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1.
Neural Comput Appl ; 35(20): 14591-14609, 2023.
Article in English | MEDLINE | ID: mdl-35250181

ABSTRACT

A SARS-CoV-2 virus-specific reverse transcriptase-polymerase chain reaction (RT-PCR) test is usually used to diagnose COVID-19. However, this test requires up to 2 days for completion. Moreover, to avoid false-negative outcomes, serial testing may be essential. The availability of RT-PCR test kits is currently limited, highlighting the need for alternative approaches for the precise and rapid diagnosis of COVID-19. Patients suspected to be infected with SARS-CoV-2 can be assessed using chest CT scan images. However, CT images alone cannot be used for ruling out SARS-CoV-2 infection because individual patients may exhibit normal radiological results in the primary phases of the disease. A machine learning (ML)-based recognition and segmentation system was developed to spontaneously discover and compute infection areas in CT scans of COVID-19 patients. The computable assessment exhibited suitable performance for automatic infection region allocation. The ML models developed were suitable for the direct detection of COVID-19 (+). ML was confirmed to be a complementary diagnostic technique for diagnosing COVID-19(+) by forefront medical specialists. The complete manual delineation of COVID-19 often requires up to 225.5 min; however, the proposed RILML method decreases the delineation time to 7 min after four iterations of model updating.

2.
J Hazard Mater ; 380: 120900, 2019 12 15.
Article in English | MEDLINE | ID: mdl-31326841

ABSTRACT

This study reports on the biodegradation of free cyanide (FCN) by cyanide degrading bacteria (CDB) that were isolated from mining wastewater and thiocyanate containing wastewater. The performance of these isolates was compared to cryopreserved CDBs that were used in previous studies. The performance of the isolates to degrade FCN was studied in batch cultures. It was observed that the CDB from the thiocyanate wastewater showed higher biodegradation rates (2.114 g CN-. L-1.O.D600 nm-1.h-1) compared to the isolates from the mining wastewater. The isolates from the cryopreserved CDBs and from the mining wastewater achieved a biodegradation rate of 1.285 g CN- L-1.O.D600 nm-1.h-1 and 1.209 g CN-.L-1.O.D600 nm-1.h-1, respectively. This study demonstrated that the source of the organisms plays a significant role on FCN biodegradation.


Subject(s)
Bacteria/metabolism , Biodegradation, Environmental , Cyanides/metabolism , Water Pollutants, Chemical/metabolism , Mining , Wastewater
3.
J Hazard Mater ; 375: 281-289, 2019 08 05.
Article in English | MEDLINE | ID: mdl-31078988

ABSTRACT

Zea mays L. dry husk extract was used to bio synthesize copper oxide nanoparticles. Red coloured cubic Cu2O nanoparticles were obtained for the first time via this simple, eco- friendly, green synthesis route. The Cu2O nanoparticles were thermally oxidized to pure monoclinic CuO nanoparticles at 600 °C. The phases of the copper oxides were confirmed from the x-ray diffraction (XRD) studies. The nanoparticle sizes as obtained from high resolution transmission electron microscope (HRTEM) analysis range from 10 to 26 nm, 36-73 nm and 30-90 nm for the unannealed Cu2O, 300 °C and 600 °C annealed CuO respectively. The values of the bandgap energies obtained from diffuse reflectance of the nanoparticles are 2.0, 1.30 and 1.42 eV respectively for the unannealed, 300 °C, and 600 °C annealed copper oxide nanoparticles. The 600 °C annealed copper oxide nanoparticles showed 91% and 90% degradation ability for methylene blue dye (BM) and textile effluent (TE) respectively under visible light irradiation. While CuO_300 is more effective to inhibit the growth of Escherichia coli 518,133 and Staphylococcus aureus 9144, Cu2O is better for Pseudomonas aeruginosa and Bacillus licheniformis. The results confirm the photo-catalytic and anti-microbial effectiveness of the copper oxide nanoparticles.


