Anti-oxidant effect of Withania somnifera glycowithanolides in chronic footshock stress-induced perturbations of oxidative free radical scavenging enzymes and lipid peroxidation in rat frontal cortex and striatum

The antioxidant activity of Withania somnifera (WS) glycowithanolides was assessed in chronic footshock stress induced changes in rat brain frontal cortex and striatum. The stress procedure, given once daily for 21 days, induced an increase in superoxide dismutase (SOD) and lipid peroxidation (LPO) activity, with concomitant decrease in catalase (CAT) and glutathione peroxidase (GPX) activities in both the brain regions. WS glycowithanolides (WSG), administered orally 1 h prior to the stress procedure for 21 days, in the doses of 10, 20 and 50 mg/kg, induced a dose-related reversal of the stress effects. Thus, WSG tended to normalise the augmented SOD and LPO activities and enhanced the activities of CAT and GPX. The results indicate that, at least part of chronic stress-induced pathology may be due to oxidative stress, which is mitigated by WSG, lending support to the clinical use of the plant as an antistress adaptogen.

Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study

The roots of Withania somnifera (WS) are used extensively in Ayurveda, the classical Indian system of medicine, and WS is categorized as a rasayana, which are used to promote physical and mental health, to provide defence against disease and adverse environmental factors and to arrest the aging process. WS has been used to stabilize mood in patients with behavioural disturbances. The present study investigated the anxiolytic and antidepressant actions of the bioactive glycowithanolides (WSG), isolated from WS roots, in rats. WSG (20 and 50 mg/kg) was administered orally once daily for 5 days and the results were compared by those elicited by the benzodiazepine lorazepam (0.5 mg/kg, i.p.) for anxiolytic studies, and by the tricyclic anti-depressant, imipramine (10 mg/kg, i.p.), for the antidepressant investigations. Both these standard drugs were administered once, 30 min prior to the tests. WSG induced an anxiolytic effect, comparable to that produced by lorazepam, in the elevated plus-maze, social interaction and feeding latency in an unfamiliar environment, tests. Further, both WSG and lorazepam, reduced rat brain levels of tribulin, an endocoid marker of clinical anxiety, when the levels were increased following administration of the anxiogenic agent, pentylenetetrazole. WSG also exhibited an antidepressant effect, comparable with that induced by imipramine, in the forced swim-induced 'behavioural despair' and 'learned helplessness' tests. The investigations support the use of WS as a mood stabilizer in clinical conditions of anxiety and depression in Ayurveda.

Effect of Withania somnifera glycowithanolides on iron-induced hepatotoxicity in rats

Glycowithanolides, consisting of equimolar concentrations of sitoindosides VII-X and withaferin A, isolated from the roots of Withania somnifera Dunal, have been reported to have an antioxidant effect in the rat brain frontal cortex and striatum. In the present study, the effect of 10 days of oral administration of these active principles, in graded doses (10, 20 and 50 mg/kg), was noted on iron overload (FeSo(4), 30 mg/kg, i.p.) induced hepatotoxicity in rats. Apart from hepatic lipid peroxidation (LPO), the serum enzymes, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase, were assessed as indices of hepatotoxicity. Silymarin (20 mg/kg, p.o.) was used for comparison. Iron overload induced marked increase in hepatic LPO and serum levels of the enzymes, which was attenuated by WSG in a dose-related manner, and by silymarin. The results indicate that the reported use of WS in Ayurveda for hepatoprotection against heavy metals and other environmental toxins, may be due the antioxidant action of WSG.

