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M S Akhtar

Publications and source records attributed to M S Akhtar.

At least 19 recordsLinked to original sources
PubMed2005

Studies on the antihypertensive, antispasmodic, bronchodilator and hepatoprotective activities of the Carum copticum seed extract.

This study describes the antihypertensive, antispasmodic, bronchodilator and hepatoprotective activities of the aqueous-methanolic extract of Carum copticum Benth. seeds (CSE) to rationalize some of its traditional uses. CSE (3-100 mg/kg) caused a dose-dependent fall in arterial blood pressure in anaesthetized rats. In isolated rabbit aorta and jejunum preparations, CSE (0.1-3.0 mg/ml) caused an inhibitory effect on the K+-induced contractions. The calcium channel blocking (CCB) effect was confirmed when CSE shifted the Ca2+ dose-response curves (DRCs) to right similar to verapamil. In isolated guinea-pig tracheal preparations, it caused inhibition of carbachol and K+-induced bronchoconstriction at 0.1-1.0 mg/ml as well as shifted the dose-response curves (DRCs) of carbachol and histamine to the right with suppression of maximum response suggestive of non-specific bronchodilator effect mediated possibly through CCB. Pretreatment of rats with CSE (500 mg/kg orally for 2 days at 12 h intervals) prevented paracetamol (640 mg/kg) and CCl4 (150 ml/kg)-induced rise in serum alkaline phosphatase (ALP) and aminotransferases (AST and ALT). The same dose of CSE was able to prevent the CCl4-induced prolongation in pentobarbital-induced sleeping time in mice confirming its hepatoprotectivity. These results indicate the presence of calcium antagonist(s) in Carum copticum seeds and thus provides sound mechanistic basis for some of their folkloric uses.

Animals↗
PubMed2003

Utility of the lithoclast in the treatment of upper, middle and lower ureteric calculi.

OBJECTIVE: The aim of this study was to evaluate the utility and efficacy of lithoclast in the treatment of upper, middle and lower ureteric calculi. PATIENTS AND METHODS: Over a period of 6 1/2 years, we have treated 529 ureteric stones which failed to pass spontaneously within a 2-week period. Patients were evaluated for number, site, size and laterality of stones. Patients with ureteroscopy failure were excluded from the study. Once the stone(s) was (were) localised with the ureteroscope, it (they) was (were) treated with the Swiss lithoclast. RESULTS: Complete fragmentation was achieved in 99% of cases with lower, 97% with mid and 71% with upper ureteric calculi, respectively. The lithotripsy time was only 8.6 minutes for stones < or =1 cm and 14.8 minutes for stones ranging from 1.1 to 2.0 cm. Completely fragmented stones cleared spontaneously within two weeks in 98% of cases and all patients were free of calculi one month after the procedure. Retreatment with the lithoclast was required in six patients for large residual fragments. The mean hospital stay was 1.2 days. Complications were encountered in 6.8% of cases and were managed conservatively. CONCLUSIONS: Pneumatic lithotripsy is an excellent form of treatment for lower and mid-ureteric calculi. It is a very reliable, highly effective, rapid and safe procedure.

Adolescent↗
PubMed2002

Hypoglycaemic activity of Alpinia galanga rhizome and its extracts in rabbits.

This investigation was carried out to study effects of Alpinia galanga rhizome on blood glucose levels. In normal rabbits, powdered rhizome and its methanol and aqueous extracts significantly lowered the blood glucose. Gliclazide also produced a significant decrease in blood glucose in the rabbits. In alloxan-diabetic rabbits, A. galanga and its methanol and aqueous extracts did not produce significant reduction in blood glucose. The hypoglycaemic effect of A. galanga in normal rabbits was comparable to gliclazide. The rhizome was found to contain high levels of certain minerals. Acute toxicity and behavioral studies revealed no visible signs of toxicity and any abnormal behavior in rabbits even at high doses. It is concluded that A. galanga produces fall in blood glucose levels in normal rabbits and the principles, both organic and inorganic, are extractable in methanol and water.

Alloxan↗
PubMed2002

Taurolidine: preclinical evaluation of a novel, highly selective, agent for bone marrow purging.