Subject(s)
Anti-Bacterial Agents/metabolism , Copper/metabolism , Metal Nanoparticles , Waste Disposal, Fluid/methods , Zea mays/metabolism , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Bacteria/growth & development , Catalysis , Copper/chemistry , Copper/pharmacology , Copper/radiation effects , Green Chemistry Technology , Industrial Waste , Metal Nanoparticles/chemistry , Metal Nanoparticles/radiation effects , Methylene Blue/chemistry , Photolysis , Textiles , Water Pollutants, Chemical/chemistry
4.
Phytother Res ; 17(6): 688-90, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12820243

ABSTRACT

The strongly basic alkaloidal fraction of the traditional medicinal plant Rhazya stricta (RS) was given orally to mice, in a single dose of 10 mg/kg (group 1) or, twice daily for 3 days at the same dose (group 2). A third group (control) received normal saline. Liver homogenates from all animals were used to assess the microsomal activity of cytochrome P450 and its isoforms as well as its catalytic activity (using theophylline as a substrate). RS alkaloidal fraction had no significant effect on the total amount of microsomal cytochrome P450, but it caused a significant increase in the cytochrome P450 isoforms CYPs 1A1 and 1A2. It also significantly increased the concentrations of some metabolites of theophylline. These results suggest that RS has the potential to interact with other drugs that are biotransformed by cytochrome P450, when given concomitantly with it.


Subject(s)
Apocynaceae , Cytochrome P-450 Enzyme System/metabolism , Microsomes, Liver/drug effects , Phytotherapy , Plant Extracts/pharmacology , Theophylline/pharmacokinetics , Administration, Oral , Animals , Drug Interactions , Male , Mice , Microsomes, Liver/metabolism
5.
Phytomedicine ; 9(6): 501-7, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12403158

ABSTRACT

The analgesic activity of the methanol and acetone extracts of Leucas inflata L. (family Labiatae) was evaluated in mice using different experimental models. The effect of the two extracts on pentobarbitone-sleeping time, motor activity, sensorimotor coordination, carrageen induced inflammation, and brewer's yeast-induced pyrexia has also been investigated. The two crude extracts have been phytochemically analyzed and some constituents isolated and characterized. These included stigmasterols, a chromone and coumarins. Extracts of L. inflata L., given at single oral doses of 0.25, 0.5, 1.0 or 2.0 g/kg, significantly and dose-dependently, reduced formalin-induced pain, acetic acid induced abdominal constrictions and increased the reaction time in the hot-plate test. Both extracts caused significant and dose-related impairment in the sensorimotor control and ambulatory and total motor activity of treated mice. Both extracts exhibited anti-inflammatory action by reducing paw edema of treated mice. The extracts did not significantly affect the rectal temperature of normothermic mice. However, they were effective in preventing Brewers yeast induced pyrexia. It is concluded that the crude methanol and acetone extract of L. inflata has CNS depressant properties, manifested as antinociception and sedation. Both extracts have anti-inflammatory and antipyretic actions.


Subject(s)
Central Nervous System Agents/pharmacology , Lamiaceae , Plant Extracts/pharmacology , Analgesics/pharmacology , Analgesics/therapeutic use , Analgesics, Non-Narcotic/pharmacology , Analgesics, Non-Narcotic/therapeutic use , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Body Temperature/drug effects , Carrageenan/administration & dosage , Central Nervous System Agents/therapeutic use , Coumarins/pharmacology , Coumarins/therapeutic use , Dose-Response Relationship, Drug , Edema/chemically induced , Edema/drug therapy , Inflammation/chemically induced , Inflammation/drug therapy , Male , Mice , Motor Activity/drug effects , Phytotherapy , Plant Extracts/therapeutic use , Psychomotor Performance/drug effects , Stigmasterol/pharmacology , Stigmasterol/therapeutic use , Toxicity Tests, Acute
6.
J Ethnopharmacol ; 81(1): 121-7, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12020936

