On the paper by E. R. Muslikhov, I. F. Sukhanova, and P. V. Avdonin entitled “arachidonic acid activates release of calcium ions from reticulum via ryanodine receptor channels in C2C12 skeletal myotubes” published in Biochemistry (Moscow), Vol. 79, No. 5, pp. 435-439 (2014).

A recent study published by Muslikhov et al. (Biochemistry (Moscow), 79, 435439 (2014)) showed that arachi donic acid increases cytosolic Ca2+ concentrations in C2C12 skeletal myotubes mainly via activation of the ryanodine (RY) receptor 1. These results are consistent with the data from another study demonstrating that arachidonic acid targets RY receptor 2 in clonal and primary pancreatic βcells (Woolcott et al.

Bicyclic tetrapeptide histone deacetylase inhibitors with methoxymethyl ketone and boronic acid zinc-binding groups.

Histone deacetylase (HDAC) inhibitors are a class of potential therapeutics for the treatment of cancer. Bicyclic tetrapeptides equipped with methoxymethyl ketone and boronic acid as zinc-binding group were designed and synthesized. The inhibitory activities of these compounds were evaluated against HDAC enzymes.

Electrospun novel super-absorbent based on polysaccharide-polyvinyl alcohol-montmorillonite clay nanocomposites.

A novel super-absorbent material was fabricated by electrospinning the natural polysaccharide pullulan (PULL) with polyvinyl alcohol (PVA) and montmorillonite (MMT) clay to form nonwoven webs, which were then heat treated. Transmission electron microscopy (TEM) micrographs, X-ray diffraction (XRD) patterns, and Fourier transform infrared (FTIR) analysis of the novel super-absorbent nanofibers suggest the coexistence of PULL, PVA, and MMT through the exfoliation of MMT layers in the super-absorbent nanofiber composite. The heat-treated PULL/PVA/MMT webs loaded with 5 wt% MMT electrospun nanofibers exhibited a water absorbency of 143.

Structure and antioxidant activity of phenolic compounds isolated from the edible fruits and stem bark of Harpephyllum caffrum.

Antioxidant activity in edible fruits is an important characteristic in the choice of fruits for human consumption, and has profound influence on nutrition and health. Two pharmacologically active triterpenoids, β-sitosterol and lupeol, and the powerful flavan-3-ol antioxidant, (+)-catechin, were isolated from the edible fruits of Harpephyllum caffrum while a mixture of cardanols, an alkyl p-coumaric acid ester, and (+)-catechin were isolated from the stem bark. This is the first report of these compounds being isolated from this plant.

Antioxidative activity and inhibition of key enzymes linked to type-2 diabetes (α-glucosidase and α-amylase) by Khaya senegalensis.

This study evaluated the in vitro antioxidative activity of Khaya senegalensis extracts and inhibitory effects of some solvent fractions on α-glucosidase and α-amylase activities. The stem bark, root and leaf samples of the plant were sequentially extracted with ethyl acetate, ethanol and water and then tested for antioxidative activity. Our findings revealed that the ethanolic extract of the root had the highest antioxidative activity.

Design and synthesis of mono and bicyclic tetrapeptides thioester as potent inhibitor of histone deacetylases.

Inhibitors of histone deacetylases (HDACs) are a promising class of anticancer agents that have an effect on gene regulation. The naturally occurring cyclic depsipeptide FK228 containing disulfide and Largazole possessing thioester functionalities act as pro-drugs and share the same HDAC inhibition mechanism in cell. Inspired from these facts, we have reported bicyclic tetrapeptide disulfide HDAC inhibitors resembling FK228 with potent activity and enhanced selectivity.

Bicyclic tetrapeptides as potent HDAC inhibitors: effect of aliphatic loop position and hydrophobicity on inhibitory activity.

Several histone deacetylase (HDAC) inhibiting bicyclic tetrapeptides have been designed and synthesized through intramolecular ring-closing metathesis (RCM) reaction and peptide cyclization. We designed bicyclic tetrapeptides based on CHAP31, trapoxin B and HC-toxin I. The HDAC inhibitory and p21 promoter assay results showed that the aliphatic loop position as well as the hydrophobicity plays an important role toward the activity of the bicyclic tetrapeptide HDAC inhibitors.

Design and synthesis of CHAP31, trapoxin B and HC-toxin based bicyclic tetrapeptides disulfide as potent histone deacetylase inhibitors.