Taurolidine has been shown to have remarkable cytotoxic activity against selected human tumor cells at concentrations that spare normal cells. In this study we have extended this observation and assessed the ability of Taurolidine to purge tumor cells from chimeric mixtures of bone marrow (BM) and neoplastic cells. Normal murine BM and human leukemic (HL-60) or ovarian (PA-1) tumor cell lines were used as models. Exposure of tumor cells to 2.5 mM Taurolidine for 1 h resulted in the complete elimination of viable cells. In contrast, exposure of BM to 5 mMTaurolidine for 1 h reduced CFU-GM, BFU-E and CFU-GEEM colony formation by only 23.0%, 19.6% and 25.2%, respectively. Inhibition of long-term BM culture (LTBMC) growth following a 1 h exposure to 5 mM Taurolidine also was approximately 20% compared to untreated LTBMC. Finally, chimeric cultures were generated from BM and HL-60GR or PA-1GR cells (tumor cells transfected with the geneticin resistance gene). Exposure of these chimeric cultures to 5 mM Taurolidine for 1 h totally eliminated viable cancer cells while minimally reducing viable BM cells. This finding was confirmed by subsequent positive selection for surviving tumor cells with geneticin. These findings reveal that Taurolidine holds promise for use in BM purging.

Animals↗
PubMed2001

Monovalent cation-induced conformational change in glucose oxidase leading to stabilization of the enzyme.

Glucose oxidase (GOD) from Aspergillus niger is an acidic dimeric enzyme having a high degree of localization of negative charges on the enzyme surface and dimer interface. We have studied the effect of monovalent cations on the structure and stability of GOD using various optical spectroscopic techniques, limited proteolysis, size exclusion chromatography, differential scanning calorimetry, and enzymic activity measurements. The monovalent cations were found to influence the enzymic activity and tertiary structure of GOD, but no effect on the secondary structure of the enzyme was observed. The monovalent cation-stabilized GOD was found to have a more compact dimeric structure but lower enzymic activity than the native enzyme. The enzyme's K(m) for D-glucose was found to be slightly enhanced for the monovalent cation-stabilized enzyme (maximum enhancement of about 35% for LiCl) as compared to native GOD. Comparative denaturation studies on the native and monovalent cation-stabilized enzyme demonstrated a significant resistance of cation-stabilized GOD to urea (about 50% residual activity at 6.5 M urea) and thermal denaturation (Delta T(m) maximum of 10 degrees C compared to native enzyme). However, pH-induced denaturation showed a destabilization of monovalent cation-stabilized GOD as compared to the native enzyme. The effectiveness of monovalent cations in stabilizing GOD structure against urea and thermal denaturation was found to follow the Hofmeister series: K(+) > Na(+) > Li(+).

Aspergillus niger↗
PubMed2000

Hypoglycaemic action of the flavonoid fraction of Cuminum nigrum seeds.

The seeds of Cuminum nigrum were screened phytochemically and were found to contain 8% flavonoids and 0.01% alkaloids. When studied for their effect on blood glucose levels, oral administration of the flavonoid contents of the plant caused a hypoglycaemic effect at a dose range of 0.5 to 1.5 g/kg, both in normal and alloxan-diabetic rabbits. The hypoglycaemic effect started 2 h after drug administration, reaching a maximum within 4-8 h and the blood glucose levels returned close to normal within 24 h of drug administration. The glibenclamide (5 mg/kg), produced a hypoglycaemic effect in the normal rabbits, whereas it had no effect on the blood glucose levels of alloxan-diabetic rabbits. The alkaloids isolated from C. nigrum seeds, however, failed to exert any significant hypoglycaemic effect in either the normal or diabetic rabbits. A 7 day acute toxicity study in rabbits did not produce any apparent adverse effect at doses as high as 5 g/kg orally. These data indicate that the total flavonoid contents of C. nigrum seeds exhibited considerable hypoglycaemic activity in rabbits and may therefore be responsible for the previously reported antidiabetic activity of the seeds. Furthermore, it is conceivable that the C. nigrum flavonoids possess insulin triggering and/or insulin-like properties.

Administration, Oral↗
PubMed1999

Studies on antihypertensive and antispasmodic activities of methanol extract of Acacia nilotica pods.

