Nat Prod Res. 2011 Feb ;25 (4):444-9 21328138
Department of Biotechnology, University of Science and Technology Bannu, Khyber Pakhtunkhwa, Pakistan. email@example.com
Caesalpinia bonducella F.(Leguminosae) has been used as a folk medicine for a variety of ailments. The crude extract of C. bonducella and its fractions were studied for antibacterial, antifungal, antispasmodic and Ca++ antagonistic properties. The strongest antibacterial effect was displayed by the n-butanol (72%) and ethyl acetate (80%) fractions, followed by the crude extract (46% and 42%), against Escherichia coli and Bacillus subtilis, respectively. The plant extract and its fractions showed mild to excellent activity in antifungal bioassays, with maximum antifungal activity against Candida glaberata (80%) and Aspergillus flavus (70%) by the n-butanol and chloroform fractions, followed by the crude extract (70% and 65%). Caesalpinia bonducella extract caused concentration-dependent inhibition of spontaneous and high K+(80 mM)-induced contractions of isolated rabbit jejunum preparations, similar to that caused by Verapamil. These results indicate that C. bonducella exhibits antibacterial, antifungal, spasmolytic and Ca++ channel blocking actions.
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Pharm Biol. 2010 Nov ;48 (11):1240-6 20822397
Pharmacological basis for the medicinal use of Holarrhena antidysenterica in gut motility disorders.
Anwarul Hassan Gilani, Aslam Khan, Arif-Ullah Khan, Samra Bashir, Najeeb-Ur Rehman, Saf-Ur-Rehman Mandukhail
Natural Product Research Division, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi, Pakistan. firstname.lastname@example.org
CONTEXT Holarrhena antidysenterica Wall.(Apocynaceae) is widely used in traditional medical system for treatment of constipation, colic, and diarrhea. AIM This study was carried out to provide pharmacological basis for medicinal use of Holarrhena antidysenterica in gastrointestinal disorders. Materials and methods: Hydro-ethanolic crude extract of Holarrhena antidysenterica (HaCE) and its fractions were studied in various gastrointestinal isolated tissue preparations. RESULTS In guinea pig ileum tissues, HaCE at 0.3-10 mg/mL caused pyrilamine-sensitive spasmogenic effect. When tested in spontaneously contracting rabbit jejunum preparations, HaCE (0.01-3.0 mg/mL) caused moderate stimulation, followed by a relaxant effect at next higher concentrations. In presence of pyrilamine, the contractile effect was blocked and the relaxation was observed at lower concentrations (0.01-0.3 mg/mL). HaCE inhibited the high K(+)(80 mM)-induced contractions at concentration range of 0.01-1.0 mg/mL and shifted Ca(++) concentration response curves to the right, like that caused by verapamil. Activity-directed fractionation revealed that the spasmogenic component was concentrated in the aqueous fraction, while the spasmolytic component was concentrated in the organic fraction. DISCUSSION AND CONCLUSION These results indicate that the gut stimulant and relaxant activities of Holarrhena antidysenterica are mediated possibly through activation of histamine receptors and Ca(++) channel blockade, respectively and this study provides sound mechanistic background for its usefulness in gut motility disorders such as constipation, colic, and possibly diarrhea.
Purification and biochemical characterization of alkaline serine protease from Caesalpinia bonducella.
Hidayatullah Khan, Irshad Ali, Arif-ullah Khan, Mushtaq Ahmed, Zamarud Shah, Ahmad Saeed, Rubina Naz, Mohamad Rais Mustafa, Atiya Abbasi
Department of Biotechnology, University of Science and Technology Bannu, Pakistan. email@example.com
A high molecular weight serine protease has been purified to electrophoretic homogeneity from the seeds of Caesalpinia bonducella Flem.(Caesalpiniaceae) by the combination of size exclusion and ion exchange chromatography. About 524 fold purification was achieved with an overall recovery of 6.8%. The specific activity was found to be 86 U/mg/min at pH 8.0. The calculated K(m) and V(max) were 1.66 mg/mL and 496.68 units/min per mg of protein, respectively. The molecular mass was estimated to be about 63 kDa by sodium dodecyl sulfate PAGE. The enzyme showed optimum activity at pH 8.0 and exhibited its highest activity at 40 degrees C. The enzyme was strongly inhibited by 2mM phenylmethylsulfonyl fluoride (PMSF), suggesting the presence of a serine residue at the active site. PMSF showed a pure competitive type of inhibition with the serine protease enzyme. It was observed that enzyme activity was enhanced in the presence of dications and was active against a variety of modified substrates and natural proteins.
