Real-time PCR-based rapid and culture-independent detection of Salmonella in dairy milk--addressing some core issues.

In this study, methodologies were developed for cost-effective, rapid and user-friendly culture-independent detection of Salmonella in milk by real-time PCR. The SYBR Green-based real-time PCR assay was standardized with primers targeting the Salmonella enterotoxin gene (stn) that have been earlier used for its detection by conventional PCR. Inclusivity tests generated the specific amplifications with a Tm corresponding to 81 ± 0·5°C. The specificity of the reaction was evaluated with a panel of 36 non-Salmonella strains. Standard curves generated, with different number of cells of this organism in milk, depicted the detection of five cells with a CT value of 37·17 (SD 0·43). To make the assays user-friendly and suitable for field applications, protocols were also established for the immobilization of the SYBR Green reaction mixes in the reaction tubes. The immobilized master mixes were stable at 25°C for 4 months and at 8°C for over 6 months. Total DNA was prepared from 150 samples of full-fat dairy milk and subjected to real-time PCR detection wherein 31 samples tested positive for Salmonella. The time of analysis was <5 h.

Novel thermostable lipase from Bacillus circulans IIIB153: comparison with the mesostable homologue at sequence and structure level.

Thermophilic Bacillus circulans IIIB153 isolated from hot springs of North West Himalayas, India, produced an extracellular lipase, which exhibited significant biofilm disruption property on the static biofilm disruption model with a single species of Actinomyces viscosous. The gene encoding the lipase was cloned and overexpressed in Escherichia coli. Recombinant Bacillus circulans lipase (BCL), a monomer with molecular mass of 43 kDa also exhibited significant biofilm disruption activity. The enzyme was optimally active at 60°C, pH 8.5 and retained >70% of its original activity after 1 h incubation at 60°C. 3D structure of BCL developed by homology modeling showed a typical α/ß hydrolase fold, a characteristic feature of lipolytic enzymes. Comparison of thermostable BCL with mesostable lipase from Chromobacterium viscosum at the sequence and structure level showed distinct variations in the structural features, with the presence of a high content of proline residues, aromatic amino acids and salt bridges. These features along with the presence of zinc-binding site observed in BCL structure could have a potential role in thermal stability of the enzyme.

Effect of precursors feeding and media manipulation on production of novel anticancer pro-drug camptothecin from endophytic fungus.

We have established methodology for the isolation and characterization of a novel endophytic fungus from the inner bark of medicinal plant Nothapodytes foetida, which produced camptothecin in Sabouraud broth (SB) under shake flask conditions. Camptothecin and its related compounds are at present obtained by extraction from intact plants, but fungal endopytes may be an alternative source of production. In present study we have observed the effect of different nutrient combinations and precursors (tryptophan, tryptamine, geraniol, citral, mevalonic acid and leucine) on the accumulation of camptothecin by endophytic fungus Entrophospora infrequens. The precursors were fed either alone or in combinations (tryptophan and geraniol, tryptophan and citral, tryptophan and mevalonic acid, tryptophan and leucine). The highest camptothecin content was observed in the range of 503 ± 25µg/100g dry cell mass in Sabouraud medium. Camptothecin content in the medium was increased by 2.5 folds by the presence of tryptophan and leucine whereas the production with trytophan was also significantly different from other treatments. Furthermore, the effect of fungal camptothecin on the morphology of human cancer cell lines was also studied. The treated cells showed reduction in size, condensation of nucleus and the protoplasmic extensions were reduced. All these characteristics are found in apoptotic cells.

Chemoprevention with aqueous extract of Butea monosperma flowers results in normalization of nuclear morphometry and inhibition of a proliferation marker in liver tumors.

