Biomedical subjects

J Lal

Publications and source records attributed to J Lal.

At least 19 recordsLinked to original sources

PubMed2005

Immunotherapeutic effects of mangiferin mediated by the inhibition of oxidative stress to activated lymphocytes, neutrophils and macrophages.

The effect of mangiferin, a naturally occurring xanthone glucoside on cyclophosphamide-induced immunotoxicity and its mode of action in the immune system were investigated. To induce immunotoxicity, adult male Wistar rats were injected weekly with cyclophosphamide intraperitoneally at 100 mg/kg bodyweight. Mangiferin was injected intraperitoneally at 10 and 20 mg/kg daily for 14 days. Levamisole (3 mg/kg, i.p., daily for 14 days), a known immunostimulant that acts in immunosuppressive conditions was used as a standard drug. The effect of mangiferin on the primary immune response to ovalbumin (200 microg/rat, s.c.) was assessed at weekly intervals by measuring the serum ovalbumin-specific IgM levels. The organ weights and cellularity of spleen, thymus and bone marrow, haematology, T and B cell-dependent mitogen stimulation of splenocytes were assessed for the cellular response. Oxidative changes in lymphocytes, neutrophils and macrophages were measured at the end of the study. As well, the in vitro effect of mangiferin on cytotoxicity caused by H2O2 in primary lymphocytes was studied. The decrease in the lymphoid organ weights, cellular responses and antigen-specific IgM levels by cyclophosphamide treatment were significantly increased by repeated intraperitoneal administration of mangiferin. The enhanced lipid peroxidation and decreased catalase and superoxide dismutase activities found in lymphocytes, polymorphonuclear cells (PMN) and macrophages from cyclophosphamide treated rats were significantly ameliorated in mangiferin treated groups. The tissue injury caused by cyclophosphamide treatment was significantly suppressed by mangiferin as shown by the decrease in serum creatine phosphokinase (CPK) activity. In vitro experiments showed that pretreatment of lymphocytes with mangiferin protected from the toxicity induced by H2O2, further confirming the in vivo findings. From this study, it is evident that mangiferin exhibits an immunoprotective role mediated through the inhibition of reactive intermediate-induced oxidative stress in lymphocytes, neutrophils and macrophages.

Adjuvants, Immunologic↗

PubMed2005

Small-angle neutron scattering studies of charged carboxyl-terminated dendrimers in solutions.

Small-angle neutron scattering was used to characterize the solution behavior of charged carboxylic acid terminated "cascade" dendrimers (Z-Cascade/methane [4]/3-oxo-6-oxa-2-azaheptylidyne/3-oxo-2-azaheptylidyne/propanoic acids) of third (G3) and fifth (G5) generations as a function of dendrimer concentration, pH, and ionic strength. An increase in dendrimer concentration leads to a single broad peak in the scattering profile arising from interdendrimer interaction. The dissociation of terminal carboxylate groups also gives rise to an interdendrimer interaction peak, which could be suppressed by the addition of excess salt. The results of contrast matching measurements indicate the accumulation of an excess concentration of tetramethylammonium counterions around the surface of these highly charged particles, and the thickness of these counterions lies somewhere between 4 and 6 A. This conclusion is consistent with our previous potentiometric titration (Zhang, H.; et al. J. Phys. Chem. B 1997, 101, 3494) and capillary electrophoresis (Huang, Q. R.; et al. J. Phys. Chem. B 2000, 104, 898) data.

Journal Article↗

PubMed2005

Effect of mangiferin on hyperglycemia and atherogenicity in streptozotocin diabetic rats.

In the present study, the effect of mangiferin (a xanthone glucoside, isolated from the leaves of Mangifera indica) on the atherogenic potential of streptozotocin (STZ)-diabetes was investigated. In addition, the effect of mangiferin on oral glucose tolerance in glucose-loaded normal rats was also determined. The chronic intraperitoneal (i.p.) administration of mangiferin (10 and 20 mg/kg) once daily (o.d.) for 28 days exhibited antidiabetic activity by significantly lowering fasting plasma glucose level at different time intervals in STZ-diabetic rats. Further, mangiferin (10 and 20 mg/kg, i.p.) showed significant antihyperlipidemic and antiatherogenic activities as evidenced by significant decrease in plasma total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) levels coupled together with elevation of high-density lipoprotein cholesterol (HDL-C) level and diminution of atherogenic index in diabetic rats. In addition, the chronic administration of mangiferin (10 and 20 mg/kg, i.p.) for 14 days significantly as well as markedly improved oral glucose tolerance in glucose-loaded normal rats suggesting its potent antihyperglycemic activity. The accumulating evidences suggest that both pancreatic and extrapancreatic mechanisms might be involved in its antidiabetic or antihyperglycemic action. In conclusion, the present study demonstrates that mangiferin possesses significant antidiabetic, antihyperlipidemic and antiatherogenic properties thus suggesting its beneficial effect in the treatment of diabetes mellitus associated with hyperlipidemia and related cardiovascular complications.