Pharmacological basis for the medicinal use of Zanthoxylum armatum in gut, airways and cardiovascular disorders.
Natural Product Research Division, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi 74800, Pakistan.
This study describes the gut, airways and cardiovascular modulatory activities of Zanthoxylum armatum DC.(Rutaceae) to rationalize some of its medicinal uses. The crude extract of Zanthoxylum armatum (Za.Cr) caused concentration-dependent relaxation of spontaneous and high K(+)(80 mM)-induced contractions in isolated rabbit jejunum, being more effective against K(+) and suggestive of Ca(++) antagonist effect, which was confirmed when pretreatment of the tissues with Za.Cr shifted Ca(++) concentration-response curves to the right, like that caused by verapamil. Za.Cr inhibited the castor-oil-induced diarrhea in mice at 300-1000 mg/kg. In rabbit tracheal preparations, Za.Cr relaxed the carbachol (1 microM) and high K(+)-induced contractions, in a pattern similar to that of verapamil. In isolated rabbit aortic rings, Za.Cr exhibited vasodilator effect against phenylephrine (1 microM) and K(+)-induced contractions. When tested in guinea pig atria, Za.Cr caused inhibition of both atrial force and rate of spontaneous contractions, like that caused by verapamil. These results indicate that Zanthoxylum armatum exhibits spasmolytic effects, mediated possibly through Ca(++) antagonist mechanism, which provides pharmacological base for its medicinal use in the gastrointestinal, respiratory and cardiovascular disorders.
Antispasmodic, bronchodilator and blood pressure lowering properties of Hypericum oblongifolium--possible mechanism of action.
Natural Product Research Division, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi-74800, Pakistan.
The crude extract of Hypericum oblongifolium (Ho.Cr), which tested positive for flavonoids, saponins and tannins caused concentration-dependent (0.1-1.0 mg/mL) relaxation of spontaneous and high K(+)(80 mM)-induced contractions in isolated rabbit jejunum preparations, suggesting a Ca(++) antagonistic effect, which was confirmed when pretreatment of the tissue with Ho.Cr produced a rightward shift in the Ca(++) concentration-response curves, like that caused by verapamil. Ho.Cr relaxed carbachol (1 microM) and high K(+)-induced contractions in guinea pig tracheal preparations. It caused a dose-dependent (3-100 mg/kg) fall in arterial blood pressure of rats under anesthesia. In isolated guinea pig atria, Ho.Cr caused inhibition of both atrial force and rate of spontaneous contractions. When tested in rabbit aortic rings, Ho.Cr exhibited a vasodilator effect against phenylephrine (1 microM) and high K(+)-induced contractions. These results indicate that Ho.Cr possesses gastrointestinal, respiratory and cardiovascular inhibitory effects, mediated via a Ca(++) antagonist mechanism.
Anwarul Hassan Gilani, Malik Hassan Mehmood, Khalid Hussain Janbaz, Arif-Ullah Khan, Sheikh Arshad Saeed
Natural Product Research Division, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi 74800, Pakistan. firstname.lastname@example.org
ETHNOPHARMACOLOGICAL RELEVANCE The ripe dried fruit of Ficus carica Linn.(Moraceae) commonly known as "Fig" has medicinal value in traditional system of medicine for its use in gastrointestinal and inflammatory disorders. AIM OF THE STUDY To rationalize the medicinal use of Fig (Ficus carica) in gastrointestinal and inflammatory disorders. MATERIALS AND METHODS The aqueous-ethanolic extract of Ficus carica (Fc.Cr) was studied for antispasmodic effect on the isolated rabbit jejunum preparations and for antiplatelet effect using ex vivo model of human platelets. RESULTS Fc.Cr tested positive for alkaloids, flavonoids, coumarins, saponins, sterols and terpenes. When tested in isolated rabbit jejunum, Fc.Cr (0.1-3.0mg/mL) produced relaxation of spontaneous and low K(+)(25 mM)-induced contractions with negligible effect on high K(+)(80 mM) similar to that caused by cromakalim. Pretreatment of the tissue with glibenclamide caused rightward shift in the curves of low K(+)-induced contractions. Similarly, cromakalim inhibited the contractions induced by low K(+), but not of high K(+), while verapamil equally inhibited the contractions of K(+) at both concentrations. Fc.Cr (0.6 and 0.12 mg/mL) inhibited the adenosine 5'-diphosphate and adrenaline-induced human platelet aggregation. CONCLUSION This study showed the presence of spasmolytic activity in the ripe dried fruit of Ficus carica possibly mediated through the activation of K(+)(ATP) channels along with antiplatelet activity which provides sound pharmacological basis for its medicinal use in the gut motility and inflammatory disorders.
