Hesperidin attenuates benzo[alpha] pyrene-induced testicular toxicity in rats via regulation of oxidant/antioxidant balance.

Benzo[alpha]pyrene (BaP) is one of the polycyclic aromatic hydrocarbons, which has shown carcinogenic, teratogenic, and mutagenic potentials. The reproductive toxicity of BaP in male was not well investigated. Thereby, we have addressed in the current study the testicular toxicity of BaP and the postulate whether or not the citrus flavonoid, hesperidin (HDN), could ameliorate such toxicity in male Swiss albino rats. In this sense, animals were challenged with BaP (50 mg/kg/day, orally) for 10 consecutive days. HDN (200 mg/kg/day, orally) was administered ahead of BaP challenge for 10 consecutive days. BaP induced testicular toxicity that was well characterized histologically and biochemically. It decreased the relative testis weight and induced pyknosis and necrobiotic changes as well as chromatolysis in the nuclei of the spermatocytes in the seminiferous tubules. It also markedly deteriorated epididymal function as shown by decreased sperm count, motility, and daily sperm production. The polyaromatic hydrocarbon also reduced the testicular activities of lactate dehydrogenase (LDH-X), superoxide dismutase (SOD), and glutathione-S-transferase (GST). Besides, it decreased the testicular reduced glutathione (GSH) but increased malondialdehyde (MDA) contents. Prior administration of HDN ahead of BaP challenge ameliorated all the histological and biochemical alterations induced by BaP. It improved the epididymal function and mitigated the injurious effects of BaP on the seminiferous tubules. In conclusion, HDN has proven protective effects in BaP-induced testicular toxicity paradigm, and this protection resides, at least in part, on its antioxidant properties.

Peroxynitrite in the pathogenesis of Parkinson's disease and the neuroprotective role of metallothioneins.

Parkinson's disease (PD) is characterized by a progressive loss of dopaminergic neurons in the substantia nigra zona compacta and in other subcortical nuclei associated with a widespread occurrence of Lewy bodies. The causes of cell death in Parkinson's disease are still poorly understood, but a defect in mitochondrial oxidative phosphorylation and enhanced oxidative stress has been proposed. We have examined 3-morpholinosydnonimine (SIN-1)-induced apoptosis in control and metallothionein-overexpressing dopaminergic neurons, with a primary objective to determine the neuroprotective potential of metallothionein (MT) against peroxynitrite-induced neurodegeneration in PD. SIN-1 induced lipid peroxidation and triggered plasma membrane blebbing. In addition, it caused DNA fragmentation, alpha-synuclein induction, and intramitochondrial accumulation of metal ions (copper, iron, zinc, and calcium), and it enhanced the synthesis of 8-hydroxy-2-deoxyguanosine. Furthermore, it downregulated the expression of Bcl-2 and poly(adenosine diphosphate-ribose) polymerase, but upregulated the expression of caspase-3 and Bax in dopaminergic (SK-N-SH) neurons. SIN-1 induced apoptosis in aging mitochondrial genome knockout cells, alpha-synuclein-transfected cells, metallothionein double-knockout cells, and caspase-3-overexpressed dopaminergic neurons. SIN-1-induced changes were attenuated with selegiline or in metallothionein-transgenic striatal fetal stem cells. SIN-1-induced oxidation of dopamine (DA) to dihydroxyphenylacetaldehyde (DopaL) was attenuated in metallothionein-transgenic fetal stem cells and in cells transfected with a mitochondrial genome, and was enhanced in aging mitochondrial genome knockout cells, in metallothionein double-knockout cells, and caspase-3 gene-overexpressing dopaminergic neurons. Selegiline, melatonin, ubiquinone, and metallothionein suppressed SIN-1-induced downregulation of a mitochondrial genome and upregulation of caspase-3 as determined by reverse transcription polymerase chain reaction. These studies provide evidence that nitric oxide synthase activation and peroxynitrite ion overproduction may be involved in the etiopathogenesis of PD, and that metallothionein gene induction may provide neuroprotection.

Neuroprotective actions of selegiline.

