Extraction of high quality DNA from polysaccharides-secreting xanthomonads

A DNA extraction method using CTAB was used for the isolation of genomic DNA from ten Xanthomonas  campestris pathovars, ten isolates of Xanthomonas albilineans and one isolate of Pseudomonas  rubrisubalbicans. High quality DNA was obtained that was ideal for molecular analyses. Extracellular polysaccharides were effectively removed thus resulting in DNA that dissolved easily and was well digested by restriction enzymes. All of the other methods tested resulted in the coprecipitation of the polysaccharides together with the nucleic acids upon addition of alcohol so that even high yields could not compensate for this contamination. DNA obtained by the CTAB method was used for cloning, Southern hybridizations and PCR for up to three years after the extraction.Keywords: Polysaccharides, CTAB, polymerase chain reaction, DNA

Traditional Medicinal Herbs and Food Plants Have the Potential to Inhibit Key Carbohydrate Hydrolyzing Enzymes In Vitro and Reduce Postprandial Blood Glucose Peaks In Vivo

We hypothesized that some medicinal herbs and food plants commonly used in the management of diabetes can reduce glucose peaks by inhibiting key carbohydrate hydrolyzing enzymes. To this effect, extracts of Antidesma madagascariense (AM), Erythroxylum macrocarpum (EM), Pittosporum senacia (PS), and Faujasiopsis flexuosa (FF), Momordica charantia (MC), and Ocimum tenuiflorum (OT) were evaluated for α-amylase and α-glucosidase inhibitory effects based on starch-iodine colour changes and PNP-G as substrate, respectively. Only FF and AM extracts/fractions were found to inhibit α-amylase activity significantly (P < 0.05) and coparable to the drug acarbose. Amylase bioassay on isolated mouse plasma confirmed the inhibitory potential of AM and FF extracts with the ethyl acetate fraction of FF being more potent (P < 0.05) than acarbose. Extracts/fractions of AM and MC were found to inhibit significantly (P < 0.05) α-glucosidase activity, with IC50 comparable to the drug 1-deoxynojirimycin. In vivo studies on glycogen-loaded mice showed significant (P < 0.05) depressive effect on elevation of postprandial blood glucose following ingestion of AM and MC extracts. Our findings tend to provide a possible explanation for the hypoglycemic action of MC fruits and AM leaf extracts as alternative nutritional therapy in the management of diabetes

Oxidative DNA damage preventive activity and antioxidant potential of plants used in Unani system of medicine

<p>Abstract</p> <p>Background</p> <p>There is increasing recognition that many of today's diseases are due to the "oxidative stress" that results from an imbalance between the formation and neutralization of reactive molecules such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), which can be removed with antioxidants. The main objective of the present study was to evaluate the antioxidant activity of plants routinely used in the Unani system of medicine. Several plants were screened for radical scavenging activity, and the ten that showed promising results were selected for further evaluation.</p> <p>Methods</p> <p>Methanol (50%) extracts were prepared from ten Unani plants, namely <it>Cleome icosandra, Rosa damascena, Cyperus scariosus, Gardenia gummifera, Abies pindrow, Valeriana wallichii, Holarrhena antidysenterica, Anacyclus pyrethrum, Asphodelus tenuifolius </it>and <it>Cyperus scariosus</it>, and were used to determine their total phenolic, flavonoid and ascorbic acid contents, in vitro scavenging of DPPH^·, ABTS^·+, NO, ^·OH, O₂^.-and ONOO^-, and capacity to prevent oxidative DNA damage. Cytotoxic activity was also determined against the U937 cell line.</p> <p>Results</p> <p>IC₅₀values for scavenging DPPH^·, ABTS^·+, NO, ^·OH, O₂^.-and ONOO^-were in the ranges 0.007 ± 0.0001 - 2.006 ± 0.002 mg/ml, 2.54 ± 0.04 - 156.94 ± 5.28 μg/ml, 152.23 ± 3.51 - 286.59 ± 3.89 μg/ml, 18.23 ± 0.03 - 50.13 ± 0.04 μg/ml, 28.85 ± 0.23 - 537.87 ± 93 μg/ml and 0.532 ± 0.015 - 3.39 ± 0.032 mg/ml, respectively. The total phenolic, flavonoid and ascorbic acid contents were in the ranges 62.89 ± 0.43 - 166.13 ± 0.56 mg gallic acid equivalent (GAE)/g extract, 38.89 ± 0.52 - 172.23 ± 0.08 mg quercetin equivalent (QEE)/g extract and 0.14 ± 0.09 - 0.98 ± 0.21 mg AA/g extract. The activities of the different plant extracts against oxidative DNA damage were in the range 0.13-1.60 μg/ml. Of the ten selected plant extracts studied here, seven - <it>C. icosandra, R. damascena, C. scariosus, G. gummifera, A. pindrow, V. wallichii </it>and <it>H. antidysenterica - </it>showed moderate antioxidant activity. Finally, potentially significant oxidative DNA damage preventive activity and antioxidant activity were noted in three plant extracts: <it>C. icosandra, R. damascena </it>and <it>C. scariosus</it>. These three plant extracts showed no cytotoxic activity against U937 cells.</p> <p>Conclusions</p> <p>The 50% methanolic extracts obtained from different plant parts contained significant amounts of polyphenols with superior antioxidant activity as evidenced by the scavenging of DPPH^·, ABTS^·+, NO, ^·OH, O₂^.-and ONOO^-. <it>C. icosandra, R. damascena </it>and <it>C. scariosus </it>showed significant potential for preventing oxidative DNA damage and radical scavenging activity, and the <it>G. gummifera, A. pindrow, V. wallichii, H. antidysenterica, A. pyrethrum, A. tenuifolius </it>and <it>O. mascula </it>extracts showed moderate activity. The extracts of <it>C. icosandra, R. damascena </it>and <it>C. scariosus </it>showed no cytotoxicity against U937 cells. In conclusion, these routinely used Unani plants, especially <it>C. icosandra, R. damascena </it>and <it>C. scariosus</it>, which are reported to have significant activity against several human ailments, could be exploited as potential sources of natural antioxidants for plant-based pharmaceutical industries.</p

