Inhibition of aflatoxin-induced liver damage in ducklings by food additives

Inhibitory effects of food additives on toxicity induced by aflatoxin B₁ was conducted in 3-day-old ducklings. Aflatoxin B₁ at a dose of 5 μg/day per animal for 14 days induced severe liver damage which included necrosis, fatty changes, and biliary hyperplasia. These changes were found to be inhibited by the daily administration of turmeric (50mg), curcumin (10 mg), and ellagic acid (10 mg) in the diet. Addition of BHA-butylated hydroxy anisole (10 mg), BHT-butylated hydroxy toluene (10 mg), garlic (500 mg), and asafoetida (50 mg) inhibited necrosis and degeneration of the tissue, while biliary hyperplasia persisted. Biochemical and haematological parameters were not significantly altered under the conditions studied.     

Chemical Composition,Cytotoxic and Antibacterial Activities of Essential Oils of Cultivated Clones of Juniperus communis and Wild Juniperus Species

Needles of seven cultivated clones (C1 – C7) of Juniperus communis at lower altitude and three wild Juniperus species (J. communis, J. recurva and J. indica) at higher altitudes were investigated comparatively for their essential oils (EOs) yields, chemical composition, cytotoxic and antibacterial activities. The EOs yields varied from 0.26 to 0.56% (v/w) among samples. Sixty‐one volatile components were identified by gas chromatography‐mass spectrometry (GC/MS) and quantified using gas chromatography GC (FID) representing 82.5 – 95.7% of the total oil. Monoterpene hydrocarbons (49.1 – 82.8%) dominated in all samples (α‐pinene, limonene and sabinene as major components). Principal component analysis (PCA) of GC data revealed that wild and cultivated Juniperus species are highly distinct due to variation in chemical composition. J. communis (wild species) displayed cytotoxicity against SiHa (human cervical cancer), A549 (human lung carcinoma) and A431 (human skin carcinoma) cells (66.4 ± 2.2%, 74.4 ± 1.4% and 57.4 ± 4.0%), respectively, at 200 μg/ml. EOs exhibited better antibacterial activity against Gram‐positive bacteria than against Gram‐negative bacteria with the highest zone of inhibition against Staphylococcus aureus MTCC 96 (19.2 ± 0.7) by clone‐7. As per the conclusion of the findings, EOs of clone‐2, clone‐5 and clone‐7 can be suggested to the growers of lower altitude, as there is more possibility of uses of these EOs in food and medicinal preparations.     

Regulation of invertase levels in Avena stem segments by gibberellic Acid, sucrose, glucose, and fructose

Gibberellic acid and sucrose play significant roles in the increases in invertase and growth in Avena stem segments. About 80% of invertase is readily solubilized, whereas the rest is in the cell wall fraction. The levels of both types of invertase change in a similar manner in the response to gibberellic acid and sucrose treatment. The work described here was carried out with only the soluble enzyme. In response to a treatment, the level of invertase activity typically follows a pattern of increase followed by decrease; the increase in activity is approximately correlated with the active growth phase, whereas the decrease in activity is initiated when growth of the segments slows. A continuous supply of gibberellic acid retards the decline of enzyme activity. When gibberellic acid was pulsed to the segments treated with or without sucrose, the level of invertase activity increased at least twice as high in the presence of sucrose as in its absence, but the lag period is longer with sucrose present. Cycloheximide treatments effectively abolish the gibberellic acid-promoted growth, and the level of enzyme activity drops rapidly. Decay of invertase activity in response to cycloheximide treatment occurs regardless of gibberellic acid or sucrose treatment or both, and it is generally faster when the inhibitor is administered at the peak of enzyme induction than when given at its rising phase. Pulses with sucrose, glucose, fructose, or glucose + fructose elevate the level of invertase significantly with a lag of about 5 to 10 hours. The increase in invertase activity elicited by a sucrose pulse is about one-third that caused by a gibberellic acid pulse given at a comparable time during mid-phase of enzyme induction, and the lag before the enzyme activity increases is nearly twice as long for sucrose as for gibberellic acid. Moreover, the gibberellic acid pulse results in about three times more growth than the sucrose pulse. Our studies support the view that gibberellic acid, as well as substrate (sucrose) and end products (glucose and fructose), play a significant role in regulating invertase levels in Avena stem tissue, and that such regulation provides a mechanism for increasing the level of soluble saccharides needed for gibberellic acid-promoted growth.     