Butea monosperma (Lam.) (family: Fabaceae) popularly known as 'Palas' or 'fire of forest' has been used traditionally as a hepatoprotective agent. This study evaluated the hepatoprotective and antitumorigenic properties of the aqueous extract and butanol fractions of B. monosperma flowers in animal models. Dried flowers of B. monosperma were extracted with water and fractionated further using n-butanol. The hepatoprotective activity of the aqueous extract was initially confirmed in a carbon tetrachloride-induced liver damage model of rats. Oral administration of the aqueous extract produced a strong hepatoprotective effect similar to silymarin and normalized the serum levels of ALT, AST, bilirubin and triglyceride in rats. However, it did not affect the levels of glutathione and malondialdehyde which are oxidative stress markers in liver. Intraperitoneal administration of the aqueous extract in the X15-myc oncomice not only maintained liver architecture and nuclear morphometry but also down-regulated the serum VEGF levels. Immunohistochemical staining of liver sections with anti-Ribosomal protein S27a antibody showed post-treatment abolition of this proliferation marker from the tumor tissue. The butanol fractions, however, did not show antitumorigenic activity. Thus, the aqueous extract of B. monosperma flowers is not only hepatoprotective but also antitumorigenic by preserving the nuclear morphometry of the liver.

Immunomodulatory activity of Asparagus racemosus on systemic Th1/Th2 immunity: implications for immunoadjuvant potential.

ETHNOPHARMACOLOGICAL RELEVANCE: Roots of Asparagus racemosus Willd (Shatavari in vernacular) are widely used in Ayurveda as Rasayana for immunostimulation, galactogogue as also in treatment of conditions like ulcers and cancer. Various studies have indicated immunomodulatory properties of Shatavari root extracts and formulations. AIM OF THE STUDY: To study the effect of standardized Asparagus racemosus root aqueous extract (ARE) on systemic Th1/Th2 immunity of SRBC sensitized animals. MATERIALS AND METHODS: We used HPTLC to quantify steroidal saponins (Shatavarin IV, Immunoside) and flow cytometry to study effects of ARE on Th1/Th2 immunity. SRBC specific antibody titres and DTH responses were also monitored as markers of Th2 and Th1 responses, respectively. We also studied lymphocyte proliferation. Cyclosporin, cyclophosphamide and levamisole were used as controls. RESULTS: Treatment with ARE (100mg/(kg b.w.p.o.)) resulted in significant increase of CD3(+) and CD4/CD8(+) percentages suggesting its effect on T cell activation. ARE treated animals showed significant up-regulation of Th1 (IL-2, IFN-g) and Th2 (IL-4) cytokines suggesting its mixed Th1/Th2 adjuvant activity. Consistent to this, ARE also showed higher antibody titres and DTH responses. ARE, in combination with LPS, Con A or SRBC, produced a significant proliferation suggesting effect on activated lymphocytes. CONCLUSION: The study suggests mixed Th1/Th2 activity of ARE supports its immunoadjuvant potential.

Studies on novel 4beta-[(4-substituted)-1,2,3-triazol-1-yl] podophyllotoxins as potential anticancer agents.

A series of 4beta-[(4-substituted)-1,2,3-triazol-1-yl] podophyllotoxin congeners have been designed and synthesized with significant regioselectivity by employing Cu(I) catalyzed 1,3-dipolar cycloaddition reaction of C4beta-azido podophyllotoxin and C4beta-azido-4'-O-demethyl podophyllotoxin with N-prop-2-yn-1-ylanilines. These compounds were evaluated for anticancer activity against a panel of seven human cancer cell lines. It was interesting to note that all the compounds exhibited promising activity especially against SF-295 (CNS), HCT-15 (colon) and 502713 (colon) cell lines. Compound 11e was found to be the most promising in this study.

