Nigella sativa fixed and essential oil modulates glutathione redox enzymes in potassium bromate induced oxidative stress.

BACKGROUND: Nigella sativa is an important component of several traditional herbal preparations in various countries. It finds its applications in improving overall health and boosting immunity. The current study evaluated the role of fixed and essential oil of Nigella sativa against potassium bromate induced oxidative stress with special reference to modulation of glutathione redox enzymes and myeloperoxidase. METHODS: Animals; 30 rats (Sprague Dawley) were divided in three groups and oxidative stress was induced using mild dose of potassium bromate. The groups were on their respective diets (iso-caloric diets for a period of 56 days) i.e. control and two experimental diets containing N. sativa fixed (4%) and essential (0.3%) oils. The activities of enzymes involved in glutathione redox system and myeloperoxidase (MPO) were analyzed. RESULTS: The experimental diets modulated the activities of enzymes i.e. glutathione-S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx) positively. Indices of antioxidant status like tocopherols and glutathione were in linear relationship with that of GPx, GR and GST (P<0.01). MPO activities were in negative correlation with GST (P<0.01) but positive correlation with some other parameters. CONCLUSIONS: Our results indicated that both Nigella sativa fixed and essential oil are effective in improving the antioxidant indices against potassium bromate induced oxidative stress.

Normalized Difference Vegetation Index as a tool for wheat yield estimation: a case study from Faisalabad, Pakistan.

For estimation of grain yield in wheat, Normalized Difference Vegetation Index (NDVI) is considered as a potential screening tool. Field experiments were conducted to scrutinize the response of NDVI to yield behavior of different wheat cultivars and nitrogen fertilization at agronomic research area, University of Agriculture Faisalabad (UAF) during the two years 2008-09 and 2009-10. For recording the value of NDVI, Green seeker (Handheld-505) was used. Split plot design was used as experimental model in, keeping four nitrogen rates (N1 = 0 kg ha(-1), N2 = 55 kg ha(-1), N3 = 110 kg ha(-1), and N4 = 220 kg ha(-1)) in main plots and ten wheat cultivars (Bakkhar-2001, Chakwal-50, Chakwal-97, Faisalabad-2008, GA-2002, Inqlab-91, Lasani-2008, Miraj-2008, Sahar-2006, and Shafaq-2006) in subplots with four replications. Impact of nitrogen and difference between cultivars were forecasted through NDVI. The results suggested that nitrogen treatment N4 (220 kg ha(-1)) and cultivar Faisalabad-2008 gave maximum NDVI value (0.85) at grain filling stage among all treatments. The correlation among NDVI at booting, grain filling, and maturity stages with grain yield was positive (R(2) = 0.90; R(2) = 0.90; R(2) = 0.95), respectively. So, booting, grain filling, and maturity can be good depictive stages during mid and later growth stages of wheat crop under agroclimatic conditions of Faisalabad and under similar other wheat growing environments in the country.

Antioxidant potential and oil composition of Callistemon viminalis leaves.

The present study was designed to investigate the antioxidant potential and oil composition of Callistemon viminalis leaves. GC-MS analysis of the n-hexane extract revealed the presence of 40 compounds. Leaves contained appreciable levels of total phenolic contents (0.27-0.85 GAE mg/g) and total flavonoid contents (2.25-7.96 CE mg/g). DPPH radical scavenging IC50 and % inhibition of linoleic acid peroxidation were found to be in the ranges of 28.4-56.2 µg/ml and 40.1-70.2%, respectively. The haemolytic effect of the plant leaves was found in the range of 1.79-4.95%. The antioxidant activity of extracts was also studied using sunflower oil as an oxidative substrate and found that it stabilized the oil. The correlation between the results of different antioxidant assays and oxidation parameters of oil indicated that leaves' methanolic extract, exhibiting higher TPC and TFC and scavenging power, was also more potent for enhancing the oxidative stability of sunflower oil.

Assessment of total phenolic content and antioxidant potential of methanol extract of Peltophorum pterocarpum (DC.) Backer ex K. Heyne.