Harmful and beneficial aspects of Parthenium hysterophorus: an update

Parthenium hysterophorus is a noxious weed in America, Asia, Africa and Australia. This weed is considered to be a cause of allergic respiratory problems, contact dermatitis, mutagenicity in human and livestock. Crop production is drastically reduced owing to its allelopathy. Also aggressive dominance of this weed threatens biodiversity. Eradication of P. hysterophorus by burning, chemical herbicides, eucalyptus oil and biological control by leaf-feeding beetle, stem-galling moth, stem-boring weevil and fungi have been carried out with variable degrees of success. Recently many innovative uses of this hitherto notorious plant have been discovered. Parthenium hysterophorus confers many health benefits, viz remedy for skin inflammation, rheumatic pain, diarrhoea, urinary tract infections, dysentery, malaria and neuralgia. Its prospect as nano-medicine is being carried out with some preliminary success so far. Removal of heavy metals and dye from the environment, eradication of aquatic weeds, use as substrate for commercial enzyme production, additives in cattle manure for biogas production, as biopesticide, as green manure and compost are to name a few of some other potentials. The active compounds responsible for hazardous properties have been summarized. The aim of this review article is to explore the problem P. hysterophorus poses as a weed, the effective control measures that can be implemented as well as to unravel the latent beneficial prospects of this weed

Blechnum Orientale Linn - a fern with potential as antioxidant, anticancer and antibacterial agent

<p>Abstract</p> <p>Background</p> <p><it>Blechnum orientale </it>Linn. (<it>Blechnaceae</it>) is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of <it>Blechnum orientale </it>Linn.</p> <p>Methods</p> <p>Five solvent fractions were obtained from the methanol extract of <it>B. orientale</it> through successive partitioning with petroleum ether, chloroform, ethyl acetate, butanol and water. Total phenolic content was assessed using Folin-Ciocalteu's method. The antioxidant activity was determined by measuring the scavenging activity of DPPH radicals. Cytotoxic activity was tested against four cancer cell lines and a non-malignant cell using MTT assay. Antibacterial activity was assessed using the disc diffusion and broth microdilution assays. Standard phytochemical screening tests for saponins, tannins, terpenoids, flavonoids and alkaloids were also conducted.</p> <p>Results</p> <p>The ethyl acetate, butanol and water fractions possessed strong radical scavenging activity (IC₅₀8.6-13.0 μg/ml) and cytotoxic activity towards human colon cancer cell HT-29 (IC₅₀27.5-42.8 μg/ml). The three extracts were also effective against all Gram-positive bacteria tested: <it>Bacillus cereus, Micrococcus luteus</it>, methicillin-susceptible <it>Staphylococcus aureus </it>(MSSA), methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) and <it>Stapylococcus epidermidis</it>(minimum inhibitory concentration MIC 15.6-250 μg/ml; minimum bactericidal concentration MBC 15.6-250 μg/ml). Phytochemical analysis revealed the presence of flavonoids, terpenoids and tannins. Ethyl acetate and butanol fractions showed highest total phenolic content (675-804 mg gallic acid equivalent/g).</p> <p>Conclusions</p> <p>The results indicate that this fern is a potential candidate to be used as an antioxidant agent, for colon cancer therapy and for treatment of MRSA infections and other MSSA/Gram-positive bacterial infectious diseases.</p

Bridging the gap in African biodiversity genomics and bioinformatics:Open Institute of the African BioGenome Project:

The Open Institute of the African BioGenome Project empowers African scientists and institutions with the skill sets, capacity and infrastructure to advance scientific knowledge and innovation and drive economic growth