Hepatoprotective activity of Woodfordia fruticosa Kurz flowers against carbon tetrachloride induced hepatotoxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: Dried flowers of Woodfordia fruticosa Kurz. Family Lythraceae are used in variety of diseases in traditional Indian system of medicine including hepatic ailments. AIMS OF STUDY: The aim of present study was to validate hepatoprotective activity of flowers of Woodfordia fruticosa Kurz. MATERIALS AND METHODS: Petroleum ether (WF1), chloroform (WF2), ethyl alcohol (WF3) and aqueous (WF4) extracts of the flowers of Woodfordia fruticosa were evaluated for hepatoprotective activity against carbon tetrachloride induced hepatotoxicity using biochemical markers, hexobarbitone sleep time, bromosulphalein (BSP) clearance test and effect on bile flow and bile solids. RESULTS: The aqueous extract (WF4) was most potent among the four extracts studied in detail. WF4 showed significant hepatoprotective activity against carbon tetrachloride induced hepatotoxicity as evident by restoration of serum transaminases, alkaline phosphatase, bilirubin and triglycerides. The restoration of microsomal aniline hydroxylase and amidopyrine-N-demethylase activities indicated the improvement in functional status of endoplasmic reticulum. Restoration of lipid peroxidation and glutathione contents suggests the antioxidant property of WF4. The recovery in bromosulphalein clearance and stimulation of bile flow suggested the improved excretory and secretary capacity of hepatocytes. Light microscopy of the liver tissue further confirmed the reversal of damage induced by hepatotoxin. CONCLUSION: Present study showed that the aqueous extract of Woodfordia fruticosa significantly restores physiological integrity of hepatocytes. WF4 did not show any sign of toxicity up to oral dose of 2g/kg in mice.

Immunomodulatory activity of biopolymeric fraction BOS 2000 from Boswellia serrata.

Oral administration of BOS 2000 (1-10 mg/kg) elicited a dose related increase in the delayed hypersensitivity reaction (early 24 h and delayed 48 h) in mice. It also stimulated the IgM and IgG titre expressed in the form of plaques (PFC) and complement fixing antibody titre. The concentration of cytokines (IL-4, IFN-gamma and TNF-alpha) in serum with respect to T cell interactions, i.e. (CD4/CD8) and the proliferation of lymphocytes were significantly increased at 10 mg/kg compared with the control. The results in these studies demonstrated the immunostimulatory effect of BOS 2000 in a dose-dependent manner with respect to the macrophage activation possibly expressing the phagocytosis and nitrite production by the enhancement of TNF-alpha and IFN-gamma production as a mode of action.

Prospecting for Camptothecines from Nothapodytes nimmoniana in the Western Ghats, South India: identification of high-yielding sources of camptothecin and new families of camptothecines.

Camptothecin (CPT), a monoterpene alkaloid, is an important anti-cancer compound obtained from several plant sources including Camptotheca acuminta (from China) and Nothapodytes nimmoniana (from India). Currently, by far the highest levels of CPT (approximately 0.3% w/w) are reported from Nothapodytes nimmoniana, a small tree distributed in the Western Ghats, India. In recent years because of the heavy demand, there has been a serious threat of extinction of the populations of the tree in the Western Ghats forest of south India. Several studies have chemically profiled populations of the species in the Western Ghats to identify sources of high yield and therefore to enable the sustainable production and harvesting of CPT. In this study, using both high-performance liquid chromatography and liquid chromatography-mass spectrometry, we report for the first time the identification of trees that produce at least 5- to 8-fold more CPT than hitherto reported. Furthermore, we show for the first time the production of a few minor camptothecines, including 10-hydroxy camptothecin, in the stem and root bark extracts of the tree. These results have important implications for not only harnessing the high-yielding individuals for clonal multiplication but also for exploiting some of the minor camptothecines, which also have been shown to have important anti-cancer and anti-viral activity.

An endophytic Neurospora sp. from Nothapodytes foetida producing camptothecin.

The medicinal plant, Nothapodytes foetida contains a number of important alkaloids like camptothecin (an anticancer drug molecule) but its concentration is less to meet the existing demand of this important molecule, so in an effort for accessible availability of camptothecin. An endophyte (designated ZP5SE) was isolated from the seed of Nothapodytes foetida and was examined as potential source of anticancer drug lead compound i.e. camptothecin, when grown in Sabouraud liquid culture media under shake flask conditions. The presence of anticancer compound (camptothecin) in this fungus was confirmed by chromatographic and spectroscopic methods in comparison with authentic camptothecin. Isolated endophyte (Neurospora crassa) producing camptothecin may become an easily accessible source for the production of precursor anticancer drug molecule in future at large scale.

Characterization of an anion-exchange porous polypropylene hollow fiber membrane for immobilization of ABL lipase.