Selegiline, a selective inhibitor of monoamine oxidase-B (MAO-B), was one of the first adjunct therapies in clinical neurology. A retrospective analysis of data from patients with Parkinson's disease found a significant increase in survival in those treated with selegiline plus L-dopa compared with L-dopa alone. The mechanism of action of selegiline is complex and cannot be explained solely by its MAO-B inhibitory action. Pretreatment with selegiline can protect neurons against a variety of neurotoxins, such as 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP), 6-hydroxydopamine, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), methyl-beta-acetoxyethyl-2-chloroethylamine (AF64A), and 5,6-dihydroxyserotonin, which damage dopaminergic, adrenergic, cholinergic, and sertoninergic neurons, respectively. Selegiline produces an amphetamine-like effect, enhances the release of dopamine, and blocks the reuptake of dopamine. It stimulates gene expression of L-aromatic amino acid decarboxylase, increases striatal phenylethylamine levels, and activates dopamine receptors. Selegiline reduces the production of oxidative radicals, up-regulates superoxide dismutase and catalase, and suppresses nonenzymatic and iron-catalyzed autooxidation of dopamine. Selegiline compensates for loss of target-derived trophic support, delays apoptosis in serum-deprived cells, and blocks apoptosis-related fall in the mitochondrial membrane potential. Most of the aforementioned properties occur independently of selegiline's efficacy to inhibit MAO-B.

WHO multicentre randomised trial of misoprostol in the management of the third stage of labour.

BACKGROUND: Postpartum haemorrhage is a leading cause of maternal morbidity and mortality. Active management of the third stage of labour, including use of a uterotonic agent, has been shown to reduce blood loss. Misoprostol (a prostaglandin E1 analogue) has been suggested for this purpose because it has strong uterotonic effects, can be given orally, is inexpensive, and does not need refrigeration for storage. We did a multicentre, double-blind, randomised controlled trial to determine whether oral misoprostol is as effective as oxytocin during the third stage of labour. METHODS: In hospitals in Argentina, China, Egypt, Ireland, Nigeria, South Africa, Switzerland, Thailand, and Vietnam, we randomly assigned women about to deliver vaginally to receive 600 microg misoprostol orally or 10 IU oxytocin intravenously or intramuscularly, according to routine practice, plus corresponding identical placebos. The medications were administered immediately after delivery as part of the active management of the third stage of labour. The primary outcomes were measured postpartum blood loss of 1000 mL or more, and the use of additional uterotonics without an unacceptable level of side-effects. We chose an upper limit of a 35% increase in the risk of blood loss of 1000 mL or more as the margin of clinical equivalence, which was assessed by the confidence interval of the relative risk. Analysis was by intention to treat. FINDINGS: 9264 women were assigned misoprostol and 9266 oxytocin. 37 women in the misoprostol group and 34 in the oxytocin group had emergency caesarean sections and were excluded. 366 (4%) of women on misoprostol had a measured blood loss of 1000 mL or more, compared with 263 (3%) of those on oxytocin (relative risk 1.39 [95% CI 1.19-1.63], p<0.0001). 1398 (15%) women in the misoprostol group and 1002 (11%) in the oxytocin group required additional uterotonics (1.40 [1.29-1.51], p<0.0001). Misoprostol use was also associated with a significantly higher incidence of shivering (3.48 [3.15-3.84]) and raised body temperature (7.17 [5.67-9.07]) in the first hour after delivery. INTERPRETATION: 10 IU oxytocin (intravenous or intramuscular) is preferable to 600 microg oral misoprostol in the active management of the third stage of labour in hospital settings where active management is the norm.

A randomized study comparing rectally administered misoprostol versus Syntometrine combined with an oxytocin infusion for the cessation of primary post partum hemorrhage.

