disruptions in the cerebellar, testicular and epididymal structures were apparent compared to those of the control group. Although the GP group showed a significantly higher sperm count and significantly lower oxidative stress than the control group (p < 0.05), with histological similarity to the control group, the GP group exhibited significantly higher prolactin levels and lower free testosterone and FSH levels than the control group (p < 0.05). Oxidative stress and decreased thiamine levels could explain the MTZ-induced neurotoxicity and infertility side effects that aggravated by GP co-administration.

Effect of metronidazole on placental and fetal development in albino rats

Metronidazole is an antiprotozoal and antibacterial used in gynecology and obstetrics for the treatment of parasitic infections. However, despite having clinical use for more than three decades, questions about the safety of its use during pregnancy is not well understood. Thus, the present study evaluated the effect of metronidazole on placental and fetal development in pregnant rats. Metronidazole was orally administered by gavage at a dosage of 130 mg/kg for 7 and 14 days. Morphological analysis, morphometry and immunohistochemistry were performed at the implantation sites and placentas with 14 days of development. The results showed that in the treated group there was a significant reduction in the number of implantation sites, total placental disc area and constituent elements of the labyrinth and spongiotrophoblast layers. Histochemical analysis revealed no significant changes in the content of collagen, elastic and reticular fibers. The TUNEL test showed apoptotic activity in the implantation sites and placentas with 14 days of development independent of the treatment. There was no evidence of malformation in the neonates. However, there was a significant reduction in the number and weight of neonates in the group treated with metronidazole when compared to the control group. Thus, it is concluded that the administration of 130 mg/kg of metronidazole during pregnancy in rats, in addition to interfering with the number of implanted embryos, promotes changes in placental structure and interferes with fetal development. This suggests that this drug should be used with caution during pregnancy.

Recent Advances in the Discovery of Novel Antiprotozoal Agents

Parasitic diseases have serious health, social, and economic impacts, especially in the tropical regions of the world. Diseases caused by protozoan parasites are responsible for considerable mortality and morbidity, affecting more than 500 million people worldwide. Globally, the burden of protozoan diseases is increasing and is been exacerbated because of a lack of effective medication due to the drug resistance and toxicity of current antiprotozoal agents. These limitations have prompted many researchers to search for new drugs against protozoan parasites. In this review, we have compiled the latest information (2012-2017) on the structures and pharmacological activities of newly developed organic compounds against five major protozoan diseases, giardiasis, leishmaniasis, malaria, trichomoniasis, and trypanosomiasis, with the aim of showing recent advances in the discovery of new antiprotozoal drugs.

New changes in pregnancy and lactation labelling: Review of dermatologic drugs

Background

The U.S. Food and Drug Administration has published new pregnancy and lactation labelling rules that set standards on the presentation of information with regard to drug usage during pregnancy and breastfeeding, as well as the effects on fertility. These guidelines became effective June 30, 2015, and classified the risks of using prescription drugs during pregnancy in three detailed subsections: Pregnancy, Lactation, and Females and Males of Reproductive Potential. These sections describe the risks within a real-world context of caring for these patients.

Objective

In this study, we reclassified and categorized drugs and treatments commonly used in dermatology according to these new guidelines.

Methods

We performed a search of the medical literature about the use of relevant prescription drugs during pregnancy and breastfeeding and their effect on fertility. The search included prospective and retrospective studies, review articles from PubMed-indexed journals (from inception to November 2018), U.S. Food and Drug Administration records, pregnancy exposure registries, relevant information and studies provided in drug labeling by companies, and updated pharmacologic texts and guidelines up to 2018.

Results

Topical immunomodulators, systemic immunomodulators (including biologics), systemic antipruritic agents, antimicrobials, as well as acne, hair, and cosmetic agents were included. We have made best attempts to review and consolidate existing and new data and include them in our guide.

