Biosorption characteristics of Aspergillus fumigatus for the decolorization of triphenylmethane dye acid violet 49.

This study focuses on the possible use of Aspergillus fumigatus to remove acid violet 49 dye (AV49) from aqueous solution. In batch biosorption experiments, the highest biosorption efficiency was achieved at pH 3.0, with biosorbent dosage of 3.0 gL(-1) within about 30 min at 40 °C. The Langmuir and Freundlich models were able to describe the biosorption equilibrium of AV49 onto fungal biomass with maximum dye uptake capacity 136.98 mg g(-1). Biosorption followed a pseudo-second-order kinetic model with high correlation coefficients (R (2) > 0.99), and the biosorption rate constants increased with increasing temperature. Thermodynamic parameters indicated that the biosorption process was favorable, spontaneous, and endothermic in nature, with insignificant entropy changes. Fourier transform infrared spectroscopy strongly supported the presence of several functional groups responsible for dye-biosorbent interaction. Fungal biomass was regenerated with 0.1 M sodium hydroxide and could be reused a number of times without significant loss of biosorption activity. The effective decolorization of AV49 in simulated conditions indicated the potential use of biomass for the removal of color contaminants from wastewater.

Separation of polyhydroxyalkanoates-producing bacterial strains using PHA synthase gene and their evaluation for PHA deposition

In this study, a variety of samples were screened for the presence of PHA synthase gene. Results showed that 16 out of 102 isolated were positive for PHA respective genes. The highest prevalence was observed in Pseudomonas aeruginosa. The capability of PHA production was also shown by growing these strains on the defined medium and subsequent analysis using intracellular granules staining and Fourier transform infrared spectroscopy (FT-IR). The microscopic analysis showed that the positive strains accumulated PHA in the cell. The FT-IR analysis showed the presence of PHA peaks in the dried cells as well as in extraction product. P aeruginosa strain P7 showed higher concentration of PHA compared to the others as demonstrated by the highest respective peaks in FT-IR.

Serum selenium concentration in liver cirrhotic patients suffering from hepatitis B and C in Pakistan.

High rates of hepatitis B and C are present in Pakistan. Epidemiological surveys demonstrated an inverse association between selenium (Se) level and regional cancer incidence, as well as viral infection. In this cross-sectional descriptive analytical study, serum selenium concentration of 150 patients suffering from hepatitis B and C patients, along with 26 healthy controls, was determined by atomic absorption spectrophotometer equipped with hydride generation system. The mean and standard deviation of serum selenium concentration observed in male and female patients with hepatitis C were 101.60 ± 0.55 and 77.43 ± 0.47 µg/l, respectively, while the mean and standard deviation of serum selenium concentration observed in male and female patients with hepatitis B was 107.58 ± 0.44 and 137.8 ± 0.36 µg/l. Analysis of t test showed significant difference between hepatitis C and B (P < 0.001) patients in serum selenium concentration when compared with control.

Naturally occurring tyrosinase inhibitors: mechanism and applications in skin health, cosmetics and agriculture industries.

Tyrosinase is a copper-containing enzyme, which is widely distributed in microorganisms, animals and plants and is a key enzyme in melanin biosynthesis, involved in determining the color of mammalian skin and hair. In addition, unfavorable enzymatic browning of plant-derived foods by tyrosinase causes a decrease in nutritional quality and economic loss of food products. The inadequacy of current conventional methods to prevent tyrosinase action encourages researchers to seek new potent tyrosinase inhibitors for food and cosmetics. This article presents a study on the importance of tyrosinase, biochemical characteristics, type of inhibitions, activators from various natural sources with its clinical and industrial importance in recent prospects is discussed in this paper.

Inhibition of nitric oxide and tumor necrosis factor-alpha by moutan cortex in activated mouse peritoneal macrophages.

Moutan cortex (MC) is one of the most widely used Oriental herbal medicines for treating inflammatory diseases. In this study, the effect of MC on lipopolysaccharide (LPS) and recombinant interferon-gamma (rIFN-gamma)-induced production of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha were examined using mouse peritoneal macrophages. MC inhibited the LPS/rIFN-gamma-induced expression of inducible nitric oxide synthase (iNOS) and TNF-alpha release. To clarify the mechanism involved, the effect of MC on the activation of nuclear factor (NF)-kappaB was examined. The LPS/rIFN-gamma-induced activation of NF-kappaB was almost completely blocked by MC at 0.5 mg/ml. These findings demonstrate that the inhibition of the LPS/rIFN-gamma-induced production of NO and TNF-alpha by MC is due to the inhibition of NF-kappaB activation.

Effects of Nelumbinis Semen on contractile dysfunction in ischemic and reperfused rat heart.

Nelumbinis Semen (NS), or lotus seed, is one of the most well-known traditional herbal medicines and is frequently used to treat cardiovascular symptoms in Korea. The anti-ischemic effects of NS on ischemia-induced isolated rat heart were investigated through analyses of changes in blood pressure, aortic flow, coronary flow, and cardiac output. The subjects in this study were divided into two groups: a control, untreated ischemia-induced group, and an ischemia-induced group treated with NS. There were no significant differences in perfusion pressure, aortic flow, coronary flow and cardiac output between the groups before ischemia was induced. The supply of oxygen and buffer was stopped for ten minutes to induce ischemia in isolated rat hearts, and NS was administered during ischemia induction. NS treatment significantly prevented decreases in perfusion pressure, aortic flow, coronary flow and cardiac output under ischemic conditions (p < 0.01). In addition, the mechanism of the anti-ischemic effects of NS was also examined through quantitation of intracellular calcium content in rat neonatal cardiomyocytes. NS significantly prevented intracellular calcium increases induced by isoproterenol (p < 0.01). These results suggest that NS has distinct anti-ischemic effects through calcium antagonism.

Survey and mechanism of skin depigmenting and lightening agents.

The type and amount of melanin synthesized by the melanocyte, and its distribution pattern in the surrounding keratinocytes, determines the actual color of the skin. Melanin forms through a series of oxidative reactions involving the amino acid tyrosine in the presence of the enzyme tyrosinase. Tyrosinase catalyses three different reactions in the biosynthetic pathway of melanin in melanocytes: the hydroxylation of tyrosine to l-DOPA and the oxidation of l-DOPA to dopaquinone; furthermore, in humans, dopaquinone is converted by a series of complex reactions to melanin. Among the skin-lightening and depigmenting agents, magnesium-l-ascorbyl-2-phosphate (MAP), hydroxyanisole, N-acetyl-4-S-cysteaminylphenol, arbutin (hydroquinone-beta-d-glucopyranoside) and hydroquinone (HQ) are the most widely prescribed worldwide. However, with reports of potential mutagenicity and epidemics of ochronosis, there has been an increasing impetus to find alternative herbal and pharmaceutical depigmenting agents. A review of the literature reveals that numerous other depigmenting or skin-lightening agents are either in use or in investigational stages. Some of these, such as kojic, glycolic and azelaic acids, are well known to most dermatologists. Others have been discovered and reported in the literature more recently. Several depigmentation and lightening agents are discussed, including their historical background, biochemical characteristics, type of inhibition and activators from various sources. In addition, the clinical importance of mushroom tyrosinase as a recent prospect is discussed in this paper.