BACKGROUND: Post partum hemorrhage is a major cause of maternal death, particularly in developing countries, and most cases are due to an atonic uterus. Hemorrhage can occur despite active management of the third stage of labor. Presently, misoprostol (Cytotec, Searle Pharmaceuticals) is the only thermostable uterotonic agent potentially available which would be economically beneficial for developing countries where refrigeration of drugs poses a problem. The objective of the study was to compare intra-muscular Syntometrine (Sandoz Pharmaceuticals) (ampoule=5 iu oxytocin and 500 mcg ergometrine maleate) plus Syntocinon (Sandoz Pharmceuticals) (10 iu oxytocin diluted in 500 ml normal saline) intravenous infusion versus 800 mcg misoprostol per rectum for treatment of primary post partum hemorrhage in a developing country. METHODS: Randomized single blinded two-center study, set in both a township and teaching hospital in South Africa. Sixty-four women with primary post partum hemorrhage due to an atonic uterus were recruited. The primary outcome measure was whether the hemorrhage ceased within 20 minutes of administering the first line treatment, once hemorrhage was clinically recognized. RESULTS: There was a 28.1% difference between the misoprostol arm and the Syntometrine and Syntocinon arm (p=0.01). This result had a greater than 80% power. Misoprostol performed better. CONCLUSION: 800 mcg misoprostol per rectum is effective at treating primary post partum hemorrhage.

Second trimester termination of pregnancy for fetal anomaly or death: comparing mifepristone/misoprostol to gemeprost.

OBJECTIVE: To assess the effect of changing the regimen for second trimester induction of labour from gemeprost to mifepristone/misoprostol. DESIGN AND SETTING: A retrospective study at a university teaching hospital over the 5-year period 1993-1997. SUBJECTS, METHODS and REGIMENS: 68 patients, 34 in the gemeprost group and 34 in the mifepristone/misoprostol group. The gemeprost group received 1mg vaginally every 3h to a maximum of five doses. The mifepristone/misoprostol group were pre-treated with 600 mg mifepristone orally followed by 800 microg misoprostol vaginally and then 400 microg orally every 3h to a maximum of four oral doses. MAIN OUTCOME MEASURES: Induction to abortion interval; delivery within 24h. RESULTS: The mifepristone/misoprostol group had a lower induction to abortion interval compared to the gemeprost group (median 8.9h versus 19.8h, respectively, p<0.01). The mifepristone/misoprostol regimen was more successful than the gemeprost regimen; 94% versus 68%, respectively, aborted without extra medical or surgical intervention, p=0.02. There were no significant differences in side effects, analgesia requirements or complications between the two groups. Three patients with previous Caesarean sections had a ruptured uterus; two from the gemeprost group and one from the mifepristone/misoprostol group. CONCLUSIONS: The new mifepristone/misoprostol regimen was more effective in second trimester induction of labour. Induction of labour with misoprostol or gemeprost should be used with care in patients with a previous Caesarean section.

Postpartum intrauterine pressure studies of the uterotonic effect of oral misoprostol and intramuscular syntometrine.

OBJECTIVES: To investigate the effect of oral misoprostol in dosages varying from 200 microg to 800 microg on postpartum uterine contractility and to establish their side effects. DESIGN: A prospective descriptive study. PARTICIPANTS: Fifty-seven women who delivered vaginally after spontaneous labours not requiring augmentation. METHODS: Within 5 minutes of delivery of the placenta, a calibrated Gaeltec catheter with an intrauterine pressure transducer at its tip was inserted transcervically into the uterine cavity. Cumulative uterine activity was recorded for 30 minutes in each woman before administering the oral misoprostol tablets and continued for a further 90 minutes after its administration. Thus each woman acted as her own control regarding changes in uterine contractility. Uterine activity was recorded on a Sonicaid Meridian fetal monitor, which measures active contraction area automatically. The incidence of side effects was also recorded. RESULTS: There was no statistical difference (P = 0.887) in the adjusted mean difference in cumulative uterine activity following all the doses of oral misoprostol, compared with intramuscular syntometrine, the largest difference being seen in oral misoprostol 200 microg (adjusted mean difference -2282 kPas s, 95% CI -7954 to 3390 kPas s). The mean onset of action of oral misoprostol (6.1, SD 2.1 min) was significantly slower than that of intramuscular syntometrine (3.2, SD 1.5 min; P = 0.002), but their durations of action were similar (P = 0.637). In the misoprostol group the commonest side effects were shivering (36%) and a rise in body temperature above 38 degrees C (40%). In the syntometrine group, the most commonly observed side effect was moderate uterine pain (nine out of ten women) and a rise in diastolic blood pressure of 20 mmHg (two out of ten women). CONCLUSION: The results of this study show that oral misoprostol has a definite uterotonic effect on the postpartum uterus. At doses of 200 microg to 400 microg, oral misoprostol has a similar uterotonic effect to intramuscular syntometrine. Higher doses of oral misoprostol are associated with significantly more side effects.

