Pyrethroid insecticides susceptibility of Stomoxys calcitrans (Linnaeus) and Stomoxys indicus Picard (Diptera: Muscidae) from cattle farms in southern Thailand

The susceptibility to six pyrethroid insecticides (permethrin, deltamethrin, alpha-cypermethrin, cypermethrin, lambda-cyhalothrin and bifenthrin), each at the recommended concentration, was evaluated for the two stable fly species Stomoxys calcitrans (Linnaeus) and Stomoxys indicus Picard, through tarsal contact using a World Health Organization (WHO) cone bioassay procedure. The field populations of stable flies were collected from three study sites (Songkhla, Phattalung and Satun provinces) in Thailand. The stable flies were exposed to insecticide-treated filter paper for 30 min and their knockdown counts at 30 min and 60 min and mortality counts at 12 hr and 24 hr were recorded. The S. calcitrans and S. indicus in Songkhla and Phattalung populations were moderately susceptible to pyrethroids for 24-hr mortality. Nonetheless, the Satun population of S. indicus was completely susceptible to permethrin with 100% mortality and the lowest susceptible to deltamethrin and bifenthrin. The results indicate a generally low susceptibility of stable flies to pyrethroids in the southern provinces of Thailand.

Assessment of genotoxic and mutagenic effects of food products by bioassay methods

The current state of studies on application and safety of food additives in various technologies for food production is examined. Considerable attention should be given to studies dedicated to analysis of food safety criteria due to a possibility of appearance of adverse consequences for human health and the trend towards increasing life quality. Special emphasis is placed on such parameters as genotoxicity and mutagenicity. It is shown that the most rapid and convenient tool for complex monitoring of product toxicity can be the bioassay procedure. Based on the review of the literature on bioassays for edible meat and meat products, canned foods, carbonated soft drinks, beer, milk and milk containing products as well as seasonings, the authors show that above mentioned products had the cyto- and genotoxic potential when tested on animal and human cell cultures, microorganisms and plants. With that, it was found that a list of relevant publications is quite small despite a significant growth in scientific research dedicated to food toxicity assessment using bioassays. A review on the conducted research on assessment of genotoxic and mutagenic effects of foods by bioassay methods will make it possible to extend the understanding of the processes and mechanisms of this toxicity and form more rational concept of consumption.

Toxicity of Tobacco (Nicotiana tobaccum) Leaf Dust on Enzymatic and Protein Synthesis Activities of African Mud Catfish (Clarias gariepinus)

The toxicity of tobacco (Nicotiana tobaccum) leaf dust with piscicidal and pesticidal properties was investigated on some enzymatic and protein synthesis activities of juvenile African mud catfish (Clarias gariepinus). Fish were exposed to both lethal and sub-lethal concentrations of tobacco leaf dust for 21 days in a renewal bioassay procedure. The median lethal concentrations (LC50) were derived using Finney probit method while protein and enzymatic activities were determined using Biuret and Randox methods respectively. The LC50 values for 48 hours acute bioassay test was 2.11g/l for tobacco leaf dust. Tobacco exposed fish showed significant increase (P≤0.05) in serum AST, ALT and ALP levels. Significant decrease (p≤0.05) were observed for liver AST (141.00 ± 2.52 to 154.67 ± 0.67), serum and liver total protein (6.47 ± 0.03 to 7.80 ± 0.40 and 3.30 ± 0.00 to 3.57 ±0.12) and serum albumin (4.23 ± 0.09 to 4.83 ±0.20) across all concentrations. The study showed that exposure of C. gariepinus juvenile to sub-lethal concentrations of tobacco (Nicotiana tobaccum) leaf dust can induce various toxicological effects in the form of enzymatic alteration. Therefore, the longer exposure of tobacco leaf dust in aquatic ecosystem is dangerous to fish and subsequently human health.

A Bradford multiplexing method for protein estimation in fermented foods: Soy sauces

<p>Proteins for foods, in addition to providing nutrition, should also possess specific functional properties that facilitate processing and serve as the basis of product performance. Soy protein is a major component of the diet of food and is increasingly important in the human diet. Hence, here in the present article, we are focusing a rapid and easy method for quantitative determination of total protein content with multiplex samples in any food products such as soy sauce or other traditional fermented foods. We described a bioassay procedure (Bradford method) for the evaluation of total protein content in foods. This method involves measurement of the protein efficiency ratio under standardized conditions. The experiment will provide researchers a scientific way to determine pretentious quality of variety of foods and/or health supplements.</p><p> </p><p><strong>VIDEO CLIPS</strong></p><p><a href="https://www.youtube.com/v/xVzg0rq4VxE">Requirement and sample preparation method:</a> 3 min 26 sec</p><p><a href="https://www.youtube.com/v/6plwYgGGFuE">Assay procedure:</a> 6 min 4 sec</p><p><a href="https://www.youtube.com/v/bV2tGWLh4ug">Measurement of absorbance using an ELISA microtiter plate reader:</a>5 min 1 sec</p>

Animal-Free Paralytic Shellfish Toxin Testing—The Canadian Perspective to Improved Health Protection

The performance characteristics of AOAC Official Method 2011.02 (the PCOX method) asa replacement for the AOAC mouse bioassay procedure have been well defined by validation studies, but these data do not communicate the complete story. Thecontext provided by analyzing 9000 regulatory monitoring samples over 3 years demonstrates not only the reduction in animal use but also the increase in foodsafety that has been realized using a chemistry-based method. Detection of lower toxin levels provided early warning to enable directed sampling as toxin levels increased. The toxin profile information generated by a chemistry-based method was used to detect potential interferences qualitatively and can be usedto assess the impact of changes recommended to monitoring programs. Such changes might include which toxins should be included in an action limit or the toxic equivalence factors used for these toxins.