Mechanisms underlying the antispasmodic and bronchodilatory properties of Terminalia bellerica fruit.
Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi 74800, Pakistan. email@example.com
AIM OF THE STUDY The present investigation was carried out to provide the pharmacological basis for the medicinal use of Terminalia bellerica in hyperactive gastrointestinal and respiratory disorders. MATERIALS AND METHODS Crude extract of Terminalia bellerica fruit (Tb.Cr) was studied in in vitro and in vivo. RESULTS Tb.Cr caused relaxation of spontaneous contractions in isolated rabbit jejunum at 0.1-3.0mg/mL. Tb.Cr inhibited the carbachol (CCh, 1microM) and K(+)(80mM)-induced contractions in a pattern similar to that of dicyclomine, but different from nifedipine and atropine. Tb.Cr shifted the Ca(++) concentration-response curves to right, like nifedipine and dicyclomine. In guinea-pig ileum, Tb.Cr produced rightward parallel shift of acetylcholine-curves, followed by non-parallel shift at higher concentration with the suppression of maximum response, similar to dicyclomine, but different from nifedipine and atropine. Tb.Cr exhibited protective effect against castor oil-induced diarrhea and carbachol-mediated bronchoconstriction in rodents. In guinea-pig trachea, Tb.Cr relaxed the CCh-induced contractions, shifted CCh-curves to right and inhibited the contractions of K(+). Anticholinergic effect was distributed both in organic and aqueous fractions, while CCB was present in the aqueous fraction. CONCLUSIONS These results indicate that Terminalia bellerica fruit possess a combination of anticholinergic and Ca(++) antagonist effects, which explain its folkloric use in the colic, diarrhea and asthma.
Gastrointestinal, selective airways and urinary bladder relaxant effects of Hyoscyamus niger are mediated through dual blockade of muscarinic receptors and Ca2+ channels.
Anwarul Hassan Gilani, Arif-Ullah Khan, Mustafa Raoof, Muhammad Nabeel Ghayur, Bina S Siddiqui, Waseem Vohra, Sabira Begum
Natural Product Research Division, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi - 74800, Pakistan. firstname.lastname@example.org
This study describes the spasmolytic, antidiarrhoeal, antisecretory, bronchodilatory and urinary bladder relaxant properties of Hyoscyamus niger to rationalize some of its medicinal uses. The crude extract of H. niger seeds (Hn.Cr) caused a complete concentration-dependent relaxation of spontaneous contractions of rabbit jejunum, similar to that caused by verapamil, whereas atropine produced partial inhibition. Hn.Cr inhibited contractions induced by carbachol (1 microM) and K(+)(80 mM) in a pattern similar to that of dicyclomine, but different from verapamil and atropine. Hn.Cr shifted the Ca(2+) concentration-response curves to the right, similar to that caused by verapamil and dicyclomine, suggesting a Ca(2+) channel-blocking mechanism in addition to an anticholinergic effect. In the guinea-pig ileum, Hn.Cr produced a rightward parallel shift of the acetylcholine curves, followed by a non-parallel shift with suppression of the maximum response at a higher concentration, similar to that caused by dicyclomine, but different from that of verapamil and atropine. Hn.Cr exhibited antidiarrhoeal and antisecretory effects against castor oil-induced diarrhoea and intestinal fluid accumulation in mice. In guinea-pig trachea and rabbit urinary bladder tissues, Hn.Cr caused relaxation of carbachol (1 microM) and K(+)(80 mM) induced contractions at around 10 and 25 times lower concentrations than in gut, respectively, and shifted carbachol curves to the right. Only the organic fractions of the extract had a Ca(2+) antagonist effect, whereas both organic and aqueous fractions had anticholinergic effect. A constituent, beta-sitosterol exhibited Ca(2+) channel-blocking action. These results suggest that the antispasmodic effect of H. niger is mediated through a combination of anticholinergic and Ca(2+) antagonist mechanisms. The relaxant effects of Hn.Cr occur at much lower concentrations in the trachea and bladder. This study offers explanations for the medicinal use of H. niger in treating gastrointestinal and respiratory disorders and bladder hyperactivity.
Antispasmodic effects of Rooibos tea (Aspalathus linearis) is mediated predominantly through K+-channel activation.
