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1.
Braz J Biol ; 84: e277636, 2024.
Article in English | MEDLINE | ID: mdl-38422286

ABSTRACT

Parasitic diseases, notably babesiosis, exert a substantial impact on the global cattle industry, posing challenges to commerce, economies, and human health. This study, conducted in Southern Punjab, Pakistan, aimed to assess the prevalence of Babesia spp. across various livestock species using microscopic and PCR methods. A total of 180 blood samples (60 from each district) were systematically collected from apparently healthy animals, with 36 samples obtained from each domestic animal species, including camel, cattle, buffalo, goat, and sheep, noting that 12 samples were collected from each district for each animal species. Overall prevalence was determined to be 32.8% (59/180), with varying rates among species: 25.0% in cattle, 41.66% in buffalo, 30.55% in goats, 33.3% in sheep, and 33.3% in camels. Microscopic examination revealed slightly varied infection rates among large and small domestic animals (22.2%), while PCR results indicated a 32.8% overall infection rate in both large and small domestic animals, with no statistical significance. District-wise analysis showed regional variations, with Muzaffargarh recording a prevalence rate of 23.33% through microscopic examination, while Lodhran and Bahawalpur recorded 21.67%. PCR results revealed higher rates (38.33%, 26.67%, and 33.33%, respectively), underlining the importance of employing PCR for accurate detection. Examining ruminant types, large ruminants exhibited a 32.4% infection rate, while small domestic animals showed 33.3%, with no significant difference (p=0.897). District-wise prevalence showcased significant variation, with Muzaffargarh demonstrating a 25% prevalence, Lodhran 22%, and Bahawalpur 22%, through microscopic examination. PCR results displayed 38.33%, 27%, and 33.3%, respectively, with no statistical significance. Detailed analysis of individual districts highlighted variations in infection rates among camels, cattle, buffalo, goats, and sheep. The binomial test indicated significant differences through microscopic analysis (P=0.011) but non-significant variations through PCR (P=0.065), emphasizing the precision of PCR. Regional variations in prevalence, notably with Punjab exhibiting the highest frequency (33.87%) and KPK the lowest (13.24%), suggest potential influences from varying veterinary practices and environmental factors. This study underscores the pivotal role of PCR alongside microscopy for accurate babesiosis diagnosis. These findings contribute to the broader understanding of babesiosis prevalence, emphasizing the necessity of advanced molecular techniques for informed control measures.


Subject(s)
Babesia , Babesiosis , Humans , Cattle , Sheep , Animals , Animals, Domestic , Babesia/genetics , Babesiosis/epidemiology , Babesiosis/parasitology , Prevalence , Buffaloes , Pakistan/epidemiology , Camelus , Goats
2.
Trop Biomed ; 38(3): 353-359, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-34508343

ABSTRACT

Curcumin is a potent antimicrobial herb used traditionally as a spice in culinary. This study was designed to evaluate the antiviral effects of curcuma longa extract against H9 influenza virus. A total of 60 embryonated eggs were equally divided into 5 groups with 12 eggs in each group. Group 1 (G1) served as uninfected negative control. Whereas Group 2 (G2) was kept as positive control infected with known virus @ 0.2 ml with 10-9.3 EID50. Group 3 (G3) was offered Curcuma longa @ 0.2 mg/0.2 ml and H9N2 virus (@ 0.2 ml with 10-9.3 EID50. Similarly, Group 4 (G4) was inoculated with extract of Curcuma longa @ 0.2 mg/0.2 ml per egg, whereas Group 5 (G5) was given Ribazole @ 0.2 ml/ egg. The crude extract and virus were administered on the 15th day of incubation and were checked after every 24 hours up to 96th hour post inoculation by random selection of 3 eggs. Death and survival rate were noted in all groups. Gross and histopathological lesions were also observed. Results revealed that Curcuma longa extract had significantly (p<0.05) reduced the mortality rate of embryos infected with H9N2 virus. In G3, increased lymphocytes and mild fatty changes were seen in liver. Whereas, mature RBCs, plasma cells and some lymphoblast's were observed in Spleen. Similarly, the bursa follicles were with lymphocytic aggregation. The G4 (Curcuma longa) and G5 (Ribazole) were with maximum embryo survival after 48 and 72 h post inoculation. This study revealed potential antiviral activity of Curcuma longa against H9N2 influenza viruses and can be opted as alternative to antibiotics and antiviral drugs to minimize the antimicrobial resistance in human and animal population.