Conclusion

This new narrative format facilitates prescribing by considering a variety of factors. One previously overlooked aspect was the impact on the reproductive potential of both male and female patients. Rather than depending on overly simplistic letter risk categories, dermatologists will now need to make prescribing decisions based on each patient and the information provided, which will allow for better decision making and patient care.

A Case of Aplastic Anemia Associated With Long-Term Metronidazole Use

Metronidazole is a nitroimidazole antibacterial agent that is highly effective for the treatment of protozoal and anaerobic infections. Metronidazole is known to cause hematologic adverse effects, including a reversible mild neutropenia; in rare circumstances, thrombocytopenia has been associated with metronidazole treatment. We present a case of aplastic anemia related to the extended use of metronidazole.

Effect of Metronidazole on the Oxidoreductive Processes in the Submandibular and Parotid Glands in Experimental Research

Oxidative stress takes part in the pathomechanisms of many diseases, including oral disorders. The imbalance between oxidative and antioxidative processes may lead to periodontitis, osteitis, or oral cancers. Furthermore, many chemotherapeutics, e.g., metronidazole (MTZ), may also cause toxic reactions and affect oxidative reactions. The research focused on MTZ influence on oxidative destruction in the parotid and submandibular gland tissue in animal experimental model. Therefore, the concentrations of enzymatic and nonenzymatic markers of oxidative stress were measured in these two rat glands in the control and experimental MTZ-treated groups. The material for analysis included parotid and submandibular glands of male Wistar rats, which were treated with metronidazole for 7 days by gastric tube in a dose of 100 mg/kg b.w. On day 8, the material was obtained and frozen in temp. -80°C. Then, the following seven enzymatic and nonenzymatic parameters were measured: GPx, TOS, TAS, SOD, LPO, CAT, and GSH. The data were analysed using Statistica 10.0. Metronidazole treatment in the experimental model showed an increase in LPO, TOS, and TOS/TAS and a decrease in CAT, SOD, GPx, and TAS. The conclusions of this research were made. Metronidazole treatment in a dose of 100 mg/kg b.w. caused imbalance between oxidative and antioxidative reactions in the rat parotid and submandibular glands. An increase was observed in LPO, TOS, and TOS/TAS in both glands exposed to metronidazole. Decreased activity of CAT, SOD, GPx, and TAS was noted, which indicates attenuation of the gland antioxidative protective barrier.

Tribulus terrestris improves metronidazole-induced impaired fertility in the male mice

INTRODUCTION

Fruit extract of Tribulus terrestris (TT) bears aphrodisiac and antioxidative properties. Antimicrobial drug, metronidazole (MTZ) impairs the spermatogenic activity and fertility in males.

OBJECTIVE

Validation of the use of fruit extract of TT as a supplement against MTZ-induced fertility impairment in males.

METHODS

Adult Swiss strain male mice were administered with 500mg/kgBW/day of MTZ for 28 days. Low (100mg/kgBW/day) and high (200mg/kgBW/day) doses of TT were administered simultaneously with MTZ (500mg/kgBW/day) for same duration. All males were cohabited with virgin proestrus females. Vaginal plug formation was observed to calculate the libido index. Cohabited females were sacrificed on fifteenth day of gestation to dissect out the ovaries and uteri. Fertility index, quantal pregnancy, pre-implantation and post-implantation losses were calculated.

RESULTS

MTZ-treated males showed unaltered mating ability, however, the females impregnated by such males exhibited marked alterations in the fertility index, quantal pregnancy and pre- and post-implantation losses. Supplementation with low dose of TT failed to restore such reproductive toxicities exhibited by administration of MTZ. However, the altered reproductive toxicities were reinstated to control values following supplementation with high dose of TT.

CONCLUSION

The fruit extract of TT may emerge as an effective herbal remedy, correcting the drug-induced fertility impairments in males.

