Antimicrobial activity of extracts of Terminalia catappa root.
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The effect against bacteria of petroleum ether (60-80 degrees C), chloroform and methanolic extract of dried root of Terminalia catappa Linn. (combrataceae) was employed by cup plate agar diffusion method. The chloroform extract showed prominent antimicrobial activity against S. aureus and E. coli as compared to other tested microorganisms, while petroleum ether extract was devoid of antimicrobial activity. The methanolic: extract exhibited MIC of 0.065 mg/ml against E. coli. and chloroform extract exhibited MIC of 0.4 mg/ml against S. aureus The chloroform has well as methanolic extracts showed good antimicrobial activity against Gram positive and Gram negative microorganisms. (+info)
Genetic diversity of the tropical tree Terminalia amazonia (Combretaceae) in naturally fragmented populations.
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The effect of long-term fragmentation on the genetic diversity of populations of the neotropical tree species, Terminalia amazonia, was studied using random amplified polymorphic DNA (RAPD) analysis. Leaf material from 104 trees was collected from three naturally fragmented gallery forest patches and three plots in nearby continuous forest in the Mountain Pine Ridge, Belize. In total, 30 RAPD bands generated by five decamer primers were used to compare the genetic diversity of the six populations in the two groups. Genetic variation within the populations (H0), as estimated by the Shannon diversity index, ranged from 0.32 to 0.38, with an overall diversity of 0.38 (Hspecies). Analysis of molecular variation revealed that most (94.4%, P<0.001) of the variation was attributable to differences among individuals within populations. Population differentiation was significantly (P=0.038) lower among the fragmented populations than among continuous forest populations. On average, the fragmented populations also had slightly, but statistically significant (P=0.046) lower levels of genetic diversity. However, one gallery forest site had a higher level of genetic diversity than two of the continuous forest sites. We suggest that the long-term effect of fragmentation on the genetic diversity of tropical trees will depend upon the amount of local forest cover in proximity to the fragmented populations. (+info)
Antioxidant and free radical scavenging activities of Terminalia chebula.
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Free radicals react with biological molecules and destroy the structure of cells, which eventually causes free-radical induced disease such as cancer, renal failure, aging, etc. In this study, 6 extracts and 4 pure compounds of Terminalia chebula RETZ. were investigated for anti-lipid peroxidation, anti-superoxide radical formation and free radical scavenging activities. The superoxide radical scavenging of the 4 pure compounds was further evaluated using electron spin resonance (ESR) spectrometry. The results showed that all tested extracts and pure compounds of T. chebula exhibited antioxidant activity at different magnitudes of potency. The antioxidant activity of each pure compound was derived from different pathways and was suggested to be specific. (+info)
Possible mechanisms of hypotension produced 70% alcoholic extract of Terminalia arjuna (L.) in anaesthetized dogs.
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BACKGROUND: The bark of Terminalia arjuna L. (Combretaceae) is used in Ayurveda since ancient times for the treatment of cardiac disorders. Previous laboratory investigations have demonstrated the use of the bark in cardiovascular complications. The present study was aimed to find the effect of 70% alcoholic extract of Terminalia arjuna on anaesthetized dog blood pressure and probable site of action. METHODS: Six dogs were anaesthetized with intraperitoneal injection of thiopental sodium and the blood pressure of each dog (n = 6) was measured from the left common carotid artery connected to a mercury manometer on kymograph. The femoral vein was cannulated for administration of drug solutions. The extract of T. arjuna (dissolved in propylene glycol) in the dose range of 5 to 15 mg/kg were administered intravenously in a pilot study and the dose (6 mg/kg) which produced appreciable hypotension was selected for further studies. RESULTS: Intravenous administration of T. arjuna produced dose-dependent hypotension in anaesthetized dogs. The hypotension produced by 6 mg/kg dose of the extract was blocked by propranolol but not by atropine or mepyramine maleate. This indicates that muscarinic or histaminergic mechanisms are not likely to be involved in the hypotension produced by the extract. The blockade by propranolol of the hypotension produced by T. arjuna indicates that the extract might contain active compound(s) possessing adrenergic beta2-receptor agonist action and/or that act directly on the heart muscle. CONCLUSION: The results indicated the likely involvement of peripheral mechanism for hypotension produced by the 70% alcoholic extract of Terminalia arjuna and lends support for the claims of its traditional usage in cardiovascular disorders. (+info)
Induction of biomolecules in mature leaves of Terminalia arjuna due to feeding of Antheraea mylitta Drury.
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Terminalia arjuna is an important food plant of the tasar silkworm, Antheraea mylitta Drury. In this study, we investigated the induction of biomolecules in mature leaves of these plants subjected to insect feeding. Increase in total tannin content, lipid peroxidation, and trypsin inhibitor activity have been observed in mature leaves damaged by the insects. The growth rate of Vth instar larvae of A. mylitta fed on previously damaged foliage reduced by 87.1%. Induction of biomolecules for defense mechanisms in relation to herbivore damage has been discussed. (+info)
New endophytic isolates of Muscodor albus, a volatile-antibiotic-producing fungus.