Subject(s)
Antiviral Agents , Curcuma , Influenza A Virus, H9N2 Subtype , Plant Extracts/pharmacology , Animals , Antiviral Agents/pharmacology , Chick Embryo , Curcuma/chemistry , Influenza A Virus, H9N2 Subtype/drug effects
3.
Tropical Biomedicine ; : 353-359, 2021.
Article in English | WPRIM (Western Pacific) | ID: wpr-905801

ABSTRACT

@#Curcumin is a potent antimicrobial herb used traditionally as a spice in culinary. This study was designed to evaluate the antiviral effects of curcuma longa extract against H9 influenza virus. A total of 60 embryonated eggs were equally divided into 5 groups with 12 eggs in each group. Group 1 (G1) served as uninfected negative control. Whereas Group 2 (G2) was kept as positive control infected with known virus @ 0.2 ml with 10-9.3 EID50. Group 3 (G3) was offered Curcuma longa @ 0.2 mg/0.2 ml and H9N2 virus (@ 0.2 ml with 10-9.3 EID50. Similarly, Group 4 (G4) was inoculated with extract of Curcuma longa @ 0.2 mg/0.2 ml per egg, whereas Group 5 (G5) was given Ribazole @ 0.2 ml/ egg. The crude extract and virus were administered on the 15th day of incubation and were checked after every 24 hours up to 96th hour post inoculation by random selection of 3 eggs. Death and survival rate were noted in all groups. Gross and histopathological lesions were also observed. Results revealed that Curcuma longa extract had significantly (p<0.05) reduced the mortality rate of embryos infected with H9N2 virus. In G3, increased lymphocytes and mild fatty changes were seen in liver. Whereas, mature RBCs, plasma cells and some lymphoblast’s were observed in Spleen. Similarly, the bursa follicles were with lymphocytic aggregation. The G4 (Curcuma longa) and G5 (Ribazole) were with maximum embryo survival after 48 and 72 h post inoculation. This study revealed potential antiviral activity of Curcuma longa against H9N2 influenza viruses and can be opted as alternative to antibiotics and antiviral drugs to minimize the antimicrobial resistance in human and animal population.

4.
Chem Biol Drug Des ; 93(2): 154-162, 2019 02.
Article in English | MEDLINE | ID: mdl-30216686

ABSTRACT

The development of functional imaging is a promising strategy for diagnosis and treatment of infectious and cancerous diseases. In this study, epirubicin was developed as a [99m Tc]-labeled radiopharmaceutical for the imaging of multi-drug-resistant Staphylococcus aureus infections. The labeling was carried out using sodium pertechnetate (Na99m TcO4 ; ~370 MBq). The other parameters such as amount of ligand, reducing agent (SnCl2 .2H2 O), and pH were optimized. The highest labeling yield ≥96.98% was achieved when 0.3 mg epirubicin, 13 µg SnCl2 .2H2 O, and ~370 MBq Na99m TcO4 were incubated at pH 7 for 15 min in the presence of ascorbic acid at room temperature. Radiochemical purity, stability, charge, and glomerular filtration rate were studied to evaluate the biological compatibility for in vivo administration. Biodistribution investigations showed radiotracer uptake (13.89 ± 1.56% ID/gm organ) by liver and 7.79 ± 0.38% ID/gm organ by kidneys at 30 min post-injection which promisingly wash out at 24 hr post-injection. Scintigraphy study showed selective uptake in S. aureus-infected tissues in contrast to turpentine oil-induced inflamed tissues. Target-to-non-target ratio (6.7 ± 0.05) was calculated at 1 hr post-injection using SPECT gamma camera. The results of this study reveal that the [99m Tc]-epirubicin can be a choice of imaging and monitoring the treatment process of multi-drug resistant S. aureus bacterial infections.