Screening,statistical optimized production,and application of β‐mannanase from some newly isolated fungi

Eighty‐eight fungi isolated from soil and decaying organic matter were screened for mannanolytic activity. Twenty‐eight fungi produced extracellular mannanase on locust bean gum as evidenced by zone of hydrolysis produced on mannan agar gel. Six prominent producers, including four Fusarium species namely Fusarium fusarioides NFCCI 3282, Fusarium solani NFCCI 3283, Fusarium equiseti NFCCI 3284, Fusarium moniliforme NFCCI 3287 with Cladosporium cladosporioides NFCCI 3285 and Acrophialophora levis NFCCI 3286 produced the β‐mannanase in the range of 84–140 nkat/mL. All these grew well on particulate substrates in solid‐state fermentation (SSF), producing relatively higher titers on mannan‐rich palm kernel cake (PKC) and copra meal. Two high yielding strains, F. equiseti (1747 nkat/gds) and A. levis (897 nkat/gds) were selected for statistical optimization of mannanase on PKC. Interaction of two critical solid state fermentation parameters, pH and moisture on mannanase production by these two molds was studied by response surface method. Optimized production on PKC resulted in three‐ to fourfold enhancement in enzyme yield was observed in case of F. equiseti (5945 nkat/gds) and A. levis (4726 nkat/gds). HPLC analysis of mannan hydrolysate indicated that F. equiseti and A. levis mannanase performed efficient hydrolysis of konjac gum (up to 99%) with exclusive mannooligosaccahride (DP of 4) production. A seminative SDS‐PAGE revealed that A. levis and F. solani produced three isoforms, F. moniliforme produced two isoforms while F. fusarioides, F. equiseti, and C. cladosporioides produced a single enzyme.     

Optimization of process parameters for the production of carbonyl reductase by <Emphasis Type="Italic">Candida viswanathii</Emphasis> in a laboratory-scale fermentor

The effect of pH, aeration and mixing on the growth and production of carbonyl reductase by Candida viswanathii was investigated in a 6.6-l fermentor. Controlling the pH at 8.0 had a very significant effect on the enzyme production. Aeration and agitation influenced the dissolved oxygen concentration which in turn affected growth as well as enzyme production. A maximum carbonyl reductase activity (53 Umg⁻¹) was attained in 24 h under the optimal cultivation conditions of controlled pH at 8.0, aeration rate 1 vvm and an agitation speed of 250 rpm at 25°C. The enzyme activity was twice as high (56 Umg⁻¹) in the fermentor as compared to a shake flask. Further, the duration of growth and enzyme production in the fermentor was shortened. Cells cultivated under the optimized conditions were used for the preparative scale reduction of N, N-dimethyl-(3-keto)-2-thienyl-propanamine to (S)-N, N-dimethyl-(3-hydroxy)-2-thienyl-propanamine, a key intermediate in the production of the important antidepressant drug (S)-duloxetine.     

Facile synthesis, ex-vivo and in vitro screening of 3-sulfonamide derivative of 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxylic acid piperidin-1-ylamide (SR141716) a potent CB1 receptor antagonist

Facile synthesis of biaryl pyrazole sulfonamide derivative of 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxylic acid piperidin-1-ylamide (SR141716, 1) and an investigation of the effect of replacement of the –CO group in the compound 1 by the –SO₂ group in the aminopiperidine region is reported. Primary ex-vivo pharmacological testing and in vitro screening of sulfonamide derivative 2 showed the loss of CB1 receptor antagonism.     

Bioisosteric replacement of dihydropyrazole of 4S-(-)-3-(4-chlorophenyl)-N-methyl-N'-[(4-chlorophenyl)-sulfonyl]-4-phenyl-4,5-dihydro-1H-pyrazole-1-caboxamidine (SLV-319) a potent CB1 receptor antagonist by imidazole and oxazole

Design, synthesis and conformational analysis of few imidazole and oxazole as bioisosters of 4S-(-)-3-(4-chlorophenyl)-N-methyl-N'-[(4-chlorophenyl)-sulfonyl]-4-phenyl-4,5-dihydro-1H-pyrazole-1-caboxamidine (SLV-319) 2 is reported. Computer assisted conformational analysis gave a direct clue for the loss of CB1 antagonistic activity of the ligands without a fine docking simulation for the homology model.     

Knowledge‐guided laboratory evolution of protein thermolability

In rare but nevertheless important cases it is of practical interest to decrease the thermostability of an enzyme, that is, to increase thermolability in a controlled manner. In the present model study, this unconventional goal has been reached by applying directed evolution to the lipase from Pseudomonas aeruginosa (PAL). By utilizing the B‐factor iterative test (B‐FIT), previously developed to increase the thermostability of enzymes, it was possible to reduce the value from 71.6°C in the case of wild type (WT‐PAL) to 35.6°C (best mutant) without affecting the catalytic profile in terms of substrate acceptance or enantioselectivity at room temperature. Accordingly, saturation mutagenesis was performed at sites in PAL, which on the basis of its X‐ray structure, have the lowest B‐factors indicative of high rigidity. Focused mutations were introduced which can be expected to decrease rigidity, the ensuing increased flexibility leading to higher thermolability without changing the actual catalytic profile. Biotechnol. Bioeng. 2009;102: 1712–1717. © 2008 Wiley Periodicals, Inc.