Plants are rich in a variety of chemical compounds. Many are secondary metabolites including aromatic substances most of them are phenols or their oxygen substituted derivatives. Medicinal plants are rich in antioxidant constituents such as phenols, tocopherols, ascorbic acid, carotenoids, and flavonoids etc. They are found to acquire free radical scavenging activity and used worldwide for the treatment of various immune system dependent diseases. Peltophorum pterocarpum (DC) Backer ex K. Heyne (Caesalpiniaceae) is a beautiful ornamental tree, widely grown in tropical regions and its parts are used in traditional medicine as medicinal agents. Fresh pods of Peltophorum pterocarpum was evaluated for its antioxidant potential by using various methods including DPPH, superoxide anion, nitric oxide scavenging, and metal chelating activity. TPC via Folin-Ciocalteau's reagent and anti haemolytic activity red blood cells respectively have also been measured. The methanol extract of pods of Peltophorum pterocarpum was found to possess the significant amount 439.21±0.17 mg GAE (gallic acid equivalents) / g of TPC. The antioxidant potential of pods extract at mature stage showed potent activity and measured as, free radical scavenging activity 73.29±0.81%, superoxide anion scavenging activity 89.03±1.07%, nitric oxide scavenging activity 84.25±1.18%, and metal chelating activity 64.12±0.11%. The extract also showed potent anti haemolytic activity 79.09± 0.75%. Peltophorum pterocarpum exhibited strong but varying level of antioxidant and anti haemolytic activity in various methods along with total phenolic contents.

Biological screening of selected flora of Pakistan.

Methanolic extracts of different parts of five medicinal plants, Ferula assafoetidaL. resin, Grewia asiaticaL. leaves, Ipomoea hederaceaJacq. seeds, Lepidium sativumL. seeds and Terminalia chebulaRetz. fruits were tested in vitrofor their cytotoxic, phytotoxic, insecticidal, nematicidal and anthelmintic activities. Ipomoea hederaceashowed very significant phytotoxic and cytotoxic activity, with 100% inhibition of Lemna minorgrowth and 100% death of Artemia salinaat concentrations of 1000 and 100 µg mL-1. Grewia asiaticaexhibited very weak activities while Lepidium sativumand Ferula assafoetidashowed moderate to good potential in all three bioassays. The results suggest screening of Ipomoea hederaceaseeds further for isolation of bioactive compounds that may be responsible for its toxic potential.

Analgesic and antiinflammatory activities of taxoids from Taxus wallichiana Zucc.

A study was conducted to identify constituents that might be responsible for analgesic and antiinflammatory conditions. Tasumatrol B, 1,13-diacetyl-10-deacetylbaccatin III (10-DAD) and 4-deacetylbaccatin III (4-DAB) were isolated from the bark extract of Taxus wallichiana Zucc. All the compounds were assessed for analgesic and antiinflammatory activities using an acetic acid-induced writhing model, a hot-plate test, a carrageenan-induced paw oedema model, a cotton-pellet oedema model and in vitro lipoxygenase inhibitory assay. All the compounds, especially tasumatrol B, revealed significant analgesic activity in comparison to a saline group based on an acetic acid-induced model. Similarly all of the test compounds, particularly tasumatrol B, showed significant antiinflammatory activity. However, all the compounds failed to exhibit any considerable activity in of the hot-plate test and the in vitro lipoxygenase inhibitory assay. This study has highlighted the potential of tasumatrol B to be further explored as a new lead compound for the management of pain and inflammation, one that has been discovered by scientific validation of the traditional medicinal use of T. wallichiana Zucc.

Platelet aggregation and anti-inflammatory effects of garden pea, Desi chickpea and Kabuli chickpea.

