Effects of Ocimum sanctum Gestational Administration on Physiological and Behavioral Aspects of Mice Offspring

Aims: Prenatal maternal stress and anxiety affect the offspring causing low birth weight, decreased motor activity, and developmental delays. Ocimum sanctum is cherished as the holiest herb in India and possesses strong adaptogenic, memory enhancer, and anti-stress properties. This study aimed to assess the effect of O. sanctum leaf aqueous extract on preventing pregnancy related stress impact on the mice offspring. Methodology: Pregnant female mice were treated with O. sanctum leaf aqueous extract throughout the gestation period at 100 mg/kg, p.o, while exposed to resident–intruder social stress paradigm. Physiological, morphological, and behavioral aspects of offspring were observed for 6 weeks. Results: Pups of O. sanctum treated mothers showed significantly (P < 0.05) improved body weight, body length, and head length. O. sanctum treatment has significantly reduced eye opening and pinna detachment period (P < 0.05-0.01), and duration for gaining surface righting and mid-air righting refluxes (P < 0.05). O. Sanctum has significantly increased (P < 0.05-0.01) number of correct entries in radial arm maze and line crossing in open field performance. Conclusion: The study outcome proves the beneficial role of O. Sanctum in ameliorating prenatal stress and anxiety induced deleterious effect on offspring.

T3P® mediated domino C(sp2)–H sulfenylation/annulation of enaminones and methylsulfinyls for the synthesis of chromone thioether derivatives

Regio-selective preparation of 3-sulfenylated chromone using T3P® has been described for the first time.

Pharmacological and biochemical analysis of interactions between N-acetylcysteine and some antiepileptic drugs on experimental seizures in mice

PURPOSE

In view of a putative role of oxidative stress in the pathophysiology of seizures, this study addressed the interactions between N-acetylcysteine (NAC), a potent antioxidant and two antiepileptic drugs sodium valproate (SVP) and phenytoin (PHT) on experimental seizures in mice.

METHODS

The interaction was studied at three fixed ratio combinations (i.e., 1:1, 1:3, and 3:1) in the mouse maximal electroshock (MES) test using isobolographic analysis. Markers of oxidative stress (reduced glutathione [GSH] and malondialdehyde [MDA]) were estimated in the cortex of mice pretreated with either of these drugs alone or their 3:1 ratio combinations at the experimentally determined ED(50) values (ED(50 exp) values). The grip strength and spontaneous alternation behavior (SAB) were also assessed. In addition, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and calcium levels were estimated.

RESULTS

We found an anticonvulsant action of NAC in the MES test. Further, the ED(50 exp) values for the combinations of PHT and NAC did not differ from the theoretically calculated ED(50) values indicating additive effects. In case of SVP and NAC, however, the ED(50 exp) values were lower than the theoretically calculated ED(50) values. The interaction of SVP with NAC at the fixed ratios of 1:3 and 3:1 was found to be synergistic. No significant changes were observed in the grip strength, SAB, cortical GSH and MDA levels, serum AST, ALT, ALP, or calcium levels.

CONCLUSION

Our results thus hold promise for the use of NAC as an adjunct to PHT and SVP therapy.

Protection against radiation clastogenecity in mouse bone marrow by Phyllanthus niruri

The effects of aqueous (PnAq) and alcoholic (PnA1 extract (50-250 mg/kg) of P. niruri on in vivo gamma radiation induced chromosome aberration and in vitro antioxidant activity (50-500 microg/ml) were studied. The antioxidant activity was studied by measuring inhibition of hydroxyl radicals generated by the fenton reaction along with pro-oxidant and iron chelating ability. PnA1 showed highly significant in vitro free radical scavenging ability when compared to DMSO above 250 microg/ml concentration. PnAq showed significant pro-oxidant activity while PnA1 was devoid of it at the tested concentrations. Exposure to gamma radiation (4 Gy) caused 29.10 % increase in the frequency of chromosomal aberrations. Administration of PnA1 (250 mg/kg) showed highly significant decrease in chromosomal aberrations compared to radiation treated group. Radioprotective potential of alcoholic extract was found to be more effective than the aqueous extract. Qualitative phytochemical investigation of PnAq and PnA1 revealed the presence of sugars, flavonoids, alkaloid, lignans, polyphenols, tannins, coumarins and saponins. Higher radioprotective effect of the alcoholic extract may be attributed to rich presence of antioxidant polyphenolic compounds.

Review on medicinal and pharmacological properties of Iresine herbstii, Chrozophora rottleri and Ecbolium linneanum

India has a rich tradition of plant-based knowledge on healthcare. A large number of plants/plant extracts/decoctions or pastes are equally used by tribals and folklore traditions in India for treatment of cuts, wounds and burns. The resistance of the microorganism has increased due to the indiscriminate use of commercial antimicrobial drugs commonly used for the treatment of infectious diseases. Resistance to antimicrobial agents has resulted in morbidity, mortality, from treatment failures and increased health care costs. There is an urgent need to discover novel, effective plant-based antimicrobial drug to the increasing problem of drug resistance. This situation forced the scientist to search for new antimicrobial substances from various sources including medicinal plants. Iresine herbstii, Ecbolium linneanum , Chrozophora rottleri have been used in folk remedies and is reported to have a broad range of therapeutic effects. Therefore this paper attempts to bridge the lacunae in the existing literature and offers immense scope for researchers engaged in validation of the traditional claims and development of safe and effective therapeutic agent.

Chromatin-bound PCNA as S-phase marker in mononuclear blood cells of patients with acute lymphoblastic leukaemia or multiple myeloma

OBJECTIVES

Proliferating cell nuclear antigen (PCNA) has often been used as a marker to aid assessment of tumour growth fraction. This paper addresses the question of whether it can be used as an S-phase marker, when the non-chromatin-bound form of the protein is removed by pepsin treatment.

MATERIALS AND METHODS

Cytofluorometric measurements were carried out after immunofluorescence staining of PCNA and counterstaining of DNA. S-phase fraction was determined with the help of windows on PCNA versus DNA scattergrams, or mathematically from DNA histograms.

RESULTS

S-phase fractions obtained using the two methods correlated well, but did not always agree, exact discrepancies depending on the mathematical model used for histogram analysis.

