title: Irregularities in glucose metabolism induced by stress and high-calorie diet can be attenuated by glycyrrhizic acid.
abstract: Stress and high-calorie diet increase the risk of developing metabolic syndrome. Glycyrrhizic acid (GA) has been shown to improve hyperglycaemia and dyslipidaemia under various physiological conditions. This study was aimed at examining the effects of stress and GA on glucose metabolism under short- or long-term stress. Forty-eight Sprague Dawley rats were divided into two groups with constant stress induced by light (300-400 lux) for either 14 days (short-term stress) or 28 days (long-term stress). Within each group, the rats were subdivided into three treatment groups i.e. Group A (control group): high-calorie diet (HCD) only; Group B: HCD + stress (14 or 28 days) and Group C: HCD + stress (14 or 28 days) + GA (100 mg/kg). The blood glucose concentrations of the rats exposed to 14-day stress were elevated significantly and GA lowered blood glucose concentration significantly in the 14-day exposure group. The 28-day exposure group adapted to stress as shown by the lower adrenaline level and gluconeogenic enzymes activities in most of the tissues than the 14-day exposure group. With regards to adrenaline and corticosterone, GA was found to increased adrenaline significantly in the short-term exposure group while lowering corticosterone in the long-term exposure group. GA-treated short- and long-term exposure groups had significant reduction in hexose-6-phosphate dehydrogenase activities in the visceral adipose tissues and quadriceps femoris respectively. The results may indicate the role of GA in improving blood glucose concentration in individuals exposed to short-term stress who are already on a high-calorie diet via selective action on gluconeogenic enzymes in different tissues.
authors.affiliation: School of Science, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia.
authors.forename: Hui Ping
authors.initials: HP
authors.lastname: Yaw
authors.affiliation: School of Science, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia.
authors.forename: So Ha
authors.initials: SH
authors.lastname: Ton
authors.affiliation: School of Science, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia.
authors.forename: Stella
authors.initials: S
authors.lastname: Amanda
authors.affiliation: School of Science, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia.
authors.forename: Irvina Geraldine Xiao Feng
authors.initials: IG
authors.lastname: Kong
authors.affiliation: School of Science, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia.
authors.forename: Hong Sheng
authors.initials: HS
authors.lastname: Cheng
authors.affiliation: School of Science, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia.
authors.forename: Hamish Alexander
authors.initials: HA
authors.lastname: Fernando
authors.affiliation: School of Science, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia.
authors.forename: Hsien Fei
authors.initials: HF
authors.lastname: Chin
authors.affiliation: School of Medicine and Health Sciences, Monash University Malaysia Jalan Lagoon Selatan, Bandar Sunway 46150, Selangor Darul Ehsan, Malaysia.
authors.forename: Khalid Abdul
authors.initials: KA
authors.lastname: Kadir
keywords: Stress; gluconeogenic enzymes; glucose-6-phosphatase; glycyrrhizic acid; hexose-6-phosphate dehydrogenase; metabolic syndrome; phosphoenolpyruvate carboxykinase