Department of Biological and Biomedical Sciences, Aga Khan University Medical College, Karachi 74800, Pakistan. email@example.com
Rooibos tea has been widely used for abdominal spasm and diarrhoea. The aim of the present study was to explore the possible mechanism for its use in such ailments. Its aqueous extract (RT) at 0.3-10 mg/ml produced relaxation of spontaneous and low K(+)(25 mM)-induced contractions of rabbit jejunum, with weak effect on high K(+)(80 mM)-induced contractions. In the presence of glibenclamide, relaxation of low K(+)-induced contractions was prevented. Cromakalim inhibited contractions induced by low K(+), but not high K(+), while verapamil did not differentiate in its inhibitory effect on contractions produced by the two concentrations of K(+). RT also exhibited antidiarrhoeal and antisecretory activities in mice. The spasmolytic effect was concentrated in organic fractions. Its constituents, chrysoeriol, orientin and vitexin showed a similar pattern of spasmolytic effects to the extract, while rutin was more like verapamil. So Rooibos tea possesses a combination of dominant K(ATP) channel activation and weak Ca(++) antagonist mechanisms and hence justifies its use in hyperactive gastrointestinal disorders.
Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi, Pakistan. firstname.lastname@example.org
Olive (Olea europea) is used in traditional medicine as a remedy for hypertension. The aqueous-methanolic crude extract of O. europea fruit (OeF.Cr) was studied in anaesthetized rats and its possible mechanism was elucidated using isolated cardiovascular preparations. Intravenous administration of OeF.Cr produced a dose-dependent (30-100 mg/kg) fall in arterial blood pressure in normotensive anaesthetized rats. This effect remained unaltered in atropinized animals. In the in vitro studies OeF.Cr (0.1-3.0 mg/ml) inhibited spontaneously beating guinea-pig atria. Moreover, it relaxed K+ and/or phenylephrine-induced contractions of rabbit aortic preparations over a dose range of 0.1-3.0 mg/ml, suggesting calcium channel blockade (CCB). The CCB effect was confirmed when pretreatment of the vascular preparations with OeF.Cr produced a dose-dependent rightward shift of the Ca2+ dose-response curves, similar to verapamil. These results suggest that the blood pressure lowering effect of olive is mediated through CCB, justifying its use in hypertension.
Studies on hepatoprotective, antispasmodic and calcium antagonist activities of the aqueous-methanol extract of Achillea millefolium.
Department of Pharmacology, Ziauddin Medical University, Karachi, Pakistan.
The crude extract of Achillea millefolium (Am.Cr) was studied for its possible hepatoprotective effect against d-galactosamine (d-GalN) and lipopolysaccharide (LPS) induced hepatitis in mice and antispasmodic effect in isolated gut preparations to rationalize some of the folklore uses. Co-administration of d-GalN (700 mg/kg) and LPS (25 microg/kg) produced 100% mortality in mice. Pre-treatment of animals with Am.Cr (300 mg/kg) reduced the mortality to 40%. Co-administration of d-GalN (700 mg/kg) and LPS (1 microg/kg) significantly raised the plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels compared with values in the control group (p < 0.05). Pre-treatment of mice with Am.Cr (150-600 mg/kg) significantly prevented the toxins induced rise in plasma ALT and AST (p < 0.05). The hepatoprotective effect of Am.Cr was further verified by histopathology of the liver, which showed improved architecture, absence of parenchymal congestion, decreased cellular swelling and apoptotic cells, compared with the toxin group of animals. In isolated rabbit jejunum preparations, Am.Cr caused a concentration-dependent (0.3-10 mg/mL) relaxation of both spontaneous and K(+)-induced contractions as well as shifting the Ca(++) concentration-response curves (CRCs) to the right, similar to that caused by verapamil. These results indicate that the crude extract of Achillea millefolium exhibits a hepatoprotective effect, which may be partly attributed to its observed calcium channel blocking activity.
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Pharm Biol. 2012 Nov 6;: 23126251
Nadjib Rahmoun, Zahia Boucherit-Otmani, Kebir Boucherit, Mohammed Benabdallah, Noureddine Choukchou-Braham
Antibiotics Antifungal Laboratory: Physical-Chemistry, Synthesis and Biological Activity, Department of Biology, Faculty of Sciences, Tlemcen University , Tlemcen , Algeria.