CONCLUSIONS

Determination of S-phase fractions with the help of PCNA immunofluorescence staining is possible, and probably more reliable than calculation of S-fractions from DNA histograms. It thus offers an alternative to assays involving BrdU labelling in vivo.

Beneficial interaction between clobenpropit and pyridoxine in prevention of electroshock-induced seizures in mice: lack of histaminergic mechanisms

Clobenpropit, an H( 3) receptor antagonist, has been reported to modulate both the release of neurotransmitters and also the activity of histidine decarboxylase (HDC). Therefore, a decarboxylase-positive modulator, namely pyridoxine, was taken for interaction studies with clobenpropit in the electroshock (ES) model of seizures in mice and subsequent changes in brain histamine levels were estimated. A significant inhibition of ES-induced seizures was seen after the simultaneous use of clobenpropit and pyridoxine. No significant effects were evident on the brain histamine levels following this combination. The combination of clobenpropit with pyridoxine appears to exhibit beneficial pharmacodynamic interaction for the prevention of ES-induced seizures, which might not be mediated by the histaminergic mechanisms.

Protection against prenatal irradiation‐induced genomic instability and its consequences in adult mice byOcimumflavonoids, orientin and vicenin

PURPOSE

To study the protective effect of orientin and vicenin against early genomic effects of foetal irradiation and their late consequences in mice.

MATERIALS AND METHODS

Fourteen-day pregnant mice were exposed to 1 Gy 60Co gamma-radiation 30 min after an intraperitoneal injection of orientin or vicenin (50 microg kg(-1) body weight). Chromosomal aberrations were studied in foetal liver cells and their spleen colonies (three passages, colony-forming units-spleen CFU-S1, CFU-S2, CFU-S3) and 1-12 months post-partum bone marrow. Peripheral blood counts and solid tumours were recorded to 12 and 20 months, respectively.

RESULTS

Irradiation significantly increased the percent aberrant cells and aberrations/cell in foetal liver and CFU-S1. These effects decreased in later passages of CFU-S and were not seen at 1-6 months post-partum, but increased significantly from 9 months. Total blood counts showed significant reduction from 6 months, while neutrophils increased from 3 months post-partum. Solid tumour incidence in adults increased significantly, with a decrease in age at detection. Orientin/vicenin significantly reduced the chromosomal anomalies in foetal and adult haemopoietic cells, restored blood counts to the normal range, and significantly reduced tumour incidence and delayed tumour development to control age.

CONCLUSIONS

Orientin and vicenin protect against foetal irradiation-induced genomic damage and instability, thereby reducing the delayed chromosomal abnormalities and tumorigenesis in adult.

Enhancement of radiation induced cell death in chicken B lymphocytes by withaferin A

Withaferin A (WA), a plant withanolide, has shown significant radiosensitizing effect in vitro and in vivo. Inhibition of DNA repair has been suggested as a mechanism of radiosensitization by WA. To test this, the effect of withaferin A on survival of DT40 chicken B-lymphocyte cell line and its repair deficient single gene mutants Rad54-/-, Ku70-/- and double mutant Ku70-/- /Rad54-/- after irradiation was studied. Exponentially growing cells were treated for 1 hr with 5 microM WA and then exposed to different doses of X-rays. Cell survival was studied by clonogenic assay. WA significantly reduced survival of DT40, Ku70-/- and Ku70-/- /Rad54-/-, but not Rad54-/- cells, suggesting that WA enhances radiosensitivity by interfering with homologous repair, the major pathway of DSB repair in these cells. Inhibition of DNA repair is further indicated in a significant decrease in surviving fraction of DT40 cells by post-irradiation incubation with WA. This could have relevance to cancer radiotherapy.

Radioprotective effect of sulfasalazine on mouse bone marrow chromosomes

Sulfasalazine (SAZ), a prescribed drug for inflammatory bowel disease, is a potent scavenger of reactive oxygen species. The present study was undertaken to ascertain its ability to protect against gamma radiation-induced damage. Acute toxicity of the drug was studied taking 24-h, 72-h and 30-day mortality after a single intraperitoneal injection of 400-1200 mg/kg body weight (b.wt.) of the drug. The drug LD(50) for 24- and 72-h/30-day survival were found to be 933 and 676 mg/kg b.wt., respectively. The optimum time of drug administration and drug dose-dependent effect on in vivo radiation protection of bone marrow chromosomes was studied in mice. Injection of 30-180 mg/kg SAZ 30 min before gamma irradiation (RT) with 4 Gy produced a significant dose-dependent reduction in the RT-induced percent aberrant metaphases and in the frequency of micronucleated erythrocytes at 24 h after exposure, with a corresponding decrease in the different types of aberrations. The optimum dose for protection without drug toxicity was 120 mg/kg b.wt. At this dose, SAZ produced >60% reduction in the RT-induced percent aberrant metaphases and micronucleated erythrocytes. SAZ also produced a significant increase in the ratio of polychromatic erythrocytes to normochromatic erythrocytes from that of irradiated control. Injection of 120 mg/kg of the drug 60 or 30 min before or within 15 min after 4 Gy whole-body RT resulted in a significant decrease in the percent of aberrant metaphases and in the frequency of micronucleated erythrocytes at 24 h post-irradiation; the maximum effect was seen when the drug was administered 30 min before irradiation. These results show that SAZ protect mice against RT-induced chromosomal damage and cell cycle progression delay. SAZ also protected plasmid DNA (pGEM-7Zf) against Fenton's reactant-induced breaks, suggesting free radical scavenging as one of the possible mechanism for radiation protection.

