EFFECTS OF CARALLUMA FIMBRIATA EXTRACT ON CARDIOVASCULAR AND METABOLIC DISORDERS A thesis submitted by Katie Astell Bachelor of Science (Nutrition) Bachelor of Science (Honours) Master of Science in Dietetics This thesis is submitted in fulfilment of the requirements for the award Doctor of Philosophy Supervisors: Dr. Xiao Q. Su & A/Prof. Michael L. Mathai Centre for Chronic Disease Prevention and Management, College of Health and Biomedicine Faculty of Health, Engineering and Science Victoria University, Melbourne, Australia 2016 ABSTRACT Central obesity, insulin resistance, atherogenic dyslipidemia and elevated blood pressure are the major components of metabolic syndrome. This complex disorder is considered to be a clinical challenge and an urgent public health issue. With the growing prevalence of obesity worldwide, effective strategies are needed to intervene in the development and progression of metabolic syndrome. Despite the short-term benefits of pharmaceutical treatment of obesity, current drug therapy is associated with adverse side effects, thus the use of complementary and alternative therapies has become increasingly popular among the general population as an alternative method for weight loss. Botanical extracts in combination with lifestyle modification may be effective agents for attenuating the development of metabolic syndrome as they often comprise of a vast range of bioactive compounds that have been associated with significant positive health outcomes with minimal side effects. However, the efficacy of many of these extracts and their chemical constituents have yet to be fully explored. The research presented in this thesis examines the effectiveness of two commonly used anti- obesity botanical extracts, namely Caralluma fimbriata and Citrus sinensis (Moro variety). The primary aim of this PhD project was to investigate the efficacy of C. fimbriata extract on the risk factors of metabolic syndrome in overweight and obese conditions. The first study was a 12-week pilot study that sought to determine whether C. fimbriata extract (1 g/day), in addition to a hypocaloric diet and regular physical activity, can attenuate metabolic disturbances in overweight and obese individuals compared to placebo (n = 33; 29- 59 years old; 26 females, 7 males; BMI: 32.15 kg/m2). The main outcome was a significant reduction in waist circumference in the experimental group (mean change: -3.847; 95 % CI; - 7.466 – 0.228). This study identified that supplementation with C. fimbriata extract may potentially play a role in curbing central obesity, the key component of metabolic syndrome. i The second study then aimed to determine whether C. fimbriata extract attenuates the metabolic changes developed in an obesity-inducing rat model (n = 40; 4 weeks old; body weight: 229.7 g). This study examined metabolic effects of chronic administration of C. fimbriata extract (100 mg/kg BW) in male wistar rats with diet induced obesity. This study revealed that treatment with C. fimbriata extract for eight weeks in lean & high fat fed rats does not have significant effects on feed intake, obesity, glucose tolerance, blood pressure and lipid profile (p >0.05). The final study aimed to explore the effect of C. fimbriata extract (1g/day) alone and in combination with C. sinensis extract (500 mg/day) on metabolic and cardiovascular risk factors in a randomised controlled clinical trial (n = 59; 46.6 years old; 19 males, 40 females; BMI: 34.3 kg/m2). The main finding was a significant time effect observed in all groups for body composition, food intake and lipid profile (p < 0.05), which might be attributed to the dietary advice provided. However, there was no significant effect observed for all data on body composition, dietary intake, cardiovascular parameters, appetite sensations and lipid profile (p > 0.05). This research has made a significant contribution to the literature, providing evidence that C. fimbriata extract and/or C. sinensis extract may not be effective in eliciting beneficial effects in metabolic and cardiovascular conditions. Furthermore, the dietary modifications to participants’ food intake were clinically meaningful, providing significant improvements to body composition parameters. In conclusion, the results presented within the current thesis do not support that botanical extracts, including C. fimbriata extract and C. sinensis extract play a significant role in the treatment of metabolic abnormalities, due to the inconsistencies of data identified within this thesis and previous work. ii CANDIDATE DECLARATION “I, Katie Astell, declare that the PhD thesis entitled, Effects of Caralluma fimbriata extract on cardiovascular and metabolic disorders is no more than 100,000 words in length including quotes and