Effects of red wine, tannic acid, or ethanol on glucose tolerance in non-insulin-dependent diabetic patients and on starch digestibility in vitro.

This study examines the effect of moderate intake of red wine, tannic acid, or ethanol during a meal in type 2 diabetic patients and the influence of tannic acid on the digestibility of starch by alpha-amylase. Thirty non-insulin-dependent diabetes mellitus (NIDDM) patients aged 53 +/- 6 years were studied (in vivo study) 10 of whom received red wine (200 mL), 10 tannic acid (150 mg), and 10 ethanol (16 g) with their midday meal (600 calories, 65 g carbohydrate, 20 g lipid, and 34 g protein). All patients were tested on two occasions (water or placebo v wine, alcohol, or tannic acid). The influence of tannic acid (0.25, 0.5, and 1 mg) on the digestibility of starch (100 mg) by alpha-amylase (100 U) was tested in vitro by sequential incubation at 37 degrees C (in vitro study). The maximum glucose excursion after lunch was 2.6 +/- 0.8 mmol/L at 90 minutes (T90) for water and 1.8 +/- 0.9 mmol/L at T90 for red wine taken with the meal. The values at T60 and T90 were significant (P < .01). Comparable results were obtained with tannic acid alone (nonalcoholic component of wine): the maximum glucose excursion after lunch was 2.76 +/- 0.9 mmol/L at T120 for placebo and 1.97 +/- 0.9 mmol/L at T90 for tannic acid (P < .01); no difference in glucose and insulin excursion was observed between water and ethanol. No interaction between tannic acid and starch was observed in the in vitro experiments, although after preincubation of alpha-amylase with tannic acid, digestion was slowed in a dose-dependent manner (6.1 +/- 1.1 minutes for 0.25 mg tannic acid and 13.1 +/- 1.59 minutes for 1 mg tannic acid). Drinking red wine with a meal did not increase blood glucose in NIDDM patients, and led to a slight decrease in some instances. The effect appeared to be mediated by the nonalcoholic compounds in wine such as tannic acid. Ethanol itself had no effect on plasma glucose or insulin levels.

[Antimicrobial activity of some medicinal species from the Dakar markets]. / Activité antimicrobienne de quelques espèces médicinales des marchés Dakarois.

After drawing up an inventory of Dakar markets popular medicinals plants, antimicrobial activity of 43 species have been screened. With the agar diffusion method, crude extracts of 24 species show an activity against Sarcina lutea or Escherichia coli. The antimicrobial spectrum of these extracts against 11 germs has been evaluated with the agar dilution method. 13 species show M.I.C. lower than 10 mg/ml against some germs. This preliminary study select some plants of potential interest for development of new antibacterial.

[Flavonoids and pycnogenols]. / Flavonoides et pycnogenols.

Pycnogenols is the term put forward by the authors to designate flavan-3-ol derivatives, so as to distinguish these substances, upon chemical and pharmacological grounds, from the heterogeneous group of flavonoid compounds.