Antipsychotic-like profile of thioperamide, a selective H3-receptor antagonist in mice

Experimental and clinical evidence points to a role of central histaminergic system in the pathogenesis of schizophrenia. The present study was designed to study the effect of histamine H(3)-receptor ligands on neuroleptic-induced catalepsy, apomorphine-induced climbing behavior and amphetamine-induced locomotor activities in mice. Catalepsy was induced by haloperidol (2 mg/kg p.o.), while apomorphine (1.5 mg/kg s.c.) and amphetamine (2 mg/kg s.c.) were used for studying climbing behavior and locomotor activities, respectively. (R)-alpha-methylhistamine (RAMH) (5 microg i.c.v.) and thioperamide (THP) (15 mg/kg i.p.), per se did not cause catalepsy. Administration of THP (3.75, 7.5 and 15 mg/kg i.p.) 1 h prior to haloperidol resulted in a dose-dependent increase in the catalepsy times (P < 0.05). However, pretreatment with RAMH significantly reversed such an effect of THP (15 mg/kg i.p.). RAMH per se showed significant reduction in locomotor time, distance traveled and average speed but THP (15 mg/kg i.p.) per se had no effect on these parameters. On amphetamine-induced hyperactivity, THP (3.75 and 7.5 mg/kg i.p.) reduced locomotor time, distance traveled and average speed (P < 0.05). Pretreatment with RAMH (5 microg i.c.v.) could partially reverse such effects of THP (3.75 mg/kg i.p.). Climbing behavior induced by apomorphine was reduced in animals treated with THP. Such an effect was, however, reversed in presence of RAMH. THP exhibited an antipsychotic-like profile by potentiating haloperidol-induced catalepsy, reducing amphetamine-induced hyperactivity and reducing apomorphine-induced climbing in mice. Such effects of THP were reversed by RAMH indicating the involvement of histamine H(3)-receptors. Findings suggest a potential for H(3)-receptor antagonists in improving the refractory cases of schizophrenia.

Modulation of pentylenetetrazole-induced seizures and oxidative stress parameters by sodium valproate in the absence and presence of N-acetylcysteine

In view of a role of oxidative stress in epilepsy and the evidence for the involvement of peroxidative injury in sodium valproate (SVP)-induced adverse effects on liver and kidneys, we investigated whether the combination of SVP with N-acetylcysteine (NAC), an antioxidant, may help us to achieve maximal efficacy in terms of seizure control, with minimal toxicity on liver and kidneys. Pentylenetetrazole (PTZ)-induced seizures were used to evaluate the anticonvulsant effect of drugs. Biochemical estimations included the determination of oxidative stress markers like thiobarbituric acid-reactive substances in brain tissue and glutathione (GSH) levels in liver and kidney tissues. Aspartate aminotransferase and alanine aminotransferase concentrations in the serum were also determined to assess liver function. In our study, NAC exhibited a nondose-dependent anticonvulsant effect. The concurrent administration of NAC with SVP significantly prolonged the latency to jerks, myoclonus and clonic generalized seizures. No significant oxidative stress was evident in brain tissue following PTZ-induced seizures, though an elevation of serum transaminase enzymes was seen. SVP at the dose studied did not produce any significant oxidative stress on the liver and kidneys, while treatment with NAC elevated liver and kidney GSH levels. The concurrent administration of NAC with SVP had beneficial effects on liver and kidney cells.

Centella asiatica treatment during postnatal period enhances learning and memory in mice

Present investigation was planned to evaluate the nootropic effect of Centella asiatica. Three months old male Swiss albino mice were injected orally with graded doses (200, 500, 700, 1000 mg/kg body weight) of C. asiatica aqueous extract for 15 days to select an effective dose for nootropic studies. Animals were tested in radial arm maze to assess the learning and memory performance. Based on these results, mice were treated orally with 200 mg/kg of C. asiatica for 15 days from day 15 to day 30 post partum (p.p.) and the nootropic effect was evaluated on the 31st day and 6 months p.p. The behavioral (open field, dark/bright arena, hole board and radial arm maze tests), biochemical (acetylcholine esterase activity) and histological studies (dendritic arborization) were carried out. Performance of juvenile and young adult mice was significantly improved in radial arm maze and hole board tests, but locomotor activity did not show any change compared to control. Treatment resulted in increased acetylcholine esterase activity in the hippocampus. Dendritic arborization of hippocampal CA3 neurons was also increased in terms of intersections and branching points, both at one month and 6 months. Results of the present investigation show that treatment during postnatal developmental stage with C. asiatica extract can influence the neuronal morphology and promote the higher brain function of juvenile and young adult mice.

Effect of Dianex, a herbal formulation on experimentally induced diabetes mellitus

Dianex, a polyherbal formulation consisting of the aqueous extracts of Gymnema sylvestre, Eugenia jambolana, Momordica charantia Azadirachta indica, Cassia auriculata, Aegle marmelose, Withania somnifera and Curcuma longa was screened for hypoglycemic activity in normal and streptozotocin induced diabetic mice. Dianex was administered in different doses of 100-500 mg/kg/day orally in acute (6 h) and long-term (6 weeks) studies. Blood glucose levels were checked 2-6 h after treatment in acute studies and every 2 weeks in long-term studies. Body weight was recorded on the first and final day of the treatment in the long-term studies with diabetic mice. After 6 weeks, high-density lipoprotein, triglycerides, total cholesterol, alanine transaminase (ALT), aspertate transaminase (AST), urea and creatinine were estimated in serum of the diabetic mice. Glycogen and total protein levels were estimated in the liver. Also, the liver and pancreas was subjected to histological examination. Oral glucose tolerance and in vitro free radical scavenging activity was also studied. Dianex produced significant (p<0.05) hypoglycemic activity at 250-500 mg/kg doses in both normal and diabetic mice in acute and long-term studies. The body weight of diabetic mice significantly (p<0.05) increased with all tested doses of Dianex. The elevated triglycerides, cholesterol, ALT, AST, urea and creatinine levels in diabetic mice were significantly (p<0.05) reduced at the doses of 250 and 500 mg/kg. The liver glycogen and protein levels were both significantly (p<0.05) increased in diabetic mice at 250 and 500 mg/kg doses. Dianex increased the glucose tolerance significantly (p<0.05) in both normal and diabetic mice at all the doses tested. Histopathological examination showed that the formulation decreased streptozotocin induced injury to the tissues at all the doses tested. It produced significant (p<0.05) free radical scavenging activity against ABTS+, DPPH and hydroxyl free radicals at the concentrations ranging between 10-1000 microg/ml.Thus, in the present study, Dianex produced significant hypoglycemic activity in both normal and diabetic animals. It also reversed other diabetic complications in diabetic mice at 250 and 500 mg/kg doses. In our earlier study, Dianex was well tolerated in laboratory animals at higher doses (upto 10 g/kg in mice, acute toxicity; up to 2.5 g/kg in rats, subacute toxicity studies for 30 days) without exhibiting any toxic manifestation. Hence, Dianex may be useful in the treatment of diabetes mellitus.