ABSTRACT

Salvia aegyptiaca L. is used for treating various unrelated conditions that include nervous disorders, dizziness, trembling, diarrhoea and piles. This work examines some effects of the crude acetone and methanol extracts of the plant given at single oral doses of 0.25, 0.5, 1 or 2 g/kg, on the central nervous system (CNS) in mice. The extracts were also tested for anti-inflammatory and antipyretic actions. Several models of nociception have been used to examine the analgesic effect of the extract. In treated mice, the extracts caused dose-related inhibition of acetic acid-induced abdominal constriction, and significantly reduced formalin-induced pain. Treatment with the extracts at doses of 0.5 and 1 g/kg significantly increased the reaction time in the hot-plate test. In treated mice both extracts caused significant and dose-related impairment of the sensorimotor control and motor activity. Treatment with both extracts did not significantly affect the rectal temperature of normothermic mice. The methanol extract (0.5 and 1.0 g/kg) did not affect the rectal temperature of hyperthermic mice, but the acetone extract was effective in significantly reducing the rectal temperature of hyperthermic mice, 0.5 and 1 h after administration of the extract at doses of 0.25-2 g/kg. It is concluded that the crude methanol and acetone extracts of S. aegyptiaca have CNS depressant properties, manifested as antinociception and sedation. Both extracts have some anti-inflammatory and antipyretic actions. On the whole, the acetone extract appeared to be slightly more effective than the methanol extract in this regard.


Subject(s)
Central Nervous System/drug effects , Plant Extracts/pharmacology , Salvia/chemistry , Acetone , Analgesics, Non-Narcotic/administration & dosage , Analgesics, Non-Narcotic/pharmacology , Analgesics, Non-Narcotic/therapeutic use , Animals , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Body Temperature/drug effects , Dose-Response Relationship, Drug , Male , Methanol , Mice , Motor Activity/drug effects , Pain/chemically induced , Pain/drug therapy , Phytotherapy , Plant Extracts/administration & dosage , Plant Extracts/therapeutic use , Psychomotor Performance/drug effects
7.
Phytother Res ; 15(7): 598-603, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11746841

ABSTRACT

This work examines the effects of lyophilized extracts of the medicinal plants Rhazya stricta, Balanites aegyptiaca and Haplophylum tuberculatum on liver damage induced by paracetamol in mice. Rapid HPLC finger prints for some of these extracts were made. The hepatoprotective effects of the plant extracts were compared with that of the standard hepatoprotective agent silymarin. The extracts (1 g/kg) and silymarin (0.1 g/kg) were given orally for 5 consecutive days. On the last day of treatment a hepatotoxic oral dose of paracetamol (0.6 g/kg) was given, and 3 h later, the hepatic function of mice was evaluated using pentobarbitone -induced sleeping time, the concentration of reduced glutathione (GSH) in liver, and the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and cholesterol concentration in plasma. The livers were weighed and examined for macro- and microscopic changes. Pretreatment with R. stricta or with silymarin protected the livers of treated mice against paracetamol hepatotoxicity as evidenced by a significant improvement of the above liver function tests. B. Aegyptiaca had a relatively modest hepatoprotective activity, while H. tuberculatum was almost ineffective. Oral pretreatment of mice for 5 consecutive days with an extract of R. stricta or silymarin protected about 57% and 92% of the treated mice, respectively, against the lethal effect of paracetamol (1 g/kg). B. aegyptiaca and H. tuberculatum protected only 27% and 16% of the animals, respectively.


Subject(s)
Antioxidants/pharmacology , Hepatocytes/drug effects , Phytotherapy , Plant Extracts/pharmacology , Plants, Medicinal , Acetaminophen/adverse effects , Animals , Apocynaceae , Female , Liver/drug effects , Liver Function Tests , Medicine, Traditional , Mice , Plant Leaves , Rutaceae , Saudi Arabia , Zygophyllaceae
8.
J Vet Med A Physiol Pathol Clin Med ; 48(10): 581-6, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11848250

ABSTRACT

A comparative randomized crossover study was conducted to determine the pharmacokinetics of theophylline in male and female camels (Camelus dromedarius) and goats (Caprus hircus). Theophylline is an established 'probe drug' to evaluate the drug metabolizing enzyme activity of animals. It was administered by the intravenous (i.v.) route and then intramuscularly (i.m.) at a dose of 2 mg/kg. The concentration of the drug in plasma was measured using a high-performance liquid chromatography (HPLC) technique on samples collected at frequent intervals after administration. Following i.v. injection, the overall elimination rate constant (lambda z,) in goats was 0.006 +/- 0.00076/min and in camels was 0.0046 +/- 0.0008/min (P < 0.01). The elimination half-life (t 1/2 lambda z) in goats (112 .7 min) was lower than in camels (154.7 min) (P < 0.01). The apparent volume of distribution (Vz) and the total body clearance (Cl) in goats were 1440.1 +/- 166.6 ml/kg and 8.9 +/- 1.4 ml/min/kg, respectively. The corresponding values in camels were 1720.3 +/- 345.3 ml/kg and 6.1 +/- 1.0 ml/min/kg, respectively. After i.m. administration, theophylline reached a peak plasma concentration (Cmax) of 1.8 +/- 0.1 and 1.7 +/- 0.2 microg/ml at a post-injection time (Tmax) of 67.5 +/- 8.6 and 122.3 +/- 6.7 min in goats and camels, respectively. The mean bioavailability (T) in both goats and camels was 0.9 +/- 0.2. The above data suggest that camels eliminate theophylline at a slower rate than goats.


