Geoffrey P. Webb

Estimation of body fat in normal and obese mice

1. Lee Index (weight (g0.33) divided by nasoanal length (mm)), density, body water and proportional weight of the gonadal fat pad were tested as estimates of body fat in a normal population of mice and a population which included obese mice. 2. In a normal population only body water and fat-pad weight correlated significantly with body fat. 3. In a population of normal and obese mice all four indices correlated significantly with body fat. 4. Lee Index had little advantage over weight:length as an estimate of body fat, and density did not correlate well enough to be used as a method of estimation. 5. Proportional weight of the gonadal fat pad is recommended as a simple reliable estimate of body fat in normal or obese mice.

Fasting-induced torpor in Mus musculus and its implications in the use of murine models for human obesity studies

1. Fasting at room temperature for 24-48 hr can induce shallow daily torpor in mice of several strains. 2. Genetically-obese (ob/ob) C57B1/6 mice show torpor even in the presence of food. 3. Chemically-obese (gold-thioglucose or bipiperidyl mustard) mice of C57B1/6 and T/O strains appear resistant to torpor. 4. During cold acclimation (3-5 degree) fasting also induces torpor in lean mice, with gradually improving rates of arousal. 5. In acute cold shock (3-5 degree), previously weight-reduced ob/ob mice show resistance to change in body temperature, while control ob/ob mice drift immediately towards hypothermia.

Validation of a HPLC method for flavonoid biomarkers in skullcap (Scutellaria) and its use to illustrate wide variability in the quality of commercial tinctures.

PURPOSE To compare the flavonoid biomarker content (baicalin, baicalein and wogonin) of eleven commercial tinctures derived from Scutellaria lateriflora aerial parts (n=7) and Scutellaria baicalensis root (n=4). S. lateriflora tinctures are used in by western herbal practitioners to treat anxiety whereas S. baicalensis tinctures are used to treat inflammatory disease. METHODS Baicalin and baicalein were purchased from Aldrich Chemical Co. and Wogonin was purchased from ChromaDex. The internal standard (4-hydroxybenzoic acid) was obtained from Acros Organics. The column used was a Luna C18, 5 m (150 x 4.6 mm, Phenomenex) maintained at ambient room temperature. A HP1050 HPLC system was used, comprising a gradient pump with degasser, a variable wavelength UV detector set to 270 nm, and an autosampler. Gradient elution was performed using 0.1% formic acid (eluent A) and methanol (eluent B). The gradient elution initial conditions were 45% B with linear gradient to 60% from 2 to 10 min, followed by linear gradient to 70% B at 30 min, and then linear gradient to 99% B at 31 min, this proportion being maintained for 1 min. The mobile phase was then returned to initial conditions at 33 min and maintained until the end of the run at 35 min. The flow rate was 1 mL/min. The assay was validated for sensitivity, accuracy and reproducibility. RESULTS The concentration range of biomarkers (baicalin, baicalein and wogonin) in commercial tinctures is reported for S. lateriflora (baicalin: 0-12.66 mg/mL; baicalein: 0-0.63 mg/mL; wogonin: 0-0.16 mg/mL) and for S. baicalensis (baicalin: 0.12-10.61 mg/mL; baicalein: 0.52-5.88 mg/mL; wogonin: 0.08-1.61 mg/mL). CONCLUSION The wide variability in biomarker concentrations between commercial tinctures has important implications for the manufacturers of commercial tinctures, for herbal practitioners in the choice of tinctures and not least for pharmacology and clinical researchers.

Nutritional supplements and conventional medicine; what should the physician know?

Almost anything that is swallowed in pill or potion form that is not a licensed medicine is, by default, legally classified as a dietary supplement. The present paper is an overview of supplement use and is intended to provide a logical framework for their discussion. Five major supplement categories are identified: essential micronutrients; other metabolites that have vitamin-like roles; natural oils; natural plant or animal extracts; antioxidants, which span the other categories. Supplement usage is also classified into broad categories. Examples of each supplement category and usage are briefly discussed. Some potential hazards of supplement use are also outlined; many substances in supplements are either not found in normal UK diets or consumed in much greater amounts than would be found in food. Many supplements are used for pharmaceutical purposes and sold as supplements to avoid the expense of acquiring a medicinal licence and to avoid the stricter quality-control regulations that apply to medicines. The use of supplements to ensure nutritional adequacy and as possible conditionally-essential nutrients is briefly discussed, as is their essentially pharmaceutical use for the prevention and alleviation of disease. There is critical discussion of whether the use of antioxidant supplements is justified or even if it is reasonable to promote a particular food on the basis of antioxidant content alone. Much of the research on supplements is reductionist, commercially sponsored or has other weaknesses; so, despite decades of use and research there is still uncertainty about their efficacy in many cases.