Tracing radiation induced genomic instabilityin vivoin the haemopoietic cells from fetus to adult mouse

The present experiment was aimed at studying the delayed expression of fetal irradiation induced genomic instability in the mouse haemopoietic cells in vivo. The abdominal area of 14 day pregnant Swiss albino mice was exposed to 0-1.5 Gy of gamma radiation. Chromosomal aberrations were studied in three passages of spleen colonies (short-term repopulating stem cells, STRSC) derived from 24 h post-irradiation fetal liver cells and in the 1-20 months postpartum bone marrow (long-term repopulating stem cells, LTRSC). Irradiation produced a significant and dose-dependent increase in the aberrant metaphases in the first passage spleen colony (CFU-S1) cells, which decreased in subsequent passages and reached normal levels by the third passage (CFU-S3). Bone marrow at 1-6 months postpartum showed similar chromosomal picture in the 0 Gy control and after 0.5-1.5 Gy, but there was a clear increase in aberrant cells from 9 months postpartum in the irradiated groups. Some mice in all irradiated groups showed a 2.5- to 5-fold increase in peripheral leukocyte counts. Bone marrow of these animals exhibited severe aneuploidy, the chromosome number ranging from less than 1n to 6n at 20 months of age. Our results indicate that unstable chromosome aberrations induced in the fetal haemopoietic STRSC are eliminated during subsequent cell divisions. However, genomic instability induced in the LTRSC persists and is expressed as chromosomal aberrations at advanced ages. Induction of chromosome aneuploidy could be an early step in the chain of events leading to adult leukaemia after prenatal irradiation.

Response of S 180 murine tumor to bleomycin in combination with radiation and hyperthermia using micronucleus assay: a multimodality approach for therapeutic augmentation

Response of a transplantable tumor, S180, grown intradermally in inbred Balb/c mice, was assessed by using micronucleus assay after treating the solid tumors with bleomycin (BLM), radiation (RT) and hyperthermia (HT) vis-a-vis multimodality approach. The frequency of micronuclei (MN) though did not vary greatly during the one week of observation in untreated tumors, it significantly increased in the drug and RT groups at 24 hr post-treatment. However, MN frequency was non-significant in the HT group from the control. A drug dose dependent linear increase in the frequency of MN induction was evident in 10, 15 and 20 mg/kg body weight BLM alone treated groups. Combination of radiation with BLM or HT further increased the MN counts in the bimodality groups. But, MN induction at 24 hr post-treatment in the trimodality group (BLM + RT + HT) was non-significant from that of the bimodality treatments. However, the tumors treated with trimodality treatment presented severe tumor necrosis, indicating increased cell loss, and resulting in immediate tumor regression. In all the bi-modality groups MN counts though declined 3 or 5 days post-treatment, the values remained significantly higher than the control, on day 7 post-treatment. Micronucleus assay could be used as a predictive parameter for the assessment of post-irradiation tumor regression response. However, the tumor response assessment with MN assay alone may not be sufficient and the role of other parameters, such as apoptosis and necrosis, in immediate tumor regression, especially radiosensitive/thermosensitive tumors can not be ignored while taking multimodality approach into consideration for cancer therapy.

Late effect of prenatal irradiation on the hippocampal histology and brain weight in adult mice

We studied the changes in the brain weight and hippocampal histology in adult offspring exposed to 0.25-1.5 Gy of 60Co gamma radiations during day 14 or 17 of gestation. Irradiation with 0.5-1.5 Gy produced a significant decrease in brain weight of the offspring at 6 and 12 months of age. Exposure to 1 Gy at day 14 or 17 of gestation resulted in significant decrease in the number of neurons in the CA3 and CA4 regions of hippocampus of 200 microm length, while 1.5 Gy significantly affected CA1 region also. The fetal period (13-18 days of gestation) of mouse development is an active phase of brain development involving proliferation, migration and differentiation of cerebral cortex and associated structures. The present results show that exposure at this period of mouse development to moderate doses of gamma radiation can induce permanent deficits in the brain histology, which can adversely affect the learning and memory in adults.

Protection of Mouse Bone Marrow against Radiation-Induced Chromosome Damage and Stem Cell Death by the Ocimum Flavonoids Orientin and Vicenin

In a previous study, orientin and vicenin, the water-soluble plant flavonoids, protected mice against radiation lethality (Uma Devi et al., Radiat. Res. 151, 74-78, 1999). To study bone marrow protection, adult Swiss mice were exposed to 0-6 Gy 60Co gamma rays 30 min after an intraperitoneal injection of 50 microg/ kg body weight of orientin/vicenin. Chromosomal aberrations in bone marrow were studied at 24 h postirradiation. Stem cell survival was studied using the exogenous spleen colony (CFU-S) assay. Radiation produced a dose-dependent increase in aberrant cells as well as in the yield of the different types of aberrations (breaks, fragments, rings and dicentrics) and a decrease in CFU-S. Pretreatment with either flavonoid significantly reduced the aberrant cells and different aberrations and increased the number of CFU-S compared to the respective radiation-alone groups. The dose modification factors for 50% reductions in the number of CFU-S were 1.6 for orientin and 1.7 for vicenin. The present finding that very low nontoxic doses of orientin and vicenin provide efficient protection against bone marrow damage at clinically relevant radiation doses suggests their potential for protection of normal tissues in radiotherapy.

Biological effects after prenatal irradiation (embryo and fetus). A report of the International Commission on Radiological Protection

In its 1990 recommendations, the ICRP considered the radiation risks after exposure during prenatal development. This report is a critical review of new experimental animal data on biological effects and evaluations of human studies after prenatal radiation published since the 1990 recommendations.Thus, the report discusses the effects after radiation exposure during pre-implantation, organogenesis, and fetogenesis. The aetiology of long-term effects on brain development is discussed, as well as evidence from studies in man on the effects of in-utero radiation exposure on neurological and mental processes. Animal studies of carcinogenic risk from in-utero radiation and the epidemiology of childhood cancer are discussed, and the carcinogenic risk to man from in-utero radiation is assessed. Open questions and needs for future research are elaborated. The report reiterates that the mammalian embryo and fetus are highly radiosensitive. The nature and sensitivity of induced biological effects depend upon dose and developmental stage at irradiation. The various effects, as studied in experimental systems and in man, are discussed in detail. It is concluded that the findings in the report strengthen and supplement the 1990 recommendations of the ICRP.

