Inhibition by natural dietary substances of gastrointestinal absorption of starch and sucrose in rats and pigs: 1. Acute studies.
Rapid gastrointestinal absorption of refined carbohydrates (CHO) is linked to perturbed glucose-insulin metabolism that is, in turn, associated with many chronic health disorders. We assessed the ability of various natural substances, commonly referred to as "CHO blockers," to influence starch and sucrose absorption in vivo in ninety-six rats and two pigs. These natural enzyme inhibitors of amylase/sucrase reportedly lessen breakdown of starches and sucrose in the gastrointestinal tract, limiting their absorption. To estimate absorption, groups of nine SD rats were gavaged with water or water plus rice starch and/or sucrose; and circulating glucose was measured at timed intervals thereafter. For each variation in the protocol a total of at least nine different rats were studied with an equal number of internal controls on three different occasions. The pigs rapidly drank CHO and inhibitors in their drinking water. In rats, glucose elevations above baseline over four hours following rice starch challenge as estimated by area-under-curve (AUC) were 40%, 27%, and 85% of their internal control after ingesting bean extract, hibiscus extract, and l-arabinose respectively in addition to the rice starch. The former two were significantly different from control. L-Arabinose virtually eliminated the rising circulating glucose levels after sucrose challenge, whereas hibiscus and bean extracts were associated with lesser decreases than l-arabinose that were still significantly lower than control. The glucose elevations above baseline over four hours in rats receiving sucrose (AUC) were 51%, 43% and 2% of control for bean extract, hibiscus extract, and L-arabinose, respectively. Evidence for dose-response of bean and hibiscus extracts is reported. Giving the natural substances minus CHO challenge caused no significant changes in circulating glucose concentrations, indicating no major effects on overall metabolism. A formula combining these natural products significantly decreased both starch and sucrose absorption, even when the CHO were given simultaneously. These results support the hypothesis that the enzyme inhibitors examined here at reasonable doses can safely lower the glycemic loads starch and sucrose.
Preuss
Harry G
HG
Georgetown University Medical Center, Department of Physiology, Washington, DC 20057, USA.
Echard
Bobby
B
Bagchi
Debasis
D
Stohs
Sidney
S
D000681:Amylases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D001089:Arabinose / Q000494:pharmacology; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D007887:Fabaceae / Q000737:chemistry; D031103:Gymnema / Q000737:chemistry; D031584:Hibiscus / Q000737:chemistry; D007408:Intestinal Absorption / Q000187:drug effects*; D008297:Male; D027845:Malus / Q000737:chemistry; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013213:Starch / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D013393:Sucrase / Q000037:antagonists & inhibitors / Q000378:metabolism; D013395:Sucrose / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D013552:Swine; D013662:Tea / Q000737:chemistry
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D010936:Plant Extracts; D013662:Tea; D013395:Sucrose; D013213:Starch; D001089:Arabinose; D000681:Amylases; D013393:Sucrase
BMJ. 2000 May 6;320(7244):1240-3
10797032
Curr Opin Clin Nutr Metab Care. 2004 Jul;7(4):485-92
15192454
J Nutr. 2001 Mar;131(3):796-9
11238761
Biosci Biotechnol Biochem. 2001 Sep;65(9):2087-9
11676026
Med Hypotheses. 2002 Jan;58(1):28-33
11863396
Can J Physiol Pharmacol. 2002 Nov;80(11):1095-105
12489929
J Clin Endocrinol Metab. 2003 Apr;88(4):1617-23
12679447
Biochim Biophys Acta. 2004 Feb 12;1696(2):181-90
14871659
Altern Med Rev. 2004 Mar;9(1):63-9
15005645
J Am Diet Assoc. 2004 Apr;104(4):537-42
15054336
Obes Rev. 2004 May;5(2):93-4
15086862
Lancet. 2004 Aug 28-Sep 3;364(9436):778-85
15337404
Postgrad Med J. 1969 Sep;45(527):602-7
5809554
Postgrad Med. 1972 May;51(5):151-4
5025215
Lancet. 1983 Oct 1;2(8353):794
6137627
Am Heart J. 1988 Feb;115(2):493-8
3277362
Eur J Clin Nutr. 1994 Aug;48(8):595-7
7957006
Obes Res. 1995 Sep;3 Suppl 2:145s-153s
8581770
Metabolism. 1996 Nov;45(11):1368-74
8931641
Br J Nutr. 2004 Nov;92(5):785-90
15533267
Chron High Educ. 2006 Feb 3;52(22):A15, A18-9
16789291
J Agric Food Chem. 2006 Jul 12;54(14):5197-202
16819935
Obesity (Silver Spring). 2006 Sep;14(9):1523-34
17030963
Biosci Biotechnol Biochem. 2000 May;64(5):1041-3
10879476