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Muscodor albus, an endophytic fungus originally isolated from Cinnamomum zeylanicum, produces a mixture of volatile organic compounds (VOCs) in culture and its spectrum of antimicrobial activity is broad. Using the original isolate of M. albus as a selection tool, it has been possible to find other culturally and biochemically unique wild-type isolates of this organism existing as endophytes in a variety of other plant species, including Grevillea pterifolia (fern-leafed grevillea), Kennedia nigriscans (snake vine) and Terminalia prostrata (nanka bakarra) growing in the northern reaches of the Northern Territory of Australia. Interestingly, none of the new isolates had a culture morphology that was identical to the original isolate, nevertheless each possessed hyphal characteristics that resembled that isolate. Furthermore, their ITS-5.8S rDNA sequences were 96-99 % identical to that of M. albus and the isolates were considered M. albus on the basis of the DNA sequence data. However, the VOCs produced by these new isolates greatly differed in quality from the original strain by virtue of the production of naphthalene, naphthalene, 1,1'-oxybis-, and one or more other compounds. In bioassays with a range of test micro-organisms, including fungi and bacteria, each isolate possessed biological activity but the range of activity was great. Artificial mixtures of some of the VOCs mimicked the effects of the VOCs of the fungus. The value of these observations to the biology and practical uses of M. albus in agriculture and other applications is discussed. (+info)
Screening of crude extracts of six medicinal plants used in South-West Nigerian unorthodox medicine for anti-methicillin resistant Staphylococcus aureus activity.
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BACKGROUND: Six Nigerian medicinal plants Terminalia avicennioides, Phylantus discoideus, Bridella ferruginea, Ageratum conyzoides, Ocimum gratissimum and Acalypha wilkesiana used by traditional medical practitioners for the treatment of several ailments of microbial and non-microbial origins were investigated for in vitro anti-methicillin Resistant Staphylococcus aureus (MRSA) activity. METHODS: Fresh plant materials were collected from the users. Water and ethanol extracts of the shredded plants were obtained by standard methods. The Bacterial cultures used were strains of MRSA isolated from patients. MRSA was determined by the reference broth microdilution methods using the established National Committee for Clinical Laboratory Standards break points. Staphylococcus aureus NCIB 8588 was used as a standard strain. Susceptibility testing and phytochemical screening of the plant extracts were performed by standard procedures. Controls were maintained for each test batch. RESULTS: Both water and ethanol extracts of T. avicennioides, P. discoideus, O. gratissimum, and A. wilkesiana were effective on MRSA. The Minimum Inhibition Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the ethanol extracts of these plants range from 18.2 to 24.0 mcg/ml and 30.4 to 37.0 mcg/ml respectively. In contrast, MIC range of 30.6 to 43.0 mcg/ml and 55.4 to 71.0 mcg/ml were recorded for ethanol and water extracts of B. ferruginea, and A. conyzoides respectively. Higher MBC values were obtained for the two plants. These concentrations were too high to be considered active in this study. All the four active plants contained at least trace amount of anthraquinones. CONCLUSION: Our results offer a scientific basis for the traditional use of water and ethanol extracts of A. wilkesiana, O. gratissimum, T. avicennioides and P. discoideus against MRSA-associated diseases. However, B. ferruginea and A. conyzoides were ineffective in vitro in this study; we therefore suggest the immediate stoppage of their traditional use against MRSA-associated diseases in Lagos, Nigeria. (+info)
Antioxidant effects of aqueous extract of Terminalia chebula in vivo and in vitro.
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The ripe fruit of Terminalia chebula RETZIUS (T. chebula RETZ) (Combretsceae), which is a native plant in India and Southeast Asia, has traditionally been used as a popular folk medicine for homeostatic, antitussive, laxative, diuretic, and cardiotonic treatments. The objective of this study was to evaluate the protective effects of an aqueous extract of fruit of T. chebula on the tert-butyl hydroperoxide (t-BHP)-induced oxidative injury observed in cultured rat primary hepatocytes and rat liver. Both treatment and pretreatment of the hepatocytes with the T. chebula extract (TCE) significantly reversed the t-BHP-induced cell cytotoxicity and lactate dehydrogenase leakage. In addition, TCE exhibited in vitro ferric-reducing antioxidant activity and 2,2-diphenyl-1-picryhydrazyl free radical-scavenging activities. The in vivo study showed that pretreatment with TCE (500 or 1000 mg/kg) by gavage for 5 d before a single dose of t-BHP (0.1 mmol/kg i.p.) significantly lowered the serum levels of the hepatic enzyme markers aspartate aminotransferase and alanine aminotransferase and reduced the indicators of oxidative stress in the liver, such as the glutathine disulfide content and lipid peroxidation, in a dose-dependent manner. Histopathologic examination of the rat livers showed that TCE reduced the incidence of liver lesions, including hepatocyte swelling and neutrophilic infiltration, and repaired necrosis induced by t-BHP. Based on the results described above, we speculate that TCE has the potential to play a role in the hepatic prevention of oxidative damage in living systems. (+info)