In VivoPostirradiation Protection by a Vitamin E Analog, α-TMG

The water-soluble vitamin E derivative alpha-TMG is an excellent radical scavenger. A dose of 600 mg/kg TMG significantly reduced radiation clastogenicity in mouse bone marrow when administered after irradiation. The present study was aimed at investigating the radioprotective effect of postirradiation treatment with alpha-TMG against a range of whole-body lethal (8.5-12 Gy) and sublethal (1-5 Gy) doses of radiation in adult Swiss albino mice. Protection against lethal irradiation was evaluated from 30-day mouse survival and against sublethal doses was assessed from micronuclei and chromosomal aberrations in the bone marrow 24 h after irradiation. An intraperitoneal injection of 600 mg/kg TMG within 10 min of lethal irradiation increased survival, giving a dose modification factor (DMF) of 1.09. TMG at doses of 400 mg/kg and 600 mg/kg significantly reduced the percentage of aberrant metaphases, the different types of aberrations, and the number of micronucleated erythrocytes. DMFs of 1.22 and 1.48 for percentage aberrant metaphases and 1.6 and 1.98 for micronuclei were obtained for 400 mg/kg and 600 mg/kg TMG, respectively. No drug toxicity was observed at these doses. The effectiveness of TMG when administered postirradiation suggests its possible utility for protection against unplanned radiation exposures.

Effect of 5-aminosalicylic acid on radiation-induced micronuclei in mouse bone marrow

5-Aminosalicylic acid (5ASA), a prescribed drug for ulcerative colitis, is a potent scavenger of oxygen-derived free radicals. The present study was undertaken to ascertain its ability to protect against radiation-induced damage. The drug dose-dependent effect, optimum time of drug administration and radiation dose-dependent effect (0-4 Gy) on in vivo radiation protection against micronuclei induction in polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) were studied in the bone marrow of mice. Intraperitoneal injection of 10-125 mg/kg of the drug 30 min before whole body irradiation with 3 Gy produced a significant reduction in the frequency of micronucleated erythrocytes at 24 h after exposure. The optimum dose for protection without drug toxicity was 25 mg/kg body weight. Injection of 25 mg/kg of the drug 60 or 30 min before or within 15 min after 3 Gy whole body gamma-irradiation resulted in a significant decrease in the radiation-induced PCE and NCE with micronuclei (MPCE and MNCE) and an increase in the ratio of PCE to NCE (P/N), at 24 h post-irradiation. Maximum effect was seen when the drug was administered 30 min before irradiation. Therefore, to study the radiation dose-response, mice were pre-treated with 25 mg/kg of 5ASA 30 min before 1-4 Gy of gamma-irradiation. Radiation increased the MN frequency linearly (r(2)=0.99) with dose. Pre-treatment with 5ASA significantly reduced the MN counts to 40-50% of the radiation (RT) alone values, giving a dose modification factor (DMF) of 2.02 (MPCE) and 2.53 (MNCE). Irradiation resulted in a dose-dependent decline in the P/N ratio at all the doses of radiation studied. 5ASA produced a significant increase in the P/N ratio from that of irradiated controls, at all doses of radiations tested. These results show that 5ASA protect mice against radiation-induced MN formation and mitotic arrest.

Radiosensitivity of the developing haemopoietic system in mammals and its adult consequences: animal studies

The haemopoietic system in the developing mammal is very sensitive to the damaging effects of ionizing radiation. Epidemiological studies have established a strong association between obstetric exposure to diagnostic radiation and an increase in the incidence of childhood leukaemia and between low dose gamma irradiation during the early fetal period and mental retardation in children. It has been suggested that insufficient oxygen supply to the developing brain due to radiation induced damage to fetal haemopoietic tissue has a role in inducing the severe mental retardation observed in the Japanese children exposed to atom bomb radiation in utero. Experimental studies have shown that X- and gamma irradiation of pregnant mice with <1 Gy during the late organogenesis or fetal period caused chromosome damage and significant depletion in the fetal haemopoietic progenitor cells and led to haematological disorders in the adults. The present paper reviews the experimental findings on the effect of pre-natal irradiation on the fetal haemopoietic system and its long-term consequences.

Preliminary studies on acute and subacute toxicity of an antidiabetic herbal preparation, Dianex

Dianex, a polyherbal formulation intended to use for diabetic patients, has been screened for toxic effects. For acute toxicity studies, Dianex was administered orally in graded doses of 0.75-10 g/kg to the mice. For subacute toxicity studies, different doses of Dianex (1.0, 1.5 and 2.5 g/kg) were administered orally to the rats once daily for 30 days. Animals were observed for physiological and behavioural responses, mortality, food and water intake and body weight changes. Hematological evaluation was performed weekly. All the animals were sacrificed on 31st day and changes in organ weights and histology were examined. Biochemical studies were done in liver and serum. No mortality was observed up to 10 g/kg of Dianex in acute toxicity study. Daily administration of as high as 2.5 g/kg dose of Dianex did not result in any mortality or changes in gross behaviour, body weight, weight and histology of different organs or serum and liver biochemistry. However, significant increase in RBC count and hemoglobin level was observed in the treated animals at all doses. Other peripheral blood constituents were in the normal range. The dose of Dianex to produce significant antidiabetic activity in mouse, 0.25-0.5 g/kg, is much lower than the doses used in the present study. Therefore such doses may be safe for daily administration without causing any serious side effects.

Long-term effects of diagnostic ultrasound during fetal period on postnatal development and adult behavior of mouse

Pregnant Swiss albino mice were exposed to diagnostic levels of ultrasound (3.5 MHz, intensity 65 mW, I(SPTP) = 1 W/cm(2), I(SATA) = 240 W/cm(2)) for 10, 20 and 30 minutes on day 14 of gestation. Sham exposed controls were maintained for comparison. Fifteen pregnant mice were exposed for each group. Exposed as well as control animals were left to complete gestation and parturition. Ultrasound induced changes in maternal vaginal temperature was recorded. The changes in the physiological reflexes and postnatal mortality up to 6 weeks of age were recorded. The litters were subjected to behavioral tests for locomotor activity, learning and memory at 4 month and 1 year of age. Neither the physiological reflexes nor the postnatal mortality was affected by ultrasound exposure. However, there was a noticeable impairment in both locomotor and learning behavior even after a 10 min exposure, which further increased with increases in exposure time. Thus the present study demonstrates the neurotoxicity of diagnostic ultrasound and the high susceptibility of early fetal brain to induction of lasting detrimental changes by ultrasound exposure.