Subject(s)
Epirubicin/chemistry , Methicillin-Resistant Staphylococcus aureus/physiology , Radiopharmaceuticals/chemistry , Staphylococcal Infections/diagnosis , Technetium/chemistry , Tomography, Emission-Computed, Single-Photon , Animals , Drug Stability , Epirubicin/blood , Epirubicin/metabolism , Glomerular Filtration Rate , Hydrogen-Ion Concentration , Isotope Labeling , Rabbits , Radiopharmaceuticals/blood , Radiopharmaceuticals/metabolism , Tissue Distribution
5.
QJM ; 106(12): 1095-101, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24082151

ABSTRACT

BACKGROUND: Anaphylaxis is a potentially fatal condition requiring immediate resuscitation. Data regarding the epidemiology of anaphylaxis are limited and inconsistent. A reason for the variability was unavailability of a universally acceptable case definition till 2005. We reviewed cases using this new definition AIM: To review the incidence, clinical presentation, cause and outcome of anaphylaxis at a tertiary-care centre in a low-income country. DESIGN: Retrospective, case series METHODS: Chart review of all patients discharged from Aga Khan University Hospital between January 1988 and December 2012 (24 years) with anaphylaxis definition as per second National Institute of Allergy and Infection disease/Food Allergy and Anaphylaxis Network Symposium RESULTS: Total of 129 cases were found with mean age of 41.6 years (SD 18.8). Majority of patients had cutaneous features (76.7%), followed by respiratory (68.9%), cardiac (64.3%) and gastrointestinal (20.9%) symptoms, respectively. About 22.4% of patients had positive history for allergens out of which 31% (n = 9) were exposed to the same allergens. The common causes identified for anaphylaxis were drugs (60.5%), food (16.3%) and intravenous contrast (10.9%), respectively. Only 22.5% of cases received epinephrine as a part of their initial management. In four patients (3.1%) the cause of death was attributed to anaphylaxis. CONCLUSION: Anaphylaxis is a rare but life-threatening condition. Though cutaneous features are most common, their absence does not exclude the diagnosis. Drugs were the most common cause and epinephrine was not commonly used as first-line agent for its management.


Subject(s)
Anaphylaxis/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Anaphylaxis/diagnosis , Anaphylaxis/etiology , Anaphylaxis/therapy , Child , Child, Preschool , Drug Hypersensitivity/complications , Drug Hypersensitivity/epidemiology , Female , Food Hypersensitivity/complications , Food Hypersensitivity/epidemiology , Glucocorticoids/therapeutic use , Histamine H1 Antagonists/therapeutic use , Humans , Incidence , Infant , Male , Middle Aged , Pakistan/epidemiology , Retrospective Studies , Tertiary Care Centers , Treatment Outcome
6.
East Mediterr Health J ; 16 Suppl: S61-8, 2010.
Article in English | MEDLINE | ID: mdl-21495590

ABSTRACT

Blindness and visual impairment are major causes of noncomrnunicable diseases in Pakistan. Two national population-based blindness surveys conducted in 1988 and 2002-04 demonstrated a reduction in prevalence of blindness from 1.78% to 0.9% with a significant drop in cataract blindness as a result of accelerated nationwide interventions and eye care integration in primary health care. In addition, between 2006 and 2008, 88 facilities were upgraded as a result of the national eye health programme. These measures resulted in a 279% increase in eye outpatient attendances and a 375% increase in eye surgeries performed. Investment in human resources development and policy change contributed significantly to the sustainability of the programme. Key challenges facing the programme include aligning national eye health strategies with health system strengthening informed through health systems research. This paper attempts to document this extraordinary success.


