Comparative cholesterol-lowering activity of citrus and tomato pectin.

Abstract

Citrus pectin, when included in a cholesterol-containing diet, was reported to be an effective hypocholesterolemic agent in several species (1-3). The purpose of the present study was to evaluate the cholesterol-lowering activity of tomato pectin compared with that of citrus pectin. Methods and Procedure. Forty-eight male weanling rats were randomly assigned to one of the four different rations shown in Table I. All rats were individually caged and allowed ad libitum access to feed and water during the 4-week feeding period. On the twenty-eighth day of the study, all rats were weighed and quickly killed in random sequence with a Harvard model 130 RM decapitator and the liver, kidneys, adrenals, and a blood sample collected from each animal. Serum and hepatic cholesterol were determined by a modification of the technique of Mann (4) and total serum and hepatic lipid measured gravimetrically after the Folch-washed tissue homogenate was evaporated to dryness (5). Results and Discussion. The performance of the four groups of rats as indicated by body weight gain (Table II) was essentially identical. The pectin-fed animals (Rations 3 and 4) consumed slightly more feed; however, body weight gain expressed in terms of feed eaten did not reveal any ration effects. Liver weights of the rats receiving Ration 1 were significantly lighter (p < 0.01) than those of the cholesterol-fed animals regardless of whether or not pectin was included in the ration. There was a trend toward heavier kidney weights in the pectin-fed rats, particularly in the rats fed tomato pectin (p < 0.01). Rats receiving citrus pectin in the ration were observed to have adrenals which were significantly smaller than any other group (p < 0.01). The ration effects on serum and hepatic lipids are presented in Table III.