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Biomedical subjects

A Gomes

Publications and source records attributed to A Gomes.

At least 19 recordsLinked to original sources
PubMed2006

Antiproliferative, cytotoxic and apoptogenic activity of Indian toad (Bufo melanostictus, Schneider) skin extract on U937 and K562 cells.

The antiproliferative, cytotoxic and apoptogenic activities of Bufo melanostictus (Indian common toad) skin extract (TSE) on U937 and K562 leukemic cell line has been investigated. TSE significantly (P<0.001) reduced the time-dependent cell proliferation and decreased MTT values in U937 and K562 cells. TSE (IC50 doses) suppressed the proliferating cell nuclear antigen expression in both the cells. It was demonstrated that, TSE (IC50 doses) primarily arrested the U937 and K562 cells at G1 phase of the cell cycle. Confocal microscopy showed the altered fragmented nuclei and apoptotic bodies formation in TSE (IC50 doses) treated U937 and K562 cells. Membrane blebbing, cell surface shrinkage and perforation were observed through scanning electron microscope. TSE-induced DNA fragmentation in U937 and K562 cells was reflected in single-cell gel electrophoresis. TSE significantly (P<0.001) increase the length-width ratio of DNA mass as compared to control in comet assay. The flow cytometric analysis of annexin-V binding to the cancer cells further supported the apoptotogenic activity of TSE. The effect of TSE on normal human peripheral blood mononuclear cells viability and cytotoxicity was studied in culture and found to be less cytotoxic than on the U937 and K562 cells. The findings from the present study suggested that TSE might possess potent antineoplastic agent having antiproliferative, cytotoxic and apoptogenic activity against U937 and K562 myeloid leukemic cells.

Animals↗
PubMed2006

CNS and anticonvulsant activity of a non-protein toxin (KC-MMTx) isolated from King Cobra (Ophiophagus hannah) venom.

In the present study, King Cobra (Ophiophagus hannah) venom was subjected to TLC followed by column chromatography/HPLC to isolate and purify a non-protein toxin designated as KC-MMTx. (1)H NMR, IR and EIMS studies showed KC-MMTx likely to be a 282 D unsaturated aliphatic acid having molecular formula C18H34O2. The minimum lethal dose of KC-MMTx was 200 microg/kg (i.v.) and 350 microg/kg (i.p.) in Swiss albino male mice. It significantly increased pentobarbitone induced sleeping time and significantly decreased the body temperature of male albino mice. It provided protection against amphetamine aggregate toxicity in mice but failed to protect amphetamine stereotypy in male albino rats. KC-MMTx provided significant protection against drug (strychnine, pentylenetetrazole, yohimbine) induced convulsions in male albino mice. It increased serum Na+ and decreased serum Ca2+ significantly in male mice. MAO activity and brain neurotransmitter levels in male mice were altered significantly. Further detailed study is warranted on the CNS, anticonvulsant potential of KC-MMTx, which may lead to the development of newer therapeutic tools in the near future.

Administration, Oral↗
PubMed2006

Daboia russellii and Naja kaouthia venom neutralization by lupeol acetate isolated from the root extract of Indian sarsaparilla Hemidesmus indicus R.Br.

The present study reports the isolation and purification of lupeol acetate from the methanolic root extract of Indian medicinal plant Hemidesmus indicus (L.) R.Br. (family: Asclepiadaceae) which could neutralize venom induced action of Daboia russellii and Naja kaouthia on experimental animals. Lupeol acetate could significantly neutralize lethality, haemorrhage, defibrinogenation, edema, PLA(2) activity induced by Daboia russellii venom. It also neutralized Naja kaouthia venom induced lethality, cardiotoxicity, neurotoxicity and respiratory changes in experimental animals. Lupeol acetate potentiated the protection by snake venom antiserum action against Daboia russellii venom induced lethality in male albino mice. Venom induced changes in lipid peroxidation and super oxide dismutase activity was antagonized by lupeol acetate. Snake venom neutralization by lupeol acetate and its possible mechanism of action has been discussed.

Animals↗
PubMed2006

Occurrence of non-protein low molecular weight cardiotoxin in Indian King Cobra (Ophiophagus hannah) Cantor 1836, venom.