Antioxidant activity of tannoid principles of Emblica officinalis (amla) in chronic stress induced changes in rat brain

Effect of tannoid principles emblicanin A, emblicanin B, punigluconin, and pedunculagin of E. officinalis was assessed on chronic unpredictable footshock-induced stress-induced perturbations in oxidative free radical scavanging enzymes in rat brain frontal cortex and striatum. Chronic stress, administered over a period of 21 days, induced significant increase in rat brain frontal cortical and striatal superoxide dismutase (SOD) activity, concomitant with significant reduction in catalase (CAT) and glutathione peroxidase (GPX) activity. The changes in the enzyme activities was accompanied by an increase in lipid peroxidation, in terms of augmented thiobarbituric acid-reactive products. Administration of Emblica tannoids (10 and 20 mg, po) for 21 days, concomitant with the stress procedure, induced a dose-related alteration in the stress effects. Thus, a tendency towards normalization of the activities of SOD, CAT and GPX was noted in both the brain areas, together, with reduction in lipid peroxidation. The results indicate that the reported antistress rasayana activity of E. officinalis may be, at least partly due to its tendency to normalize stress-induced perturbations in oxidative free radical scavenging activity, in view of the postulate that several stress-induced diseases, including the process of aging, may be related to accumulation of oxidative free radicals in different tissues.

Antioxidant activity of Bacopa monniera in rat frontal cortex, striatum and hippocampus

The effect of a standardized extract of Bacopa monniera Linn. was assessed on rat brain frontal cortical, striatal and hippocampal superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities, following administration for 7, 14 or 21 days. The effects induced by this extract (bacoside A content 82% +/- 0.5%), administered in doses of 5 and 10 mg/kg, orally, were compared with the effects induced by (-) deprenyl (2 mg/kg, p. o.) administered for the same time periods. Bacopa monniera (BM) induced a dose-related increase in SOD, CAT and GPX activities, in all the brain regions investigated, after 14 and 21 days of drug administration. On the contrary, deprenyl induced an increase in SOD, CAT and GPX activities in the frontal cortex and striatum, but not in the hippocampus, after treatment for 14 or 21 days. The results suggest that BM, like deprenyl, exhibits a significant antioxidant effect after subchronic administration which, unlike the latter, extends to the hippocampus as well. The results suggest that the increase in oxidative free radical scavenging activity by BM may explain, at least in part, the cognition- facilitating action of BM, recorded in Ayurvedic texts, and demonstrated experimentally and clinically.

Effect of bioactive tannoid principles of Emblica officinalis on iron-induced hepatic toxicity in rats

The tannoid principles of the fruits of the plant Emblica officinalis Gaertn comprising of emblicanin A. emblicanin B, punigluconin and pedunculagin, have been reported to exhibit antioxidant activity in vitro and in vivo. In the present study, an emblicanin A (37%) and B (33%) enriched fraction of fresh juice of Emblica fruits (EOT), administered prophylactically (10, 20 and 50 mg/kg, p.o.) for 10 consecutive day, was found to inhibit acute iron overload (30 mg/kg, i.p.) hepatic lipid peroxidation and the increase of serum levels of alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase, used as markers of the induced hepatic dysfunction. A similar effect was produced by silymarin (20 mg/kg, p.o.), an antioxidant hepatoprotective agent. The results support the use of Emblica fruits for hepatoprotection in Ayurveda.

3'-deoxyribonucleosides and their derivatives as anti-amoebic agents

In general nucleoside analogues were found to possess in vitro amoebicidal property against trophozoites of Entamoeba histolytica. The acid-labile nature of these compounds completely destroyed their ability to cure caecal amoebiasis of rats. However the therapeutic efficacy of one of these compounds yielded most promising results, with 10% cures when it was administered as enteric coated formulation.