Subject(s)
Camelus/metabolism , Goats/metabolism , Phosphodiesterase Inhibitors/pharmacokinetics , Theophylline/pharmacokinetics , Animals , Chromatography, High Pressure Liquid/veterinary , Cross-Over Studies , Female , Half-Life , Injections, Intramuscular/veterinary , Injections, Intravenous/veterinary , Male , Phosphodiesterase Inhibitors/blood , Species Specificity , Theophylline/blood
9.
J Pharm Pharmacol ; 52(10): 1297-300, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11092575

ABSTRACT

The effect of treatment with the medicinal plant Rhayva stricta Decne, on monoamine oxidase (MAO) and cholinesterase activity, and on the concentration of brain biogenic amines was studied in rats. R. stricta extract, at doses of 0.2 and 0.5 g kg(-1), significantly (P < 0.05-0.01) increased the hepatic and cerebral activity of MAO by 36-127%. The higher doses used (2.0 and 8.0 g kg(-1)) produced smaller (10-26%) and statistically insignificant increases in MAO activity in liver and brain. Cholinesterase activity in blood, liver and brain was not significantly influenced by treatment with R. stricta. The concentrations of the measured biogenic amines (noradrenaline, adrenaline, 5-hydroxytryptamine and dopamine) were significantly lowered in rats treated with R. stricta. The observed increase in MAO activity may be responsible for the lowered biogenic amines levels and may, in part, be responsible for the pharmacological effects of R. stricta extract in rats.


Subject(s)
Biogenic Amines/metabolism , Brain/drug effects , Cholinesterases/drug effects , Liver/drug effects , Monoamine Oxidase/drug effects , Plant Extracts/pharmacology , Animals , Brain/metabolism , Cholinesterases/metabolism , Liver/metabolism , Male , Monoamine Oxidase/metabolism , Plants, Medicinal , Rats , Rats, Wistar
10.
Phytother Res ; 14(6): 469-71, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10960906

ABSTRACT

The effects of a leaf extract of the traditional medicinal plant Rhazya stricta (0.25, 1.0 and 4.0 g/kg/day for 3 days) on reduced glutathione (GSH), lipid peroxidation (LP) and ascorbic acid (AA) concentrations in the liver and kidneys were studied in rats 24 h after the last dose. The plant extract, at a dose of 0.25 g/kg, did not significantly affect the concentrations of GSH, LP or AA in the liver or kidneys. At a dose of 1.0 g/kg, the plant extract significantly increased the GSH concentration in the liver, but did not affect the GSH concentration in the kidneys, or LP or AA in the liver or kidneys. The plant extract (4.0 g/kg) significantly increased the GSH and decreased LP peroxidation, but did not affect the AA concentrations in the liver and kidneys. It may be concluded that the R. stricta extract, at some of the doses used, has antioxidant actions in the rat.


Subject(s)
Antioxidants/pharmacology , Kidney/drug effects , Liver/drug effects , Plant Extracts/pharmacology , Animals , Ascorbic Acid/metabolism , Glutathione/metabolism , Lipid Peroxidation/drug effects , Male , Medicine, Traditional , Plant Leaves , Rats , Rats, Wistar , Saudi Arabia
11.
Phytother Res ; 14(4): 229-34, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10861963

ABSTRACT

Phytochemical, pharmacological and toxicological properties of the medicinal plant Rhazya stricta Decne. are reviewed. Several types of alkaloids and a few flavonoids have been isolated and their structures and stereochemistry characterized. However, in most cases the biological activity of these compounds has not been studied. Most of the pharmacological activity of the plant resides in its alkaloidal fractions which cause depression of the central nervous system and hypotension. Extracts of R. stricta appear to have low toxicity, although its use in pregnant women may be inadvisable.