A methanol extract of Acacia nilotica pods (AN) caused a dose-dependent (3-30 mg/kg) fall in arterial blood pressure. Treatment of animals with atropine abolished the vasodilator response of acetylcholine (ACh), whereas the antihypertensive effect of the plant extract remained unaltered. Phentolamine (an alpha-adrenergic blocker) abolished the vasoconstrictor effect of norepinephrine (NE), whereas pretreatment of the animal with AN, did not modify the NE response. These results indicate that the antihypertensive effect of plant extract is independent of muscarinic receptor stimulation or adrenoceptor blockade. In the in vitro studies, AN produced a dose-dependent (0.3-3.0 mg/mL) inhibitory effect on force and rate of spontaneous contractions in guinea-pig paired atria. Similarly, it inhibited the spontaneous contraction of rabbit jejunum in a concentration-dependent (0.1-3.0 mg/mL) manner. AN also inhibited K(+)-induced contractions in rabbit jejunum at a similar concentration range, which suggests that the antispasmodic action of AN is mediated through calcium channel blockade, and this may also be responsible for the blood pressure lowering effect of AN, observed in the in vivo studies.

Acacia↗
PubMed1999

Chemoradiotherapy for advanced inoperable head and neck cancer: A phase II study.

The beneficial effects of chemotherapy in patients with advanced head and neck cancer remain controversial in terms of survival, but have shown some promise in improving locoregional control and quality of life. In an effort to improve locoregional control and survival, a prospective phase II study was initiated using paclitaxel and carboplatin with concurrent conventional fractionated external-beam radiotherapy. Paclitaxel and carboplatin have both shown excellent radiosensitization through two discrete mechanisms, cell blockage in G2/M phase and inhibition of DNA repair, respectively. Patients were stratified as either operable or inoperable. This report pertains to the inoperable patient group, who received eight cycles of weekly paclitaxel (60 mg/m2), carboplatin (area under the concentration-time curve of 1) with conventional radiotherapy (72 Gy). Chemoradiotherapy was followed by neck dissection for those patients who presented with clinically palpable lymph nodes. Thirty-three patients were enrolled in this group (23 men and 10 women with a median age of 56 years). Eleven patients (33%) had stage III disease; 22 (67%), stage IV disease. The median follow-up period was 14 months. Clinical complete response occurred in 20 patients (60%) and partial response occurred in 10 (30%), for an overall response rate of 90%. Following completion of therapy, 18 patients have undergone biopsy at the primary tumor site and 17 were negative. Eight of the 16 patients with clinically palpable neck nodes at presentation underwent neck dissection; five (63%) had negative nodes. Mucositis was the most common toxicity. Grade 3 or 4 mucositis occurred in 30 of the 33 (90%) patients. Other grade 3 or 4 toxicities included skin (22%), candidiasis (19%), neutropenia (9%), and dehydration (6%). One patient with laryngeal carcinoma who had pathologic complete response developed cartilage necrosis and is undergoing hyperbaric oxygen therapy. Survival data are early but encouraging. Concurrent paclitaxel, carboplatin, and external-beam radiotherapy yielded excellent clinical and pathologic responses. Mucositis remains the most common and significant morbidity. The study will continue for necessary accrual.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Whole blood screening test for factor V Leiden using a Russell viper venom time-based assay.

Factor V Leiden (FVR506Q) is a genetic defect in the factor V (FV) molecule that confers resistance to proteolysis by activated protein C (APC) and is the most common abnormality detected in patients studied for hereditary thrombophilia. The initial screening test for this abnormality was a comparison of the activated partial thromboplastin time (APTT) in the presence and absence of APC, expressed as a ratio. But this has been shown to lack sensitivity for the FV mutation. Other clot-based screening tests, such as the modified APTT, using FV-deficient plasma, or the Russell viper venom (RVV) time assay have improved sensitivity. Eighty-seven samples were studied using the RVV-based assay. This assay was performed on platelet-poor plasma (PPP-RVV) and whole blood (WB-RVV). All samples were analyzed by polymerase chain reaction (PCR) for the FV Leiden defect: 77 were PCR negative; 10 were PCR positive. Using a threshold ratio of 1.8, all samples were correctly categorized in the PPP-RVV and the WB-RVV tests, showing an observed sensitivity and specificity of 1.0. These results suggest that an RVV-based assay using whole blood could be an effective screening test for this common abnormality.

Adolescent↗
PubMed1996

Selective protective effect of an extract from Fumaria parviflora on paracetamol-induced hepatotoxicity.