Sodium channel blockers and uridine triphosphate: effects on nasal potential difference in cystic fibrosis mice

Sodium channel inhibitors block the enhanced Na+ reabsorption in cystic fibrosis (CF). Extracellular nucleotides facilitate Cl- secretion via Ca2+ gated Cl- channels. A combination of these effects may produce less viscid secretions in CF which are easier to expectorate. This study examined the effects of combining sodium channel blockers with uridine triphosphate (UTP) on nasal membrane potential difference (PD) in CF insertional null mutant mice (cftr(tm1HGU)), deltaF508 homozygous mice (cftr(tm1Cam)) and matched control animals. Median basal PD in the insertional CF mice and deltaF508 CF mice were -28 and -34 mV respectively. These values were significantly different to the control animals (-20 mV). Amiloride and loperamide reduced the PD in cftr(tm1HGU) CF mice (deltaPD 13 mV & 15 mV respectively) suggesting Na+ blockade. The subsequent addition of UTP in a chloride-free vehicle increased the PD (deltaPD -8- -12.5 mV). DeltaF508 mice showed significantly greater responses compared with CF insertional null mutant mice (p<0.05). The action of UTP was brief and not prolonged by the addition alpha-beta-methylene-adenosine 5' diphosphate. Suramin, a competitive antagonist of P2 purinoceptors blocked the action of UTP. In conclusion, this study demonstrated dose dependant nasal membrane potential changes in differences mice with uridine triphosphate in the presence of sodium channel blockers suggestive of chloride secretion. More stable analogues of uridine triphosphate in combination with long acting sodium channel blockers such as loperamide may have therapeutic potential in cystic fibrosis.

A chemically labeled cytotoxic agent: two-photon fluorophore for optical tracking of cellular pathway in chemotherapy

Chemotherapy is commonly used in the treatment of cancers. However, the mechanism of action of many of these agents is not well understood. We present the synthesis of a two-photon fluorophore (C625) and its biological application when chemically linked to a chemotherapeutic agent (AN-152). By using two-photon laser-scanning microscopy, the drug:fluorophore conjugate can be observed directly as it interacts with receptor-positive cell lines. The results of this project visually show the receptor-mediated entry of AN-152 into the cell cytoplasm and subsequently into the nucleus. These observations will allow for better understanding of the drug's therapeutic mechanism, which is a subject of ongoing research aimed at improving present methods for cancer therapy.

Antioxidant activity of active tannoid principles of Emblica officinalis (amla)

The antioxidant activity of tannoid active principles of E. officinalis consisting of emblicanin A (37%), emblicanin B (33%), punigluconin (12%) and pedunculagin (14%), was investigated on the basis of their effects on rat brain frontal cortical and striatal concentrations of the oxidative free radical scavenging enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and lipid peroxidation, in terms of thiobarbituric acid-reactive products. The results were compared with effects induced by deprenyl, a selective monoamine oxidase (MAO) B inhibitor with well documented antioxidant activity. The active tannoids of E. officinalis (EOT), administered in the doses of 5 and 10 mg/kg, i.p., and deprenyl (2 mg/kg, i.p.), induced an increase in both frontal cortical and striatal SOD, CAT and GPX activity, with concomitant decrease in lipid peroxidation in these brain areas when administered once daily for 7 days. Acute single administration of EOT and deprenyl had insignificant effects. The results also indicate that the antioxidant activity of E. officinalis may reside in the tannoids of the fruits of the plant, which have vitamin C-like properties, rather than vitamin C itself.

Gastric emptying and intestinal transit of pancreatic enzyme supplements in cystic fibrosis

OBJECTIVE

To investigate gastric emptying and intestinal transit of pelleted pancreatin in relation to food boluses.

METHODS

Dual isotope scintigraphy combined with breath hydrogen sampling was used to track the concurrent gastric emptying and intestinal transit of 111indium labelled microspheres and a 99mtechnetium labelled tin colloid test meal. Twelve pancreatic insufficient cystic fibrosis patients aged 5 to 38 years performed the study.

RESULTS

50% gastric emptying times showed patient to patient variation. The mean discrepancy in 50% gastric emptying times between the two labels was > 67 minutes. Mean small bowel transit time for the food bolus was prolonged at 3.6 minutes. A significant correlation was seen between weight standard deviation score and 50% emptying time for pancreatin (r = +0.73).