Subject(s)
Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Animals , Female , Plant Extracts/chemistry , Plant Extracts/toxicity , Pregnancy
12.
Pharmacol Res ; 41(3): 369-78, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10675291

ABSTRACT

The hypotensive action of Rhazya stricta lyophilized leaf extract was found to be partly caused by the electrolyte content of the extract, and partly caused by a strongly basic alkaloidal fraction (AF). AF (0.05-1.6 mg animal(-1)) caused a dose-dependent reduction in mean arterial blood pressure (MAP) of urethane-anaesthetized rat preparations. In naiuml;ve pithed rats, AF administration (0.5-2.0 mg animal(-1)) significantly increased MAP. In pithed or spinalized rats made normotensive by noradrenaline infusion, AF (0.25 mg animal(-1)) did not cause any significant changes. Direct intracerebroventricular injection of AF (0.1-0.4 mg) markedly and significantly reduced MAP. It is suggested that the hypotensive action of AF to be mediated by a central mechanism.


Subject(s)
Antihypertensive Agents/pharmacology , Plants, Medicinal/chemistry , Alkaloids/pharmacology , Anesthesia , Animals , Blood Pressure/drug effects , Dose-Response Relationship, Drug , Electrolytes/pharmacology , Freeze Drying , Heart Rate/drug effects , Hydrochloric Acid/metabolism , Male , Plant Extracts/pharmacology , Rats , Rats, Wistar
13.
Phytother Res ; 14(2): 107-11, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10685107

ABSTRACT

The present work examines the effects of hexane, ethyl acetate and methanol extracts of Psidium guajava leaves (20,100,500 and 1250 mg/kg) on the central nervous system in mice. The three extracts exhibited mostly dose-dependent antinociceptive effects in chemical and thermal tests of analgesia. The extracts also produced dose-dependent prolongation of pentobarbitone-induced sleeping time. However, they had variable and mostly non-significant effects on locomotor coordination, locomotor activity or exploration. In the pharmacological tests used, the ethyl acetate extract seemed to be the most active, followed by the hexane and then the methanol extracts.


Subject(s)
Analgesics/pharmacology , Central Nervous System/drug effects , Motor Activity/drug effects , Rosales , Animals , Dose-Response Relationship, Drug , Male , Mice , Plant Extracts/pharmacology , Plant Leaves/chemistry
14.
Pharmacol Biochem Behav ; 64(3): 455-60, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10548255

ABSTRACT

The effect of acute and chronic treatment of rats with a lyophilized extract of the leaves of the medicinal plant Rhazya stricta on total and ambulatory activity was studied. Given acutely at single oral doses of 1, 2, 4, and 8 g/kg, the extract produced dose-dependent decreases in total activity and ambulatory activity. Diazepam (20 mg/kg, orally) produced a decrease in rat activity comparable to that produced by a dose of 1 g/kg of the extract. When given daily at an oral dose of 2 g/kg for 21 consecutive days, the extract produced, on the last day of treatment, significant decrease in activity amounting to about 30% of control activity levels. Subcutaneous (SC) treatment of rats with caffeine (7.5, 15, and 30 mg/kg), dose-dependently and significantly increased total activity and ambulatory activity. These effects were dose-dependently attenuated when the extract was given concomitantly with caffeine at oral doses of 1, 2, and 4 mg/kg. Treatment of rats with zoxazolamine alone (10, 20, or 40 mg/kg, SC) or R. Stricta (1 and 4 g/kg orally) alone significantly decreased total and ambulatory activities. Concomitant treatment with zoxazolamine and R. Stricta decreased the rats activity to a greater degree than with either treatment given alone.