Animals↗

PubMed2005

Antipyretic and analgesic activities of Caesalpinia bonducella seed kernel extract.

Ethanolic extract (70%) of Caesalpinia bonducella seed kernel has been subjected for its antipyretic and antinociceptive activities in adult albino rats or mice of either sex at 30, 100 and 300 mg/kg orally. The extract demonstrated marked antipyretic activity against Brewer's yeast-induced pyrexia in rats. The extract had significant central analgesic activity in hot plate and tail flick methods. It also exhibited marked peripheral analgesic effect in both acetic acid-induced writhing test in mice and Randall-Selitto assay in rats. It also significantly inhibited the formalin-induced hind paw licking in mice. In conclusion, the present study suggests that the ethanolic extract of Caesalpinia bonducella seed kernel possesses potent antipyretic and antinociceptive activities and thus, validates its use in the treatment of pain and pyretic disorders.

Acetic Acid↗

PubMed2004

Unusual behaviour of poly(ethylene-oxide) in aqueous mixtures.

The model system of poly(ethylene-oxide) or PEO, where the changing hydrogen-bond connectivity of the water has large effect on the conformation of the polymer chain, in mixtures of water and acetonitrile, is experimentally studied. The results show the existence of a threshold water content in the system at which the 3d connectivity of the water network begins. Unusual expansion of the polymer chain, an effect larger than that observed in either of the pure solvents, is seen. Upon addition of small amounts of a monovalent salt, binding of ion to polymer takes place in pure acetonitrile solutions. Salt ions begin to co-ordinate with water molecules at the same solvent ratio as the threshold for water network formation. Ions now no longer complex to PEO; instead, hydrogen bonding of water to the polymer strongly dictates conformation in this regime.

Absorption↗

PubMed2003

Liquid chromatography-tandem mass spectrometric assay with a novel method of quantitation for the simultaneous determination of bulaquine and its metabolite, primaquine, in monkey plasma.

A sensitive and selective liquid chromatography-tandem mass spectrometry method (LC-MS-MS) for the simultaneous estimation of bulaquine and primaquine has been developed and validated in monkey plasma. The mobile phase consisted of acetonitrile/ammonium acetate buffer (20 mM, pH 6) (50:50 v/v) at a flow-rate of 1 ml/min. The chromatographic separations were achieved on two spheri cyano columns (5 microm, 30 x 4.6 mm I.D.) connected in series. The quantitation was carried out using a Micromass LC-MS-MS with an electrospray source in the multiple reaction monitoring (MRM) mode. The analytes were quantified from the summed total ion value of their two most intense molecular transitions. This is another novel method leading to increased sensitivity and precision. A simple liquid-liquid extraction with 2 x 1.0 ml n-hexane/ethyl acetate/dimethyloctyl amine (90:10:0.05, v/v) was utilized. The method was validated in terms of recovery, linearity, accuracy and precision (within- and between-assay variation). The recoveries from spiked control samples were >or=90 and 50% for bulaquine and primaquine, respectively. Linearity in plasma was observed over a dynamic range of 1.56-400 and 3.91-1000 ng/ml for bulaquine and primaquine, respectively.

Animals↗

PubMed2003

Surface dynamics of polymer films.

The dynamics of supported polymer films were studied by probing the surface height fluctuations as a function of lateral length scale using x-ray photon correlation spectroscopy. Measurements were performed on polystyrene (PS) films of thicknesses varying from 84 to 333 nm at temperatures above the PS glass transition temperature. Within a range of wave vectors spanning 10(-3) to 10(-2) nm(-1), good agreement is found between the measured surface dynamics and the theory of overdamped thermal capillary waves on thin films. Quantitatively, the data can be accounted for using the viscosity of bulk PS.

Journal Article↗

PubMed2003

Antinociceptive and antipyretic activities of Pongamia pinnata leaves.