Design, Synthesis and Preliminary Antimicrobial Evaluation of N-Alkyl Chain Tethered C-5 Functionalized Bis-Isatins

A series of N-alkyl tethered C-5 functionalized bis-isatins were synthesized and evaluated for antimicrobial activity against pathogenic microorganisms. The preliminary evaluation studies revealed the compound 4t, with an optimal combination of bromo-substituent at the C-5 position of isatin ring along with propyl chain linker being most active among the synthesized series exhibiting an IC50 value of 3.72 μM against Trichomonas vaginalis while 4j exhibited an IC50 value of 14.8 μM against Naegleria fowleri, more effective than the standard drug Miltefosine. The compound 3f with an octyl spacer length was the most potent among the series against Giardia lamblia with an IC50 of 18.4 μM while 3d exhibited an IC50 of 23 μM against Entamoeba histolytica. This library was also screened against the fungal pathogen Aspergillus parasiticus. A number of the compounds demonstrated potency against this fungus, illustrating a possible broad-spectrum activity. Furthermore, an evaluation of these synthesized compounds against a panel of normal flora bacteria revealed them to be non-cytotoxic, demonstrating the selectivity of these compounds. This observation, in combination with previous studies that isatin is non-toxic to humans, presents a new possible scaffold for drug discovery against these important protozoal pathogens of humans and animals.

Recent progress on the discovery of antiamoebic agents

A large number of protozoans infect humans but Entamoeba histolytica is the only organism responsible for causing amoebiasis, a deadly disease after malaria. Numerous heterocycle-based antiamoebic agents have been previously synthesized as E. histolytica inhibitors and while some of these agents have shown moderate activity, the search for a novel and ideal antiamoebic compound is still ongoing. In this digest Letter, we present the latest data on antiamoebic agents from 2011 to 2016 based on the different classes of heterocyclic agents.

Synthesis, antiamoebic and molecular docking studies of furan-thiazolidinone hybrids

In continuation of our previous work, a series of furan-thiazolidinone hybrids was prepared by Knoevenagel condensation of 3-(furan-2-ylmethyl)-2-(phenylimino)-1, 3-thiazolidin-4-one with different aryl aldehydes in presence of strong base. Some members of the series exhibited remarkable antiamoebic activity and cell viability. Three compounds (3, 6 and 11) showed excellent binding energy for Entamoeba histolytica O-acetyle-l-serine sulfohydrolase and Entamoeba histolytica thioredoxin reductase. These compounds demonstrated significant inhibition of O-acetyle-l-serine sulfohydrolase. The promising antiamoebic activity and enzymatic assay of 3, 6 and 11 make them promising molecules for further lead optimization in the development of novel antiamoebic agents.

Curcumin Protects the Seminal Vesicles from Metronidazole‑induced Reduction of Secretion in Mice

Seminal vesicle secretion is important for increasing the stability of sperm chromatin, inhibition of the immune activity in the female reproductive tract and so on. Metronidazole (MTZ), a drug used for treatment of infections caused by anaerobic bacteria and protozoa, may have negative effects on the genital gland including the seminal vesicles. Curcumin exhibits antioxidant as well as anti‑inflammatory properties. The present study aims to evaluate the negative effects of MTZ on the seminal vesicle structure and ameliorative effects of curcumin using stereological methods. Thirty balb/c mice were divided into six groups. The control group was received distilled water. The second and the third received higher doses of MTZ (500 mg/kg body weight/day) and MTZ (500 mg/kg/day) + 100 mg/kg/day curcumin, respectively. The fourth and the fifth were treated with lower doses of MTZ (165 mg/kg body weight/day) and MTZ (165 mg/kg body weight/day) + curcumin (100 mg/kg body weight/day), respectively. The sixth group received 100 mg/kg body weight/day curcumin. All the administrations were done by oral gavages for 14 days. After 30 days, seminal vesicles were removed. Stereological study of the seminal vesicle structure revealed a significant reduction in gland and vesicular fluid volume in MTZ‑treated (higher or lower doses) animals. Curcumin protected the reduction of both parameters in therapeutic‑dose treated animals. Metronidazole treatment does not induce structural changes in the seminal gland; however, it can have a significant impact on its secretion ability. Importantly, these deteriorations might be preventable by curcumin co‑treatment.