Context: Lawsonia inermis Linn.(Lythraceae) or henna has been used since the earliest times as a medicine, preservative, and cosmetic. It has long been recommended in traditional medicine as an astringent, purgative, and abortifacient. Objective: Lawsone and six extracts of L. inermis plant, used by Algerian traditional healers to treat infectious diseases, were screened for their antifungal activity against filamentous fungi. Materials and methods: Water and five organic extracts - DMSO, ethanol, chloroform, ethyl acetate, and di-ethyl ether - of L. inermis leaves, collected in the area of Adrar (Algeria), were prepared by soaking 25 g of powdered plant in 100 mL of solvent. The extracts were screened for antifungal activity using the poisoned food technique against five filamentous fungi. Results: Results demonstrated that the best yield (8.03%) was obtained with the ethanol extract. The commercial lawsone showed potentially interesting MICs against the strains Fusarium oxysporum (12 µg/mL) and Aspergillus flavus (50 µg/mL). The ethanol extract showed the only interesting MIC (230 µg/mL of crude extract) against the strain F. oxysporum compared with other extracts. Discussion and conclusion: These results suggest that the Algerian L. inermis plant has antifungal activity that can be related to the presence of lawsone in the leaves plant. The results can be exploited largely in research of new antifungal drugs.
Department of Pharmacy, University of Peshawar, Peshawar, Pakistan.
Valeriana wallichii DC (Valerianaceae) is one of the most widely used traditional remedies for various complications associated with nervous system and digestion. No antimicrobial and anti-inflammatory studies have so far been carried out on the aerial parts of the plant. The present work was focused to evaluate the antimicrobial (antifungal and antibacterial) and anti-inflammatory properties of V. wallichii using reported methods. Chloroform fraction (VW-2) and hexane fraction (VW-3) exhibited significant activity against S. aureus and B. subtilus, respectively. The chloroform fraction (VW-2) showed significant activity against S. aureus with 0.27 mg/ml MIC, where 0.31 mg/ml MIC was deduced for VW-3 fraction against B. subtilus. VW-3 fraction was also found to be the most potent inhibitor of M. canis, showing 70% inhibition with an MIC value of 0.19 mg/ml. Considerable inhibitory activity was also observed for VW-2 and water fraction (VW-6) against M. canis and A. flavus. A remarkable anti-inflammatory like activity was observed for the crude extract at a dose of 200 mg/kg at all observed durations. Other doses of the sample also showed excellent activity. Looking to these results it may be concluded that V. wallichii may be a potential source for activity guided isolation of natural products with antimicrobial and anti-inflammatory-like properties.
Mansoor Ahmad, Noor Muhammad, Mehjabeen, Noor Jahan, Manzoor Ahmad, Obaidullah, Mahmood Qureshi, Syed Umar Jan
Department of Pharmacognosy, University of Karachi, Karachi, Pakistan. email@example.com
Scrophularia nodosa (figwort), an indigenous medicinal plant grows in moist and cultivated waste ground. It contains saponins, cardioactive glycosides, flavonoids, resin, sugar and organic acids. It is traditionally used for anti-inflammatory purpose and in skin disorders. It has diuretic and cardiac stimulant properties. The present studies were carried out on crude extract of Scrophularia nodosa and its n-hexane, chloroform, ethyl acetate, n-butanol and aqueous fractions. During phytochemical studies seven known compounds of flavonoid nature were isolated from the chloroform fraction of crude extract of S. nodosa. The structures of these compounds were elucidated by spectroscopic (UV, IR, Mass (EIMS, HREIMS) and NMR ((1)H-NMR,(13)C-NMR, DEPT, and (1)H-(1)H, COSY, HMQC, HMBC and NOESY) techniques. Compound 1 was identified as 5, 4`-hydroxy-3, 6, 7-trimethoxyflavone, compound 2 as 5-hydroxy-3,6,7,4'-tetramethoxyflavone, compound 3 as Centaurein, compound 4 as 5-hydroxy-7,8,2',3',4'-pentamethoxyflavone (Serpyllin), compound 5 as Kaempferol 7-O-α-L-rhamnopyranoside, compound 6 as sakuranetin 4'-O (6''-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (Vitexoside) and compound 7 as Spinoside. Crude extract and its fractions were tested on isolated rabbit intestine (in vitro) for their effects. The results of crude extract and its fractions in different doses showed the decrease in normal movement of the smooth muscles of rabbit intestine (jejunum). The chloroform fraction showed maximum relaxant effect (77.37%) at 15mg/ml dose and aqueous fraction showed 38.56% spasmogenic response which was not present in the crude extract. Further study was carried out on different fractions to investigate the possible mechanism of action of S. nodosa extract. For this purpose spasmolytic effect of different fractions were compared with agonist and antagonist activities of standard drugs including adrenaline, atropine andacetylcholine (1x10(-2), 1x10(-4) and 10(-6) M conc.). It is concluded that the chemical constituents present in S. nodosa having spasmolytic action are possibly acting through muscarinic receptors.
Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan. firstname.lastname@example.org
The antimicrobial activities of crude methanolic extract of leaves of Acacia nilotica L., Albizia lebbeck L. and Mimosa himalayana Gamble belonging to family mimosaceae were investigated in this research work. Antibacterial activity was studied by agar well diffusion method against one gram-positive Bacillus subtilis and three gram-negative Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumonia. Crude extract of all plants showed best activity against gram-negative bacterial strains while minor inhibition zones were found against gram positive bacterial strains. Antifungal activity of crude plant extract was screened by agar tube dilution method against Aspergillus nigar and Aspergillus flavus. These results showed that these plants extracts have potential against bacterias, while against fungi their activity is not much effective.
Acute toxicity, brine shrimp cytotoxicity and relaxant activity of fruits of callistemon citrinus curtis.
Department of Pharmacology, Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, KPK, Pakistan. email@example.com
BACKGROUND Callistemon citrinus Curtis belongs to family Myrtaceae that has a great medicinal importance. In our previous work, fruits of Callistemon citrinus were reported to have relaxant (antispasmodic) activity. The current work describes the screening of fractions of the crude methanol extract for tracing spasmolytic constituents so that it shall help us for isolation of bioactive compounds. Acute toxicity and brine shrimp cytotoxicity of crude methanol extract are also performed to standardize it. METHODS The crude methanol extract was obtained by maceration with distilled water (500 ml) three times and fractionated successively with n-hexane, chloroform, ethyl acetate and n-butanol (300 ml of each solvent). Phytochemical analysis for crude methanol extract was performed. Acute toxicity studies were performed in mice. Brine shrimp cytotoxicity studies were performed to determine its cytotoxicity and standardize it. In other series of experiments, rabbits' jejunum preparations were used in screening for possible relaxant activities of various fractions. They were applied in concentrations of 0.01, 0.03, 0.1, 0.3, 1.0, 3.0, 5.0 and 10.0 mg/ml on spontaneous rabbits' jejunum preparations. In similar fashion, fractions were also tested on KCl (80 mM)-induced contractions. Calcium chloride curves were constructed in K-rich Tyrode's solution. The effects of various fractions were tested on calcium chloride curves at concentrations 1.0, 3.0, 5.0 and 10.0 mg/ml. Curves of verapamil used as reference drug at concentration 0.1 μM and 0.3 μM were also constructed. The curves were compared with their respective controls for possible right shift. RESULTS Methanol extract tested strongly positive for saponins and tannins. However, it tested mild positive for presence of proteins, amino acids, carbohydrates and phenolic compounds. LD(50) value for crude methanol extract is 476.25 ± 10.3 (470-481, n = 4) mg/ml. Similarly, EC(50) value for brine shrimp cytotoxicity is 65.5 ± 7.28 (60.8- 69.4, n = 4) mg/ml. All the fractions relaxed the spontaneous and KCl-induced contractions. EC(50) values (mg/ml) for effects of ethyl acetate fraction on spontaneous and KCl induced contractions are 2.62 ± 0.78 (2.15-3.0, n = 4) and 3.72 ± 0.86 (3.38-4.28, n = 4) respectively. Respective EC(50) values (mg/ml) for n-butanol fraction are 3.59 ± 0.2(3.07-3.9, n = 4) for spontaneous, and 5.57 ± 0.2 (5.07-6.11, n = 4) for KCl- induced contractions. EC(50) value for control calcium chloride curve (without extract) is -2.73 ± 0.19 (-2.6 --2.81, n = 4) while EC(50) for curves treated with 5.0 mg/ml of chloroform is -2.22 ± 0.02 (-2.16 --2.3, n = 4). EC(50) value for ethyl acetate treated (1.0 mg/ml) tissues is -1.95 ± 0.10 (-1.88 --2.0, n = 4) vs. control EC(50)=-2.71 ± 0.08 (-2.66 --2.76, n = 4). All the fractions, except n-hexane, showed a right shift like that of verapamil (EC(50)=-1.72 ± 0.15 (-1.62 --1.8, n = 4) vs. Control EC(50)=-2.41 ± 0.06 (-2.38 -- 2.44, n = 4), a standard drug that blocks voltage operated calcium channels. CONCLUSION Relaxant constituents were more concentrated in ethylacetate fraction followed by chloroform, n -butanol and aqueous fractions that warrant for its isolation. The crude methanol extract is safe at concentration 250 mg/ml or below and results of brine shrimp cytotoxicity assay imply the plant specie may be a source of cytotoxic agents.
