Purification and partial characterization of two azoreductases from Shigella dysenteriae Type 1

Two azoreductases (I and II) were purified to homogeneity from extracts of Shigella dysenteriae (type 1). Azoreductase I was a dimer of identical subunits of M(r) 28,000, whereas azoreductase II was a monomer of 11,000 M(r). Both were flavoproteins, each containing 1 mol of FMN per mol enzyme. Both NADH and NADPH functioned as electron donors for the azoreductases. Azoreductase I used Ponceau SX, Tartrazine, Amaranth and Orange II as substrates. Azoreductase II utilized all the dyes except Amaranth.     

Structure of the d-galactan isolated from aloe barbadensis miller

Hot-water extraction of the pulp obtained by dehydrating the jelly of the fleshy leaves of Aloe barbadensis furnished a mixture of polysaccharides containing mainly pectic acid, along with a d-galactan, a glucomannan, and an arabinan. The pectic acid was partly removed by treatment with calcium chloride, and the resulting, hexose-enriched, polysaccharide mixture was fractionated through a column of DEAE-cellulose to yield a d-galactan containing d-galactose (92.9% and d-galacturonic acid (3.8%). Hydrolysis of the permethylated d-galactan furnished 2,3,4,6-tetra-, 2,3,6-tri-, and 2,3-di-O-methylgalactose in the molar ratios of 1:26:1. On periodate oxidation, the d-galactan reduced 0.95 molar equivalent of the oxidant per hexosyl residue, and liberated one molar equivalent of formic acid per 26 galactosyl residues. Smith degradation of the d-galactan afforded mainly threitol. From these results, a structure has been assigned to the repeating unit of the d-galactan. The number-average, molecular weight of the peracetylated galactan has been found to be 3.74 x 10⁴.     

Scale up, optimization and stability analysis of Curcumin C3 complex-loaded nanoparticles for cancer therapy

ABSTRACT: BACKGROUND: Nanoparticle based delivery of anticancer drugs have been widely investigated. However, a very important process for Research & Development in any pharmaceutical industry is scaling nanoparticle formulation techniques so as to produce large batches for preclinical and clinical trials. This process is not only critical but also difficult as it involves various formulation parameters to be modulated all in the same process. METHODS: In our present study, we formulated curcumin loaded poly (lactic acid-co-glycolic acid) nanoparticles (PLGA-CURC). This improved the bioavailability of curcumin, a potent natural anticancer drug, making it suitable for cancer therapy. Post formulation, we optimized our process by Reponse Surface Methodology (RSM) using Central Composite Design (CCD) and scaled up the formulation process in four stages with final scale-up process yielding 5 g of curcumin loaded nanoparticles within the laboratory setup. The nanoparticles formed after scale-up process were characterized for particle size, drug loading and encapsulation efficiency, surface morphology, in vitro release kinetics and pharmacokinetics. Stability analysis and gamma sterilization were also carried out. RESULTS: Results revealed that that process scale-up is being mastered for elaboration to 5 g level. The mean nanoparticle size of the scaled up batch was found to be 158.5 [PLUS-MINUS SIGN] 9.8 nm and the drug loading was determined to be 10.32 [PLUS-MINUS SIGN] 1.4 %. The in vitro release study illustrated a slow sustained release corresponding to 75 % drug over a period of 10 days. The pharmacokinetic profile of PLGA-CURC in rats following i.v. administration showed two compartmental model with the area under the curve (AUC0-[INFINITY]) being 6.139 mg/L h. Gamma sterilization showed no significant change in the particle size or drug loading of the nanoparticles. Stability analysis revealed long term physiochemical stability of the PLGA-CURC formulation. CONCLUSIONS: A successful effort towards formulating, optimizing and scaling up PLGA-CURC by using Solid-Oil/Water emulsion technique was demonstrated. The process used CCD-RSM for optimization and further scaled up to produce 5 g of PLGA-CURC with almost similar physicochemical characteristics as that of the primary formulated batch.     

