Ian Yip

Anti-hyperglycemic activity of zinc plus cyclo (his-pro) in genetically diabetic Goto-Kakizaki and aged rats

We previously reported that treatment of streptozotocin-Induced diabetic rats with zinc plus cyclo (his-pro) (CHP) decreased fed blood glucose levels and water intake. The present study was conducted to examine the dose-dependent, acute, and chronic treatment effects of CHP on oral glucose tolerance (OGT), fed blood glucose levels, water intake, and plasma Insulin levels in young and aged Sprague-Dawley (S-D) rats, nondiabetic Wistar rats, and genetically diabetic Goto-Kakizaki (G-K) rats. Acute gastric gavage of 10 mg zinc plus 1.0 mg CHP/kg body weight significantly improved OGT in 4- and 13-month-old nondiabetic S-D rats and in 2-month-old diabetic G-K rats. Young S-D and G-K rats returned to pretreatment OGT values 1 week after acute gavage of zinc plus CHP (ZC), but improved OGT values persisted for at least 1 week after gavage in aged S-D rats. OGT values and fed blood glucose decreased to the greatest extent among other treatments when G-K rats were given free access to drinking water containing 1.0 to 1.5 mg CHP/L plus 10 mg zinc/L for 2 weeks. Although food and water intake showed a tendency to decrease, no statistically significant differences were observed in young G-K rats. Plasma insulin levels and blood glucose levels in both normal and diabetic G-K rats decreased with 2-week treatment with ZC. To test the direct effects of ZC on muscle tissue, we observed the effect of various doses of ZC on normal and G-K rat muscle slices. The optimal level of CHP alone for maximal muscle glucose uptake in muscle slices from normal rats was 10 μg/mL and 5.0 μg/mL in G-K rats, and ZC stimulated glucose uptake. However, no statistically significant difference was demonstrated between normal and G-K rat tissues in this study. These results indicate that oral intake of an optimal dose of ZC stimulates blood glucose metabolism, probably by stimulating muscle glucose utilization.

NUTRITION AND PROSTATE CANCER

Scientific evidence suggests that differences in the diet may, in large part, account for the variability of prostate cancer rates around the world. Epidemiologic studies and animal experiments have yielded compelling results to warrant clinical intervention studies on nutrition from scientists who work on the prevention and treatment of prostate cancer. This article reviews the most recent evidence as to possible mechanisms of action of various dietary constituents, and explores evidence of various nutritional strategies for the prevention of prostate cancer progression.

Effects of cyclo (his–pro) plus zinc on glucose metabolism in genetically diabetic obese mice

Aims:  The specific objective of this study was to determine acute and long‐term effects of cyclo (his–pro) (CHP) plus zinc and l‐histidine (CZH) treatment on glucose metabolism in genetically obese (ob/ob), type 2 diabetic mice.

Insulin-leptin-visceral fat relation during weight loss.

Introduction The relation between insulin-leptin-visceral fat axis during weight loss has not been studied previously. Aims To evaluate the insulin, leptin, and abdominal adiposity relation during weight loss in patients with upper body obesity. Methodology Twenty volunteers (7 men, 13 women) with mean age 50.6 ± 6.3 (SD) and upper body obesity (weight 105.4 ± 12.3 kg, BMI 35.9 ± 2.5 kg/m 2 ) were recruited. Participants were enrolled in a one-arm clinical study using a calorie-deficient diet and an escalating dose regimen of sibutramine, starting with 5 mg daily and increasing in 5-mg increments to 20 mg per day. Body weight, insulin, leptin, glucose, lipids, abdominal computed tomography (CT), and total body electrical conductance (TOBEC) were measured serially at weeks 0, 4, 8, 12, and 24. Results Eighteen patients completed the 6-month study: one man and one woman discontinued because of adverse events. With diet and sibutramine, body weight was significantly and continuously reduced throughout the 6-month study. There was a 16.0% (p = 0.0001) reduction in body weight (p < 0.001) and 22.5% (p = 0.0001) decrease in total body fat mass. Abdominal CT scans showed a 28.3% (p = 0.0001) reduction in total abdominal fat, a 26.0% (p = 0.0001) reduction in subcutaneous fat (p < 0.001), and a 31.0% (p = 0.0003) reduction in visceral fat (p < 0.001). There was a 32.0% (p = 0.0008) reduction in leptin levels and 37.9% (p = 0.0001) reduction in insulin levels between baseline and week 4, but no further significant reduction in leptin and insulin levels was observed for the duration of the study. There was a significant correlation between insulin and leptin concentrations throughout the study (p = 0.0001). Leptin was presented as a function of insulin measured at the same time. Significant associations between visceral abdominal fat, subcutaneous fat, and leptin were also observed. Conclusion In this study, we found that leptin and insulin were related in weight loss. The data suggest that insulin may act as a strong regulator of leptin secretion during weight loss and that circulating leptin levels can be predicted by insulin level. Using sibutramine in conjunction with hypocaloric diet reduced body weight and decreased fat mass significantly. Visceral and subcutaneous abdominal fat depots were shown to decrease. Whether sibutramine exerts any selective reduction of visceral abdominal fat as opposed to total body fat mass will require further clinical investigation.