CONCLUSION

Gastric mixing of food and pancreatin may be limited by rapid emptying of microspheres. Patients with high dosage requirements could benefit from changing the pattern of their pancreatin supplementation.

The use of dual-isotope imaging to compare the gastrointestinal transit of food and pancreatic enzyme pellets in cystic fibrosis patients

Cystic fibrosis patients require pancreatic enzyme supplements to aid food digestion. It is suspected that incorrect delivery of this enzyme may result in both significant malabsorption and the development of strictures in the proximal colon caused by the high-dose supplement reaching this region before the food. Investigations into the drug's delivery were performed using dual-isotope imaging; a method was developed to directly label the enteric-coated enzyme pellets with 111In, re-applying the enteric coating afterwards, and this was then ingested with a pancake meal labelled with 99Tcm-tin colloid. Consecutive image data, acquired over a period of > or = 4 h using a dual-headed gamma camera, were analysed to assess intestinal transit. In-vitro stability checks on these labelling techniques were encouraging, showing < 2% 99Tcm and < 7% 111In elution over 90 min in hydrochloric acid. In 5 of the 12 patients studied to date, the pellets were seen to pass through significantly faster than the food, with a mean difference in 50% gastric emptying time of greater than 93 min. The mean absolute difference in emptying time for all 12 patients was > 67 min. Thus, a technique has been developed to effectively radiolabel pancreatic enzyme pellets, and analysis of dual-isotope images using this preparation, together with radiolabelled solid food, has demonstrated significant differences in the transit of these two substances through the gastrointestinal tract of some cystic fibrosis patients.

Anxiolytic activity of ginkgolic acid conjugates from Indian Ginkgo biloba

Ginkgolic acid conjugates (GAC) (6-alkylsalicylates, namely n-tridecyl-, n-pentadecyl-, n-heptadecyl-, n-pentadecenyl- and n-heptadecenylsalicylates) isolated from the leaves of Indian Ginkgo biloba Linn., (IGb) were tested for their putative role in anxiety in rats. Elevated plus maze, open-field behaviour, novelty-induced feeding latency and social interaction were the rodent behavioural models used in this study. GAC (0.3 and 0.6 mg/kg, each, p.o.) on single acute administration, showed dose-related changes in the behaviour. GAC (0.6 mg/kg) and DZ augmented open arm entries, the open arm/closed arm entries ratio and increased time spent in the open arm on the elevated plus maze. In the open field, GAC (0.6 mg/kg) and DZ significantly increased ambulation and reduced the immobility time. EGb 761 showed a similar profile. GAC (0.6 mg/kg) and DZ significantly attenuated the increased latency to feed in novel environment. By contrast, EGb 761 and Ginkocer further augmented feeding latency. None of the drugs tested showed any significant effect in the social interaction test. GAC showed consistent and significant anxiolytic activity in all the variables investigated. By contrast, EGb 761 and Ginkocer, which are devoid of GAC, did not evoke significant activity. However, increased rearing and decreased immobility time only in open field behaviour shown by EGb 761 may be due to some antianxiety activity of a lesser degree. Our observations suggest that GAC may be the active constituents of Ginkgo biloba responsible for the anxiolytic activity.

Antioxidant activity of glycowithanolides from Withania somnifera

Antioxidant activity of active principles of Withania somnifera, consisting of equimolar concentrations of sitoindosides VII-X and withaferin A, was investigated for their effects on rat brain frontal cortical and striatal concentrations of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). Results were compared with effects induced by deprenyl, an agent with well documented antioxidant activity. Active glycowithanolides of W. somnifera (WSG) (10 and 20 mg/kg, i.p.), administered once daily for 21 days, induced a dose-related increase in SOD, CAT and GPX activity in frontal cortex and striatum, which was statistically significant on days 14 and 21, except with the lower dose of WSG on GPX activity, where the effect was evident only on day 21. The data were comparable to those induced by deprenyl (2 mg/kg/day, i.p.) with respect to SOD, CAT and GPX activities, which were evident by day 14. These findings are consistent with the therapeutic use of W. somnifera as an Ayurvedic rasayana and medhyarasayana. Antioxidant effect of active principles of W. somnifera may explain, at least in part, the reported antistress, immunomodulatory, cognition-facilitating, anti-inflammatory and anti-aging effects produced by them in experimental animals, and in clinical situations.