Synthesis, characterization and antiamoebic activity of chalcones bearing N-substituted ethanamine tail

A series of chalcones (4-21) possessing N-substituted ethanamine were synthesized by the aldol condensation reaction of 1-(4-(2-substituted ethoxy)phenyl)ethanones with different aldehydes preceded by the reaction of 2-chloro N-substituted ethanamine hydrochloride and 4-hydroxy acetophenone. The structure of all the synthesized compounds was elucidated by various spectral and X-ray diffraction studies. The compounds were screened against HM1: IMSS strain of Entamoeba histolytica and cytotoxicity was performed on A549 (non-small cell lung cancer cell line) cells by MTT assay. Out of eighteen compounds twelve showed better activity then the standard drug metronidazole. The compound 9, 14 and 19 showed good cell viability, hence were least toxic.

Synthesis and antiprotozoal activity of mono- and bis-uracil isatin conjugates against the human pathogen Trichomonas vaginalis

A library of mono- and bis-uracil isatin conjugates were synthesized and subjected for the assessment of their in vitro activity against the protozoal pathogen Trichomonas vaginalis. The structure activity studies (SAR) revealed that the bis-uracil-isatin based conjugates were more effective than their corresponding mono conjugates in inhibiting the growth of T. vaginalis at approximately 10 μM with no visual effect on mammalian cells at the same concentration.

Curcumin protects metronidazole and X-ray induced cytotoxicity and oxidative stress in male germ cells in mice

Metronidazole (MTZ) is a common antiparasitic and antibacterial drug. The drug and X-ray induced effects in mouse sperm count, sperm head abnormality and some oxidative stress parameters have been studied. Simultaneously the protective role of curcumin has been evaluated. MTZ, 40 mg/kg bw and 13.4 mg/kg bw × 3 days exposure induced abnormal sperm head and reduced total sperm count in Swiss albino mice both after 24 h and 35 days of exposure. However, MTZ treatment in mice receiving X-ray irradiation (0.5 Gy) did not changed the incidence of abnormal sperm population or decrease in the total sperm count. Hepatic glutathione (GSH), superoxide dismutase (SOD) declined significantly during the treatment phase with significant rise in lipid peroxidation of the tissue. The cellular changes were estimated by using lipid peroxidative indices like thiobarbituric acid reactive substances (TBARS). Elevated TBARS is indicative of oxidative stress in treated mice. Furthermore, curcumin pre-treatment apparently reduced the frequency of sperm head abnormality and TBARS induced by MTZ alone or in combination with X-ray and increased the levels of hepatic GSH and SOD. The additive effects of MTZ and X-ray could not be observed with regards to sperm head abnormality and total sperm count in the tested dose range although the cellular antioxidants were found to be significantly lowered and lipid peroxidantion increased. The possible role of MTZ and X-ray inducing sperm abnormality, decreased sperm count and alteration in GSH, SOD and TBARS and defensive role of curcumin have been evaluated.