Subject(s)
Blindness/prevention & control , National Health Programs/organization & administration , Blindness/epidemiology , Blindness/etiology , Health Policy , Health Surveys , Humans , Pakistan/epidemiology , Prevalence , Program Evaluation
7.
(East. Mediterr. health j).
in English | WHO IRIS | ID: who-118023

ABSTRACT

Blindness and visual impairment are major causes of noncommunicable diseases in Pakistan. Two national population-based blindness surveys conducted in 1988 and 2002-04 demonstrated a reduction in prevalence of blindness from 1.78% to 0.9% with a significant drop in cataract blindness as a result of accelerated nationwide interventions and eye care integration in primary health care. In addition, between 2006 and 2008r 88 facilities were upgraded as a result of the national eye health programme. These measures resulted in a 279% increase in eye outpatient attendances and a 375% increase in eye surgeries performed. Investment in human resources development and policy change contributed significantly to the sustainability of the programme. Key challenges facing the programme include aligning national eye health strategies with health system strengthening informed through health systems research. This gaper attempts to document this extraordinary success


Subject(s)
Health Systems Plans , Blindness , Vision, Low , Primary Health Care , National Health Programs , Delivery of Health Care, Integrated
8.
J Perinatol ; 28 Suppl 2: S61-8, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19057570

ABSTRACT

Newborn cord care practices may directly contribute to infections, which account for a large proportion of the four million annual global neonatal deaths. This formative research study assessed current umbilical and skin care knowledge and practices for neonates in Sylhet District, Bangladesh, in preparation for a cluster-randomized trial of the impact of topical chlorhexidine cord cleansing on neonatal mortality and omphalitis. Unstructured interviews (n=60), structured observations (n=20), rating and ranking exercises (n=40) and household surveys (n=400) were conducted to elicit specific behaviors regarding newborn cord and skin care practices. These included hand-washing, skin and cord care at the time of birth, persons engaged in cord care, cord cutting practices, topical applications to the cord at the time of birth, wrapping/dressing of the cord stump and use of skin-to-skin care. Overall 90% of deliveries occurred at home. The umbilical cord was almost always (98%) cut after delivery of the placenta, and cut by mothers in more than half the cases (57%). Substances were commonly (52%) applied to the stump after cord cutting; turmeric was the most common application (83%). Umbilical stump care revolved around bathing, skin massage with mustard oil and heat massage on the umbilical stump. Overall 40% of newborns were bathed on the day of birth. Mothers were the principal provider for skin and cord care during the neonatal period and 9% of them reported umbilical infections in their infants. Unhygienic cord care practices are prevalent in the study area. Efforts to promote hand-washing, cord cutting with clean instruments and avoiding unclean home applications to the cord may reduce exposure and improve neonatal outcomes. Such efforts should broadly target a range of caregivers, including mothers and other female household members.


Subject(s)
Anti-Infective Agents, Local/administration & dosage , Chlorhexidine/administration & dosage , Infant, Newborn, Diseases/prevention & control , Inflammation/prevention & control , Skin Care , Administration, Topical , Bangladesh , Female , Humans , Infant, Newborn , Umbilical Cord
9.
Br J Radiol ; 81(971): e276-8, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18941042

ABSTRACT

Congenital cystic adenomatoid malformation (CCAM) is a rare developmental, non-hereditary, hamartomatous abnormality of the lung with adenomatoid proliferation of cysts resembling bronchioles. It is usually unilateral with involvement of a single lobe. We report an unusual case of a 33-year-old man who presented with this disease with the involvement of an entire lung. We discuss the patient's pathogenesis, histological findings, clinical presentation, imaging characteristics and treatment, and review the associated literature.


Subject(s)
Cystic Adenomatoid Malformation of Lung, Congenital/diagnostic imaging , Adult , Cystic Adenomatoid Malformation of Lung, Congenital/pathology , Humans , Male , Tomography, X-Ray Computed
10.
Toxicol In Vitro ; 18(5): 555-61, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15251172