Immunogenicity and tolerability of a trivalent influenza subunit vaccine (Influvac) in high-risk children aged 6 months to 4 years

Fifty-two children, aged less than 5 years, with chronic lung disease or congenital heart disease were entered into a two-centre open study to determine the immunogenicity and tolerability of Influvac, a trivalent influenza sub-unit vaccine. Seroresponses were determined following two intramuscular vaccinations with 0.25 ml of Influvac, four weeks apart. Any local or systemic reaction was sought. Seroresponses were age and antigen specific, with children older than 9 months showing better seroresponses to all three antigens. Both A/Taiwan and B/Panama strains met all efficacy criteria. A/Shangdong met two of the three criteria: seroconversion and mean geometric titre increase. Local (23%) and systemic (48%) reactions following either of the two vaccinations were minor in nature and resolved within a few days. The vaccine induced a strong antibody response against all three haemagglutinin antigens and was well tolerated. The incidence of local and systemic reactions was comparable with those reported in healthy adults.

Systemic administration of defined extracts from Withania somnifera (Indian Ginseng) and Shilajit differentially affects cholinergic but not glutamatergic and GABAergic markers in rat brain

Although some promising results have been achieved by acetylcholinesterase inhibitors, an effective therapeutic intervention in Alzheimer's disease still remains an important goal. Sitoindosides VII-X, and withaferin-A, isolated from aqueous methanol extract from the roots of cultivated varieties of Withania somnifera (known as Indian Ginseng), as well as Shilajit, a pale-brown to blackish brown exudation from steep rocks of the Himalaya mountain, are used in Indian medicine to attenuate cerebral functional deficits, including amnesia, in geriatric patients. The present investigation was conducted to assess whether the memory-enhancing effects of plant extracts from Withania somnifera and Shilajit are owing to neurochemical alterations of specific transmitter systems. Therefore, histochemistry to analyse acetylcholinesterase activity as well as receptor autoradiography to detect cholinergic, glutamatergic and GABAergic receptor subtypes were performed in brain slices from adult male Wistar rats, injected intraperitoneally daily with an equimolar mixture of sitoindosides VII-X and withaferin-A (prepared from Withania somnifera) or with Shilajit, at doses of 40 mg/kg of body weight for 7 days. Administration of Shilajit led to reduced acetylcholinesterase staining, restricted to the basal forebrain nuclei including medial septum and the vertical limb of the diagonal band. Systemic application of the defined extract from Withania somnifera, however, led to differential effects on AChE activity in basal forebrain nuclei: slightly enhanced AChE activity was found in the lateral septum and globus pallidus, whereas in the vertical diagonal band AChE activity was reduced following treatment with sitoindosides VII-X and withaferin-A. These changes were accompanied by enhanced M1-muscarinic cholinergic receptor binding in lateral and medial septum as well as in frontal cortices, whereas the M2-muscarinic receptor binding sites were increased in a number of cortical regions including cingulate, frontal, piriform, parietal and retrosplenial cortex. Treatment with Shilajit or the defined extract from Withania somnifera affected neither GABAA and benzodiazepine receptor binding nor NMDA and AMPA glutamate receptor subtypes in any of the cortical or subcortical regions studied. The data suggest that Shilajit and the defined extract from Withania somnifera affect preferentially events in the cortical and basal forebrain cholinergic signal transduction cascade. The drug-induced increase in cortical muscarinic acetylcholine receptor capacity might partly explain the cognition-enhancing and memory-improving effects of extracts from Withania somnifera observed in animals and humans.