In the present study, the antinociceptive activity of a 70% ethanol extract of Pongamia pinnata leaves (PLE) was investigated in different models of pain in mice and rats. Further, PLE was also evaluated for its antipyretic activity in Brewer's yeast-induced pyrexia in rats. Per os (p.o.) administration of the PLE (100-1000 mg/kg) produced significant antinociceptive activity in the hotplate and tail flick (central) as well as in acetic acid writhing and Randall-Selitto (peripheral) nociceptive tests suggesting the involvement of both central and peripheral mechanisms in alleviating the pain response. In addition, PLE also exhibited a significant antipyretic response in Brewer's yeast-induced pyrexia in rats. These results demonstrated that PLE possesses marked antinociceptive as well as antipyretic activities and thus scientifically validated its use in the treatment of pain and pyretic disorders.

Acetic Acid↗

PubMed2003

Effect of oral magnesium supplementation on the lipid profile and blood glucose of patients with type 2 diabetes mellitus.

BACKGROUND AND OBJECTIVES: Controversial reports are available regarding the effect of magnesium (Mg) on lipid profile and glycaemic control in diabetic patients. The present study was designed on 1) compare serum Mg levels in diabetic patients with those of non-diabetic controls and 2) to assess the effect of oral Mg supplementation on lipid profile and blood glucose of these patients. METHODS: The study included 40 patients of type 2 diabetes mellitus (DM) and 54 age and sex matched non-diabetic controls. After the baseline investigations of all the subjects (n=94) including blood glucose, serum lipid and magnesium, the diabetic patients (study group) were supplemented with 600 mg of Mg oxide daily for 12 weeks. They were followed up every four weeks (for a total duration of twelve weeks) and investigated for the above parameters. RESULTS: Mean serum magnesium at baseline in the diabetic patients was significantly lower than that in controls (1.44 +/- 0.48 mg/dl Vs 2.29 +/- 0.33 mg/dl; p < 0.001). A significant fall in serum total cholesterol, LDL cholesterol and triglycerides and a rise in HDL cholesterol levels was observed 4 to 8 weeks after initiation of magnesium supplementation and continued till the end of the study i.e. 12 weeks. Fasting and post-prandial blood glucose levels did not show any significant change after twelve weeks of magnesium supplementation when compared with baseline. CONCLUSIONS: A significant hypomagnesemia was observed in diabetic patients as compared to controls and Mg supplementation resulted in a beneficial effect on the lipid profile of these patients with no significant effect on blood glucose levels.

Administration, Oral↗

PubMed2002

Mangiferin protects the streptozotocin-induced oxidative damage to cardiac and renal tissues in rats.

The role of oxidative stress in streptozotocin (STZ)-induced toxicity and its prevention by a xanthone glucoside, mangiferin was investigated. To induce diabetes mellitus, adult male Wistar rats were injected STZ intravenously at 55 mg/kg body weight. The effect of mangiferin (10 and 20 mg/kg, i.p., 28 days) was investigated in STZ-induced diabetic male rats. Insulin-treated rats (6 U/kg, i.p., 28 days) served as positive control. Diabetic rats given normal saline served as negative control. Normal rats that neither received STZ nor drugs served as normal control. On day 28, the diabetic rats showed significant increase in serum creatine phosphokinase (CPK) and total glycosylated haemoglobin. Kidney revealed tubular degeneration and decreased levels of superoxide dismutase (SOD) and catalase (CAT) with an elevation of malonaldehyde (MDA). Cardiac SOD, CAT and lipid peroxidation were significantly increased. Histopathological findings revealed cardiac hypertrophy with haemorrhages. Analysis of erythrocyte revealed significantly elevated levels of MDA with insignificant decrease in CAT and SOD. Repeated intraperitoneal injections of mangiferin (10 and 20 mg/kg) and insulin (6 U/kg) controlled STZ-induced lipid peroxidation and significantly protected the animals against cardiac as well as renal damage. From the study, it may be concluded that oxidative stress appears to play a major role in STZ-induced cardiac and renal toxicity as is evident from significant inhibition of antioxidant defence mechanism in renal tissue or a compensatory increase in antioxidant defence mechanism in cardiac tissue. Intraperitoneal administration of mangiferin exhibited significant decrease in glycosylated haemoglobin and CPK levels along with the amelioration of oxidative stress that was comparable to insulin treatment.

Animals↗

PubMed2002

Evaluation of interaction potential of certain concurrently administered drugs with pharmacological and pharmacokinetic profile of centchroman in rats.