Antifertility potentials of metronidazole in male Wistar rats

There is a growing concern about the decline in the quality of human sperm in recent years. Following reports by previous studies on the toxic effects of metronidazole on testicular functions, this study is designed to investigate further its direct effects on fertility potentials and that of the introduction of vitamin E and testosterone to metronidazole treated rats. A total of 105 adult male and 50 female Wistar rats weighing 170 +/- 10 g (70-90 day old) were used for the experiment. The rats were randomly divided into a control and experimental groups. There were four major groups with 5 subgroups consisting of 5 rats each. Varying doses of metronidazole were used depending on the experiment. Experiment 1; animals were fed with 15 mg kg(-1) of metronidazole, experiment 2, fed with 30 mg kg(-1) of metronidazole, experiment 3, administered with 200 mg kg(-1) of metronidazole and experiment 4, fed with 400 mg kg(-1) of metronidazole. Each experimental group has 5 sub-groups. A: control, B: group fed with the experimental dose, C: experimental dose with vitamin E, D: experimental dose with testosterone, E: fed with experimental dose, vitamin E and testosterone and sub-group F, a reversal group which was left for 8 weeks after cessation of treatment. Parameters assessed were sperm count/motility, hormonal assay, Fertility test for control and treated rats were also carried out. Results showed that metronidazole at the therapeutic dose of 15 mg kg(-1) did not have significant negative effect on the parameters assessed. At the dose of 200 and 400 mg kg(-1), there was reduction in testosterone and follicle stimulating hormone while on the other hand, luteinizing hormone was increased mostly with 400 mg kg(-1) of metronidazole treatment. Body weight was also found to be significantly reduced in rats treated with 200 and 400 mg kg(-1) of metronidazole. The results of this study indicate that metronidazole administration (200 or 400 mg kg(-1)), for 8 weeks, caused a harmful effect on fertility potentials in male rats.

Synthesis, characterization, and anti-amoebic activity of N-(pyrimidin-2-yl)benzenesulfonamide derivatives

A new series of N-(pyrimidin-2-yl)benzenesulfonamide derivatives, 3a-3i and 4a-4i, was synthesized from pyrimidin-2-amines, 2a-2i, with the aim to explore their effects on in vitro growth of Entamoeba histolytica. The chemical structures of the compounds were elucidated by elemental analysis, FT-IR, (1) H- and (13) C-NMR, and ESI mass-spectral data. In vitro anti-amoebic activity was evaluated against HM1 : IMSS strain of Entamoeba histolytica. The IC50 values were calculated by using the double dilution method. The results were compared with the IC50 value of the standard drug 'metronidazole'. The selected compounds were tested for their cytotoxic activities by cell-viability assay using H9C2 cardiac myoblasts cell line, and the results indicated that all the compounds displayed remarkable >80% viabilities to a concentration of 100 μg/ml.

Micronuclei in genotoxicity assessment: from genetics to epigenetics and beyond

Micronuclei (MN) are extra-nuclear bodies that contain damaged chromosome fragments and/or whole chromosomes that were not incorporated into the nucleus after cell division. MN can be induced by defects in the cell repair machinery and accumulation of DNA damages and chromosomal aberrations. A variety of genotoxic agents may induce MN formation leading to cell death, genomic instability, or cancer development. In this review, the genetic and epigenetic mechanisms of MN formation after various clastogenic and aneugenic effects on cell division and cell cycle are described. The knowledge accumulated in literature on cytotoxicity of various genotoxins is precisely reflected and individual sensitivity to MN formation due to single gene polymorphisms is discussed. The importance of rapid MN scoring with respect to the cytokinesis-block micronucleus assay is also evaluated.

Synthesis of 1H-1,2,3-triazole linked β-lactam-isatin bi-functional hybrids and preliminary analysis of in vitro activity against the protozoal parasite Trichomonas vaginalis

Twenty-two different triazoles were prepared to examine the anti-Trichomonas vaginalis structure-activity relationships (SAR) within the β-lactam-isatin-triazole conjugate family. The compounds were synthesized by copper-catalyzed 'click chemistry.'In vitro activity against T. vaginalis was determined at 10 and 100 μM for each compound, with eighteen of the synthesized hybrids showing 100% growth inhibition at 100 μM. The compound 5i, with no cytotoxicity on cultured CHO-K1 cells, is considered a good compound for further analysis.

Biochemical, mutational and in silico structural evidence for a functional dimeric form of the ornithine decarboxylase from Entamoeba histolytica

BACKGROUND

Entamoeba histolytica is responsible for causing amoebiasis. Polyamine biosynthesis pathway enzymes are potential drug targets in parasitic protozoan diseases. The first and rate-limiting step of this pathway is catalyzed by ornithine decarboxylase (ODC). ODC enzyme functions as an obligate dimer. However, partially purified ODC from E. histolytica (EhODC) is reported to exist in a pentameric state.

