HYPOCHOLESTEROLEMIC EFFECTS OF FISH AND VEGETABLE OILS ON THE SERUM LIPID PROFILE OF EXPERIMENTALLY INDUCED HYPERCHOLESTEROLEMIC RATS

Aims: This study was conducted to find out the effect of fish and vegetable oils on the serum lipid profile of experimentally induced hypercholesterolemic rats. Methods: Long Evan rats were fed with cholic acid and cholesterol for 14 days to make them hypercholesterolemic. The hypercholesterolemic rats were then supplemented with the oils of Pangsius pangasius fish, Soybean, Flaxseed, Sesame, Black seed and Mustard for 35 days. Serum lipid profile (total cholesterol-TC, low density lipoprotein-LDL, high density lipoprotein-HDL and triglyceride-TG) was determined with ELISA plate reader using commercial kits. Results: All of the oils tested were noted to reduce the serum TC, LDL and TG, but had increase the good cholesterol HDL level in the hypercholesterolemic rats. Among these oils, Pangsius pangasius fish oil showed the strongest anticholesterol property. In reduction of total cholesterol, after the Pangsius fish oil, the next prominent activity was given by black seed oil followed by flaxseed oil, sesame oil, mustard oil and soybean oil and in term of lowering of LDL level, the effect was in order of black seed, flaxseed, mustard, sesame and soybean oil. In giving the effect on good cholesterol HDL level, mustard oil showed the strongest increasing effect, which was followed by black seed oil, flaxseed oil, sesame oil, Pangsius oil and soybean oil. The drop of triglyceride level by the tested oils, it was in line of Pangsius oil, sesame oil, black seed oil, flaxseed oil, soybean oil and mustard oil. Conclusion: The present study showed that both the fish and vegetable oils have significant anticholesterol effects on hypercholesterolemic rats. However, compared to the vegetable oil, fish oil has stronger effect on the blood lipid profile. Regular dietary intake of fish and vegetable oils would reduce the risk of cardiovascular complication

Arsenic accumulation in rice (Oryza sativa L.): Human exposure through food chain

Although human exposure to arsenic is thought to be caused mainly through arsenic-contaminated underground drinking water, the use of this water for irrigation enhances the possibility of arsenic uptake into crop plants. Rice is the staple food grain in Bangladesh. Arsenic content in straw, grain and husk of rice is especially important since paddy fields are extensively irrigated with underground water having high level of arsenic concentration. However, straw and husk are widely used as cattle feed. Arsenic concentration in rice grain was 0.5±0.02 mg kg-1 with the highest concentrations being in grains grown on soil treated with 40 mg As kg-1 soil. With the average rice consumption between 400 and 650 g/day by typical adults in the arsenic-affected areas of Bangladesh, the intake of arsenic through rice stood at 0.20-0.35 mg/day. With a daily consumption of 4 L drinking water, arsenic intake through drinking water stands at 0.2 mg/day. Moreover, when the rice plant was grown in 60 mg of As kg-1 soil, arsenic concentrations in rice straw were 20.6±0.52 at panicle initiation stage and 23.7±0.44 at maturity stage, whereas it was 1.6±0.20 mg kg-1 in husk. Cattle drink a considerable amount of water. So alike human beings, arsenic gets deposited into cattle body through rice straw and husk as well as from drinking water which in turn finds a route into the human body. Arsenic intake in human body from rice and cattle could be potentially important and it exists in addition to that from drinking water. Therefore, a hypothesis has been put forward elucidating the possible food chain pathways through which arsenic may enter into human body. © 2007 Elsevier Inc. All rights reserved

Towards a target label-free suboptimum oligonucleotide displacement-based detection system

A novel method for the future development of label-free DNA sensors is proposed here. The approach is based on the displacement of a labelled suboptimum mutated oligonucleotide hybridised with the immobilised biotin-capture probe. The target fully complementary to the biotin-capture probe can displace the labelled oligonucleotide causing a subsequent decrease of the signal that verifies the presence of the target. The decrease of signal was demonstrated to be proportional to the target concentration. A study of the hybridisation of mutated and complementary labelled oligonucleotides with an immobilised biotin-capture probe was carried out. Different kinetic and thermodynamic behaviour was observed for heterogeneous hybridisation of biotin-capture probe with complementary or suboptimum oligonucleotides. The displacement method evaluated colourimetrically achieved the objective of decreasing the response time from 1 h for direct hybridisation of 19-mer oligonucleotides in the direct enzyme-linked oligonucleotide assay (ELONA) to 5 min in the case of displacement detection in the micromolar concentration range