Diet can influence the ability of nicotinamide to prevent diabetes in the non-obese diabetic mouse : a preliminary study

The non‐obese diabetic (NOD) mouse is a widely used model of Type 1 diabetes mellitus (Type 1 DM), which displays many of the characteristics of the disease found in humans. Nicotinamide (NA) is currently being tested in large‐scale, multi‐centre human trials for the prevention of Type 1 DM in subjects considered ‘at risk’ of developing the disease. Human trial populations will certainly differ in their dietary patterns and alterations were made to the diet given to NOD mice to determine if this could alter the effect of NA administration on Type 1 DM incidence.

The significance of protein in human nutrition

A brief historical review charting the rise and fall of protein deficiency as a suspected major factor in human malnutrition over the last fifty years is presented. In the 1960s and early 1970s primary protein deficiency was regarded as a vast problem and yet is now regarded as relatively uncommon. This diminution in the importance attached to protein in human nutrition has been relatively slow to permeate beyond the ranks of specialist nutritionists and this paper aims to increase awareness of this decline amongst those teaching in biological subjects. The reasons for the previously exaggerated importance attached to protein in human malnutrition are discussed in relation to the potential pitfalls of biomedical research in general. The wider consequences of this overemphasis on protein are considered and the implications for nutrition education and health education in general discussed.

A selective critique of animal experiments in human-orientated biological research

The advantages and justifications for using small animals in human-orientated research are briefly over-viewed. Some of the potential pitfalls of extrapolating animal-derived data to humans are then discussed more fully, using examples biased towards nutrition. A number of particular problems of animal experimentation are highlighted: the applicability of the results of controlled, deliberately reductionist, laboratory experiments to arguments about free-living animals and humans; species differences in nutrient requirements; differences in pattern of feeding and type of diet of mammalian species; and various facets of the problem of scaling from small to large species. The enormous contribution of animal experimentation to the advancement of human biological understanding is accepted, but by focusing attention of biological educators on examples, perceived by the author to have involved inappropriate cross-species extrapolation, it is hoped that this paper may help to increase the future effectiveness an...

The induction of obesity in the rat with bipiperidyl mustard

1. Bipiperidyl mustard produced increased adiposity in the rat without excessive weight gain or hyperphagia. 2. The results suggest a metabolic aetiology for the obesity as opposed to a disorder of food intake regulation.

Vitamins/minerals as dietary supplements: a review of clinical studies

The efficacy of micronutrient supplements in preventing deficiency diseases, ensuring adequate vitamin/mineral status and in preventing some non-deficiency diseases is critically reviewed. The roles of folic acid supplements in preventing neural tube defects, and vitamin D supplements in preventing osteoporosis, are discussed in depth. Alternative strategies for increasing micronutrient intakes, especially food fortification, are evaluated. In theory, micronutrient supplements might be expected to improve immune function, especially in the elderly, but there is no substantial or reliable evidence to support this. Micronutrient supplements are usually only beneficial if intake from food is inadequate and even then supplements are rarely taken by those who need them.

A critical survey of methods used to investigate links between diet and disease

The various methods used to investigate possible causative links between diet (or other environmental variables) and disease are summarized and discussed. Nutritional examples are selected to illustrate the various methods that are available. The problem of assessing when the results of such studies merit health education intervention is considered, together with the difficulties encountered in trying to convert any hypothesis about dietary causation of disease into guidelines for nutrition education, and into practical advice about changes in the selection of food. A general appreciation of the methods used, their strengths and their limitations, should help biological educators in the evaluation of the numerous reports of association between environmental factors and disease that appear in the media.