Effects of arachidonic acid plus zinc on glucose disposal in genetically diabetic (ob/ob) mice.

Aim: The present study is designed to determine whether arachidonic acid (AA) plus zinc improves clinical signs of diabetes in genetically diabetic ob/ob mice.

Stimulation of Intestinal Mucosal Afferent Nerves Increases Superior Mesenteric Artery and Decreases Mesenteric Adipose Tissue Blood Flow

We tested the hypothesis that stimulation of intestinal mucosal afferent nerves produces an increase in superior mesenteric artery (SMA) but a decrease in mesenteric adipose tissue (MAT) blood flow. In anesthetized rats, blood flow in the SMA (pulsed Doppler flowmetry) and MAT (hydrogen gas clearance) was measured simultaneously before and after administration of 0.9% saline, 640 μM capsaicin, or 5% dextrose into the intestinal lumen. The changes in the SMA were 3.8 ± 3.0, 15.9 ± 4.0, and 18.8 ± 7.6%; and those in the MAT, 4.7 ± 4.0, −11.5 ± 3.4, and −0.07 ± 3.4% of baseline, respectively. The data indicate that exposure of the intestinal lumen to an afferent nerve stimulant or nutrient induced a dichotomous pattern of blood flow changes, an increase in the SMA and a reduction in MAT. The capsaicin-sensitive afferent nerves may be instrumental in mediating these energy responses.

Body Weight Loss with Phentermine Alone Versus Phentermine and Fenfluramine with Very-Low- Calorie Diet in an Outpatient Obesity Management Program: A Retrospective Study

BACKGROUND Obesity, which is epidemic in the United States, is associated with increased morbidity and mortality. The combination of diet, exercise, and a behavior-modification program often does not result in ideal body weight. OBJECTIVE The aim of this study was to determine the efficacy of phentermine (Phen) alone compared with phentermine plus fenfluramine (Phen-Fen), when used in combination with a very-low-calorie diet (VLCD) for weight loss in an outpatient obesity center. METHODS We analyzed data collected at the UCLA outpatient University Obesity Center between 1993 and 1999. Data for patients who attended the center for at least 12 weeks and at least 4 visits, who were taking Phen or Phen-Fen, and whose body mass index (BMI) was ≥30 kg/m(2) were included in this retrospective study. RESULTS During the study period, 3200 visits were recorded. Of 1133 potential participants, 446 patients were included in the analysis (309 women, 137 men; mean [SD] age, 46.7 [11.4] years; mean [SEM] body weight, 109.6 [26.7] kg; mean [SEM] BMI, 38.0 [7.6] kg/m(2)). Of these, 128 women and 60 men (mean [SEM] body weight at baseline, 103.4 [24.0] kg and 124.9 [28.2] kg, respectively) received Phen alone; 181 women and 77 men (mean [SEM] body weight at baseline, 102.5 [21.4] kg and 124.9 [30.2] kg, respectively) received Phen-Fen. No statistically significant differences were found between the Phen and Phen-Fen groups in mean age, body weight, or BMI for women or men at baseline. No significant differences in the time of weight loss were found when a VLCD was used with Phen alone compared with the Phen-Fen combination for either sex even at 12 weeks. For women, the mean total body weight loss was 7.4% in the Phen group and 8.7% in the Phen-Fen group, but these differences were not significant. For men, the mean total body weight loss was 7.8% in the Phen group and 8.2% in the Phen-Fen group, but these differences were not significant. No significant differences in BMI, severe adverse events, or dropout rate were found between the 2 treatment groups for men or women. CONCLUSIONS This outpatient study did not detect any significant difference between adjunctive uses of Phen compared with Phen-Fen pharmacotherapy when used with VLCD over 12 weeks. Phen can be used to achieve significant weight loss when combined with VLCD. The tolerability and positive physical response further suggest that Phen is a valuable medication for obesity management in the outpatient setting.

Nutritional approaches to the prevention of prostate cancer progression.

Prostate cancer is becoming an increasingly important public health problem in the United States. As our population ages, the number of patients with clinically significant prostate cancer will be expected to increase. Prostate cancer is now the most commonly diagnosed cancer in men as well as the second leading cause of male cancer deaths in this country1. In 1995, an estimated 244,000 U.S. men will be diagnosed with prostate cancer and about 40,000 men will die of the disease1. Despite extensive efforts to study its pathogenesis, the origins of prostate cancer and the factors that promote its progression are not well established 2. Nonetheless, there is a great deal of evidence suggesting that this disease is the result of genetic and environmental interactions. One of the most widely accepted risk factors for prostate cancer is the race-ethnicity background3–4. African-American men have the highest prostate cancer rates in the world, whereas Japanese and Chinese men native to their countries have the lowest rate of prostate cancer4. However, Chinese and Japanese men who immigrate to this country have been found to have an increased risk of developing clinical prostate cancers within a generation to approach that of the U.S. average5. In addition, the incidence of prostate cancer in Japan has been increasing at a time when Western diets and lifestyles are being adopted into that country6–7. These epidemiologic data suggest that the diet consumed in Western industrialized nations may be among one of the most important environmental factors which affect the development of prostate cancer.