Hollow fiber membrane offers the advantage to integrate catalytic conversion, product separation and catalyst recovery into a single separation process compared to conventional systems. Polypropylene (PP) hollow fiber membrane is a chemically inert and stable membrane with high potential for enzyme immobilization. The surface properties of polypropylene have been modified by radiation induced graft polymerization. Samples were prepared by grafting of glycidylmethacrylate (GMA) using gamma radiation, at different monomer concentrations and irradiation dose. The resulting epoxy was converted into a diethylamino group as an anion-exchange medium to bind the lipase molecules. Surface properties of the grafted and amine treated samples were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM) and contact angle measurements. AFM revealed higher surface roughness for grafted samples than that of virgin polymer. SEM micrographs illustrated that the porous network was retained at high degree of grafting. Contact angle measurements showed excellent wetting properties with water for the grafted and amine treated membranes. Thermal properties were studied using differential scanning calorimeter (DSC) and thermogravimetic analysis (TGA). It was observed that grafting occurred mainly in the amorphous region of the membranes. Activity and operational stability of ABL lipase, isolated from Arthobacter sp. were assayed after immobilizing it to the modified PP hollow fiber. Immobilized lipase retained 20U/g activity after ten hydrolysis cycles and 68% residual activity after 12 weeks of storage.

Protective efficacy of semi purified fraction of high altitude podophyllum hexandrum rhizomes in lethally irradiated Swiss albino mice.

A fraction of high altitude Podophyllum hexandrum rhizome, REC-2006, was evaluated for its radioprotective efficacy against lethal gamma-irradiation (10 Gy, whole body) in Swiss albino mice. The maximum tolerated dose (MTD) and LD50 of this fraction were found to be 45 mg/kg b.w. and 74 mg/kg b.w. respectively. Pre-irradiation (- 2 h, ) administration (i.p.) of 6 or 8 mg/kg b.w. of REC-2006 rendered > 90% survival in lethally irradiated mice. The dose reduction factor was calculated to be 1.62 considering survival as the end point. REC-2006 treatment marked in significant increase in endogenous spleen colony forming units. In REC-2006 treated group, super oxide dismutase activity was increased significantly compared to the radiation control group (Liver, p = 0.00, Jejunum p = 0.00). The extract also inhibited radiation induced lipid peroxidation in liver (p = 0.00) at 24 h. REC-2006 administration (100-200 microg/ml) significantly reduced the halo diameter in mice thymocytes. Nearly 10 fold difference between the effective dose (6 mg/kg b.w.) and LD50 and the high degree of whole body survival (> 90% against 10 Gy irradiation) indicates REC-2006 to be safe and highly promising to achieve significant radioprotection against lethal radiation. Further purification and identification of active molecules and their efficacy studies in higher animals therefore demand attention.

Cytoprotective effect of Podophyllum hexandrum against gamma radiation is mediated via hemopoietic system stimulation and up-regulation of heme-oxygenase-1 and the prosurvival multidomain protein Bcl-2.

The radioprotective effect of a hydroalcoholic extracted material (REC-2000) from the rhizome of Podophyllum hexandrum was studied in mice exposed to lethal gamma radiation (10 Gy). The extract (REC-2000) was found to restore the hemoglobin content (14.73 +/- 0.33) and total leukocyte count (TLC) (4166.66 +/- 0.02) in lethally (10 Gy) gamma-irradiated mice on the 15th day in comparison to the radiation control mice. The hemoglobin content of the drug + radiation group was observed to be significantly (21.25%) higher than the radiation control group on the 10th day. Similarly, the TLC was significantly increased (83.33 times) in the drug + radiation group as compared to a radiation (10 Gy) only group on the 10th day. Enhanced expression of heme-oxygenase-1 and Bcl-2 protein observed by Western blotting further supports the observation of hemopoietic recovery in irradiated mice. These findings indicate that the bioactive constituents present in REC-2000 exert the radioprotective effect by modulating the hemopoietic system.

Immunomodulatory activity of biopolymeric fraction RLJ-NE-205 from Picrorhiza kurroa.