Inflammation is the natural body defense mechanism for the removal of injurious agents, necrosed cells and tissues from the body. This study was aimed to evaluate the anti-inflammatory and platelet aggregation effects of three medicinal plants of Pakistan. Methanolic extract of garden pea inhibited arachidonic acid (AA)-induced platelet aggregation (IC50 = 35 microg/mL) and platelet activating factor (PAF)-induced platelet aggregation (IC50 = 38 microg/mL) in a dose dependent fashion. Methanolic extract of Desi chickpea inhibited arachidonic acid (AA) induced platelet aggregation (IC50 value = AA = 46 microg/mL) in dose dependent fashion while was found not active against PAF-induced platelet aggregation. Methanolic extract of Kabuli chickpea was found not active against both arachidonic acid (AA)-induced platelet aggregation and PAF-induced platelet aggregation. The best potential to inhibit in vitro COX-2 activity showed garden pea (Pisum sativum: the synthesis of PGE2 reduced by 92% in comparison with untreated control wells) followed by Desi chickpea (Cicer arietinum var; 87% inhibition) and Kabuli chickpea extracts (Cicer arietinum var: 65% inhibition). All extracts were tested at concentration 20 microg/mL. in COX-2 assay. The results indicate that if the same were happening in vito, Garden pea, Desi chickpea and Kabuli chickpea could be useful as natural antithrombotic anti-inflammatory materials.

Chemical composition, antioxidant and antimicrobial potential of essential oils from different parts of Daphne mucronata Royle.

This research work was executed to determine chemical composition, anti-oxidant and anti-microbial potential of the essential oils extracted from the leaves and stem of Daphne mucronata Royle. From leaves and stem oils fifty-one different constituents were identified through GC/MS examination. The antioxidant potential evaluated through DPPH free radical scavenging activity and %-inhibition of peroxidation in linoleic acid system. The stem's essential oil showed the good antioxidant activity as compared to leaves essential oil. Results of Antimicrobial activity revealed that both stem and leaves oils showed strong activity against Candida albicans with large inhibition zone (22.2 ± 0.01, 18.9 ± 0.20 mm) and lowest MIC values (0.98 ± 0.005, 2.44 ± 0.002 mg/mL) respectively. Leaves essential was also active against Escherichia coli with inhibition zone of 8.88 ± 0.01 mm and MIC values of 11.2 ± 0.40 mg/mL. These results suggested that the plant's essential oils would be a potential cradle for the natural product based antimicrobial as well as antioxidant agents.

Sansevieria roxburghiana Schult. & Schult. F. (Family: Asparagaceae) Attenuates Type 2 Diabetes and Its Associated Cardiomyopathy.

BACKGROUND: Sansevieria roxburghiana Schult. & Schult. F. (Family: Asparagaceae) rhizome has been claimed to possess antidiabetic activity in the ethno-medicinal literature in India. Therefore, present experiments were carried out to explore the protective role of edible (aqueous) extract of S. roxburghiana rhizome (SR) against experimentally induced type 2 diabetes mellitus (T2DM) and its associated cardiomyopathy in Wistar rats. METHODS: SR was chemically characterized by GC-MS analysis. Antidiabetic activity of SR (50 and 100 mg/kg, orally) was measured in high fat diets (ad libitum) + low-single dose of streptozotocin (35 mg/kg, intraperitoneal) induced type 2 diabetic (T2D) rat. Fasting blood glucose level was measured at specific intermissions. Serum biochemical and inflammatory markers were estimated after sacrificing the animals. Besides, myocardial redox status, expressions of signal proteins (NF-κB and PKCs), histological and ultrastructural studies of heart were performed in the controls and SR treated T2D rats. RESULTS: Phytochemical screening of the crude extract revealed the presence of phenolic compounds, sugar alcohols, sterols, amino acids, saturated fatty acids within SR. T2D rats exhibited significantly (p < 0.01) higher fasting blood glucose level with respect to control. Alteration in serum lipid profile (p < 0.01) and increased levels of lactate dehydrogenase (p < 0.01) and creatine kinase (p < 0.01) in the sera revealed the occurrence of hyperlipidemia and cell destruction in T2D rats. T2DM caused significant (p < 0.05-0.01) alteration in the biochemical markers in the sera. T2DM altered the redox status (p < 0.05-0.01), decreased (p < 0.01) the intracellular NAD and ATP concentrations in the myocardial tissues of experimental rats. While investigating the molecular mechanism, activation PKC isoforms was observed in the selected tissues. T2D rats also exhibited an up-regulation in nuclear NF-κB (p65) in the cardiac tissues. So, oral administration of SR (50 and 500 mg/kg) could reduce hyperglycemia, hyperlipidemia, membrane disintegration, oxidative stress, vascular inflammation and prevented the activation of oxidative stress induced signaling cascades leading to cell death. Histological and ultra-structural studies of cardiac tissues supported the protective characteristics of SR. CONCLUSIONS: From the present findings it can be concluded that, SR could offer protection against T2DM and its associated cardio-toxicity via multiple mechanisms viz. hypoglycemic, antioxidant and anti-inflammatory actions.

