Introduction

1. Acknowledgements Food and Water Intake Two Hours into Dark Period Summary of Results Introduction Status of Hypothesis Hypothesis Methods Twenty-Four Hour Food and Water Intake Discussion The effect of over-the-counter Hoodia gordonii (a nutriceutical marketed as an appetite suppressant) on food and water consumption in laboratory ratsTravis Boyd and G.R. DavisDepartment of Biology, Wofford College, Spartanburg, SC Stems and leaves of Hoodiagordoniihave been used as an appetite and thirst suppressant for hundreds of years by the San peoples while on hunting excursions in the Kalahari Desert (Vermeylen, 2008). Pharmaceutical companies such as Phytopharm have isolated and patented the active ingredient, a steroidal glycoside named P57. Van Heerden et al. (2007) in collaboration with Phytopharmand the Council for Scientific and Industrial Research in South Africa demonstrated that P57 is a strong anorectic agent in rats when administered by oral gavage. Other commercial entities are marketing powdered dehydrated Hoodia stem shavings as an over-the-counter appetite suppressant. The current study sought to evaluate the efficacy of over-the-counter Hoodiagordoniias an appetite suppressant and thirst quencher in male Sprague-Dawley rats. Average Water Intake during 1st two hours of Dark Period for 3 Days of Hoodia Treatment (Gray bars) and 2 days of Vehicle (black bars) • Hoodia stem shavings supplied by Delmar Labs: • Significantly increased the 2-hour food intake of male rats receiving the low (1x) dose. • Did not effect the amount of rat chow eaten in the first two hours of the dark period at the medium (10x) or high doses (25x). • Did not effect daily intake of rat chow. • Did not effect water intake by rats acutely nor chronically. • Other Notable Observation: • Cookie dough was found to be an effective vehicle for the administration of Hoodia . Average Food Intake during 1st two hours of Dark Period for 3 Days of Hoodia Treatment (Gray bars) and 2 days of Vehicle (black bars) * Rats receiving of Hoodia (gray bars) at the low dose consumed significantly more rat chow in the first two hours of the dark period than rats receiving vehicle (black bars). There was no effect of Hoodia at the low dose on acute water intake. Compared to vehicle, medium and high doses of Hoodia had no effect on food or water intake in the first two hours of the dark period. Hoodia did not significantly reduce the amount of food or water consumed in laboratory rats at dose up to 25 times that recommended for humans. Surprisingly, at the lowest dose tested, Hoodia actually produced a significant increase in food intake on the second day of testing. Orally ingested Hoodia will decrease the amount of food and water consumed by laboratory rats in a dose-dependent manner. • Subjects: Twenty-two male Sprague-Dawley rats were housed individually in plastic cages with bedding on a 12:12 light:dark cycle (lights off at 0900) and provided ablibitum rat chow (Harlan Teklad 8604) and water. Rats were ~ 90 days old at the onset of this experiment and weighed 442± 6 grams. • Grouping: Rats were initially separated into four groups of 5-6 rats each. There was no difference in the mean body mass of each group at the onset of the experiment. • Hoodia administration: Powdered stem shavings of Hoodiagordoniisold as Dex-L10 and supplied by Delmar Labs were mixed into vehicle (cookie dough) to mask the potentially unpalatable flavor of Hoodia shavings. On the first three days of each week (MTW) at the onset of their dark period (when rats tend to eat a large meal) rats in 3 of the 4 groups received a one gram cube of cookie dough into which Hoodia was mixed such that the dose was either 1x (low; 1 mg Hoodia /70g body mass) , 10x (medium), or 25 x (high) that recommended for humans. On the fourth and fifth days of each week (Th,F) rats received only vehicle. On days six and seven, rats received neither Hoodia nor vehicle. Experiments were counter-balanced over three weeks such that eat rat was tested with the low, medium, and high dose of Hoodia. A fourth group of control rats received vehicle only weekly M-F and were never exposed to Hoodia. • Acute (2 hr) Study: At 0830 hrs, food and water were removed and a cube of Hoodia or vehicle was placed into the cage with each rat. At 0900 hrs, water and rat chow was returned. The mass of food and water was measured two hours later (1130) in order to access the efficacy of Hoodia as an acute thirst and appetite suppressant. • Chronic (24hr) Study: At the conclusion of the 2 hour food and water intake measurements, sufficient food and water were provided such that 22 hours later at 0830 hrs, food and water intake were recorded . Twenty-four hour food and water intakes were the sum of 22 hr and 2 hr intakes. • Statistics: Data was analyzed using SPSS 16.0 Repeated Measures ANOVA and post-hoc pairwise t- tests (p< 0.05). Need to address issue that Hoodia mixed with cookie dough might be expected have stimulated thirst because of the osmotic properties of the mixture, but that water intake was not altered acutely or chronically. Also, if you have the body mass data, that should be mentioned. Should have a list of factors that could account for hoodia NOT being effective as an appetite suppressant in rats (i.e. rats ability to detoxify ingested substances, concentration of the active ingredient (P57) may be below threshold for a response, possibility that Dex-L10 does not contain P57, or that doses we used weren’t high enough to produce a response. Do we have any explanation for the INCREASE of food intake on day 2 at the low dose? Average 24 Four Food Intake for 3 Days of Hoodia Treatment (Gray bars) and 2 days of Vehicle (black bars) Average 24 Four Water Intake for 3 Days of Hoodia Treatment (Gray bars) and 2 days of Vehicle (black bars) Neither the low, medium or high dose of Hoodia (gray bars) significantly altered food or water intake in rats over a 24 hour period when compared to rats receiving only the vehicle (black bars). Note: The low dose of Hoodia which increased food intake acutely (2 hr study) did not result in increased food intake over the 24 hour period. Thus, rats receiving the low dose of Hoodia must have compensated for their elevated 2 hr intake by reducing their intake during the subsequent 22 hour period such that overall food intake was not different from vehicle or the medium and high doses of Hoodia. These rats appear to regulate their daily caloric intake to approximately 100 calories (energy density of Harlan Tecklad rodent chow is 3.3 cal/g). Thus 30 grams of chow provides 100 cal/day which is typical of this strain of rats. It appears that rats in this study consumed slightly less than 100 cal/day as rodent chow but likely achieved 100 cal/day since their diet was supplemented with cookie dough 5 days per week. The authors are indebted to Brandon Hunt for help with data collection and animal care and to Dr. Kara Bopp for assistance with statistical analysis. This project was funded by a Community of Scholars grant from the Fullerton Foundation to Wofford College. Need a graph of body mass, or at least text which addresses the issue of body mass. It would be nice to conclude that Hoodia does not result in weight loss in rats and thus is likely ineffective as a weight reduction strategy for humans. (There is room for a small graph here if we move this whole block upward a bit on the poster.