Subject(s)
Motor Activity/drug effects , Plants, Medicinal/chemistry , Animals , Anti-Anxiety Agents/pharmacology , Caffeine/pharmacology , Central Nervous System Stimulants/pharmacology , Diazepam/pharmacology , Dopamine/physiology , Drug Interactions , Male , Muscle Relaxants, Central/pharmacology , Plant Extracts/pharmacology , Rats , Rats, Wistar , Time Factors , Zoxazolamine/pharmacology
16.
Life Sci ; 62(15): 1361-9, 1998.
Article in English | MEDLINE | ID: mdl-9566778

ABSTRACT

Gentamicin (G) treatment (5, 20, 40 and 80 mg kg[-1] day[-1] given intramuscularly for 6 days) was shown to cause a dose-related platelet proaggregatory effect in mouse pial microcirculation. This was associated with a reduction in mouse renal function, indicated by high plasma creatinine and urea concentrations. When G was given at the same doses but as a single injection, it caused no change in renal function or platelet aggregation. Gentamicin (20 and 80 mg kg/day, given intramuscularly for 6 days) significantly (P < 0.05) impeded the platelet antiaggregatory effect of acetylsalicylic acid (100 mg kg[-1], intraperitoneally).


Subject(s)
Aspirin/pharmacology , Gentamicins/pharmacology , Pia Mater/blood supply , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation/drug effects , Animals , Arterioles/drug effects , Drug Interactions , Male , Mice
17.
J Appl Toxicol ; 18(2): 111-6, 1998.
Article in English | MEDLINE | ID: mdl-9570693

ABSTRACT

Haematological, biochemical and pathological effects in rats produced by the salt-tolerant plant Avicennia marina given at oral doses of 1 or 4 g kg(-1) for three consecutive days or 0.5 g kg(-1) day(-1) for 28 consecutive days are reported. No overt behavioral changes, moribundity or mortality were seen in either of the two experiments. A dose of 1 g kg(-1) did not affect significantly either body or liver weights. However, at a dose of 4 g kg(-1) the extract reduced both body and liver weights. The extract at both doses significantly increased leucocyte (mainly neutrophil) counts but did not affect significantly erythrocyte counts, haemoglobin concentration or the haematocrit. Except for a slight, but statistically significant, decrease in plasma glucose concentration and an increase in Na, Ca, Cu, Mg and cholesterol concentrations and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, the extract exerted no significant effects on plasma biochemistry. The treatment produced dose-related mild cellular degeneration in the liver and congestion in the central veins. There were also prominent Kupffer's cells and monocellular infiltrations. In the kidneys there was shrinkage and cellular degeneration of glomeruli and patches of medullary haemorrhage. In the spleen a slight activation of the germinal centre in the white pulp was noted. Subchronic treatment with the extract did not affect significantly the body and liver weights, the water intake, faecal and urinary output, leucocyte and erythrocyte counts, haemoglobin or haematocrit. There was a significant decrease in the number of platelets and an increase in the number of neutrophils. No significant changes in plasma biochemistry were observed, except for a 15% increase in AST activity. Subchronic treatment produced a significant reduction in glutathione concentration, amounting to about 20%. Histopathological findings after the subchronic treatment were similar in nature but milder than those seen after the acute treatment.


Subject(s)
Animal Feed/toxicity , Liver/drug effects , Plants, Medicinal/toxicity , Administration, Oral , Animals , Body Weight/drug effects , Dose-Response Relationship, Drug , Liver/enzymology , Liver/pathology , Male , Plant Extracts/toxicity , Plant Leaves/toxicity , Rats , Rats, Wistar , Trees
18.
Res Vet Sci ; 64(1): 69-72, 1998.
Article in English | MEDLINE | ID: mdl-9557809

ABSTRACT

Single bolus intravenous (i.v.) and intramuscular (i.m.) doses of furosemide (1.5 mg kg(-1)) were administered in a crossover design to three female and three male adult, dromedary camels. Plasma furosemide concentrations were assayed by HPLC and sodium, potassium and chloride concentrations were measured using ion-selective electrodes. Plasma furosemide concentration-time plots indicated multi-compartment disposition, and there was considerable intersubject variability in the pharmacokinetic parameters. The mean (SD) i.v. terminal elimination half-life was 118 (67) minutes. The systemic clearance was 5.4 (1.2) ml min(-1) kg(-1). and the steady-state volume of distribution was 0.43 (0.14) litre kg(-1). The mean absorption time after i.m. dosing was 33 (62) minutes, while the absolute bioavailability was 71 (20) per cent. The glucuronide metabolite of furosemide was not detected in plasma. Clearance was lower, volume of distribution was larger, and half-life was longer compared with published data for dogs, horses, rats and humans. Plasma potassium and sodium concentrations were significantly diminished (P<0.05) by an average of 35.6 per cent (two to six hours post-dose) and 11.3 per cent (eight hours post-dose), respectively. Plasma chloride concentrations were not significantly affected by furosemide administration.