Pathophysiology due to snakebite is a combined effect of various actions of the complex venom constituents. Importance of protein toxins in snake envenomation is well known. The present investigation reports the existence of nonprotein/nonpetide low molecular weight toxin in Indian King Cobra venom, which plays an important role in envenomation consequences in experimental animal models. A group of non-peptidic toxins (OH-NPT1) was isolated from Indian King Cobra Ophiophagus hannah by thin layer chromatography and silica gel column chromatography. UV, IR, NMR and (ESI) TOF-MS studies characterized the OH-NPT1 as a mixture of aliphatic acids having molecular weights 256, 326 and 340Da. The minimum lethal dose of OH-NPT1 was found to be 2.5 microg/20g (iv) and 4microg/20g (ip) in male albino mice. The cardiotoxic property of OH-NPT1 was established through studies on isolated guinea pig heart and auricle preparations, ECG studies in albino rat and estimation of LDH1/LDH and CPK-MB/CPK ratio in Swiss albino mice. Commercial antiserum failed to neutralize the lethality and cardiotoxicity of the toxin. However, calcium and magnesium effectively neutralized the lethal action.

Animals↗
PubMed2005

Monoazo and diazo dye decolourisation studies in a methanogenic UASB reactor.

Mixed anaerobic bacterial consortia have been show to reduce azo dyes and batch decolourisation tests have also demonstrated that predominantly methanogenic cultures also perform azo bond cleavage. The anaerobic treatment of wool dyeing effluents, which contain acetic acid, could thus be improved with a better knowledge of methanogenic dye degradation. Therefore, the decolourisation of two azo textile dyes, a monoazo dye (Acid Orange 7, AO7) and a diazo dye (Direct Red 254, DR254), was investigated in a methanogenic laboratory-scale Upflow Anaerobic Sludge Blanket (UASB), fed with acetate as primary carbon source. As dye concentration was increased a decrease in total COD removal was observed, but the acetate load removal (90%) remained almost constant. A colour removal level higher than 88% was achieved for both dyes at a HRT of 24h. The identification by HPLC analysis of sulfanilic acid, a dye reduction metabolite, in the treated effluent, confirmed that the decolourisation process was due mainly to azo bond reduction. Although, HPLC chromatograms showed that 1-amino-2-naphthol, the other AO7 cleavage metabolite, was removed, aeration batch assays demonstrated that this could be due to auto-oxidation and not biological mineralization. At a HRT of 8h, a more extensive reductive biotransformation was observed for DR254 (82%) than for AO7 (56%). In order to explain this behaviour, the influence of the dye aggregation process and chemical structure of the dye molecules are discussed in the present work.

Azo Compounds↗
PubMed2005

Collaboration in support of curricular innovations.

The migration of traditional anatomy and pathology wet labs to a digital format requires significant planning and collaboration amongst key faculty, administrative, and technology personnel. In addition to conversion of course materials, the changed format necessitated the refurbishment of a traditional bench lab as a state-of-the art digital classroom, significant IT investment, and ongoing coordination by library, classroom and computer resources personnel. Standardized policies and procedures were developed to guide additional requests for software to support new educational initiatives.

Anatomy↗
PubMed2005

Lethal, oedema, haemorrhagic activity of spotted butterfish (Scatophagus argus, Linn) sting extract and its neutralization by antiserum and pharmacological antagonists.

An attempt has been made in this communication to develop antiserum in rabbit against Scatophagus. argus sting extract. Antiserum did not neutralized the sting extract induced proinflammatory and haemorrhagic activity but successfully neutralized lethality upto 2LD50. Cyproheptadine, indomethacin and BW 755C pretreatment significantly reduced sting extract induced proinflammatory activity. The haemorrhagic activity of sting extract was significantly inhibited by temperature, UV-exposure, EDTA, cyproheptadine, indomethacin and BW 755C pretreatment. The results conclude that the local effects of S.argus venom is likely to be mediated through release of mediators and may be encountered by pharmacological antagonists better than the antiserum.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed2004

Anti-inflammatory activity of tea (Camellia sinensis) root extract.

Pharmacological studies were carried out with methanol-water (1:1) extract of dried tea (Camellia sinensis) root extract (TRE). TRE was found to possess anti-inflammatory, analgesic and antipyretic activities at 1/10th of its LD50 dose of 100 mg/kg i.p. It was found that TRE inhibited the arachidonic acid-induced paw oedema in rats which indicated that TRE produced the anti-inflammatory activity by inhibiting both the cyclooxygenase and lypooxygenase pathways of arachidonic acid metabolism. TRE also enhanced peritoneal cell count and the number of macrophages in normal mice. It is plausible that the saponins present in TRE may be responsible for these activities of TRE.

Animals↗
PubMed2004

Isolation and partial structural evaluation of a cardiotoxic factor from Indian common murrel (Channa striatus L.) skin extract.