The misoprostol third stage of labour study: a randomised controlled comparison between orally administered misoprostol and standard management.

OBJECTIVE: To compare misoprostol with standard oxytocic regimens in the prevention of postpartum haemorrhage. DESIGN: Randomised controlled trial. SETTING: Obstetric unit in a large teaching hospital. METHODS: One thousand women randomised to 500 microg misoprostol given orally or to standard oxytocic regimens of oxytocin, oxytocin with ergometrine, or ergometrine. MAIN OUTCOME MEASURES: Incidence of postpartum haemorrhage and the incidence and severity of side effects. RESULTS: Postpartum haemorrhage occurred in 12% of women given misoprostol and in 11% of women given standard oxytocic drugs (relative risk (RR) 1.10, 95% confidence interval (CI) 0.79, 1.55). Blood loss of 1000 mL or more occurred in 2% of women in each group. Nausea, headache, dizziness and tiredness were less frequent with misoprostol (RR (95% CI) 0.71 (0.59, 0.84); 0.53 (0.38, 0.74); 0.73 (0.61, 0.87) and 0.88 (0.83, 0.94) respectively). The main side effects of misoprostol were shivering (RR 1.95, 95% CI 1.69, 2.25) and a rise in temperature (difference in mean rise 0.34 degrees C, 95% CI 0.26, 0.42). CONCLUSION: Oral misoprostol for the prevention of postpartum haemorrhage was comparable to standard oxytocics. Many side effects were less common with misoprostol but shivering and pyrexia were more common. Larger randomised trials are needed before establishing the equivalence between misoprostol and standard oxytocic drugs in the prevention of postpartum haemorrhage.

Rectally administered misoprostol for the treatment of postpartum hemorrhage unresponsive to oxytocin and ergometrine: a descriptive study.

OBJECTIVE: To investigate whether rectally administered misoprostol is an effective treatment for postpartum hemorrhage unresponsive to conventional first-line management. METHODS: We studied 14 women with postpartum hemorrhage unresponsive to oxytocin and ergometrine (n = 10) or, when ergometrine was contraindicated, oxytocin alone (n = 4). While awaiting carboprost, misoprostol 1000 microg (five tablets) was administered rectally. RESULTS: In all 14 women, the hemorrhage was controlled, and sustained uterine contraction produced within three minutes of administration of misoprostol. CONCLUSION: Misoprostol appears to be absorbed effectively from rectal as well as oral and vaginal mucosa. Rectally administered misoprostol appears to be an effective treatment for postpartum hemorrhage unresponsive to oxytocin and ergometrine; therefore, it might be an alternative to parenteral prostaglandins or at least minimize the number of women requiring this invasive treatment. Given that it is an inexpensive and stable drug, misoprostol has considerable potential to reduce maternal mortality from postpartum hemorrhage in developing countries.

Identification of metallothionein receptors in human astrocytes.