Subject(s)
Camelus , Diuretics/pharmacokinetics , Furosemide/pharmacokinetics , Animals , Biological Availability , Chlorides/blood , Chromatography, High Pressure Liquid , Cross-Over Studies , Diuretics/administration & dosage , Dogs , Female , Furosemide/administration & dosage , Half-Life , Horses , Humans , Injections, Intramuscular , Injections, Intravenous , Male , Metabolic Clearance Rate , Models, Biological , Potassium/blood , Rats , Sodium/blood , Species Specificity
19.
Pharmacol Biochem Behav ; 59(3): 671-5, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9512070

ABSTRACT

Rhazya stricta leaves, which have both antidepressant and sedative properties in animal models, are widely used in folk medicine in the Arabian peninsula. In this study, the effects of oral administration of leaf extracts on rat brain tribulin levels [endogenous monoamine oxidase (MAO) A and B inhibitory activity], were determined. In an acute study, low doses brought about an increase in MAO A inhibitory activity, while intermediate doses caused a significant reduction. The highest doses had no significant effects on activity. There were no significant effects on MAO B inhibitory activity at any dose. Subchronic administration (21 days) caused a significant decrease in MAO A inhibitory activity, most prominent at low dosage, and an increase in MAO B inhibitory activity. Acute intramuscular administration also resulted in a similar pattern. Such paradoxical effects were at least partially explained when different extracts of the leaves were used; a weakly basic chloroform fraction caused an increase in MAO A inhibitory activity, whereas butanol extracts brought about a decrease. These fractions had no significant effects on MAO B inhibitory activity. The findings show that Rhazya stricta leaves contain at least two different components that affect MAO inhibitory activity in opposite directions. It may be that the antidepressant and sedative actions of the plant are explicable in terms of these different components.


Subject(s)
Brain Chemistry/drug effects , Isatin , Monoamine Oxidase Inhibitors/metabolism , Plants, Medicinal/chemistry , Animals , Brain/drug effects , Brain/enzymology , Chromatography, High Pressure Liquid , Injections, Intramuscular , Male , Monoamine Oxidase/metabolism , Plant Extracts/administration & dosage , Plant Extracts/pharmacology , Rats , Rats, Wistar , Spectrophotometry, Ultraviolet
20.
Pharmacol Biochem Behav ; 59(2): 547-50, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9477006

ABSTRACT

Immobility induced by forced swimming is well known as an animal model of depression. Using this paradigm, we have, in the present work, tested the possibility that the medicinal plant Rhazya stricta, which has previously been found to affect the monoamine oxidase inhibitory activity in rat brain, may have an antidepressant-like action. Rats were pretreated with various doses (0.025-6.4 g/kg) of the lyophilized extract of the plant leaves, or with desipramine (10, 20, and 40 mg/kg) and were subjected to the forced swimming test. The results indicated that the plant extract produced a biphasic (bell-shaped) effect on the immobility time. The lower doses (0.1, 0.2, and 0.4 g/kg) elicited a highly significant and inversely dose-dependent decrease in immobility time, and the higher doses (0.8, 1.6, and 6.4 g/kg) showed a dose-dependent decrease in immobility time. Under the same experimental conditions desipramine (20 and 40 mg/kg) produced dose-dependent significant decreases in immobility time. Following administration of R. stricta (6.4 g/kg) the immobility time recovered progressively with time, and 4 h after its administration the immobility time was about 70% of the control level (statistically insignificant). It is concluded that R. stricta extract [or component(s) thereof] may possess an antidepressant-like effect.


Subject(s)
Antidepressive Agents/pharmacology , Motor Activity/drug effects , Plants, Medicinal/chemistry , Animals , Antidepressive Agents, Tricyclic/pharmacology , Desipramine/pharmacology , Dose-Response Relationship, Drug , Male , Monoamine Oxidase Inhibitors/pharmacology , Plant Extracts/pharmacology , Rats , Rats, Wistar , Swimming
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