Centchroman (Ormeloxifene) is a nonsteroidal, selective estrogen receptor modulator, oral contraceptive and anticancer agent, and is intended for long-term use by women. In view of its vast clinical application and the interaction of steroidal oral contraceptives with certain commonly used therapeutic agents, evaluation of interaction of certain concomitantly administered therapeutic agents (ibuprofen, rifampicin, diazepam, salbutamol, nifedipine, paracetamol, haloperidol, and tetracycline), in terms of both the postcoital contraceptive efficacy and pharmacokinetic profile, with centchroman was undertaken in female Sprague-Dawley rats. Among the representatives from each commonly used therapeutic category, interaction (pharmacokinetic) was observed with ibuprofen (60 mg/kg, twice daily), haloperidol (0.7 mg/kg, twice daily), and tetracycline (140 mg/kg, twice daily) coadministration on Days 1 through 5 postcoitum. Of these three therapeutic agents, only tetracycline interfered with the contraceptive efficacy of centchroman. It reduced the bioavailability of centchroman and its active metabolite by increasing their excretion through bile and feces. Increased metabolite excretion on tetracycline coadministration indicates the enterohepatic recirculation of the metabolite, not the parent drug. However, the effect of tetracycline was negated by the inclusion of lactic acid bacillus spores in the regimen.

Animals↗

PubMed2002

Inhibitory role of Syzygium cumini on autacoid-induced inflammation in rats.

The ethanolic extract of Syzygium cumini bark has been reported to possess anti-inflammatory activity in our previous studies. The present study is an attempt to elucidate the anti-inflammatory activity of S. Cumini bark against inflammation induced by individual autacoid insult. Histamine (1 mg/ml), 5-HT (1 mg/ml), bradykinin (0.02 mg/ml) and PGE2 (0.001 mg/ml) were used as inflammogens. One of these agents (0.1 ml) was injected s.c. into the right hind paw of each rat. The ethanolic extract of S. cumini bark was tested at the doses of 100, 300 and 1000 mg/kg, p.o. The results indicated the anti-inflammatory activity of S. cumini bark in histamine, 5-HT and PGE2-induced rat paw oedema. However, there was no such significant inhibition of oedema volume observed in bradykinin-induced rat paw oedema at any dose level. Thus, it is concluded that S. cumini exhibits inhibitory role on inflammatory response to histamine, 5-HT and PGE2.

Animals↗

PubMed2001

Optimization of contraceptive dosage regimen of Centchroman.

Centchroman (Ormeloxifene), a non-steroidal oral contraceptive, is used at a dose of 30 mg once a week. To prevent failures in the beginning of the therapy, it is recommended that a dose of 30 mg twice a week for 12 weeks be administered to build up adequate blood levels. The present study was undertaken to simplify the dosing schedule without sacrificing the purpose of twice a week dosing regimen, using modeling and measurement approaches. The drug was given to 60 female volunteers who were divided into seven groups: group I, 30 mg weekly; group II, 30 mg twice a week; group III, 30 mg twice a week for 12 weeks followed by 30 mg weekly; group IV, 30 mg twice a week for 6 weeks followed by 30 mg weekly; group V, 60 mg weekly; and groups VI and VII, single 60 mg loading dose followed by 30 mg weekly doses. The blood samples were collected and analyzed by HPLC. In group I, mean trough concentrations of centchroman and its active metabolite, 7-desmethyl centchroman, were comparable to the steady-state trough concentrations in groups III, IV, VI, and VII. The metabolite to parent drug ratio remained constant in all the groups. The pharmacokinetic parameters in group VII were comparable to those reported after a single 30 mg dose. Dosage regimen VI was more convenient and provided better pregnancy protection (Pearl index 1.18; unpublished report) than regimen III, which is currently on the market and, thus, could be effectively used for contraception.

Centchroman↗

PubMed2001

Anti-inflammatory activity of Dalbergia sissoo leaves.

The possible anti-inflammatory activity of the 90% ethanolic extract of Dalbergia sissoo leaves (DSELE) was studied in different models of inflammation in rats after oral administration at doses of 100, 300 and 1000 mg/kg. DSELE significantly inhibited carrageenin, kaolin and nystatin-induced paw oedema, as well as the weight of granuloma induced by a cotton pellet. It also inhibited dye leakage in acetic acid-induced vascular permeability test in mice. DSELE was devoid of ulcerogenic effect on the gastric mucosa of rats in acute and chronic tests. In acute toxicity studies, it was found to be safe up to 10.125 g/kg, p.o. in the rat. It was concluded that the D. sissoo leaf extract possessed significant anti-inflammatory activity (in acute, sub-acute and chronic models of inflammation) without any side effect on gastric mucosa.