ABSTRACT

It is believed that anticancer and apoptosis inducing properties of green tea are mediated by it's polyphenolic constituents particularly catechins. A number of reports have shown that green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is among the most effective chemopreventive and apoptosis-inducing agents present in the beverage. Plant polyphenols are naturally occurring antioxidants but they also exhibit prooxidant properties. Over the last several years we have shown that various classes of plant polyphenols including flavonoids, curcuminoids and tannins are capable of catalyzing oxidative DNA cleavage particularly in the presence of transition metal ions such as copper and iron. With a view to understand the chemical basis of various pharmacological properties of green tea, in this paper we have compared the prooxidant properties of green tea polyphenols--EGCG and EC ((-)-epicatechin). The rate of oxidative DNA degradation as well as hydroxyl radical and superoxide anion formation was found to be greater in the case of EGCG as compared with EC. It was also shown that copper mediated oxidation of EC and EGCG possibly leads to the formation of polymerized polyphenols. Further, it was indicated that copper oxidized catechins were more efficient prooxidants as compared with their unoxidized forms. These results correlate with the observation by others that EGCG is the most effective apoptosis inducing polyphenol present in green tea. They are also in support of our hypothesis that prooxidant action of plant polyphenols may be an important mechanism of their anticancer properties. A model for binding of Cu(II) to EC has been presented where the formation of quinone and a quinone methide has been proposed.


Subject(s)
Antineoplastic Agents/pharmacology , Antioxidants/pharmacology , Catechin/analogs & derivatives , Catechin/pharmacology , Plant Extracts/pharmacology , Tea , Animals , Antineoplastic Agents/metabolism , Antioxidants/metabolism , Catechin/metabolism , Cattle , Chemoprevention , Copper/metabolism , Copper/pharmacology , DNA/drug effects , DNA/metabolism , Oxidation-Reduction , Plant Leaves/chemistry , Reactive Oxygen Species/analysis
11.
Toxicol In Vitro ; 18(4): 435-40, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15130600

ABSTRACT

Previous reports from this laboratory have shown that flavonoids including apigenin are capable of inducing oxidative DNA cleavage in the presence of copper ions. In the present report, we have examined the ability of amentoflavone, a biflavonoid which is a dimer of apigenin, to catalyze the degradation of DNA. Amentoflavone was found to degrade calf thymus DNA in the presence of Cu(II) at a rate almost twice that of apigenin. Amentoflavone was also shown to reduce Cu(II) to Cu(I) and to generate hydroxyl radicals in the presence of copper ions. In the presence of Cu(II), the absorption spectrum of amentoflavone undergoes a shift and a quenching effect indicating that the biflavonoid is capable of binding to copper ions. Amentoflavone and apigenin were isolated from Cycas rumphii and Trifolium alexandrinum, respectively. The results are discussed in relation to the putative chemopreventive mechanism of amentoflavone.


Subject(s)
Biflavonoids/toxicity , Copper/pharmacology , DNA Damage , DNA/metabolism , Animals , Anticarcinogenic Agents/pharmacology , Cattle , Chemoprevention , Hydroxyl Radical/chemistry , Oxidants/chemistry , Oxidation-Reduction , Thymus Gland/chemistry
12.
Toxicol In Vitro ; 16(6): 669-74, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12423649

ABSTRACT

It has been proposed that considerable DNA damage may be caused by endogenous metabolites produced during the body's normal metabolic processes. 5-hydroxytryptamine (serotonin) is an important neurotransmitter in brain and spinal cord. We have previously shown that serotonin induces oxidative cleavage of DNA strands in the presence of copper ions. In the present paper we have examined the mechanism of copper binding by serotonin using absorption spectroscopy, Cu(II)-mediated lipid peroxidation and by determining the oxidation of the serotonin molecule. Addition of increasing concentrations of Cu(II) to serotonin leads to a progressive enhancement in the absorption band and is accompanied by a shift towards a lower wavelength indicative of the formation of an oxidised species of serotonin. Studies with the structurally related molecules tryptophan and melatonin showed that only serotonin is able to reduce Cu(II) to Cu(I). Similarly, only serotonin was found to be able to abolish the copper-mediated peroxidation of mitochondria. These results suggested the involvement of the phenolic group in copper binding. Further, it was also shown that the binding of copper to serotonin leads to the formation of a quinone in the absence of molecular oxygen. Based on these results, a model has been proposed in which serotonin reduces two molar equivalents of Cu(II) to Cu(I) through a reaction involving two electron oxidation of the phenolic ring to a quinone methide.