Dietary fish oil associated with increased apoptosis and modulated expression of Bax and Bcl-2 during 7,12-dimethylbenz(alpha)anthracene-induced mammary carcinogenesis in rats

The present study investigated the chemopreventive effect of dietary fish oil (Maxepa), rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on induction of apoptosis in mammary carcinogenesis model. Mammary carcinogenesis was initiated by a single, tail vein injection of 7,12-dimethylbenz(alpha)anthracene (DMBA) (0.5mg/0.2ml corn oil/100g body weight) at 7 weeks of animal age. Ninety female Sprague-Dawley rats were divided into two parts: part one was used for histology and immunohistochemical study and part two for morphological analysis. Each part consists of three experimental groups having 15 animals, i.e., Group A (DMBA control), Group B (DMBA+fish oil) and Group C (DMBA+corn oil). Rats were fed either fish oil or corn oil (0.5ml/day/rat) by oral gavage, 2 weeks prior to DMBA injection. Treatment was continued 25 weeks, studying histopathology, expression of Bax and Bcl-2 proteins by immunohistochemistry and apoptosis by TUNEL assay and morphological study at 36 weeks. Results showed that the fish oil-treated group exhibited a substantial increase in Bax (p<0.05) immunolabelling and a reduction of Bcl-2 immunopositivity (p<0.05), and increased TUNEL-positive apoptotic cells (p<0.05); however, corn oil treatment did not show these beneficial effects toward mammary preneoplasia. We conclude that fish oil has the potential to play a significant role in limiting mammary tumourigenesis in vivo.     

Effect of Streptomycin on Some Enzyme Systems of Bacillus subtilis

Streptomycin slightly inhibited lactic and malic dehydrogenases of Bacillus subtilis, and inhibited isocitric dehydrogenase to about 60%. The formation of lactic dehydrogenase, glutamic dehydrogenase, alpha-alanine dehydrogenase, and succinic dehydrogenase was stimulated by the antibiotic at a concentration causing 50% inhibition of bacterial growth. Streptomycin had practically no influence on the formation of malic dehydrogenase, but the antibiotic produced 48% inhibition of the synthesis of isocitric dehydrogenase.     

Oxidation of the capsular polysaccharide of pneumoccal type IX by periodate

1. The pneumococcal type IX polysaccharide (polysaccharide S IX) has been oxidized by sodium metaperiodate and reduced by sodium borohydride. Of the constituent monosaccharides, N-acetylglucosamine and N-acetylmannosamine remain unaltered, whereas 40% of the glucose and 90% of the glucuronic acid are oxidized. 2. The effect of oxidation and subsequent reduction on the precipitation of polysaccharide S IX in anti-(pneumococcal) sera is described and interpreted in structural terms. 3. Oligosaccharides produced by oxidation, reduction and hydrolysis with dilute acid have been isolated and partially characterized. 4. The results in this paper and the preceding one (Higginbotham et al., 1972) are used to postulate a possible structure for polysaccharide S IX.     

A comparative study of physiological strain of underground coal miners in India

Ninety-eight healthy underground coal miners aged between 23-58 years were studied during their activity period. Physiological strain of different category of miners in terms of heart rate was monitored continuously with heart rate monitor that revealed the tasks as heavy to very heavy for them. Oxygen consumption was measured directly by using oxylog-2 machine that corresponded to metabolic costs for different activities ranging from 4.96 kcal/min to 5.47 kcal/min. The mean relative aerobic strain varied from 47.4%-56.8%--depicting acceptable level of physical strain was well encroached by the miners who irrespective of ages and categories showed poor recovery responses. This entails that miners are exerting themselves beyond their capacities where inevitably older workforce face the maximum burden.     

Cardiovascular load assessment of coal mine shovelers in west Bengal, India: a comparison between middle age groups

Cardiovascular load of underground shovelers was assessed in terms of heart rate changes at work in haulage coalmines. Twenty underground shovelers of two different age groups (those of age 31-39 and those of age 40-49) served as subjects. Working heart rate was significantly higher (p < 0.01) in the older group (138.2 beats/min) than in the younger group (130.4 beats/min). Though the net cardiac cost did not differ significantly between the groups (64.8 beats/min and 69.4 beats/min in younger and older groups, respectively), difference in the relative cardiac cost (54.17% and 64.86% in younger and older groups, respectively) proved to be highly significant (p < 0.001). The heart rate up to the third minute of recovery showed significant differences between the groups (p < 0.01). While analysis of physiological responses indicated that the task was very strenuous irrespective of age, cardiac strain was found to be more excessive in the older subjects if continued. The arduous nature of the working environment in the coalfaces was also reported.