The naturally occurring cyclic depsipeptide, FK228 inhibits histone deacetylase (HDAC) enzymes after reductive cleavage of intra-molecular disulfide bond. One of the sulfhydryl groups produced in the reduction interacts with zinc atom that involved in the catalytic mechanism of type 1 and 2 HDACs such as HDAC1, HDAC4, and HDAC6. In the present study, we describe the development of CHAP31, trapoxin B and HC-toxin based cyclic tetrapeptides with intra-molecular disulfide bond as HDAC inhibitors.

Development of an alternative non-obese non-genetic rat model of type 2 diabetes using caffeine and streptozotocin.

Background: The aim of the present study was to develop an alternative non-obese non-genetic rat model of type 2 diabetes (T2D).

Methods: Six-week-old male SD rats were randomly divided into six groups, namely: Normal Control (NC), Diabetic Control (DBC), Caffeine 5mg/kg BW+STZ (CAF5), Caffeine 10mg/kg BW+STZ (CAF10), Caffeine 20mg/kg BW+STZ (CAF20) and Caffeine 40mg/kg BW+STZ (CAF40) and were fed a normal rat pellet diet and drinking water ad libitum throughout the experimental period. After a one week acclimatization period, diabetes was induced in the animals in DBC and all CAF groups with an injection (i.

Butanol fraction of Khaya senegalensis root modulates β-cell function and ameliorates diabetes-related biochemical parameters in a type 2 diabetes rat model.

Ethnopharmacological Relevance: Khaya senegalensis A. Juss (Meliaceae) is commonly exploited for the traditional treatment of diabetes mellitus in Nigeria and Togo. The present study was conducted to examine the anti-diabetic activity of Khaya senegalensis butanol fraction (KSBF) of root ethanolic extract in a type 2 diabetes (T2D) model of rats.

Role of transient receptor potential melastatin-like subtype 5 channel in insulin secretion from rat β-cells.

Objective: Several studies have reported that the transient receptor potential melastatin-like subtype 5 (TRPM5) channel, a Ca(2+)-activated monovalent cation channel, is involved in the stimulus-secretion coupling in the mouse pancreatic β-cells. We have studied the role of the TRPM5 channel in regulating insulin secretion and cytoplasmic free Ca(2+) concentration ([Ca(2+)](i)) in the rat β-cells by using triphenylphosphine oxide, a selective inhibitor of the channel.

Methods: Insulin secretion from islets from Sprague-Dawley rats was measured in batch incubations.

Physico-chemical characteristics of gamma-irradiated gelatin.

This article reports the effects of gamma irradiation (dose ranges 0.1-10 kGy from Co source) on the characteristics of solid gelatin and the physico-mechanical, microstructural and bioactive properties of the scaffold prepared from irradiated gelatin solution. FTIR, intrinsic viscosity, bloom strength, thermal properties, SEM, tensile properties, water uptake ability and antimicrobial activities of non-irradiated and irradiated solid gelatin and its scaffolds were investigated.

A convenient preparation of N (ε)-methyl-L-lysine derivatives and its application to the synthesis of histone tail peptides.

A convenient route is established for the preparation of N (α)-Fmoc-N (ε)-(Boc, methyl)-L-lysine and N (α)-Fmoc-N (ε)-dimethyl-L-lysine as building blocks to be used for the synthesis of methylated peptides. This methodology is based on the use of malonate derivatives and dibromobutane to produce key intermediates, L-2-amino-6-bromohexanoic acid derivatives, which could be modified to the required group at the ε-position. Fmoc-protection is accessible, so these compounds can be used in solution as well as in solid-phase peptide synthesis.

African medicinal plants with antidiabetic potentials: a review.

Diabetes mellitus is one of the major health problems in Africa. The conventional oral synthetic antidiabetic drugs available to manage the disease are costly and not readily affordable to the majority of the affected population. Interestingly, the continent is endowed with a tremendous number of medicinal plants that have been explored for their folkloric treatment of diabetes mellitus.

Microarray analysis of the Ler regulon in enteropathogenic and enterohaemorrhagic Escherichia coli strains.