Subject(s)
Copper/metabolism , Copper/pharmacology , DNA Damage , Serotonin/pharmacology , Animals , Cattle , Humans , Lipid Peroxidation , Mitochondria , Oxidative Stress , Spectrum Analysis , Thymus Gland/cytology
13.
J Ethnopharmacol ; 82(1): 23-8, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12169401

ABSTRACT

The effect of aqueous and alcohol extracts of the leaves and seeds of Psoralea corylifolia, on the spontaneous movements of both the whole worm and the nerve muscle preparation of Setaria cervi and on the survival of microfilariae in vitro was studied. Alcohol extracts of both leaves and seeds caused the inhibition of spontaneous movements of the whole worm and the nerve muscle preparation of S. cervi, characterised by initial, short lasting small increase in tone of contractions followed by paralysis. The initial stimulatory effect was not observed by alcohol extract of leaves on nerve muscle preparation. The concentrations required to inhibit the movements of whole worm and nerve muscle preparations for alcohol extracts of leaves and seeds were 160, 30, and 150, 20 microg/ml, respectively suggesting a cuticular permeability barrier. Alcohol extracts of both leaves and seeds caused death of microfilariae in vitro, LC(50) and LC(90) being 15 and 25 ng/ml for alcohol extract of leaves and 12 and 18 ng/ml for alcohol extract of seeds, respectively.


Subject(s)
Filaricides/pharmacology , Psoralea , Setaria Nematode/drug effects , Animals , Cattle , Dose-Response Relationship, Drug , Ethanol , Neuromuscular Junction/drug effects , Plant Extracts/pharmacology , Plant Leaves/chemistry , Seeds/chemistry
14.
Heart Surg Forum ; 4(2): 172-3, 2001.
Article in English | MEDLINE | ID: mdl-11544619

ABSTRACT

A patient, with post myocardial infarction (MI) thrombolysis, underwent emergency off-pump coronary artery bypass graft. Her post-operative course was complicated by excessive bleeding. At re-exploration, the bleeding was caused by a graze on the lung surface by the needle used during the insertion of the deep pericardial retraction suture.


Subject(s)
Hemorrhage/etiology , Lung/pathology , Lung/surgery , Coronary Artery Bypass/adverse effects , Coronary Artery Bypass/methods , Female , Humans , Intraoperative Complications/etiology , Middle Aged , Myocardial Infarction/complications , Myocardial Infarction/surgery , Postoperative Complications/etiology , Suture Techniques/adverse effects
15.
Chem Biol Interact ; 137(1): 59-74, 2001 Jul 31.
Article in English | MEDLINE | ID: mdl-11518564

ABSTRACT

Bilirubin, which is derived from its metabolic precursor biliverdin, is the end product of heme catabolism. It has been proposed as a physiological antioxidant present in human extracellular fluids. We have earlier shown that bilirubin in the presence of the transition metal ion Cu(II) causes strand cleavage in DNA through generation of reactive oxygen species, particularly the hydroxyl radical. Thus bilirubin possesses both antioxidant and prooxidant properties. In order to understand the chemical basis of various biological properties of bilirubin, we have studied the structure-activity relationship between bilirubin and its precursor biliverdin. The latter has also been reported to possess both antioxidant and toxic properties. In the present studies bilirubin was found to be more effective in the DNA cleavage reaction and a more efficient reducer of Cu(II). The rate of formation of hydrogen peroxide and hydroxyl radicals by the compounds also showed a similar pattern. The relative antioxidant activity was also examined by studying the effect of these compounds on DNA cleavage by a hydroxyl radical generating system and their quenching effect on hydroxyl radicals. The results indicate that bilirubin is more active both as an antioxidant as well as an oxidative DNA cleaving agent. A model for binding of copper to bilirubin has been proposed where two copper ions are bound to two molecules of bilirubin through their terminal pyrrole nitrogens. In order to account for the enhanced copper reducing capacity of bilirubin we have further proposed that an additional copper binding site is provided for in the case of bilirubin due to the absence of a double bond between pyrrole rings II and III. Further it would appear that the structural features of the bilirubin molecule which are important for its prooxidant action are also the ones that render it a more effective antioxidant.