A moment-based unified approach to image feature detection

In this paper, a novel model-based approach is proposed for generating a set of image feature maps (or primal sketches). For each type of feature, a piecewise smooth parametric model is developed to characterize the local intensity function in an image. Projections of the intensity profile onto a set of orthogonal Zernike-moment-generating polynomials are used to estimate model-parameters and, in turn, generate the desired feature map. A small set of moment-based detectors is identified that can extract various kinds of primal sketches from intensity as well as range images. One main advantage of using parametric model-based techniques is that it is possible to extract complete information (i.e., model parameters) about the underlying image feature, which is desirable in many high-level vision tasks. Experimental results are included to demonstrate the effectiveness of proposed feature detectors.

Modification of nasal membrane potential difference with inhaled amiloride and loperamide in the cystic fibrosis (CF) mouse

BACKGROUND

In the airway of subjects with cystic fibrosis (CF) the combination of defective cAMP mediated chloride secretion and enhanced sodium absorption leads to dehydration of mucosal mucus and is reflected in an increased trans-epithelial potential difference (PD). The airway secretions may be less viscid and easier to expectorate if sodium (and water) reabsorption is inhibited.

METHODS

To evaluate the response to sodium blocking agents, changes in the nasal PD in 20 transgenic CF mice were compared with 14 control mice (MF1 strain) before and after administration of nebulised amiloride and loperamide (both in a concentration of 1 mmol/l). The duration of action for both drugs was also determined after a single inhaled dose of 1 mmol/l for two minutes.

RESULTS

The median basal PD was -24 mV in controls and -28 mV in CF mice (p < 0.01). This fell in CF mice after amiloride and loperamide administration by 15 mV and 14 mV, respectively, compared with a decrease of 7 mV and 5.5 mV in controls (p < 0.01). There was no further change in PD when loperamide was given after amiloride. This suggests that loperamide and amiloride may act on sodium absorption via similar mechanisms. Loperamide had a longer duration of action after a single administration than amiloride.

CONCLUSION

The administration of amiloride and loperamide reduces the transepithelial potential and inhibits sodium reabsorption in the CF mouse airway. Further studies are required to determine if the more prolonged action of loperamide could be of therapeutic use.

Antitumor, immunomodulatory and anti-HIV effect of mangiferin, a naturally occurring glucosylxanthone

Mangiferin, a C-glucosylxanthone (1,3,6,7-tetrahydroxyxanthone-C2-beta-D-glucoside) purified from plant sources was shown to have in vivo growth-inhibitory activity against ascitic fibrosarcoma in Swiss mice. Following in vivo or in vitro treatment, it also enhanced tumor cell cytotoxicity of the splenic cells and peritoneal macrophages of normal and tumor-bearing mice. In vitro treatment of the splenic cells of tumor-bearing mice with mangiferin resulted in augmented killing of tumor cells, both resistant and sensitive to natural killer cells. Mangiferin was also found to antagonize in vitro the cytopathic effect of HIV. The drug appears to act as a potent biological response modifier with antitumor and antiviral effect.

Head growth in cystic fibrosis following early diagnosis by neonatal screening

Growth in length, weight gain, and head circumference were recorded from 3 months to 4 years of age in 25 children with cystic fibrosis diagnosed by neonatal screening. Mean standard deviation (SD) scores at 3 months for length, weight, and head circumference were -0.78, -0.91, and -0.52 respectively. Over the first 2 years length SD scores showed a consistent improvement and stabilised at 0.1 SD below mean from 2 to 4 years. Weight SD scores remained essentially unaltered throughout, approximately 1 SD below the mean. Head circumference, however, after an initial increase from -0.52 at 3 months to -0.25 at 18 months, slowed and fell to 1 SD below the mean at 4 years. The data suggest that head growth continues to lag behind somatic growth in children with cystic fibrosis despite early diagnosis and good nutritional management in early infancy. These data also support functional expression of cystic fibrosis transmembrane conductance regulator in the brain.