1. The hepatoprotective activity of an aqueous-methanolic extract of Fumaria parviflora was investigated against paracetamol- and CCI4-induced hepatic damage. 2. Paracetamol (1 g/kg; orally) produced 100% mortality in mice; pretreatment of animals with the plant extract (500 mg/kg; orally) reduced the death rate to 50%. 3. Pretreatment of rats with plant extract (500 mg/kg, orally twice daily for 2 days) prevented (P < 0.001) the paracetamol (640 mg/kg)-induced rise in serum enzymes alkaline phosphatase (ALP) and transaminases (GOT and GPT), whereas the same dose of the extract was unable to prevent (P > 0.05) the CCI4-induced rise in serum enzyme levels. 4. Posttreatment with 3 successive doses of the extract (500 mg/kg, 6 hourly) also restricted the paracetamol-induced hepatic damage. 5. The plant extract (500 mg/kg; orally) caused significant prolongation in pentobarbital (75 mg/ kg)-induced sleep as well as increased strychnine-induced lethality in mice (P < 0.05), suggestive of an inhibitory effect on microsomal drug metabolizing enzymes (MDME). 6. It is conceivable therefore, that Fumaria parviflora extract exhibits a selective protective effect against paracetamol-induced hepatotoxicity, probably mediated through MDME inhibition.

Acetaminophen↗
PubMed1995

Antifasciolic efficacy of indigenous plant drugs: kalonji, shahterah and karanjwa in buffaloes.

A study was carried out to evaluate antifasciolic effect of powdered plant drugs including Kalonji (Nigella sativa seeds), Shahterah (Fumaria parviflora aerial parts) and Karanjwa (Caesulpinia crista seeds) in buffaloes. During the search for the infected animals, prevalence of fascioliasis in the random samples was 33.1 +/- 0.7% but in symptomatically suspected cases it came to be 64 +/- 3.2%. The drug trial results showed that all the three drugs possess significant efficacies against fascioliasis. Their highest doses tested produced highly significant (P<0.001) decrease in EPG counts on 15th days. Maximum antifasciolic efficacy, judged on the basis of % EPG count reduction was shown by Shahterah (93.2 +/- 0.5%) which was followed by Karanjwa (89.7 +/- 1.7%) and Kalonji (88.2 +/- 0.4%). No visible side effects were produced by any of these plant drugs. Single oral treatment with 25 mg/kg of Kalonji or 60 mg/kg of Shahterah and 40 mg/kg of Karanjwa exerts highly significant antifasciolic efficacies on the day 15 after treatment. From these data, it is conceivable that at these dosages the drugs are sufficiently potent and safe to treat fasciola infection in buffaloes. However, further chemical and pharmacological studies would decide the exact mechanism(s) of action, the active principles contained and the real worth of these indigenous drugs for the treatment of fascioliasis in the ruminants.

Journal Article↗
PubMed1994

Bicyclic hydantoins with a bridgehead nitrogen. Comparison of anticonvulsant activities with binding to the neuronal voltage-dependent sodium channel.

The anticonvulsant activity of diphenylhydantoin (DPH or phenytoin) is consistent with its actions on the neuronal voltage-dependent sodium channel. To further elucidate the binding requirements for this site, we synthesized several hydantoin analogs and evaluated these in in vitro sodium channel-binding and/or in vivo whole animal anticonvulsant assays. 5-Pentyl-5-phenylhydantoin (8), the most potent binder to the sodium channel in this study, had the same affinity as DPH (IC50 = 40 microM), revealing that one phenyl ring is sufficient for good interactions. Since our previous studies with monophenyl-substituted bicyclic 2,4-oxazolidinediones suggested that N3-alkylation and the conformational constraint of a 5-alkyl substituent over one face of the oxazolidinedione ring improved activity, we synthesized two examples of analogous bicyclic hydantoins. However, the bicyclic hydantoins were much less potent binders to the neuronal voltage-dependent sodium channel than their monocyclic counterparts. The binding activity for the more potent bicyclic hydantoin, 1,8-diaza-9,10-dioxo-7-phenylbicyclo[5.2.1]decane (4) (IC50 = 427 microM), was comparable to that of the ring-opened, N3-methylated monocyclic hydantoin model, 5-butyl-3-methyl-5-phenylhydantoin (9) (IC50 = 285 microM), and these were 8-11 times less potent than the monocyclic model 8, which contains a free imide NH. Furthermore, 5-butyl-5-phenylhydantoin (7; IC50 = 103 microM) was less potent than 8, suggesting that increased log P may enhance binding. Thus, unlike 2,4-oxazolidinediones, N3-alkylation of hydantoins dramatically decreases sodium channel-binding activity. Bicyclic hydantoin 4 was nevertheless a good anti-MES anticonvulsant in mice (ED50 = 86 mg/kg), although this activity likely results from mechanisms other than interactions at the neuronal voltage-dependent sodium channel. Compound 4 was also relatively neurotoxic (TD50 = 124 mg/kg). These results suggest that the binding of hydantoins to the sodium channel may be enhanced by (a) a free imide NH group and (b) an increased log P. Furthermore, 2,4-oxazolidinediones and hydantoins must either orient differently in the same binding site or interact with different sites on the neuronal voltage-dependent sodium channel.