Subject(s)
Bilirubin/metabolism , Biliverdine/metabolism , Animals , Antioxidants/chemistry , Antioxidants/metabolism , Bacteriophage lambda/metabolism , Bilirubin/chemistry , Biliverdine/chemistry , Copper/chemistry , Copper/metabolism , DNA/metabolism , Humans , Hydrogen Peroxide/metabolism , Levodopa/chemistry , Levodopa/metabolism , Molecular Structure , Oxidants/chemistry , Oxidants/metabolism , Oxidation-Reduction , Quercetin/pharmacology , Reactive Oxygen Species/metabolism , Spectrometry, Fluorescence , Structure-Activity Relationship
16.
Cancer Lett ; 169(2): 139-46, 2001 Aug 28.
Article in English | MEDLINE | ID: mdl-11431102

ABSTRACT

Capsaicin is the pungent phenolic principle of the Capsicum species, and has shown a wide range of pharmacological properties, including antigenotoxic, antimutagenic, and anticarcinogenic effects. Other studies have, however, shown it to be a tumor promoter and potential mutagen, and a carcinogen, resulting in capsaicin being termed a 'double edged sword'. In the present study, we show that capsaicin is capable of causing strand scission in calf thymus and plasmid DNA in the presence of Cu(II) and that this breakage is mediated by reactive oxygen species, especially the hydroxyl radical. Our results further show that capsaicin can directly generate hydroxyl radicals in the presence of Cu(II). To explore the chemical basis of the DNA breakage reaction by capsaicin, we have compared these properties of capsaicin with its saturated structural analog dihydrocapsaicin (DHC). The rate of DNA degradation, as well as hydroxyl radical formation, was found to be greater in the case of capsaicin. Both capsaicin and DHC are able to reduce Cu(II) to Cu(I), which was shown to be an essential intermediate in the DNA cleavage reaction. Stoichiometric analysis indicated that whereas 1 mol of capsaicin reduced 3 mol of Cu(II), 1 mol of DHC reduced only 2 mol of Cu(II). This explains the greater activity of capsaicin and also leads to a model for copper binding to the capsaicins.


Subject(s)
Capsaicin/analogs & derivatives , Capsaicin/pharmacology , Copper/pharmacology , DNA Damage , DNA/drug effects , Oxygen/metabolism , Animals , Cattle , Copper/metabolism , Dose-Response Relationship, Drug , Free Radical Scavengers/metabolism , Models, Chemical , Oxidative Stress , Phenanthrolines/pharmacology , Plasmids/metabolism , Protein Binding , Thymus Gland/drug effects , Thymus Gland/metabolism , Time Factors
17.
Phytother Res ; 14(1): 63-6, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10641054

ABSTRACT

The effect of aqueous and alcohol extracts of the roots of Saxifraga stracheyi Engl. On the spontaneous movements of both the whole worm and the nerve muscle preparation of Setaria cervi and on the survival of microfilariae in vitro was studied. Both extracts caused the inhibition of spontaneous movements of the whole worm and the nerve-muscle preparation of S. cervi, characterized by an increase in the amplitude and a decrease in the rate of contractions, while the tone of the contractions remained visibly unaffected. The concentration required to inhibit the movements of the whole worm preparation was 140 microg/ml for the aqueous and 250 microg/ml for the alcohol extract. The concentration of S. stracheyi extracts required to produce an equivalent effect on the nerve-muscle preparation was 30 microg/ml for aqueous, and 20 microg/ml for the alcohol extract, suggesting a cuticular permeability barrier.


Subject(s)
Cattle Diseases/parasitology , Filariasis/veterinary , Filaricides/chemistry , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Setaria Nematode/drug effects , Animals , Cattle , Filariasis/parasitology , Filaricides/isolation & purification
18.
Phytother Res ; 13(7): 609-12, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10548756

ABSTRACT

DNA strand scission reactions of flavonoids in the presence of Cu(II) have been extended by using flavonoids with a variety of patterns of hydroxyl substitution. In particular we have examined for the first time a flavonoid (7,8-dihydroxyflavone) that lacks the possibility of forming a complex involving the oxygen at position 4. By comparing the reactivities of several flavonoids, including data from the literature, we draw generalizations for the correlation of structure and activity and present evidence for at least three different modes of action of flavonoids as genotoxic agents.


