A review of characterization of tocotrienols from plant oils and foods

Tocotrienols, members of the vitamin E family, are natural compounds found in a number of vegetable oils, wheat germ, barley and certain types of nuts and grains. Vegetable oils provide the best sources of these vitamin E forms, particularly palm oil and rice bran oil contain higher amounts of tocotrienols. Other sources of tocotrienols include grape fruit seed oil, oats, hazelnuts, maize, olive oil, buckthorn berry, rye, flax seed oil, poppy seed oil and sunflower oil. Tocotrienols are of four types, viz. alpha (α), beta (β), gamma (γ) and delta (δ). Unlike tocopherols, tocotrienols are unsaturated and possess an isoprenoid side chain. A number of researchers have developed methods for the extraction, analysis, identification and quantification of different types of vitamin E compounds. This article constitutes an in-depth review of the chemistry and extraction of the unsaturated vitamin E derivatives, tocotrienols, from various sources using different methods. This review article lists the different techniques that are used in the characterization and purification of tocotrienols such as soxhlet and solid–liquid extractions, saponification method, chromatography (thin layer, column chromatography, gas chromatography, supercritical fluid, high performance), capillary electrochromatography and mass spectrometry. Some of the methods described were able to identify one form or type while others could analyse all the analogues of tocotrienol molecules. Hence, this article will be helpful in understanding the various methods used in the characterization of this lesser known vitamin E variant.     

Whole-genome sequencing as a first-tier diagnostic framework for rare genetic diseases

Rare diseases affect nearly 300 million people globally with most patients aged five or less. Traditional diagnostic approaches have provided much of the diagnosis; however, there are limitations. For instance, simply inadequate and untimely diagnosis adversely affects both the patient and their families. This review advocates the use of whole genome sequencing in clinical settings for diagnosis of rare genetic diseases by showcasing five case studies. These examples specifically describe the utilization of whole genome sequencing, which helped in providing relief to patients via correct diagnosis followed by use of precision medicine.     

Determinants of host specificity and comments on attachment site specificity of tetraphyllidean cestodes infecting rajid skates from the northwest Atlantic

The objectives of this study were to (1) describe the host range for 6 tetraphyllidean species and quantify their host specificity using 5 specificity indices; (2) determine the role of morphological determinants in the host specificity of tetraphyllideans by comparing villar and bothridial measurements of species examined herein; and (3) determine the role of a physiological component in the host specificity of tetraphyllideans by exposing tetraphyllideans to blood sera from different fish species and other solutions. Our results indicate that Echeneibothrium dubium abyssorum (ex Amblyraja radiata), Echeneibothrium canadensis (ex A. radiata), and Zyxibothrium kamienae (ex Malacoraja senta) exhibit the highest degree of specificity, followed by Echeneibothrium vernetae (ex Leucoraja erinacea and Leucoraja ocellata), Pseudanthobothrium hanseni (ex A. radiata and M. senta), and Pseudanthobothrium purtoni (ex Leucoraja erinacea and L. ocellata). However, these results vary based on the specificity index used. Compatible bothridial and villar measurements indicate that there is no morphological determinant of host specificity but that there is a morphological determinant to attachment site specificity. Our data indicate that attachment site specificity may also be phylogenetically determined. Additionally, the exposure of parasites to blood sera from various hosts confirms that host specificity in this system has a physiological determinant. Therefore, host specificity in this system is determined, at least in part, by physiological factors, whereas attachment site specificity is an extension of host specificity and is phylogenetically determined.     

Elevated serum levels of TNF-alpha, sTNF-RI and sTNF-RII in murine schistosomiasis correlate with schistosome oviposition and circumoval granuloma formation

Levels of circulating tumour necrosis factor (TNF-alpha) and its soluble receptors are elevated in chronic human schistosomiasis. However, the kinetics of TNF-alpha production and release of its soluble receptors have not been studied in humans or animals. Here we report on increased levels of TNF-alpha and its soluble receptors in murine schistosomiasis, beginning with schistosome oviposition and circumoval granuloma formation. TNF-alpha, sTNF-RI and sTNF-RII were measured in sera of mice infected with Schistosoma mansoni each week for 10 weeks postinfection. TNF-alpha levels increased gradually in all mice during the first 3 weeks. From 6th week postinfection, TNF-alpha levels in infected mice increased steadily, whereas those of uninfected mice remained essentially unchanged. sTNF-RI levels fluctuated in all mice during the first 3 weeks, and increased in infected mice during the following 5 weeks. sTNF-RII levels were similar in all mice for the first 4 weeks but increased in infected mice throughout the remainder of the experimental period. These data may be helpful in understanding pathogenesis in schistosomiasis as TNF-alpha plays a crucial role in circumoval granuloma formation and adversely affects schistosome fecundity.     