Cytoprotective and Antioxidant Effects of an Edible Herb, Enhydra fluctuans Lour. (Asteraceae), against Experimentally Induced Lead Acetate Intoxication.

BACKGROUND: Enhydra fluctuans Lour. (Asteraceae), an edible aquatic herb, is traditionally employed against toxic effects of heavy metals in India. The present study was planned to discover the protective effect of edible extract of E. fluctuans (AEEF) against Pb toxicity. METHODS: The cytoprotective role of AEEF was determined on murine hepatocytes employing MTT assay and Hoechst staining. The effects on lipid peroxidation, protein carbonylation, endogenous redox systems and the transcription levels of apoptotic proteins were studied after incubating the hepatocytes with AEEF (400 µg/ml) + Pb-acetate (6.8 µM). The defensive role of AEEF (100 mg/kg) against Pb-acetate (5 mg/kg) intoxication was measured in mice by in vivo assays. Biochemical, haematological and histological parameters, intracellular Pb burden and redox status were measured. RESULTS: AEEF exhibited a concentration dependent cytoprotective effect against Pb-induced cytotoxicity in vitro. Pb-acetate incubation significantly (p < 0.01) altered the extents of ROS production ↑, protein carbonylation ↑, lipid peroxidation ↑, endogenous antioxidant enzymes ↓ and GSH ↓ in vitro. Besides, Pb-acetate significantly (p < 0.01) induced apoptosis in the hepatocytes apparent from the altered expressions of apoptotic proteins viz. Apaf-1 ↑, Bad ↑, Bcl-2 ↓, Cyt C ↑, cleaved caspases↑, Bid ↑ and Fas ↑. However, AEEF (400 µg/ml) could significantly (p < 0.05-0.01) attenuate the Pb-acetate mediated toxic manifestation in vitro. In in vivo assay, Pb-acetate (5 mg/kg) treated mice exhibited significantly (p < 0.01) high intracellular Pb content. A high Pb-burden within the tissues caused significant (p < 0.05-0.01) patho-physiological alterations viz. ROS production ↑, protein carbonylation↑, lipid peroxidation ↑, DNA fragmentation ↑, ATP formation ↑, mitochondrial co-enzymes Q ↓, endogenous antioxidant enzymes ↓ and GSH ↓ within the selected tissues. The haematological and serum biochemical parameters were significantly (p < 0.05-0.01) different in the Pb-acetate treated mice. Finally, histological assessment imposed significant toxic occurrence within the organs of Pb-intoxicated animals. However, concurrent administration of AEEF (100 mg/kg) could significantly (p < 0.05-0.01) reinstate the Pb-acetate mediated toxicity. CONCLUSION: Presence of metal chelators and phyto-antioxidants within AEEF would offer overall protection through promoting Pb clearance coupled with restoring redox balance.

Water Spinach, Ipomoea aquatic (Convolvulaceae), Ameliorates Lead Toxicity by Inhibiting Oxidative Stress and Apoptosis.