Metallothionein (MT) isoforms are low molecular weight (6000-7000 Da) zinc binding proteins containing 60-68 amino acid residues, 25-30% cysteine, no aromatic amino acids, and binding between 5-7 g zinc/mol of protein. Since the synthesis of MT is induced by endotoxin, cytokines, and glucocorticoids, MT is now considered to be an acute phase protein protecting against oxygen radicals and oxidative damages caused by inflammation, tissue injury, and stress to the central nervous system. By postulating that a specific mechanism must exist to foster the induction of MTs I and II by numerous and diversified factors, we searched for and identified for the first time, MT receptors on U373MG cell membrane preparations, by using fluoresceinated MT I isoform probe; and by employing cysteine, glutathione, and four MT isoforms to determine high affinity and specific binding. MT receptors revealed a Kd value of 0.84 nM and a Bmax of 99.82 fmol/mg protein. Moreover, MT receptors were found in greater density on the surface of aggregated astrocytes. We postulate that conditions or agents generating reactive oxygen species may influence the expression of MT receptors.

Use of oral misoprostol in the prevention of postpartum haemorrhage.

OBJECTIVE: To investigate the use of the oral prostaglandin E1 analogue, misoprostol in the prevention of postpartum haemorrhage. DESIGN: A prospective observational study. SETTING: A university teaching hospital. PARTICIPANTS: Two hundred and thirty-seven consecutive women undergoing vaginal delivery. METHODS: All the women were given 600 micrograms oral misoprostol just after delivery. MAIN OUTCOME MEASURES: Rates of postpartum haemorrhage; need for therapeutic oxytocic drugs; retained placenta and length of the third stage of labour. RESULTS: Postpartum haemorrhage occurred in 6% of the women; the need for therapeutic oxytocics in 5%, retained placenta in 2% and the median length of the third stage was 5 min. Vomiting and diarrhoea in the first hour after delivery occurred in 8% and 3% respectively and shivering in 60%. CONCLUSIONS: Misoprostol may be effective in the prevention of postpartum haemorrhage, and has few side effects. A double blind randomised trial is required.

Methods of induction of labour.

Several research groups around the world reported on the use of the drug misoprostol in the medical management of miscarriage, abortion and induction of labour. This review examines the evolution of interest in this drug, with special emphasis on its role in induction of labour.

PIP: The induction of labor by prostaglandin agents has been a central research focus for the past 30 years, but their use has been compromised by the high incidence of gastrointestinal side effects. During the late 1970s, the research focus shifted to sequential vaginal administration of different prostaglandin analogues. Currently, the pharmaceutical industry is especially interested in the role of misoprostol in inducing uterine contractibility. Required first, however, is the determination of the correct dosage and frequency that will induce effective uterine contractions without producing uterine hyperstimulation and adverse effects on the fetal heart rate. Because of its thermostability, efficacy, and low cost, the therapeutic use of misoprostol is expected to increase throughout the world in the years ahead.

The antioxidant properties of zinc and metallothionein.

Support for the hypothesis that metallothionein isoforms participate in intracellular defense against reactive oxygen and nitrogen species is derived from observations that substances causing oxidative stress, such as ethanol and iron, and agents involved in inflammatory processes, such as interleukin-1 and tumour necrosis factor alpha, induce the synthesis of metallothionein. Moreover, animals deficient in metallothionein isoforms exhibit greater susceptibility to oxidative stress; metallothionein genes are transcriptionally activated in cells and tissues during oxidative stress; and over expression of metallothionein reduces the sensitivity of cells and tissues to free radical-induced injury. In this study, we have shown that the i.c.v. administration of ZnSO4 increases the synthesis of metallothionein I mRNA and metallothionein II mRNA. In addition, the i.c.v. administration of ZnSO4 enhances the concentration of zinc and in direct proportion the synthesis of metallothionein mRNAs. Agents known to generate free radicals and to cause oxidative stress such as 6-hydroxydopamine, iron, hydrogen peroxide, and various alcohols lead to induction of metallothionein in the hippocampal neurons in primary culture and in Chang liver cells in culture. In view of the fact that zinc and 6-hydroxydopamine induce the level of brain metallothionein and its mRNAs and zinc and metallothionein concentrations vary in different regions of the brain, it is postulated that metallothionein may play a major role in nullifying the iron-mediated generation of free radicals and in protecting against oxidative stress in the brain.

Induction of abortion with mifepristone (RU 486) and oral or vaginal misoprostol.