The type III protein secretion system is an important pathogenicity factor of enteropathogenic and enterohaemorrhagic Escherichia coli pathotypes. The genes encoding this apparatus are located on a pathogenicity island (the locus of enterocyte effacement) and are transcriptionally activated by the master regulator Ler. In each pathotype Ler is also known to regulate genes located elsewhere on the chromosome, but the full extent of the Ler regulon is unclear, especially for enteropathogenic E.

[6]-shogaol induces Ca²⁺ signals by activating the TRPV1 channels in the rat insulinoma INS-1E cells.

Context: [6]-shogaol is a vanilloid compound present in steamed ginger (Zingiber officinale), a commonly used spice. Pancreatic beta-cells respond to nutrients like glucose, amino acids and fatty acids, by an increase in the cytoplasmic free Ca²⁺ concentration ([Ca²⁺](i)), which mediates diverse cellular processes in these cells. Some vanilloid compounds activate the transient receptor potential vanilloid receptor type 1 (TRPV1) channel.

In vitro antioxidant activities of leaf and root extracts of Albizia antunesiana harms.

The antioxidative activities of the ethanol and aqueous extracts of the leaf and root samples of Albizia antunesiana were determined across a series of four in vitro models. The results showed that all the extracts had reducing power (Fe(3+)- Fe2+), DPPH, hydroxyl and nitric oxide radical scavenging abilities. The ethanol root extract had more potent antioxidant power in all the experimental models and possesses a higher total phenol content of 216.

Animal models of diabetic neuropathy: progress since 1960s.

Diabetic or peripheral diabetic neuropathy (PDN) is one of the major complications among some other diabetic complications such as diabetic nephropathy, diabetic retinopathy, and diabetic cardiomyopathy. The use of animal models in the research of diabetes and diabetic complications is very common when rats and mice are most commonly used for many reasons. A numbers of animal models of diabetic and PDN have been developed in the last several decades such as streptozotocin-induced diabetic rat models, conventional or genetically modified or high-fat diet-fed C57BL/Ks (db/db) mice models, streptozotocin-induced C57BL6/J and ddY mice models, Chinese hamster neuropathic model, rhesus monkey PDN model, spontaneously diabetic WBN/Kob rat model, L-fucose-induced neropathic rat model, partial sciatic nerve ligated rat model, nonobese diabetic (NOD) mice model, spontaneously induced Ins2 Akita mice model, leptin-deficient (ob/ob) mice model, Otsuka Long-Evans Tokushima Fatty (OLETF) rat model, surgically-induced neuropathic model, and genetically modified Spontaneously Diabetic Torii (SDT) rat model, none of which are without limitations.

In vitro anti-oxidative activities and GC-MS analysis of various solvent extracts of Cassia singueana parts.

The present study was conducted to investigate the anti-oxidative activities of different solvent extracts of Cassia singueana parts. Our results indicate that all the extracts have reducing power (Fe3+ --> Fe2+) and DPPH radical scavenging abilities. However, the ethyl acetate extract of the stem bark has the highest total reducing power whilst the ethanol extract of the stem bark has more potent free radical scavenging activity than all the other extracts.

Optimization of Multiple Pathogen Detection Using the TaqMan Array Card: Application for a Population-Based Study of Neonatal Infection.

Identification of etiology remains a significant challenge in the diagnosis of infectious diseases, particularly in resource-poor settings. Viral, bacterial, and fungal pathogens, as well as parasites, play a role for many syndromes, and optimizing a single diagnostic system to detect a range of pathogens is challenging. The TaqMan Array Card (TAC) is a multiple-pathogen detection method that has previously been identified as a valuable technique for determining etiology of infections and holds promise for expanded use in clinical microbiology laboratories and surveillance studies.

Phenolics-rich fraction of Khaya senegalensis stem bark: antitrypanosomal activity and amelioration of some parasite-induced pathological changes.

Context: The stem bark of Khaya senegalensis A. Juss (Meliaceae) is currently used for the treatment of trypanosomiasis by traditional practitioners in Nigeria.

Objectives: The present study investigated the anti-Trypanosoma brucei brucei activity of phenolics-rich fraction of K.

Expression of the coiled coil domain containing protein 116 in the pancreatic islets and endocrine pancreatic tumors.

Aims: Coiled coil domain containing protein 116 (CCDC116) is a product of the gene coiled coil domain containing 116 located on human chromosome 22. Its function has not yet been established. The present study focuses on the expression of this protein in human pancreatic islets and in the endocrine pancreatic tumors (EPTs).