Tissue Raman spectroscopy for the study of radiation damage: brain irradiation of mice

Radiotherapy is routinely employed in the treatment of head and neck cancers. Acute cell death, radiation-activated chemical cascades, and the induction of genes coding for protective factors like cytokines are considered to be the major processes involved in radiation damage and repair. It should be possible to follow these processes by monitoring the biochemical interactions initiated by radiation. We have carried out Raman spectroscopy studies on tissue from mice subjected to brain irradiation to identify the biochemical changes occurring in tissue and brain as a result of radiation injury. These studies show that brain irradiation produces drastic spectral changes even in tissue far removed from the irradiation site. The changes are very similar to those produced by the stress of inoculation and restraint and the administration of an anesthetic drug. While the changes produced by stress or anesthetics last for only a short time (a few hours to 1 or 2 days), radiation-induced changes persist even after 1 week. The spectral changes can be interpreted in terms of the observation of new spectra that are dominated by bands due to proteins. The results thus support the hypothesis that various protective factors are released throughout the body when the central nervous system (CNS) is exposed to radiation.

Tissue Raman spectroscopy for the study of radiation damage: brain irradiation of mice

Radiotherapy is routinely employed in the treatment of head and neck cancers. Acute cell death, radiation-activated chemical cascades, and the induction of genes coding for protective factors like cytokines are considered to be the major processes involved in radiation damage and repair. It should be possible to follow these processes by monitoring the biochemical interactions initiated by radiation. We have carried out Raman spectroscopy studies on tissue from mice subjected to brain irradiation to identify the biochemical changes occurring in tissue and brain as a result of radiation injury. These studies show that brain irradiation produces drastic spectral changes even in tissue far removed from the irradiation site. The changes are very similar to those produced by the stress of inoculation and restraint and the administration of an anesthetic drug. While the changes produced by stress or anesthetics last for only a short time (a few hours to 1 or 2 days), radiation-induced changes persist even after 1 week. The spectral changes can be interpreted in terms of the observation of new spectra that are dominated by bands due to proteins. The results thus support the hypothesis that various protective factors are released throughout the body when the central nervous system (CNS) is exposed to radiation.

Radiation protection of human lymphocyte chromosomes in vitro by orientin and vicenin

Orientin (Ot) and Vicenin (Vc), two water-soluble flavonoids isolated from the leaves of Indian holy basil Ocimum sanctum have shown significant protection against radiation lethality and chromosomal aberrations in vivo. In the present study the protective effect of Ot and Vc against radiation induced chromosome damage in cultured human peripheral lymphocytes was determined by micronucleus test. In order to select the most effective drug concentration, fresh whole blood was exposed to 4Gy of cobalt-60 gamma-radiation with or without a 30 min pre-treatment with 6.25, 12.5, 15.0, 17.5 or 20 microM of Ot/Vc. Micronucleus (MN) assay was done by cytochalasin induced cytokinesis block method. Radiation significantly increased the MN frequency (16 times normal). Pre-treatment with either Ot or Vc at all concentrations significantly (P<0.05-0.001) reduced the MN count in a concentration dependent manner, with the optimum effect at 17.5 microM. Therefore, fresh blood samples were incubated with/without 17.5 microM Ot/Vc for 30 min and then exposed to 0.5-4Gy of gamma-radiation. Radiation increased the MN frequency linearly (r(2)=0.99) with dose. Pre-treatment with Ot or Vc significantly (P<0.01-0.001) reduced the MN counts to 51-67% of RT alone values, giving DMFs of 2.62 (Ot) and 2.48 (Vc). Both the compounds showed significant antioxidant activity in vitro at the above concentrations, which was significantly higher than that of DMSO at equimolar concentrations. Thus, the results demonstrate that both the flavonoids give significant protection to the human lymphocytes against the clastogenic effect of radiation at low, non-toxic concentrations. The radioprotection seems to be associated with their antioxidant activity. The clinical potential of these protectors in cancer therapy needs to be investigated.

In vivo radioprotective effect of Moringa oleifera leaves

Radioprotective property of Moringa oleifera leaves was investigated in healthy adult Swiss albino mice. Animals were injected (ip) with 150 mg/kg body weight of 50% methanolic extract (ME) of M. oleifera leaves, as a single dose, or in 5 daily fractions of 30 mg/kg each, and exposed to whole body gamma irradiation (RT, 4 Gy) 1 hr later. Five animals from each group were sacrificed at 1, 2 and 7 days after treatment. Bone marrow protection was studied by scoring aberrations in metaphase chromosomes and micronucleus induction in polychromatic erythrocytes and normochromatic erythrocytes. Pretreatment with a single dose of 150 mg/kg ME significantly reduced the percent aberrant cells to 2/3rd that of RT alone group on day 1 and brought the values to normal range by day 7 post-irradiation. A similar effect was also seen for the micronucleated cells. Fractionated administration of ME (30 mg/kg x 5) gave a higher protection than that given by the same dose administered as a single treatment. ME also inhibited the Fenton reaction-generated free radical activity in vitro in a concentration dependent manner. These results demonstrate that pretreatment with the methanolic leaf extract of M. oleifera confers significant radiation protection to the bone marrow chromosomes in mice and this may lead to the higher 30 day survival after lethal whole body irradiation.