METHODOLOGY AND RESULTS

In present study, the oligomeric state of EhODC was re-investigated. The enzyme was over-expressed in Escherichia coli and purified. Pure protein was used for determination of secondary structure content using circular dichroism spectroscopy. The percentages of α-helix, β-sheets and random coils in EhODC were estimated to be 39%, 25% and 36% respectively. Size-exclusion chromatography and mass spectrophotometry analysis revealed that EhODC enzyme exists in dimeric form. Further, computational model of EhODC dimer was generated. The homodimer contains two separate active sites at the dimer interface with Lys57 and Cys334 residues of opposite monomers contributing to each active site. Molecular dynamic simulations were performed and the dimeric structure was found to be very stable with RMSD value ∼0.327 nm. To gain insight into the functional role, the interface residues critical for dimerization and active site formation were identified and mutated. Mutation of Lys57Ala or Cys334Ala completely abolished enzyme activity. Interestingly, partial restoration of the enzyme activity was observed when inactive Lys57Ala and Cys334Ala mutants were mixed confirming that the dimer is the active form. Furthermore, Gly361Tyr and Lys157Ala mutations at the dimer interface were found to abolish the enzyme activity and destabilize the dimer.

CONCLUSION

To our knowledge, this is the first report which demonstrates that EhODC is functional in the dimeric form. These findings and availability of 3D structure model of EhODC dimer opens up possibilities for alternate enzyme inhibition strategies by targeting the dimer disruption.

Effect of bovine lactoferrin in a therapeutic hamster model of hepatic amoebiasis

Entamoeba histolytica is the causative agent of amoebiasis, a disease that produces dysentery as a result of the perforation of the large intestine. This parasite often invades other organs, primarily the liver, leading to an amoebic liver abscess (ALA), which can cause death. Metronidazole is the drug of choice for the treatment of ALA; however, it produces toxic side effects in patients. Lactoferrin (Lf) is a glycoprotein of the innate immune response that sequesters iron in the mucosae. Lf possesses immune-regulatory properties, such as antiinflammatory and antioxidant activities. Moreover, the microbicidal activity of apoLf, which lacks bound iron, has been shown. In this study, we evaluated the therapeutic effect of bovine Lf (bLf) against ALA in a model of hepatic amoebiasis in hamsters. Interestingly, hamsters treated intragastrically with Lf (2.5 mg/100 g mass) over a period of 8 days showed no clinical signs of disease and ALA was effectively decreased, with only 0.63% detectable lesion, compared with 63% in untreated animals. Furthermore, liver function and blood cells approached normal levels among those receiving bLf treatment. These results suggest that bLf may aid in the therapy of amoebiasis, likely without producing undesirable effects in patients.

Synthesis, characterization, antiamoebic activity and cytotoxicity of new pyrazolo[3, 4-d]pyrimidine-6-one derivatives

A new series of pyrazolo[3,4-d]pyrimidine-6-one derivatives (2a-2j) were prepared by using the Biginelli multicomponent cyclocondensation of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one (1a), different aromatic aldehydes, and urea with a catalytic amount of HCl at reflux temperature. These compounds were characterized by IR, (1)H NMR, (13)C NMR, and Mass spectral data. In vitro antiamoebic activity was performed against HM1:IMSS strain of Entamoeba histolytica. The results showed that the compounds 2b, 2i, and 2j with IC(50) values of 0.37 µM, 0.04 µM, and 0.06 µM, respectively, exhibited better antiamoebic activity than the standard drug metronidazole (IC(50) = 1.33 µM). The toxicological studies of these compounds on human breast cancer MCF-7 cell line showed that the compounds 2b, 2i, and 2j exhibited >80% viability at the concentration range of 1.56-50 µM.