Nat Prod Res. 2011 Oct 18;: 22007784
Bioassays guided fractionation of Coronopus didymus for its antifungal activity against Sclerotium rolfsii.
a Institute of Agricultural Sciences, University of the Punjab , Lahore , Pakistan.
Sclerotium rolfsii Sacc. is a pathogen of about 500 plant species. In a laboratory screening bioassay, methanolic extracts of 15 mg mL(-1) concentrations of different parts of Coronopus didymus (L.) Sm.(Brassicaceae) namely leaf, stem, inflorescence and root reduced the biomass of S. rolfsii by 67%, 26%, 40% and 58%, respectively. Methanolic root extract was successively fractionated with n-hexane, chloroform, ethyl acetate and n-butanol. All the concentrations (3.125-200 mg mL(-1)) of ethyl acetate fraction completely inhibited the target fungal growth. Two compounds A and B were separated from this fraction by Thin Layer Chromatography (TLC). TLC fraction A was found highly effective against S. rolfsii with MIC value 15.62 µg mL(-1) as compared to MIC value 7.81 µg mL(-1) of the commercial fungicide mencozeb. This compound may be used for the synthesis of natural product based fungicide for the control of S. rolfsii.
Institute of Basic Medical Sciences, Khyber Medical University, KPK, Peshawar, Pakistan.
Methanolic extract of Onosma griffithii and its fractions were evaluated for possible effects on rabbits' jejunum preparations. Rabbits of either sex (weight 1.5-2.0 kg) were used in experiments. Studies were carried out on rabbits' jejunum preparations. Crude methanolic extract of Onosma griffithii (Meth.OG) was tried in concentrations of 0.01, 0.03, 0.1, 0.3, 1.0, 3.0, 5.0 and 10.0 mg/ml on rabbits' jejunum preparations. Meth.OG was also tried on KCl-induced contractions to explain its possible mode of actions in the presence and absence of atropine (0.03 µM). Fractions of Meth.OG were tried in similar manner. Calcium chloride curves were constructed for Meth.OG treated tissues that were compared with curves constructed for verapamil in same fashion. Preliminary phytochemical screening of the plant was also performed. Meth.OG increased the amplitude of spontaneous activity of rabbits' jejunum preparations at concentrations of 0.1, 0.3 and 1.0 mg/ml. However, spasmolytic effects were observed at higher concentrations 3.0, 5.0 and 10.0 mg/ml. Mean EC(50) values (mg/ml), respectively, in absence and presence of atropine were 7.5 ± 0.25 (6.9-8.4, n=6) and 3.0 ± 0.17 (2.3-3.5, n=6, p<0.05). Mean EC(50) values, respectively, for effects on spontaneous and KCl-induced contractions were 7.5 ± 0.25 (6.9-8.4, n=6) and 7.3 ± 0.35 (6.25-8.2, n=6, p<0.05). n-Hexane, chloroform and ethyl acetate fractions showed their respective EC(50) values (mg/ml) 9.7 ± 0.25 (8.6-10.2, n=6), 4.0 ± 0.2 (3.5-4.6, n=6) and 1.07 ± 0.093 (0.78-1.5, n=6). EC(50) values for calcium chloride curves in presence of 0.3 mg/ml Meth.OG were - 2.27 ± 0.038 (- 2.4 to - 2.10, n=6) vs. control - 2.78 ±0.04 (-2.9 to - 2.6, n=6, p<0.05) Log [Ca(++)]M. Comparing with curves of calcium chloride constructed in presence of 0.1 µM verapamil, the EC(50)(log [Ca(++)] M) values were - 1.82 ± 0.087 (- 2.0 to - 1.65, n=6) vs. control - 2.64 ± 0.089 (- 2.9 to - 2.4, n=6) demonstrated a right shift (p<0.05). Meth.OG tested positive for terpenes, saponins, sterols, flavonoids and carbohydrates. We concluded that the relaxant effect of Meth.OG is exerted through blocking of calcium channels. However, n-butanolic and aqueous fractions produced spasmogenic effects that require further work for isolation of pharmacologically active substances.