In vivo radioprotection by alpha-TMG: preliminary studies

alpha-TMG is a novel water-soluble derivative of Vitamin E that has shown excellent antioxidant activity. The parent compound has demonstrated protection against radiation induced chromosomal damage in vivo. Hence, the preliminary experiments to determine the radioprotective activity of alpha-TMG were carried out in adult Swiss albino mice. Acute toxicity of the drug was studied taking 24h, 72 h and 30 day mortality after a single intraperitoneal injection of 500-2000 mg/kg body weight of the drug. The drug LD(50) for 24h and 72 h/30 day survival were found to be 1120 and 1000 mg/kg body weight, respectively. The optimum time of drug administration and drug dose-dependent effect on in vivo radiation protection of bone marrow chromosomes was studied in mice. Injection of 600 mg/kg of the drug 15 min before or within 5, 15 or 30min after 3Gy whole body gamma radiation resulted in a significant decrease in the aberrant metaphases percent at 24h post-irradiation; the maximum effect was seen when the drug was given immediately after irradiation. Injection of 200-800 mg/kg TMG within 5 min of irradiation with 3 Gy produced a significant dose-dependent reduction in the radiation induced percent aberrant metaphases and in the frequency of micronucleated erythrocytes at 24h after exposure, with a corresponding decrease in the different types of aberrations. The optimum dose for protection without drug toxicity was 600 mg/kg body weight. At this dose, TMG produced 70 and >60% reduction in the radiation induced percent aberrant metaphases and micronucleated erythrocytes, respectively. The high water solubility and effectiveness when administered post-irradiation favor TMG as a likely candidate for protection in case of accidental exposures.

Effect of early fetal irradiation on the postnatal development of mouse

BACKGROUND

An earlier study has shown that irradiation at the late fetal stage of Swiss albino mice disturbed postnatal growth and appearance of physiological markers. The present study was done to determine the effect of irradiation at the early fetal stage on the postnatal development of mouse.

METHODS

Fourteen-day pregnant Swiss albino mice were exposed to 0.1-1.5 Gy of cobalt-60 gamma-rays. F1 pups were observed for < or = 6 weeks of age. Postnatal mortality, body weight and length, head length and width, tail length, and the time of appearance of physiological markers (pinna detachment, eye opening, fur development, vaginal opening and testes descent) were noted.

RESULTS

There was no increase in congenital anomalies. Postnatal mortality and percentage of growth-retarded pups increased significantly at doses of 0.5-1.5 Gy. A significant delay in the appearance of all the physiological markers was also noted at these doses. Body length, head length, and tail length remained significantly lower than in the controls throughout the observation period at doses of 0.3-1.5 Gy, whereas body weight and head width showed such a persistent change only at > or = 0.5 Gy.

CONCLUSIONS

The early fetal day 14 in mouse is sensitive to radiation-induced postnatal mortality and impairment of growth and temporal development of physiological markers, but not to induction of congenital anomalies. While mortality and physiological markers are not affected at <0.5 Gy, growth retardation appears to have a lower threshold of approximately 0.3 Gy.

Influence of clamping-induced ischemia and reperfusion on the response of a mouse melanoma to radiation and hyperthermia

PURPOSE

To study the response of a mouse melanoma to radiation and hyperthermia under acute hypoxia and reperfusion.

MATERIALS AND METHODS

B16F1 melanoma of 100+/-10 mm3, in C57BL mouse, were locally exposed to 10Gy gamma radiation (RT), 43 degrees C for 30 min (HT) in a water bath, or RT followed immediately by HT, under clamping (acute hypoxia) or 1 h after reperfusion. Tumour regression, volume doubling time (VDT), growth delay (GD), apoptosis and microvascular density (MVD) were studied.

RESULTS

Under clamping, HT increased the VDT and GD to > 20 days above control and resulted in > 50% regression (PR) in all the tumours, whilst RT + HT synergistically enhanced VDT and GD. Under reperfusion, HT produced 25% PR against 16% by RT, with no increase in VDT and GD compared to RT. RT + HT significantly enhanced VDT and GD above that of RT or HT, but did not further increase PR of reperfused tumours. HT under clamping caused > 50% increase in apoptic cells over control and decreased MVD to 1/3rd of control. RT + HT further enhanced apoptotic cells to > 70% and reduced MVD to 1/6th of control.

CONCLUSIONS

These results suggest that combination of radiotherapy with hyperthermia could benefit treatment of tumours with ischemia-induced acute hypoxia.

Effect of irradiation at the early foetal stage on adult brain function of mouse: learning and memory

PURPOSE

To study the long-term effect of early foetal irradiation on the learning and memory in the adult mouse.

MATERIALS AND METHODS

The abdominal area of pregnant Swiss albino mice was exposed to a single dose of 0.25-1.5Gy gamma-radiation on the 14th day of gestation and the mice were left to deliver their offspring. At 6 months of age, the learning and memory functions of the F(1) mice were tested by hole-board activity, conditioned avoidance response and radial arm maze performance. The animals were again subjected to the radial arm maze test at 12 and 18 months of age.

RESULTS

There was a significant dose-dependent decrease in the learning ability and memory retention of 6-month-old mice at doses > 0.25Gy. The significant changes persisted to 18 months of age in mice exposed to >or= 0.5Gy. All changes showed a linear dose-response at doses < 1Gy.

CONCLUSIONS

The gestational day 14 of Swiss albino mice is a sensitive stage in brain development to gamma-ray-induced impairment of learning and memory during the adult life. Permanent deficits in these functions can be induced by a dose of approximately 0.5Gy at this stage, when the developmental activity of the cerebral cortex is at its peak.

Induction of chromosomal instability in mouse hemopoietic cells by fetal irradiation

Mice were exposed to 0.25-1.5Gy of gamma radiation on day 14 or 17 of gestation and chromosomal aberrations were scored in the bone marrow at 12 months of age. Irradiation had resulted in low peripheral blood counts, while some animals developed very high leukocyte counts. Exposed animals showed a significant dose dependent increase in the number of aberrant metaphases, compared to unexposed animals. Fragments and polyploidy were the major types of aberrations. Mice with abnormally high blood leukocyte counts showed a higher incidence of chromosomal aberrations, especially high levels of polyploidy than in animals with low blood counts. It is concluded that radiation induced genomic instability in the fetal hemopoietic cells of mouse is transmitted to postnatal and adult bone marrow which may lead to the development of hematological disorders, including malignancies.

Effect of irradiation at the early fetal stage on adult brain function in the mouse: locomotor activity

PURPOSE

To study long-term changes in the adult locomotor activity of mice after exposure to gamma radiation at the early fetal stage of development.