BACKGROUND: Medical termination of pregnancy can be successfully performed with a combination of mifepristone (RU 486) and a prostaglandin analogue. We conducted a prospective, randomized trial to compare oral with vaginal administration of the prostaglandin E1 analogue misoprostol for first-trimester abortion in women treated initially with mifepristone. METHODS: The study population consisted of 270 women seeking abortion within 63 days after the onset of amenorrhea. The dose of mifepristone was 600 mg, and the dose of misoprostol was 800 micrograms. The study had two primary end points: expulsion of the conceptus without the need for a surgical procedure, and abortion within four hours after the administration of misoprostol. RESULTS: Expulsion of the conceptus without the need for a surgical procedure occurred in 95 percent of the women who received misoprostol vaginally and in 87 percent of those who received it orally (P = 0.03). The rate of continued pregnancy was 7 percent with the oral regimen and 1 percent with the vaginal regimen (P = 0.01). Ninety-three percent of the women receiving misoprostol vaginally had abortions within four hours, as compared with only 78 percent of the women receiving the drug orally (P < 0.001). Vomiting and diarrhea were reported more frequently by the women who received oral misoprostol than by those who received vaginal misoprostol (P = 0.04 and P = 0.002, respectively). CONCLUSIONS: After the administration of mifepristone, vaginal administration of misoprostol is more effective and better tolerated than oral administration for the induction of first-trimester abortion.

PIP: During June 1993-January 1994 in Scotland, clinicians recorded data on 270 women attending the fertility control clinic at Aberdeen Royal Hospitals for voluntary termination of early pregnancy (within 63 days from onset of amenorrhea). They received 600 mg of oral RU-486 on day 1 and either 800 mcg of oral misoprostol or 800 mcg misoprostol inserted deep into the vagina 36-48 hours later. Researchers wanted to compare the safety and efficacy of 800 mcg oral misoprostol with the safety and efficacy of 800 mcg vaginal misoprostol in women who had previously received RU-486. 2.6% aborted before receiving misoprostol. Complete abortion without surgical intervention was more frequent in the vaginal misoprostol group than the oral misoprostol group (95% vs. 87%; p = 0.03). The continued pregnancy rate was lower in the vaginal misoprostol group than the oral misoprostol group (1% vs. 7%; p = 0.01). Expulsion of the conceptus was more likely to occur within 4 hours of receiving misoprostol among the vaginal group than the oral group (93% vs. 78%; p 0.001). The oral misoprostol group had a higher incidence than the vaginal misoprostol group of vomiting (44% vs. 31%; p = 0.04) and diarrhea (36% vs. 18%; p = 0.002). The two groups did not differ significantly with respect to other side effects or severity of symptoms. The women in the oral misoprostol group were more likely to think that the antiemetic drug took minutes rather than 1 or more hours to act than those in the vaginal misoprostol group (61% vs. 34%; p 0.001). These findings show that, following administration of RU-486, vaginal misoprostol was better tolerated and more effective than oral misoprostol at inducing abortion in women in the first trimester of pregnancy.

Induction of abortion in the second trimester by a combination of misoprostol and mifepristone: a randomized comparison between two misoprostol regimens.

The combination of mifepristone (RU486) and prostaglandin is effective in the induction of abortion in the second trimester. The optimal regimen is still under development, but is likely to be characterized by a short induction-to-abortion interval, low incidence of side-effects and high acceptability. We have investigated further whether misoprostol, a synthetic prostaglandin E1 analogue, can reliably induce second trimester abortion in 70 women pre-treated with mifepristone, and whether different routes of administration affect the induction-to-abortion interval. Abortion was achieved in 97% [95% confidence interval (CI) 90-100%] of cases without resort to other prostaglandin agents. The mean induction abortion time for the studied population was 6.4 h (95% CI 5.6-7.0 h). No significant difference was found between two different routes of administration, namely vaginal versus a combination of vaginal and oral. Misoprostol has a number of advantages over other prostaglandin preparations. We recommend that, following pre-treatment with mifepristone, misoprostol is used as the prostaglandin of choice to induce abortion in the second trimester.