Subject(s)
Copper/chemistry , DNA/chemistry , Flavonoids/chemistry , Hydroxyl Radical/chemistry , Hydrolysis
19.
Chem Biol Interact ; 121(2): 161-75, 1999 Jul 01.
Article in English | MEDLINE | ID: mdl-10418962

ABSTRACT

Curcumin, a naturally occurring phytochemical responsible for the colour of turmeric shows a wide range of pharmacological properties including antioxidant, anti-inflammatory and anti-cancer effects. We have earlier shown that curcumin in the presence of Cu(II) causes strand cleavage in DNA through generation of reactive oxygen species, particularly the hydroxyl radical. Thus, curcumin shows both antioxidant as well as pro-oxidant effects. In order to understand the chemical basis of various biological properties of curcumin, we have studied the structure-activity relationship between curcumin and its two naturally occurring derivatives namely demethoxycurcumin (dmC) and bisdemethoxycurcumin (bdmC). Curcumin was found to be the most effective in the DNA cleavage reaction and a reducer of Cu(II) followed by dmC and bdmC. The rate of formation of hydroxyl radicals by the three curcuminoids also showed a similar pattern. The relative antioxidant activity was examined by studying the effect of these curcuminoids on cleavage of plasmid DNA by Fe(II)-EDTA system (hydroxyl radicals) and the generation of singlet oxygen by riboflavin. The results indicate that curcumin is considerably more active both as an antioxidant as well as an oxidative DNA cleaving agent. The DNA cleavage activity is the consequence of binding of Cu(II) to various sites on the curcumin molecule. Based on the present results, we propose three binding sites for Cu(II). Two of the sites are provided by the phenolic and methoxy groups on the two benzene rings and the third site is due to the presence of 1,3-diketone system between the rings. Furthermore, both the antioxidant as well as pro-oxidant effects of curcuminoids are determined by the same structural moieties.


Subject(s)
Antioxidants/pharmacology , Coumaric Acids/pharmacology , Curcumin/analogs & derivatives , Curcumin/pharmacology , DNA, Superhelical/drug effects , Animals , Antioxidants/chemistry , Cattle , Copper/chemistry , Copper/metabolism , Coumaric Acids/chemistry , Curcumin/chemistry , DNA, Superhelical/metabolism , DNA, Viral/drug effects , DNA, Viral/metabolism , Diarylheptanoids , Electrophoresis, Agar Gel , Hydroxyl Radical/metabolism , Oxidation-Reduction , Oxygen/metabolism , Plasmids/genetics , Structure-Activity Relationship
20.
Indian J Exp Biol ; 35(2): 168-72, 1997 Feb.
Article in English | MEDLINE | ID: mdl-9315227

ABSTRACT

Effect of aqueous and alcoholic extracts of the roots of A. adscendens was studied on the spontaneous movements of whole worm and nerve muscle (n.m.) preparation of S. cervi and on the survival of microfilariae in vitro. Aqueous as well alcoholic extracts caused inhibition of spontaneous motility of whole worm and n.m. preparation of S. cervi characterized by initial, short lasting small increase in amplitude and tone of contractions followed by paralysis. The initial stimulatory effect was not observed by aqueous extract on n.m. preparation. The concentration required to inhibit the movements of n.m. preparation was 1/4th for aqueous and 1/3rd for alcoholic extract suggesting a cuticular permeability barrier. The effect of acetylcholine on n.m. preparation was concentration related being more with a concentration of 5 micrograms/ml as compared to 1 microgram/ml. Both alcoholic as well as aqueous extracts caused death of microfilariae in vitro, LC50 and LC90 being 8 and 16 ng/ml for aqueous, 3 and 12 ng/ml for alcoholic extracts respectively.


Subject(s)
Anthelmintics/pharmacology , Liliaceae/chemistry , Setaria Nematode/drug effects , Animals , Anthelmintics/chemistry , Female , Plant Roots/chemistry
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