BACKGROUND: Ipomoea aquatica (Convolvulaceae), an aquatic edible plant, is traditionally used against heavy metal toxicity in India. The current study intended to explore the protective role of edible (aqueous) extract of I. aquatica (AEIA) against experimentally induced Pb-intoxication. METHODS: The cytoprotective role of AEIA was measured on mouse hepatocytes by cell viability assay followed by Hoechst staining and flow cytometric assay. The effect on ROS production, lipid peroxidation, protein carbonylation, intracellular redox status were measured after incubating the hepatocytes with Pb-acetate (6.8 µM) along with AEIA (400 µg/ml). The effects on the expressions of apoptotic signal proteins were estimated by western blotting. The protective role of AEIA was measured by in vivo assay in mice. Haematological, serum biochemical, tissue redox status, Pb bioaccumulation and histological parameters were evaluated to estimate the protective role of AEIA (100 mg/kg) against Pb-acetate (5 mg/kg) intoxication. RESULTS: Pb-acetate treated hepatocytes showed a gradual reduction of cell viability dose-dependently with an IC50 value of 6.8 µM. Pb-acetate treated hepatocytes exhibited significantly enhanced levels (p < 0.01) of ROS production, lipid peroxidation, protein carbonylation with concomitant depletion (p < 0.01) of antioxidant enzymes and GSH. However, AEIA treatment could significantly restore the aforementioned parameters in murine hepatocytes near to normalcy. Besides, AEIA significantly reversed (p < 0.05-0.01) the alterations of transcription levels of apoptotic proteins viz. Bcl 2, Bad, Cyt C, Apaf-1, cleaved caspases [caspase 3, caspase 8 and caspase 9], Fas and Bid. In in vivo bioassay, Pb-acetate treatment caused significantly high intracellular Pb burden and oxidative pressure in the kidney, liver, heart, brain and testes in mice. In addition, the haematological and serum biochemical factors were changed significantly in Pb-acetate-treated animals. AEIA treatment restored significantly the evaluated-parameters to the near-normal position. CONCLUSION: The extract may offer the protective effect via counteracting with Pb mediated oxidative stress and/or promoting the elimination of Pb by chelating. The presence of substantial quantities of flavonoids, phenolics and saponins would be responsible for the overall protective effect.

Bronchodilator, vasodilator and spasmolytic activities of Cymbopogon martinii.

Cymbopogon martinii (Cm.Cr) is traditionally used in south Asian communities for the management of multiple ailments including gastrointestinal, respiratory and vascular disorders and the present study was undertaken to validate these folkloric uses. The application of a methanol extract of the plant (Cm.Cr) to isolated rabbit jejunum preparation exhibited relaxation through decrease in magnitude and frequency of spontaneous contractions. The Cm.Cr also exerted relaxant effect on high K(+) (80 mM) induced contractions in isolated rabbit jejunum preparations. The Cm.Cr and its dichloromethane (Cm.Dcm) and aqueous (Cm.Aq) fractions also caused concentration-dependent relaxation in spontaneous and K(+) (80 mM) induced contractions which are comparables to effects produced by verapamil. Cm.Cr caused shifting of the Ca(2+)-curves toward right, suggesting the presence of a Ca(2+) channel blocking activity. Subsequently, Cm.Cr, Cm.Dcm and Cm.Aq caused relaxation of CCh (1 µM) and K(+) (80 mM) induced contractions in isolated rabbit tracheal preparations, suggesting that the observed relaxant effect can be mediated through antimuscarinic and/or Ca(2+) channel blocking activities. Cm.Cr tested against phenylephrine (PE; 1 µM) and K(+) (80 mM) induced contractions exhibited partial relaxation of isolated rabbit aortic preparations. The above-mentioned studies provided a scientific basis for the folkloric use of Cymbopogon martini in the management of multiple ailments in traditional systems of medicines.

Nigella sativa Fixed and Essential Oil Supplementation Modulates Hyperglycemia and Allied Complications in Streptozotocin-Induced Diabetes Mellitus.