It was earlier reported from this laboratory that, Channa striatus, L a common edible fish, whose skin extract (CSSE) was pharmacologicaclly potent and contains several bioactive compounds. In the present communication a cardiotoxic factor was isolated and purified by thin layer chromatography followed by silica gel and neutral alumina column chromatography. Spectroscopic studies (UV, IR, 1H and 13C NMR, FAB-MS) indicated that the lethal cardiotoxic factor (CSS-CTF II) was an aromatic alkaloid compound with -NH, > C = C < and -OH functional groups. The molecular weight was found to be 413 dalton. LD50 of CSS-CTF II was found to be 42.5 mg/kg (i.v) in Swiss albino male mice. Pharmacological studies showed that CSS-CTF II possesses hypotensive and cardiotoxic activities and produced death through apnoea in experimental animals but had no effect on nerve muscle preparations. The haematological and biochemical data also indicated the toxic nature of CSS-CTF II, through significant fall in haemoglobin, total RBC, WBC, platelet count and increased cardiac marker enzyme CPK and CPK-MB value in experimental animals. The present investigation thus established the toxic nature of CSS-CTF II isolated from edible fish C. striatus skin extract. Further work is needed to identify CSS-CTF II's mechanism of action and its antagonism for therapeutic purpose.

Animals↗
PubMed2004

Isolation of a haemorrhagic protein toxin (SA-HT) from the Indian venomous butterfish (Scatophagus argus, Linn) sting extract.

A haemorrhagic protein toxin (SA-HT) was isolated and purified from the spine extract of the Indian venomous butterfish, S. argus Linn, by two step ion exchange chromatography. The toxin was homogeneous in native and SDS-PAGE gel. SDS-molecular weight of the toxin was found to be 18.1 +/- 0.09 kDa. SA-HT produced severe haemorrhage on stomach wall but devoid of cutaneous haemorrhage. UV, EDTA, trypsin, protease, cyproheptadine, indomethacin, acetylsalicylic acid and BW755C treatment significantly antagonized the haemorrhagic activity of SA-HT. The toxin produced dose and time dependent oedema on mice hind paw, which was significantly encountered by cyproheptadine, indomethacin and BW755C. SA-HT increased capillary permeability on guinea pig dorsal flank. On isolated guineapig ileum, rat fundus and uterus, SA-HT produced slow contraction which was completely antagonised by prostaglandin blocker SC19220. On isolated rat duodenum, SA-HT produced slow relaxation. SA-HT significantly increased plasma plasmin, serum MDA level and decreased serum SOD level indicating the possible involvement of cyclooxygenase and lipooxygenase pathway.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed2004

Pharmacological studies on the venomous spotted butterfish (Scatophagus argus Linn) sting extract on experimental animals.

A sting of the fish S. argus, a venomous edible spotted butterfish, produces tremendous local pain, severe swelling, rise of body temperature, throbbing sensation etc. To establish the pharmacological activities of S. argus sting extract, the present investigation, was carried out on experimental animals. The LD50 of extract was found to be 9.3 mg/kg (iv) in male albino mice. The extract showed loss of sensation, urination and salivation in mice. It potentiated pentobarbitone induced sleeping time in male albino mice and produced hypothermia. Extract produced a fall of cat and guinea pig blood pressure, which was completely abolished by mepyramine. It produced a transient reduction of respiratory rate in rat, but decreased respiratory amplitude in cat, which was abolished after vagotomy. On isolated toad heart, the extract increased both the amplitude and rate of contraction. On isolated guinea pig heart, the sting extract decreased both the rate and amplitude of contraction leading to cardiac arrest, but it had no effect on isolated guinea pig auricle. The extract produced a reversible blockade of electrically induced twitch response of isolated chick biventer cervices preparation, but it had no effect on the isolated rat phrenic nerve diaphragm preparation. It produced a slow contractile response on isolated guinea pig ileum, rat uterus and rat fundal strip preparations but produced slow relaxation on isolated rat duodenum preparation. The contractile response on isolated guinea pig ileum and rat fundal strip was antagonised by SC19220. It did not produce any significant cutaneous haemorrhage in mice and did not produce any haemolysis on saline washed erythrocytes. The sting extract significantly increased capillary permeability of guinea pig dorsal flank and produced oedema in mice hind paw.

Animals↗
PubMed2004

Antisnake venom activity of ethanolic seed extract of Strychnos nux vomica Linn.