In the last three decades, numerous biopolymeric fractions have been isolated from medicinal plants and used as a source of therapeutic agents. The most promising biopharmacological activities of these biopolymers are their immunomodulatory effects. The biopolymeric fraction RLJ-NE-205 was isolated and purified from the rhizomes of Picrorhiza kurroa. We evaluated the effects of biopolymeric fraction RLJ-NE-205 from P. kurroa on the in vivo immune function of the mouse. Balb/c mice were treated with the biopolymeric fraction RLJ-NE-205 (12.5, 25 and 50 mg/kg body weight) for 14 days with sheep red blood cells (SRBC) as an antigen. Haemagglutination antibody (HA) titre, plaque forming cell (PFC) assay, delayed type hypersensitivity (DTH) reaction, phagocytic index, proliferation of lymphocytes, analysis of cytokines in serum and CD4/CD8 population in spleen (determined by flowcytometry) were studied. At the dose of 50 mg/kg, significant increases in the proliferation of lymphocytes (p<0.001) and cytokine levels (IL-4 and IFN-gamma) in serum (p<0.001) were observed. A dose dependent increase was demonstrated in HA titre (p<0.05), DTH (p<0.01), PFC (p<0.05), phagocytic index (p<0.05) and CD4/CD8 (p<0.01) population. This suggests that the biopolymeric fraction RLJ-NE-205 improves the immune system and might be regarded as a biological response modifier.

Augmentation and proliferation of T lymphocytes and Th-1 cytokines by Withania somnifera in stressed mice.

Stress has been associated with reports of both greater severity and prolongation of diseases in patients with the infectious origin as well as other immune-mediated diseases. Withania somnifera, an Indian medicinal plant used widely in the treatment of many clinical conditions in India, was investigated for its anti-stress properties using BALB/c mice subjected to chronic stress. The study aimed to investigate chronic stress-induced alterations on Th1 lymphocyte subset distribution and corresponding cytokine secretion patterns. Oral administration of chemically standardized and identified aqueous fraction of W. somnifera root (WS) at the graded doses of 25, 50, 100 and 200 mg/kg p.o. caused significant increase in the stress-induced depleted T-cell population and increased the expression of Th1 cytokines in chronically stressed mice.

Synthesis and bronchodilator activity of new quinazolin derivative.

Taking lead from a naturally occurring quinazolin vasicine, a number of compounds were developed and evaluated for bronchodilator and anti-allergic activities. One of these compounds was 2,4-diethoxy-6,7,8,9,10,12-hexahydroazepino[2,1-b]quinazolin-12-one, hereinafter named 95-4, exhibited marked bronchodilator activity evaluated on contracted trachea or constricted tracheo-bronchial tree. On intestinal smooth muscle too it showed relaxant effect. Tracheal relaxant effect was not found to be mediated through beta-adrenoceptors. Cumulative dose-response study with acetylcholine and histamine indicated for its non-specific direct effect on smooth muscles. 95-4 was found to be more potent than theophylline and less to that of salbutamol on dose basis. Tested by a number of experimental models, it was found devoid of anti-allergic activity. It was also found to be free from any adverse effect. 95-4 due to its marked bronchial muscle relaxant effect can find use in conditions associated with spasm of bronchial muscles.

Characterization of two epimers, 4alpha and 4beta, of a novel podophyllotoxin-4-O-(D)-6-acetylglucopyranoside from Podophyllum hexandrum by LC-ESI-MS-MS.

High-performance liquid chromatography (HPLC) with diode array detection interfaced to electrospray ionization (ESI) mass spectrometry (MS) is applied to identify the two epimers of a novel and minor constituent, podophyllotoxin-4-O-(D)-6-acetylglucopyraniside from high-altitude Podophyllum hexandrum for the first time. This is done by matching the structural information from the tandem MS data with the reported lignan markers. The results show that LC-MS-MS is the method of choice for fast detection and detailed chemical analysis of mixtures in the crude extracts of Podophyllum. The method can be employed in the absence of reference standards for the markers and is particularly useful in view of the scarcity of these rare chemical standards.