MATERIALS AND METHODS

Pregnant Swiss albino mice were exposed locally on the abdominal area to a single dose of 0.25-1.5 Gy of 60Co gamma radiation at the dose rate of 1 Gy/min. When the F1 offspring were 6 months old, their locomotor and exploratory behaviour was assessed by the open-field and dark/bright arena tests. Animals were again subjected to the dark/bright arena test at 12 and 18 months of age in order to study the persistence of the effects.

RESULTS

Irradiation produced a noticeable disturbance in the normal behaviour pattern of the mice. There was a significant dose-dependent decrease in the open-field activity of 6-month-old mice. In the dark/bright arena test, the time spent and lines crossed in the dark area showed a significant decrease, while their activities in the brightly lit area increased significantly, indicating a reduced aversion to bright light. These effects were evident even at a dose of 0.3 Gy and increased linearly with dose. The significant behavioural changes persisted at 12 months, but at 18 months the difference in the time spent and lines crossed in the dark and bright areas were not significantly different from sham-irradiated control values below 0.5 Gy.

CONCLUSIONS

These results show that day 14 of gestation in Swiss albino mice is a time of high risk for inducing long-term changes in the adult locomotor function by gamma-radiation doses below 1 Gy. Using a range of radiation doses and different observation times we have demonstrated that the effect increases linearly with dose, but there appears to be a threshold of 0.3-0.5 Gy for producing significant persistent changes in the adult ambulatory activity.

Radiation protection by the ocimum flavonoids orientin and vicenin: mechanisms of action

In previous studies, flavonoids, orientin and vicenin, that were isolated from the leaf extract of Ocimum sanctum, were found to protect mice against radiation injury. Several flavonoids are known to be good antioxidants. Therefore, the effect of orientin and vicenin on radiation-induced lipid peroxidation in vivo and their antioxidant activity in vitro were studied. Adult mice were injected intraperitoneally with 50 microgram/kg of orientin or vicenin and exposed whole-body to 3 Gy of gamma radiation. Lipid peroxidation was measured in the liver 15 min to 8 h postirradiation. The antioxidant activity of orientin/vicenin (10-500 microM) was studied by measuring inhibition of hydroxyl radicals generated by the Fenton reaction (Fe(3+)-EDTA-ascorbic acid-H(2)O(2)) in vitro. The compounds were also tested for possible pro-oxidant and iron chelation activities at the above concentrations in the in vitro system. Orientin and vicenin provided almost equal protection against radiation-induced lipid peroxidation in mouse liver. Both compounds showed a significantly greater free radical-inhibiting activity in vitro than DMSO. Neither orientin nor vicenin showed any pro-oxidant activity at the concentrations tested. Both compounds inhibited free radical formation in the absence of EDTA. Free radical scavenging appears to be a likely mechanism of radiation protection by these flavonoids.

Influence of gestational age to low-level gamma irradiation on postnatal behavior in mice

The present investigation was carried out to study the effects of in utero exposure to low-level gamma radiation (0.25, 0.35, or 0.50 Gy) on the postnatal neurophysiology and neurochemistry of the mouse. Pregnant Swiss albino mice were irradiated on days 11.5, 12.5, 14.5, or 17.5 post coitus (PC) and allowed to deliver. Locomotor and exploratory activities, learning and memory functions, and emotional activities were tested at 3 months of age using behavior tests. A representative group of animals was killed and hippocampal biogenic amines, noradrenaline, dopamine, serotonin (5-HT), and 5-HT's metabolite 5-hydroxy indoleactetic acid (5-HIAA), were measured. Exposure to 0.25 Gy at any of the gestation days did not produce any significant impairment in brain functions. However, an increase in gamma irradiation to 0.50 Gy on all the gestation days produced significant impairment in locomotor (open-field test) and anxiolytic (light and dark area test) activities, learning (hole board test), memory functions (active avoidance test), and emotional activity (rearings). The late fetal period is relatively resistant to radiation-induced impairment of brain functions. Both of the organogenesis gestation days showed a higher sensitivity than the fetal gestation days studied. Even a lower dose of 0.35 Gy when exposed on the late organogenesis days 11.5 and 12.5 PC, produced significant reduction in locomotor and exploratory activities. Day 11.5 PC showed a higher sensitivity than the other PC days studied. Biogenic amines did not show significant change after any of the exposures on any of the gestation days. The results suggest a threshold between 0.25 to 0.35 Gy for postnatal neurobehavior changes.

Modification of radiation induced damage in mouse intestine by WR-2721

Intestinal protection in mice against radiation injury by WR-2721 (300 mg/kg body wt, i.p., 30 min before irradiation) was studied after whole body gamma irradiation (0.5, 1.5, 3.0, 4.5, or 6.0 Gy). Crypt survival and induction of apoptosis, and abnormal mitoses in crypt cells in the jejunum were studied on day 1, 3 and 7 after irradiation. Irradiation produced a significant decrease in crypt survival, whereas apoptosis and abnormal mitoses showed a significant increase from sham-treated control animals. Maximum changes in all the parameters were observed on day 1 after irradiation and the effect increased linearly with radiation dose. There was recovery at later intervals, which was inversely related to radiation dose. WR-2721 pre-treatment resulted in a significant increase in the number of surviving crypts, whereas the number of apoptotic cells in the crypts showed a significant decrease from respective irradiated controls on day 1 after exposure. The recovery was also faster in WR-2721 pre- treated animals. It is concluded that WR-2721 protects against gastrointestinal death by reducing radiation induced cell death, thereby maintaining a higher number of stem cells in the proliferating compartment.

Radiosensitization of a mouse melanoma by withaferin A: in vivo studies

The radiosensitizing effect of a plant withanolide, withaferin A, on the B16F1 mouse melanoma was studied in vivo. Treatment of 100 mm3 tumours with 10 to 60 mg/kg withaferin A intraperitoneally produced a dose dependent increase in growth delay and volume doubling time. Injection of 30-50 mg/kg withaferin A, followed by 30 Gy local gamma irradiation, significantly enhanced the tumour response. No systemic or local adverse reactions were noted in these groups. The drug was most effective when injected intraperitoneally 1 h before irradiation. However, neither the individual agents nor their combination could produce any complete response (tumour cure). Melanoma is a relatively radioresistant tumour. The present results indicate that the radiation response of this tumour can be significantly enhanced by pretreatment with withaferin A.