The whole seed extract of S. nux vomica (in low doses) effectively neutralized Daboia russelii venom induced lethal, haemorrhage, defibrinogenating, PLA2 enzyme activity and Naja kaouthia venom induced lethal, cardiotoxic, neurotoxic, PLA2 enzyme activity. The seed extract potentiated polyvalent snake venom antiserum action in experimental animals. An active compound (SNVNF) was isolated and purified by thin layer chromatography and silica gel column chromatography, which effectively antagonised D. russelii venom induced lethal, haemorrhagic, defibrinogenating, oedema, PLA2 enzyme activity and N. kaouthia induced lethal, cardiotoxic, neurotoxic, PLA, enzyme activity. Polyvalent snake venom antiserum action was significantly potentiated by the active compound. Spectral studies revealed it to be a small, straight chain compound containing methyl and amide radicals. Detailed structure elucidation of the compound (SNVNF) is warranted before its clinical trials as a snake venom antagonist.

Action Potentials↗
PubMed2003

Antidiarrhoeal activity of hot water extract of black tea (Camellia sinensis).

The effect of a hot water extract of black tea (Camellia sinensis (L.) O. Kuntze, Theaceae) on upper gastrointestinal transit and on diarrhoea was investigated employing conventional rodent models of diarrhoea. Black tea extract was found to possess antidiarrhoeal activity in all the models of diarrhoea used. Naloxone (0.5 mg/kg i.p.) significantly inhibited the antidiarrhoeal activity of the extract as well as loperamide, thus indicating a role of the opioid system in the antidiarrhoeal activity of the extract.

Animals↗
PubMed2003

Glycosmis arborea extract as a hepatoprotective agent.

Glycosmis arborea is a plant possessing various medicinal properties. The aim of the present study was to investigate the hepatoprotective efficacy of the butanol extract obtained from the aerial parts of the plant. The test sample was prepared by extracting the material through different steps. The extract thus obtained was dissolved in normal saline. Albino rats were prophylactically treated with the extract (i.p.) for 3 weeks. At the end of 3rd week all the groups were injected with hepatotoxic agents. After 48 h of injection, blood was collected and livers were taken out. Different enzymes in the serum were assayed and histopathological study was performed with liver. Glycosmis arborea extract was able to overcome the toxic effects of hepatotoxic agents in terms of lowering the levels of serum GPT, alkaline phosphatase and increased level of SOD in serum. TBARS generation in liver was also altered. Moreover, necrosis of liver produced by carbon tetrachloride was reversed by the extract.

Acetaminophen↗
PubMed2003

Snake venom neutralization by Indian medicinal plants (Vitex negundo and Emblica officinalis) root extracts.

The methanolic root extracts of Vitex negundo Linn. and Emblica officinalis Gaertn. were explored for the first time for antisnake venom activity. The plant (V. negundo and E. officinalis) extracts significantly antagonized the Vipera russellii and Naja kaouthia venom induced lethal activity both in in vitro and in vivo studies. V. russellii venom-induced haemorrhage, coagulant, defibrinogenating and inflammatory activity was significantly neutralized by both plant extracts. No precipitating bands were observed between the plant extract and snake venom. The above observations confirmed that the plant extracts possess potent snake venom neutralizing capacity and need further investigation.

Animals↗
PubMed2002

Fimicolous Histeridae coleoptera in Campo Grande, MS, Brazil.

Fecal masses recently excreted and/or almost dry were collected weekly in a pasture of Brachiaria decumbens Stapf, from May 1990 to April 1992. The feces were conditioned in 15-liter opaque plastic buckets, containing lateral and top openings, where flasks were fastened for capturing Histeridae beetles present in these masses. Three thousand two hundred ninety-nine specimens were collected belonging to 11 species in the Genus: Phelister, Hister, Euspilotus, Acritus, and Xerosaprinus. The most frequent, constant, and abundant species were Phelister sp. nr. carinifrons and P. haemorrhous.

Animals↗
PubMed2002

Antidiarrhoeal activity of seed extract of Albizzia lebbeck Benth.

The antidiarrhoeal activity of the seed extract of Albizzia lebbeck (Benth.) was investigated employing conventional rodent models of diarrhoea, i.e. castor oil-induced diarrhoea, upper gastrointestinal transit (u.g.t.) and fluid secretion. It was found that the aqueous methanol extract of Albizzia lebbeck seeds (2.5-5 mg/kg i.p.) possessed antidiarrhoeal activity which strengthens the earlier use of the seeds in the treatment of diarrhoea and dysentery. The antidiarrhoeal dose of the extract was at least 10-30 times less than the LD(50) dose. The extract (2.5-5 mg/kg i.p.) potentiated the antidiarrhoeal activity of loperamide (1 mg/kg i.p.). Nalaxone (0.5 mg/kg i.p.) significantly inhibited the antidiarrhoeal activity of the extract as well as loperamide, thus indicating a role of the opioid system in the antidiarrhoeal activity of the extract.

Animals↗