The Aspartate-Semialdehyde Dehydrogenase of Edwardsiella ictaluri and Its Use as Balanced-Lethal System in Fish Vaccinology

asdA mutants of Gram-negative bacteria have an obligate requirement for diaminopimelic acid (DAP), which is an essential constituent of the peptidoglycan layer of the cell wall of these organisms. In environments deprived of DAP, i.e., animal tissues, they will undergo lysis. Deletion of the asdA gene has previously been exploited to develop antibiotic-sensitive strains of live attenuated recombinant bacterial vaccines. Introduction of an Asd+ plasmid into a ΔasdA mutant makes the bacterial strain plasmid-dependent. This dependence on the Asd+ plasmid vector creates a balanced-lethal complementation between the bacterial strain and the recombinant plasmid. E. ictaluri is an enteric Gram-negative fish pathogen that causes enteric septicemia in catfish. Because E. ictaluri is a nasal/oral invasive intracellular pathogen, this bacterium is a candidate to develop a bath/oral live recombinant attenuated Edwardsiella vaccine (RAEV) for the catfish aquaculture industry. As a first step to develop an antibiotic-sensitive RAEV strain, we characterized and deleted the E. ictaluri asdA gene. E. ictaluri ΔasdA01 mutants exhibit an absolute requirement for DAP to grow. The asdA gene of E. ictaluri was complemented by the asdA gene from Salmonella. Several Asd+ expression vectors with different origins of replication were transformed into E. ictaluri ΔasdA01. Asd+ vectors were compatible with the pEI1 and pEI2 E. ictaluri native plasmids. The balanced-lethal system was satisfactorily evaluated in vivo. Recombinant GFP, PspA, and LcrV proteins were synthesized by E. ictaluri ΔasdA01 harboring Asd+ plasmids. Here we constructed a balanced-lethal system, which is the first step to develop an antibiotic-sensitive RAEV for the aquaculture industry

Efficacy of Major Plant Extracts/Molecules on Field Insect Pests

Insect pests are considered the major hurdle in enhancing the production and productivity of any farming system. The use of conventional synthetic pesticides has led to the emergence of pesticide-resistant insects, environmental pollution, and negative effects on natural enemies, which have caused an ecological imbalance of the predator-prey ratio and human health hazards; therefore, eco-friendly alternative strategies are required. The plant kingdom, a rich repertoire of secondary metabolites, can be tapped as an alternative for insect pest management strategies. A number of plants have been documented to have insecticidal properties against various orders of insects in vitro by acting as antifeedants, repellents, sterilant and oviposition deterrents, etc. However, only a few plant compounds are applicable at the field level or presently commercialised. Here, we have provided an overview of the broad-spectrum insecticidal activity of plant compounds from neem, Annona, Pongamia, and Jatropha. Additionally, the impact of medicinal plants, herbs, spices, and essential oils has been reviewed briefl

Weed management implications of introducing dry-seeding of rice in the Barind Tract of Bangladesh

A single crop of transplanted rainfed rice each year provides a major component of livelihoods for farm families in the Barind Tract of Bangladesh. Variable rainfall, frequent drought during grain filling and limited irrigation constrain intensification of the cropping system in this region. Dry seeding allows earlier rice establishment, reduces the impact of late drought and allows timely planting of a subsequent chickpea crop to exploit residual soil moisture. Although the potential of this modified cropping system has been demonstrated in research trials, early season weed growth, which is suppressed by puddling and partially controlled by flooding in transplanted rice, remains a major constraint to farmer adoption. On-farm studies indicated that yield gap between production of transplanted rice under farmer management and the potential yield under weed free conditions in three villages in Rajshahi averaged from 0.29 to 0.47 t/ha, with 34% of farmers losing over 0.5 t/ha. Labour availability constrains timeliness of first weeding in this system. A range of weed management practices, including the integration of a pre-emergence herbicide with inter-row weeding with a hand-pushed weeder, resulted in similar yields of direct seeded rice to hand weeding. The use of these labour saving practices in relation to the potential adoption of dry seeding, maintaining rice yield and increasing the productivity of the cropping system is discussed