Animals↗

PubMed2001

Anti-inflammatory activity of Syzygium cumini bark.

The ethanolic extract of the bark of Syzygium cumini was investigated for its anti-inflammatory activity in animal models. The extract did not show any sign of toxicity up to a dose of 10.125 g/kg, p.o. in mice. Significant anti-inflammatory activity was observed in carrageenin (acute), kaolin-carrageenin (subacute), formaldehyde (subacute)-induced paw oedema and cotton pellet granuloma (chronic) tests in rats. The extract did not induce any gastric lesion in both acute and chronic ulcerogenic tests in rats. Thus, the present study demonstrated that S. cumini bark extract has a potent anti-inflammatory action against different phases of inflammation without any side effect on gastric mucosa.

Animals↗

PubMed2001

Evaluation of anti-inflammatory activity of Pongamia pinnata leaves in rats.

In the present study, the anti-inflammatory activity of 70% ethanolic extract of Pongamia pinnata leaves (PLE) in acute, subacute and chronic models of inflammation was assessed in rats. Per os (p.o.) administration of PLE (300, 1000 mg/kg) exhibited significant anti-inflammatory activity in acute (carrageenin, histamine, 5-hydroxytryptamine and prostaglandin E2-induced hind paw edema), subacute (kaolin-carrageenin and formaldehyde-induced hind paw edema) and chronic (cotton pellet granuloma) models of inflammation. PLE did not show any sign of toxicity and mortality up to a dose level of 10.125 g/kg, p.o. in mice. Both acute as well as chronic administration of PLE (100, 300 and 1000 mg/kg, p.o.) did not produce any gastric lesion in rats. These results indicate that PLE possesses significant anti-inflammatory activity without ulcerogenic activity suggesting its potential as an anti-inflammatory agent for use in the treatment of various inflammatory diseases.

Administration, Oral↗

PubMed2001

LC determination of the anti-ischemic and anti-hypertensive agent CDRI-93/478 in rat serum.

CDRI-93/478 is a potent anti-ischemic and anti-hypertensive agent. This compound is in advanced stage of pre-clinical trials. A high-performance liquid chromatographic (HPLC) method was developed for the analysis of CDRI-93/478 in rat serum, a species used for safety evaluation. The HPLC analysis, applicable to 1 ml volumes of serum, involved double extraction of serum samples with diethyl ether at alkaline pH followed by separation on a spheri-5 cyano column and the use of fluorescence detector at excitation wavelength 250 nm and emission wavelength 372 nm. The method was sensitive with a limit of quantitation of 10 ng ml(-1) in rat serum and the recovery was more than 84%. The linearity was satisfactory as indicated by correlation of >0.99, in addition to the visual examination of the calibration curves. The precision and accuracy were acceptable as indicated by relative standard deviation (R.S.D.) ranging from 1.73 to 9.51%, bias values ranging from -7.31 to 8.68%. Moreover, CDRI-93/478 was stable in rat serum after being subjected to three freeze-thaw cycles. In-process stability evaluation showed the stability of the compound in processed samples lasted up to 168 h. The assay was found to be sensitive, specific, accurate, precise, and reliable for use in pharmacokinetic or toxicokinetic studies.

Animals↗

PubMed2001

Effect of exposure to a country liquor (Toddy) during gestation on lipid metabolism in rats.

The objective of this study was to determine the effects of country liquor Toddy and its equivalent quantity of ethanol on lipid metabolism during gestation in rats. Female rats weighing an average of 125 g were exposed to Toddy (24.5 ml/body weight/day) and ethanol (0.52 ml/kg body weight/day) for 15 days before conception and throughout gestation. On the 19th day of gestation, altered liver function and hyperlipidemia was seen in both the treated groups. Altered liver function was evidenced by the increased activity of alcohol dehydrogenase, aldehyde dehydrogenase, glutamic oxaloacetic transaminase or aspartate amino transferase (GOT), glutamic pyruvic transaminase or alanine amino transferase (GPT) and gamma glutamyl transpeptidase (GGT). Hyperlipidemia was caused by increased biosynthesis and decreased degradation of lipids. The incorporation of 14C acetate in lipids and activities of HMG CoA reductase and lipogenic enzymes were elevated and activity of LPL and bile acids contents were decreased. Toddy treated rats were more severely affected than those receiving an equivalent quantity of ethanol. Toddy seemed to potentiate the toxicity induced by alcohol indicating the role of the nonethanolic portion. Hepatic functions were also affected.

Alcohol Drinking↗