Computational design, construction, and characterization of a set of specificity determining residues in protein-protein interactions

Proteins interact with different partners to perform different functions and it is important to elucidate the determinants of partner specificity in protein complex formation. Although methods for detecting specificity determining positions have been developed previously, direct experimental evidence for these amino acid residues is scarce, and the lack of information has prevented further computational studies. In this article, we constructed a dataset that is likely to exhibit specificity in protein complex formation, based on available crystal structures and several intuitive ideas about interaction profiles and functional subclasses. We then defined a “structure‐based specificity determining position (sbSDP)” as a set of equivalent residues in a protein family showing a large variation in their interaction energy with different partners. We investigated sequence and structural features of sbSDPs and demonstrated that their amino acid propensities significantly differed from those of other interacting residues and that the importance of many of these residues for determining specificity had been verified experimentally. Proteins 2012;. © 2012 Wiley Periodicals, Inc.     

Effect of thiamazole on kainic acid-induced seizures in mice

Kainic acid (KA) induced epileptic seizures in mice is a commonly used experimental model of epilepsy. Previous studies have suggested the roles of various neurotransmitters and oxidative stress in KA-induced seizures. An important role of hypothyroidism has also been suggested in epilepsy. Thiamazole (TZ) is an anti-hyperthyroid drug with antioxidant property. This study reports the effect of TZ on KA-induced epileptic seizures in mice, produced by intraperitoneal (IP) injection of KA (18 mg/kg). Prior to KA injection, the animals were treated with TZ (12.5, 25 and 50 mg/kg IP). Our results showed that in KA alone group, about half of the animals developed seizures. Pre-treatment of mice with TZ significantly increased the frequency of seizures in dose-dependent manner. Administration of TZ significantly reduced the latency time and aggravated the severity of seizures. TZ also increased the mortality in KA-treated mice. Striatal dopamine and serotonin levels were markedly increased in KA alone treated mice, which were not significantly affected by TZ treatment. Among the indices of oxidative stress, we observed a significant reduction in cerebral vitamin E whereas the levels of cerebral malondialdehyde and conjugated dienes were significantly increased in animals with high severity of seizures. In conclusion, TZ potentiated the frequency and severity of experimental seizure in mice. There is a possibility of altered metabolism of KA in presence of TZ that might have potentiated the toxicity of KA. These findings suggest a caution while administering anti-hyperthyroid drugs in epileptic seizures.     

Effects of Echis pyramidum Snake Venom on Hepatic and Renal Antioxidant Enzymes and Lipid Peroxidation in Rats

The effects of Echis pyramidum venom (EPV) (0.25, 0.50, and 1.00 mg/kg) on activities of superoxide dismutase (SOD) and catalase (CAT) and levels of thiobarbituric acid reactive substances (TBARS) and total thiols (T‐SH) in liver and kidneys of rats were investigated. EPV significantly and dose dependently decreased the activities of SOD and CAT in livers. Although the kidney SOD and CAT activities were not affected by low and medium doses of EPV, the high dose significantly reduced the activities of these enzymes. Liver and kidney TBARS levels were not affected by the low and medium doses of EPV, whereas the high dose significantly increased the TBARS after 6 h postdosing. There was a significant depletion of T‐SH in liver and kidneys of rats exposed to a high dose of EPV. The acute phase oxidative stress due to an EPV injection points toward the importance of an early antioxidant therapy for the management of snake bites.     

Single-nucleotide polymorphisms in peroxisome proliferator-activated receptor <Emphasis Type="Italic">γ</Emphasis> and their association with plasma levels of resistin and the metabolic syndrome in a South Indian population

Studies on the association of the Pro12Ala and C1431T polymorphisms of PPARγ with diabetes and obesity have revealed extensive population-dependent variations. However, association of these polymorphisms with the metabolic syndrome and its individual components has not been well investigated in the Indian population. The Indian population harbours the maximum number of diabetics in the world who are thus more susceptible to metabolic disorders. We screened a South Indian population (N = 699) for a possible association of these polymorphisms with the metabolic syndrome (MS) and type 2 diabetes. We also investigated the correlation of these two single-nucleotide polymorphisms (SNPs) with plasma resistin levels. The C1431T SNP was associated with higher levels of plasma resistin (P = 0.017). Furthermore, C1431T was associated with resistin in different tertiles. Prevalence of the ‘Pro-C’ haplotype decreased with increasing tertiles of resistin (84.1% to 75.4%, P = 0.037). Plasma resistin levels were not found to be associated with MS and type 2 diabetes. These results point to a likely association of plasma resistin levels with PPARγ polymorphisms in the Indian population.