In the recent era, diabetes mellitus has emerged as one of the significant threats to public health and this situation demands the attention of the researchers and allied stakeholders. Dietary regimens using functional and nutraceutical foods are gaining wide range of acceptance and some traditional medicinal plants are of considerable importance. The main objective of this instant study was to explore the antidiabetic potential of Nigella sativa fixed oil (NSFO) and essential oil (NSEO). Three experimental groups of rats received diets during the entire study duration, that is, D1 (control), D2 (NSFO: 4.0%), and D3 (NSEO: 0.30%). Experimental diets (NSFO & NSEO) modulated the lipid profile, while decreasing the antioxidant damage. However, production of free radicals, that is, MDA, and conjugated dienes increased by 59.00 and 33.63%, respectively, in control. On the contrary, NSFO and NSEO reduced the MDA levels by 11.54 and 26.86% and the conjugated dienes levels by 32.53 and 38.39%, respectively. N. sativa oils improved the health and showed some promising anti-diabetic results.

A convenient method for the synthesis of (prop-2-ynyloxy)benzene derivatives via reaction with propargyl bromide, their optimization, scope and biological evaluation.

A highly convenient method has been developed for the synthesis of (prop-2-ynyloxy) benzene and its derivatives. Differently substituted phenol and aniline derivatives were allowed to react with propargyl bromide in the presence of K2CO3 base and acetone as solvent. The compounds were synthesized in good yields (53-85%). Low cost, high yields and easy availability of compounds helped in the synthesis. Electron withdrawing groups favor the formation of stable phenoxide ion thus in turn favors the formation of product while electron donating groups do not favor the reaction. Phenol derivatives gave good yields as compared to that of aniline. As aprotic polar solvents favor SN2 type reactions so acetone provided best solvation for the reactions. K2CO3 was proved to be good for the synthesis. Antibacterial, Antiurease and NO scavenging activity of synthesized compounds were also examined. 4-bromo-2-chloro-1-(prop-2-ynyloxy)benzene 2a was found most active compound against urease enzyme with a percentage inhibition of 82.00±0.09 at 100 µg/mL with IC50 value of 60.2. 2-bromo-4-methyl-1-(prop-2-ynyloxy)benzene 2d was found potent antibacterial against Bacillus subtillus showing excellent inhibitory action with percentage inhibition of 55.67±0.26 at 100 µg/ml wih IC50 value of 79.9. Based on results, it can be concluded that some of the synthesized compounds may have potential antiurease and antibacterial effects against several harmful substances.

Bronchodilator, vasodilator and spasmolytic activities of methanolic extract of Myrtus communis L.

The present study was undertaken to validate some of the folkloric claims about the effectiveness of the use of a Myrtus communis L. crude methanol extract (Mc.Cr) in gastrointestinal, respiratory and vascular diseases. Mc.Cr caused complete relaxation of spontaneous and K⁺ (80 mM)-induced contractions in isolated rabbit jejunum. It caused right ward parallel shift of calcium concentration response curves. Mc.Cr exhibited relaxant effect on CCh- and K⁺ (80 mM)-induced contractions in isolated rabbit tracheal preparations. Furthermore, Mc.Cr caused relaxation of phenylephrine (1 µM)- and K⁺ (80 mM)-induced contractions in isolated rabbit aorta preparations. These effects were similar to verapamil, a standard calcium channel blocker. These findings could be the basis for explaining the spasmolytic, bronchodilator and vasodilator activities of the extract, through a possible calcium channel blocking activity.

Pharmacological Effects of Lactuca serriola L. in Experimental Model of Gastrointestinal, Respiratory, and Vascular Ailments.