Pharma Biotech Research Lab, Centre of Biotechnology and Microbiology, University of Peshawar, Khyber Pakhtunkhwa, Pakistan. firstname.lastname@example.org
Plants are very useful, self-generating machines, producing a variety of useful bioactive products. Keeping in view this idea, the crude methanolic extract and various fractions of Zizyphus jujuba were screened for antifungal, cytotoxic, antitermite and insecticidal activities. Low activity was shown by the crude methanolic extract (12%), n-hexane (9%), chloroform (20%) and ethyl acetate (14%) fraction against Penicillium notatum. Low activity was shown by the n-hexane fraction against Aspergillus niger (10%) and Trichoderma harzianum (13%) and inactive against Aspergillus flavus, Fusarium oxysporum and Rhizopus stolonifer. The CHCl(3) fraction exhibited low activity of 10% against F. oxysporum while showing no activity against the rest of the test fungi. All the test samples were inactive against Rhizopus stolonifer. The crude methanolic extract was highly cytotoxic (73.33%) at the concentration of 1000 (µg/ml) while the rest of the test samples were low in toxicity at the same concentration. The crude methanolic extract of Zizyphus jujuba showed significant antitermite activity against Heterotermes indicola, among the test samples. Against Tribolium castaneum, Rhizopertha dominica and Callosbruchus analis the insecticidal activity was determined. All the test samples except n-hexane showed low activity (20%) against T. castaneum. The n-hexane fraction showed low activity (20%) against R. dominica while the rest of the fractions were inactive against it. Low activity of 40% and 20% was shown by the chloroform and n-hexane fraction respectively against C. analis. The results of the present study revealed that the plant could be as potent source of cytotoxic drugs.
Nat Prod Res. 2012 ;26 (7):609-18 21834640
School of Chemical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia.
The aqueous methanolic extracts of Melastoma malabathricum L. exhibited antibacterial activity when assayed against seven microorganisms by the agar diffusion method. Solvent fractionation afforded active chloroform and ethyl acetate fractions from the leaves and the flowers, respectively. A phytochemical study resulted in the identification of ursolic acid (1), 2α-hydroxyursolic acid (2), asiatic acid (3), β-sitosterol 3-O-β-D-glucopyranoside (4) and the glycolipid glycerol 1,2-dilinolenyl-3-O-β-D-galactopyanoside (5) from the chloroform fraction. Kaempferol (6), kaempferol 3-O-α-L-rhamnopyranoside (7), kaempferol 3-O-β-D-glucopyranoside (8), kaempferol 3-O-β-D-galactopyranoside (9), kaempferol 3-O-(2″,6″-di-O-E-p-coumaryl)-β-D-galactopyranoside (10), quercetin (11) and ellagic acid (12) were found in the ethyl acetate fraction. The structures of these compounds were determined by chemical and spectral analyses. Compounds 1-4, the flavonols (6 and 11) and ellagic acid (12) were found to be active against some of the tested microorganisms, while the kaempferol 3-O-glycosides (7-9) did not show any activity, indicating the role of the free 3-OH for antibacterial activity. Addition of p-coumaryl groups results in mild activity for 10 against Staphylococcus aureus and Bacillus cereus. Compounds 2-5, 7 and 9-12 are reported for the first time from M. malabathricum. Compound 10 is rare, being reported only once before from a plant, without assignment of the double bond geometry in the p-coumaryl moiety.
Pharm Biol. 2011 Aug ;49 (8):821-5 21501037
Gut modulatory effects of Daphne oleoides are mediated through cholinergic and Ca++ antagonist mechanisms.
Department of Biological and Biomedical Sciences, Aga Khan University Medical College, Karachi, Pakistan.
CONTEXT The present study describes the spasmogenic and spasmolytic activities of Daphne oleoides Schreb.(Thymelaeaceae), exploring the possible underlying pharmacological mechanisms. AIM Pharmacological investigation of Daphne oleoides to provide evidence for its therapeutic application in gastrointestinal motility disorders. MATERIALS AND METHODS Methanol crude extract of Daphne oleoides (Do.Cr) was studied in gastrointestinal isolated tissues. RESULTS In spontaneously contracting rabbit jejunum preparations, Do.Cr at 0.3-3.0 mg/mL caused moderate stimulation, followed by relaxant effect at the next higher concentrations (5.0-10 mg/mL). In presence of atropine, spasmogenic effect was blocked and the relaxation was emerged, suggesting that the spasmogenic effect of Daphne oleoides is mediated through activation of muscarinic receptors. When tested against the high K+(80 mM)-induced contractions, Do.Cr (0.3-5.0 mg/mL), like verapamil, inhibited the induced contractions, suggesting Ca++ channel blockade (CCB) effect. The CCB effect was further confirmed when pre-treatment of the tissue with Do.Cr shifted the Ca++ concentration-response curves to the right, similar to that caused by verapamil. DISCUSSION AND CONCLUSION These results indicate that Daphne oleoides exhibits gut excitatory and inhibitory effects, occurred via cholinergic and Ca++ antagonistic pathways, respectively.