Effect of acarbose on glucose homeostasis, lipogenesis and lipogenic enzyme gene expression in adipose tissue of weaned rats

Abstract

Acarbose is a potent intestinal glucosidase inhibitor which could have an anti-obesity property by reducing postprandial plasma glucose and insulin levels, potentially responsible for high rates of lipid synthesis in adipose tissue. We have tested this hypothesis by studying rats during the weaning period, when the lipogenic capacity of the adipose tissue develops. Rats were treated from age 19 days onwards with acarbose (10 mg/100 g diet) and studied at age 30 days. Acarbose was efficient in reducing postprandial excursions of both blood glucose and plasma insulin. Acarbose-treated rats behave like rats continuously infused with glucose with no metabolic signs of carbohydrate deprivation since gluconeogenesis was not activated. There was no massive caecal fermentation of carbohydrate since volatile fatty acids did not significantly increase in the portal blood. One of the most striking features of the acarbose-treated rats was the reduction of adipose tissue weight due to a reduced adipocyte size. This was concomitant with a reduced lipogenic capacity from glucose in isolated adipocytes under insulin stimulation. The activity of fatty acid synthase and acetyl-CoA carboxylase was decreased concomitantly with a reduced expression of their specific mRNA. This study allows the conclusion that postprandial hyperinsulinaemia and hyperglycaemia have a major role in the control of expression of lipogenic enzymes and thus on adipose tissue lipogenic capacity.

Anti-obesity effect of Nelumbo nucifera leaves extract in mice and rats

“…Natural ␣-amylase inhibitors have been demonstrated to be beneficial in reducing post-prandial hyperglycemia by slowing down the digestion of carbohydrates and, consequently, the absorption of glucose. Reducing post-prandial hyperglycemia prevent glucose uptake into adipose tissue to inhibit synthesis and accumulation of triacylglycerol (Maury et al, 1993). On the other hand, it is well known that dietary lipid is not directly absorbed from the intestine unless it has been subjected to the action of pancreatic lipase.…”

Mechanisms by Which Carbohydrates Regulate Expression of Genes for Glycolytic and Lipogenic Enzymes

“…Weaning the rat onto a high-fat diet prevents these changes, which suggests they are caused by a change in diet rather than by a change in developmental stage (11,79). Moreover, if an inhibitor of the intestinal α-glucosidases (acarbose) is introduced into the normal weaning diet, it decreases the changes of glucose and insulin concentrations following a meal and the level of expression of fatty acid synthase (FAS) and ACC (68). Thus, the amount of carbohydrate in the diet appears to be instrumental in turning on transcription of genes coding for lipogenic enzymes in liver and adipose tissue.…”

In- vitroantioxidant and anti-obesity properties of Bauhinia variegata

“…The α-amylase from the pancreas and salivary glands is involved in the digestion of carbohydrates. α-amylase inhibitors from natural sources found to be useful in decreasing post-prandial hyperglycemia by reduction in carbohydrates digestion and glucose absorption, which in turn reduces glucose uptake into adipose tissue and reduces synthesis and accumulation of triacylglycerol 22 . Dietary lipid has to be hydrolysed into fatty acid and 2-monoacylglycerol by pancreatic lipase for its absorption by intestine.…”