Lactuca serriola L. has traditionally been used in folkloric medicine to manage respiratory, gastrointestinal, and multiple other ailments. The present study was undertaken to explore the effect of methanol extract of L. serriola on isolated rabbit tissue preparations, that is, jejunum, trachea, and aorta in an attempt to validate its folkloric use in traditional medicine for gastrointestinal, respiratory, and vascular ailments. The application of the methanol extract to isolated rabbit jejunum preparations exhibited concentration-dependent spasmogenic effect (0.03 to 3.0 mg/mL), but interestingly further increase in concentration (5.0 mg/mL) resulted in complete spasmolytic effect. The pretreatment of the tissue preparations with atropine (0.1 µ M) caused the suppression of the contractile response. Moreover, the same extract also caused relaxation of K(+)-(80 mM) induced spastic contractions of isolated rabbit jejunum preparations (5.0 mg/mL) and shifted the Ca(++) dose response curves towards right at concentration range of 0.3-1.0 mg/mL. Similarly, the extract application to isolated rabbit tracheal preparations relaxed the carbachol-(1 µ M) induced (0.3-1.0 mg/mL) as well as K(+)-(80 mM) induced contractions (3.0 mg/mL). Furthermore, it relaxed the phenylephrine (1 µ M)-induced contractions in isolated rabbit aorta preparations (3.0 mg/mL) and K(+) (80 mM)-induced contractions (1.0 mg/mL). These effects were found comparable to that of dicyclomine, as an antagonist of muscarinic receptors as well as a possible Ca(++) channel blocker. The previously mentioned findings may partially justify the folkloric use of Lactuca serriola in the management of conditions pertaining to spasm of intestine, bronchioles, and vasculature.

Gastrointestial and respiratory activities of Acacia leucophloea.

ETHNOPHARMACOLOGICAL RELEVANCE: The barks of Acacia leucophloea (Fabaceae) are used in Pakistan traditional medicine as an astringent, a bitter, a thermogenic, a styptic, a preventive of infections, an anthelmintic, a vulnery, a demulcent, an expectorant, an antipyretic, an antidote for snake bites and in the treatment of bronchitis, cough, vomiting, wounds, ulcers, diarrhea, dysentery, internal and external hemorrhages, dental caries, stomatitis, and intermittent fevers and skin diseases. MATERIALS AND METHODS: A study was carried out for the possible elucidation of mechanisms justifying the traditional medicinal uses of A. leucophloea (Fabaceae) in gastrointestinal and respiratory diseases. In vitro experiments were carried out over isolated rabbit jejunum and guinea-pig ileum in order to determine spasmolytic and bronchorelaxant activities, while in vivo studies were conducted in mice for antidiarrheal properties. RESULTS: A methanol crude extract of barks of the plant caused a concentration-dependent relaxation (0.1-3 mg/ml) of isolated rabbit jejunum preparations in a pattern similar to that of nifedipine and dicyclomine, suggesting a Ca(2+) channel-blocking mechanism in addition to an anticholinergic effect. In guinea-pig ileum the extract caused a parallel shift in the Ach-curves without suppression of maximum contractile response, followed by a non-parallel shift with the suppression of maximum contractile response at higher concentration similar to that caused by dicyclomine. Moreover, in rabbit trachea, it also caused the relaxation of carbachol (1 µM) and high K(+)-induced contractions at a dose ranging between 0.1578 and 0.734 mg/ml and 0.46-0.94 mg/ml, respectively. These findings indicate that the extract possesses spasmolytic and bronchodilator activities, mediated possibly through blockade of Ca(2+) channels, thus justifying its medicinal use in diarrhea and asthma. Acacia leucophloea methanol extract exhibited dose-dependent (100-500 mg/ml) protective effect against castor oil induced diarrhea. CONCLUSIONS: The data obtained contribute to the validation of the traditional use of Acacia leucophloea bark in treating gastrointestinal and respiratory disorders, providing an hypothesis on the possible mechanisms of action.

Biological screening of selected flora of Pakistan

Methanolic extracts of different parts of five medicinal plants, Ferula assafoetidaL. resin, Grewia asiaticaL. leaves, Ipomoea hederaceaJacq. seeds, Lepidium sativumL. seeds and Terminalia chebulaRetz. fruits were tested in vitrofor their cytotoxic, phytotoxic, insecticidal, nematicidal and anthelmintic activities. Ipomoea hederaceashowed very significant phytotoxic and cytotoxic activity, with 100% inhibition of Lemna minorgrowth and 100% death of Artemia salinaat concentrations of 1000 and 100 µg mL-1. Grewia asiaticaexhibited very weak activities while Lepidium sativumand Ferula assafoetidashowed moderate to good potential in all three bioassays. The results suggest screening of Ipomoea hederaceaseeds further for isolation of bioactive compounds that may be responsible for its toxic potential.