exclusive of tables, figures, appendices, bibliography, references and footnotes. This thesis contains no material that has been submitted previously, in whole or in part, for the award of any other academic degree or diploma. Except where otherwise indicated, this thesis is my own work”. Signature: Date: iii ACKNOWLEDGMENTS The work undertaken over the past four years contained within this thesis was completed at Victoria University and the Howard Florey Institute, The University of Melbourne. The human clinical trials and animal study were supported by the College of Health and Biomedicine, Victoria University and additional financial support was received from Gencor Pacific, Inc, Hong Kong. On my journey to attain an achievement such as this, I received an overwhelming amount of support, guidance and encouragement from my supervisors, mentors, fellow students, family, friends and my fiancé. First and foremost, I would like to extend my sincere gratitude and appreciation to my primary supervisor, Dr Xiao Su. Thank you for all the wonderful support you have provided me with over the years and encouragement for future endeavours in the field of human nutrition. Thank you for presenting me with the opportunity of conducting and coordinating the human trial research, as you know I am very passionate about working in the area of nutrition and dietetics. I am very grateful for all the time and effort you spent going over many drafts, your contribution and expertise has been much appreciated. To my co-supervisor, A/Prof Michael Mathai, thank you for your expertise and support throughout my studies. In particular, thank you for introducing me to animal research and providing ongoing assistance during my research projects. To A/Prof Andrew McAinch and Dr Christos Stathis, thank you for your advice and experience provided in experimental procedures for the pilot study and I am also appreciative of the time and effort you both put in with helping me in refining and completing the pilot study paper. I would like to give a special thank you to the late Dawn Bannon, for her iv assistance and cooperation with the pilot study. To Hayley Loftus, thank you for providing a helping hand throughout the human trial process. Thank you to all the laboratory technicians at Victoria University and at the Howard Florey Institute, The University of Melbourne for their support throughout the whole candidature. To all the PhD students that I shared this experience with, thank you for your friendship, support and advice during these challenging and enjoyable years. To my wonderful family, in particular my parents, Zelda and Fred who have been very understanding and provided unconditional love, support and encouragement during the course of my schooling, I will always be grateful. Also thanks to my older brother, Jamie for always being there and making me laugh in times of stress. Finally, thank you to my partner David, for your devotion, patience and love during our time together so far. I look forward to our future together and know that you will be supportive in my future career aspirations. v ABBRIVIATIONS 4-AAP 4-aminoantipyrine ACE Angiotensin converting enzyme AEC Animal Ethics Committee AgRP Agouti-related protein AIP Atherogenic index of plasma ALT Alanine aminotransferase ANOVA Analysis of variance ANZCTR Australian New Zealand Clinical Trials Registry ASF Abdominal subcutaneous fat ATP Adenosine triphosphate AVF Abdominal visceral fat BDNF Brain-derived neurotropic factor BioLED Biomedical and Lifestyle Diseases Unit BMI Body mass index BP Blood pressure CART Cocaine and amphetamine-regulated transcript CDK Cyclin-dependent kinase CETP Cholesteryl ester transfer protein CFE Caralluma fimbriata extract CHD Coronary heart disease CRP C-reactive protein CT-scan Computed tomography scan CVD Cardiovascular disease DALYs Disability-adjusted life years DAP Dihydroxyacetone phosphate vi 3, 5 DHBS 3,5-dichloro-2-hydroxybenzene sulfonate DQESV2 Dietary Questionnaire for Epidemiological Studies Version 2 EDTA Ethylenediaminetetraacetic acid EGIR European Group for the Study of Insulin Resistance ELISA Enzyme linked immunosorbent assay FFA Free fatty acids FFQ Food Frequency Questionnaire GGT γ-glutamyltransferase GLP Good laboratory Practice GPO Glycerolphosphate oxidase HBA Hydroxbenzoic acid HCA Hydroxycitric acid HDAOS N-(2-hydroxy-3-sulfoprophyl)-3,5-dimethoxyaniline HDL High density lipoprotein H & E Haematoxylin and Eosin HK Hexokinase II HOMA Homeostatic model assessment HREC Human Research Ethics Committee HRP horseradish peroxidase ICAM-1 Intercellular adhesion molecule-1 IDF International Diabetes Federation IL-6 Interleukin 6 IPAQ International Physical Activity Questionnaire IPGTT Intraperitoneal glucose tolerance test LDL Low density