Alkylation↗
PubMed1994

Comparative anthelminthic efficacy and safety of Caesalpinia crista seed and piperazine adipate in chickens with artificially induced Ascaridia galli infection.

The antiascarid activity of Caesalpinia crista Linn. seeds, popularly known as Karanjwa, was evaluated in chickens of the Fumi breed, suffering from artificially induced Ascaridia galli infection. Eggs per gram (EPG) counts were determined in the droppings of chickens prior and after treatment with powdered C. crista at doses of 30, 40 and 50 mg/kg of body weight along with its extracts in water and methanol in amounts representing 50 mg/kg of crude powder. The crude drug at the dose rates of 40 and 50 mg/kg and its methanol extract induced a significant (P < 0.001) effect on post-treatment days 10 and 15 while the 30 mg/kg dose was efficacious (P < 0.05) on day 15 only. However, the aqueous extract did not show significant results. These results suggest that a 50 mg/kg dose of C. crista seed powder, its equivalent methanolic extract and piperazine (200 mg/kg) are equieffective in treating the ascarid infection of poultry. The crude C. crista powder appears to be potent and safer than its methanol extract on the basis of the side effects observed.

Animals↗
PubMed1992

Comparative effect of cimetidine and gefarnate on normal and ulcerated albino rats.

Antiulcerogenic efficacies of cimetidine and gefarnate were compared in the normal, aspirin, acetic acid and stress induced ulcerated albino rats. In addition, their effects on output of gastric acid, pepsin and hexosamine were studied in normal and experimentally ulcerated rats. Gefarnate increased the glucosamine. levels in normal and ulcerated rats A significant reduction in ulcer formation was observed with gefarnate in aspirin, acetic acid and stress induced ulcerous rats. Cimetidine did not reduce acid output in the presence of exogenous hydrochloric acid in aspirin treated rats. A decrease in glucosamine concentration was also observed with cimetidine in aspirin treated rats. Thus cimetidine did not significantly reduced ulcer formation in ulcerated rats. In the present study, gefarnate was found to be more effective than cimetidine because of its effect in normalization of mucus barrier.

Journal Article↗
PubMed1991

Evaluation of the hypoglycaemic effect of Achyranthes aspera in normal and alloxan-diabetic rabbits.

Blood glucose levels of normal and alloxan diabetic rabbits were determined after oral administration of various doses of Achyranthes aspera powdered whole plant and certain aqueous and methanolic extracts. Oral administration of 2, 3 and 4 g/kg of A. aspera powder produced a significant dose-related hypoglycaemic effect in normal as well as in diabetic rabbits. The water and methanol extracts also decreased blood glucose levels in normal and alloxan diabetic rabbits. A 7-day acute toxicity study in rabbits did not reveal any adverse or side effects of this folk medicine at dosages up to 8 g/kg orally. It is possible that the plant could act by providing certain necessary elements like calcium, zinc, magnesium, manganese and copper to the beta-cells.

Administration, Oral↗
PubMed1991

Field trial of Saussurea lappa roots against nematodes and Nigella sativa seeds against cestodes in children.

Antinematodal efficacy of Saussurea lappa roots (Qust-e-Shereen) and anticestodal effect of Nigella sativa seeds (Kalonji) was studied in children infected naturally with the respective worms. The activities were judged on the basis of percentage reductions in the faecal eggs per gram (EPG) counts. The 50 mg/kg single dose of S. lappa and equivalent amount of its methanolic extract produced on days 7 and 15 percentage EPG reduction similar to 10 mg/kg of pyrantel pamoate. Similarly, single oral administration of 40 mg/kg of N. sativa, equivalent amount of its ethanolic extract and 50 mg/kg of niclosamide reduced the percentage of EPG counts not significantly different from each other on the days 7 and 15. Therefore, it is conceivable that these indigenous medicinal plants contain active principles effective against nematodes and cestodes. The crude drugs did not produce any adverse side effects in the doses tested.

Anticestodal Agents↗